Scielo RSS <![CDATA[Investigaciones geográficas]]> http://www.scielo.org.mx/rss.php?pid=0188-461120150002&lang=es vol. num. 87 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.org.mx/img/en/fbpelogp.gif http://www.scielo.org.mx <![CDATA[Editorial]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200004&lng=es&nrm=iso&tlng=es <![CDATA[Dimensiones relevantes para la evaluación ambiental proactiva de la movilidad urbana]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200005&lng=es&nrm=iso&tlng=es ResumenLa evaluación ambiental aplicada a la movilidad urbana evoluciona en los últimos tiempos propiciando nuevos enfoques y modelos conceptuales motivados principalmente por la necesidad de obtener resultados más válidos para orientar y gestionar las decisiones sobre la movilidad urbana.En este contexto de innovación metodológica se sitúa este artículo que considera la movilidad urbana como un ámbito de conocimiento, proyecto y planificación que resulta específico por el carácter complejo de sus impactos y la demanda de un enfoque integrado al evaluar su calidad ambiental. Las limitaciones de los enfoques, más o menos, convencionales de la evaluación ambiental, son identificadas para el caso de los proyectos de movilidad urbana, señalando fundamentos alternativos adecuados para generar modelos de evaluación proactiva. En este sentido, resulta esencial progresar de una visión constreñida basada en el impacto ambiental a otra más compleja basada en el rendimiento ambiental.En consecuencia, el artículo plantea las dimensiones relevantes para la evaluación ambiental proactiva de la movilidad urbana, para lo que es necesario basarse en indicadores de rendimiento ambiental que articulen un modelo de umbrales ambientales que facilite el enfoque integrado sobre diversos entornos de movilidad. Rendimiento, umbrales, entornos de movilidad y evaluación proactiva son integrados en un ejemplo de aplicación a un corredor urbano en el que se implanta un nuevo modo de transporte público (área metropolitana de Granada, España), diagnosticando opciones de gestión de la calidad ambiental de los diversos entornos de movilidad urbana articulados por el corredor en cuestión.<hr/>AbstractA reduction of negative environmental impacts in urban transportation (air pollution, energy consumption, etc.) is thought to be crucial in promoting sustainable development outcomes in cities, however evidence shows that this objective is hardly achieved in practice. In the case of urban transport planning, the transition to sustainability requests that its performance must be assessed. This has originated important challenges for the academia in providing efficient assessment tools. As a response to these challenges, sustainability assessment has become a rapidly developing area associated with the family of impact assessment tools ((e.g. Environmental Impact Assessment and Strategic Environmental Assessment). In recent years, many countries have conferred to sustainability assessment, and specifically to Environmental Impact Assessment (EIA), an important and decisive role into their planning systems.The effectiveness of the traditional methods for evaluating urban transport plans/interventions (e.g. EIA, EAE, Cost-Benefit Analysis) is contested as strongly argued by several academics. A key problem is that these methods currently focus too much on identifying environmental impacts that might happen rather than on finding ways of preventing them from happening. They are used reactively rather than proactively. Underlying this is the belief that traditional evaluation methods have difficulty guiding improvements in urban transport plans and projects in decision-making and their capacity to support technical decisions becomes limited. First, this is a consequence of the fact that the environmental assessment (EA) process mainly includes EA-makers and they are not integrated enough in the transport planning process. Second, the used methods not always are the most suitable to identify ways of preventing potential impacts with respect to the particular nature of urban transportation.In seeking to answer these problems, the paper presents a strategy for proactive environmental instruments design. Accordingly to this strategy, EA instruments must fulfil two key criteria: i) be spatial integration-oriented; ii) be performance and threshold-based. The strategy is presented here as a complementary vision to traditional instruments. To illustrate and assess the worth of this strategy, the Environmental Thresholds Values Model ('ETV-model') was developed following these criteria and applied to evaluate alternative plans for a transit corridor in the city of Granada, Spain. This Spanish case is very illustrative of the described problems.The development of ETV-Model and its application to MAG permitted to test the proactive dimension of the EA process with respect to: i) interaction level between EA-makers and transport planners; ii) the Abstraction level of the EA process with respect to traditional EA instruments; iii) the Role of the EA in urban transport planning;The reduction of abstraction level from the evaluation was a highlighted aspect to foster a more holistic dimension during the process. This meant to develop an integrated conceptual framework between the EA-makers and transport planners. The identification of 'mobility environments' in the first stage of the 'ETV-model' was very significant in this respect. Under these geographical units, the involved practitioners not only established the first criteria for the evaluation, but prescriptions on the final design of alternatives were emitted by EA-makers taking into account these spatial references. The estimation of an aggregated environmental performance value was considered by transport planners as an excellent way to obtain comprehensive conclusions, as well as, the adoption of reference values facilitated the understanding of specific environmental problems of alternatives between the two focus groups.Another highlighted aspect during the application of the 'ETV-Model' was the fact that the evaluation had a central role not only during the selection of alternatives, but also to modify the alternative selected in the last phase of the evaluation process. Since the earliest, the outcomes of the model reflected in general that Alternative S.1 had less environmental negative impact than Alternative S.0, although this statement was dependent on the 'mobility environment' considered. During the application of the ETV-model the outcomes were related to dynamics characteristics of urban transportation, covering different temporal periods and including the interaction between EA-makers and transport planners in different workshops/meetings. After analysing the two possible alternatives the decision module of ETV-model through the indicators 'Absorption capacity' and 'Improvement capacity' assessed possible changes to optimize the alternative selected (alternative S.1). The outcomes obtained oriented transport planners to modify the alternative with respect to the number of lines of public transport in the case of 'motorized traffic environment' and 'local and circulation environment', as well as, the walkable areas in the case of 'Local oriented environment'. <![CDATA[Cálculo del flujo ambiental como sustento para la reserva de agua al ambiente del río Piaxtla, Sinaloa, México]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200025&lng=es&nrm=iso&tlng=es El cálculo del caudal fluvial necesario para mantener los servicios ambientales de los diferentes tipos de cuenca en los ríos de México, ha sido un elemento a cumplir en la Norma Mexicana, lo que permite una adecuada administración del recurso hídrico. Para dicho cálculo se han propuesto diferentes metodologías, una de las cuales por su sencillez es la hidrológica, requiriendo para ello una base de datos de escurrimientos que permitan determinar el volumen de agua necesario para las funciones de los ecosistemas. Con base en lo anterior, el objetivo de este estudio fue estimar dicho caudal en el río Piaxtla, Sinaloa. Para ello se compararon bases de datos de escurrimientos de 36 y nueve años que mostraron diferencias fundamentalmente entre la frecuencia de las máximas avenidas y sus orígenes, lo que recomienda contar con base de datos mayores a veinte años; sin embargo, en el cálculo final del caudal ambiental los resultados fueron semejantes, es decir, reservar del volumen total del escurrimiento el 62.1% considerando un lapso de 36 años de estudio y 57.7% tomando en cuenta nueve años de información.<hr/>The calculation of river flows necessary to maintain the environmental services of the diverse river basins in Mexico has been an element to be considered in complying with the Mexican Norm and in allowing an adequate administration of water resources. Several methods have been proposed for this calculation, among which a very simple one is a hydrological method that requires a data base on runoff to determine the volume of water that ecosystem functions need. Hydrological methodology proposed by the NMX cited above, provides guidelines for establishing a regime as a percentage of average annual runoff and it is assumed maintain biological attributes at certain levels of conservation. It also analyzes the regime of seasonal normal flow for wet hydrological conditions, socks, dry and very dry, and the system of avenues (considered as the sudden increase in the volume and speed of the current in a river due to runoff resulting from rain cyclical or extraordinary, it is also known as flooding), considering at least three categories of avenues (intra-annual, annual and interannual low magnitude of average size) with corresponding attributes of magnitude, duration, frequency, time of occurrence and rate exchange. For greater certainty calculation it will always be necessary to have records in the three levels of a basin. This level of analysis is to determine the final volume of ecological flow, considering the benchmark to achieve the previously defined environmental objective. For ecological calculation referred by the NMX, some fundamental aspects were considered, such as: ecology importance (which ranks among very high, high, medium and low based on the concepts of the rule itself); use pressures (determined as the ratio percentage of the volume allocated over the concession between the annual average availability basin or aquifer, determined as high ≥ 80%, ≥ 40% high, medium and low ≥ 11% ≤ 10%) ; the environmental objective (ecological status to be achieved within the watershed to maintain the integrity of existing ecosystems or when they believe that they are degraded, contributing to the recovery or rehabilitation); and annual percentage rate recommended for environmental protection. Based on this, the purpose of this study was to quantify the river flow of the Piaxtla river, in the state of Sinaloa. The river runoff data bases for 36 and nine years were compared, showed differences mainly between the frequency of maximum runoff and its origin, and indicated that it is advisable to use a data base of more than 20 years. However, results were similar in the final calculation of the environmental or ecological river flows; that is to say, total runoff volume was 62.1% considering 36 years and 57.7% for nine years of information. We conclude that the ecological importance of Piaxtla river was very high and the use of water pressure was low (considering that database runoff only included until 1999 and did not take into account population growth and activities). To determine the final volume reserved for the environment or ecological flow, could be estimated not only with a database of 36 years, but for nine years also confirming that those rivers that have databases of 10 years can the methodology used hydrological indicated by the NMX said. Particularly in this study it was determined that for parameters more detailed as the volume of the base rate of the annual volume, according to the frequency of occurrence, both very dry years, dry, average and wet, and influence of meteorological events that determine periods separate return, it is advisable to use minimum data bases as brand NMX 20 years. <![CDATA[Enfoque metodológico para la construcción de una Geobase como apoyo a la investigación en agricultura y recursos naturales]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200039&lng=es&nrm=iso&tlng=es La realización de operaciones con sistemas de información geográfica (SIG) y sistemas de análisis de imágenes de satélite, producen resultados que se insertan y manejan en bases de datos geoespaciales; estos repositorios se convierten en el centro de aplicaciones, en este caso, relacionadas con la investigación en agricultura y recursos naturales. Cada sistema cuenta con un modelo de datos propio y funciones específicas de manejo de sus bases de datos. Al no existir aún un modelo de datos ni funciones estándar para esas bases de datos comúnmente aceptados, el compartir y reutilizar resultados de diversas aplicaciones es un proceso tedioso y que requiere intervención manual del usuario. Esto se dificulta porque numerosos productores de información geográfica no proporcionan suficientes datos descriptivos y concisos (metadatos) acerca de los resultados de sus trabajos. Este artículo aborda una metodología para la construcción de la base de datos geoespacial "GeoBase-L9", que facilita la construcción del repositorio y el intercambio de productos geográficos entre usuarios. La metodología se basa en un esquema de metadatos propio que permite implementar un sistema de visualización de los insumos y de los productos de investigación vía web.<hr/>AbstractGeospatial databases are a central part in applications and projects within the context of research in agriculture and natural resources. Performing operations with geographic information systems and with software for the enhancement, display or analysis of geographic data and information contained in digital maps, satellite images and aerial photographs generate results which are inserted within geospatial databases. These repositories are the core of geo-based applications, in particular, those related with a variety of research topics. Each system manages geospatial databases according to its own data model, and performs specific database management functions according to the procedures requested by users. A data model is an essential tool either for software developers or for users. A data model assists in the comprehension, at different levels of depth and detail, of the contents, organization and capabilities of databases, as well as to the comprehension of software restrictions and functionalities required to access the data. Current commercial informatics technology is designed for relational which are the most common types in use; in general this technology is not oriented to the needs of geospatial databases.Relational databases are the most common data repositories in managerial or business applications. In these databases the DBMS or data base management system is based on the relational model, a formal prescription for the organization and structure of data introduced in the 1970s by E. F. Codd. The relational model and the associated Structured Query Language (SQL) are recognized standards for relational databases. Thus, relational DBMS all are based on a common data model which means that at the logical and at the user levels the data are seen through a same lens, which facilitates data exchange among systems and users. Object databases are oriented towards applications where data are inherently more complex than relational tables, such as the data in digital maps. There is no standard object data model, but basic object-oriented concepts for structuring and relating objects such as aggregation, semantic links and the inheritance of properties are commonplace.Following recommendations by the Open Geospatial Consortium, some proprietary database management systems have included in recent years basic constructs to manage geospatial information. Anyway most database management systems, relational or otherwise, do not make public how they manage the internal storage of data items nor how the manipulation functionalities are implemented, since these are trade secrets.The lack of standards for geospatial databases makes the exchange, sharing and reutilization of results among diverse applications and among different users a very tedious process. Normally manual user intervention is required and the task is made difficult and prone to errors because many geographic information producers do not provide sufficient concise descriptive data (metadata) about the results of their work. Most systems offer export/import functions to move geospatial data to/from other systems, but the verification of compatibility for appropriate use of the data is left to the user. She is made responsible for correction or modification of aspects which are significant regarding the applicability of processes or functions. These aspects include file format compatibilities or cartographic projections which when misunderstood lead to repetitive and accumulative errors, with a negative impact on the quality of end products.Multidisciplinary and interdisciplinary research in Geomatics is present in many organizations and institutions worldwide. The objective of the research and development project reported here was to analyze ways to gather in a unique repository geospatial information products to be shared among the group of people working within the research line "Geomatics Applied to the Study and Management of Natural Resources and Agrosystems" of the Colegio de Postgraduados. In the medium term the repository should be able to support decision making using products derived from the research of this group.This article refers to the methodology to build the geospatial database "GeoBase-L9", which facilitates the construction of the repository and the exchange of geographical products among users. We present the part of the methodology that is based on our own metadata schema which adheres to Mexican national standards which in turn follow international standards. The methodology has allowed the implementation of a pilot version to visualize via web the items that have been input to the GeoBase-L9 and also check the research products offered to the user. <![CDATA[Análisis de dos áreas naturales protegidas en relación con el crecimiento del Área Metropolitana de Xalapa, Veracruz]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200051&lng=es&nrm=iso&tlng=es Con el objetivo de analizar la dinámica espacio-temporal en cuanto a la relación del hombre con la naturaleza en un contexto urbano, se estudiaron las áreas naturales protegidas "Molino de San Roque" y "Cerro de la Galaxia" en relación con el crecimiento metropolitano de Xalapa, Veracruz, México. El análisis de imágenes aéreas de 1993 a 2009 reveló que 41.8% de Molino de San Roque y 50.7% del Cerro de la Galaxia no mostraron cambio en la densidad y extensión de la vegetación; 12.2 y 26.7%, respectivamente, mostraron cierto crecimiento de la vegetación, mientras que 46 y 22.6%, correspondientemente, mostraron disminución en la cubierta arbórea y arbustiva. El análisis micro histórico-geográfico hizo evidente que en el interior de estas áreas, en donde es menor la afluencia de personas, hubo cierta regeneración de la vegetación, mientras que en las periferias se detectó deforestación. La progresiva invasión humana fue la mayor amenaza para estas áreas a lo que se sumó el abandono por parte de las autoridades. La protección efectiva de las áreas naturales protegidas no se logrará si continúan como espacios abandonados, pues ello deriva en la desvinculación de la sociedad con la naturaleza al resultar espacios a los que el ciudadano no tiene derecho para su uso y recreación.<hr/>AbstractThe establishment of natural protected areas and the urban growth are two inseparable processes as they are functionally connected, but their dynamics tend to be troublesome and turn into the epitome of the wicked relationship between humans and nature. The urban natural protected areas are usually agricultural fields remains or woods saved from their destruction caused by the constant expansion of the urban spot. However, if this rescue is not clear and definitive, either because the governmental actions are incomplete, unsuitable or corrupt, or because people do not get to use these areas (difficult access, dangerous places, or inappropriate facilities), the threats for these territories will then reappear as the urban extension will tend to surround, invade and take up the natural protected areas.With the aim of analyzing the spatio-temporal dynamics of the human and nature relationship in an urban context, the natural protected areas "Molino de San Roque" and "Cerro de la Galaxia" were studied in correlation with the urban growth of Xalapa, Veracruz, Mexico. Both areas look deserted and defenseless. The interpretation of aerial photographs from 1993 to 2009 revealed that 41.8% of the Molino de San Roque's area and 50.7% of the Cerro de la Galaxia's area showed no alteration in the density and expansion of their vegetation; 12.2% and 26.7%, respectively, showed some vegetation growth, meanwhile 46% and 22.6%, again respectively, reflected a decrease in the bushy and arboreal cover. Micro historic-geographical analysis proved that in the inner parts of these areas, being the lower trafficked ones, we could notice some vegetation recovery, whereas in the periphery segments, deforestation was observed. The progressive human invasion was the biggest threat for these areas, but the abandonment by authorities constitutes another one. The greatest loss was not so much about the natural protected areas shrinkage, but rather about the quality of the landscape. An effective protection of the natural areas will never be reached if these areas keep remaining as deserted places. Indeed, this desertion leads to a separation between society and nature as citizens have no opportunity of using these natural areas in a practical or recreational way. <![CDATA[El debate de la creatividad y la economía en las ciudades actuales y el papel de los diferentes actores: algunas evidencias a partir del caso de estudio de Madrid]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200062&lng=es&nrm=iso&tlng=es Este artículo analiza de manera crítica los conceptos de economía creativa y clase creativa a través de una revisión de la literatura internacional. De esta forma se ponen de manifiesto las lagunas teóricas y conceptuales de los enfoques dominantes al respecto. A continuación propone algunas ideas para interpretar el papel de la creatividad en la economía de las ciudades desde una perspectiva más compleja, y lleva a cabo una aproximación al caso de la ciudad de Madrid. En ella se pone de manifiesto tanto la debilidad de las perspectivas dominantes como la necesidad de llevar a cabo estudios más complejos, que abarquen manifestaciones más plurales de la economía creativa, para lo que resulta más eficiente una metodología que combina el análisis estadístico con el trabajo sobre el terreno.<hr/>Over the last decades there has been a profusion of studies that put their emphasis on the importance of the so-called creative economy on economic growth and regional development. In the case of Europe, has been highlighted the potential of cultural and creative economy to become the new engine of the economy after the slowdown experienced by financial services during the economic crisis of 2008 (Pratt, 2009:495). This topic has been the subject of attention even supranational organizations such as the United Nations Conference on Trade and Development (UNCTAD), the European Union or the United Nations Educational, Scientific and Cultural Organization (UNESCO). Thus, there has been widespread the interest in introducing this concept into the political agendas of many cities, resulting in new competitive dynamics between those seeking to become creative cities (Martí-Costa y Pradell, 2012:93). However, despite the strong development of the concept of creative economy and its broad impact in political and academic circles, the literature on the creative economy, creative classes and creative cities has been criticized both for its conceptual definition and character asepticsuch as for responding to interests of certain economic groups or hide phenomena of urban segregation.From these ideas, this paper proposes a reinterpretation of the role of creativity in the economic and regional development, considering that it is itself one of its key elements and that certain "emerging" sectors use the creativity in its operation. In this paper the focus is on creativity as an engine of development rather than as a binding factor of the sectors that generate it. From this perspective, emphasizes the importance of creativity in the economic and regional development through its impact on a number of "emerging and creative industries" (audiovisual, architecture, design, etc.) mentioned in most studies. However, they also exist other economic areas (usually excluded, as the culture itself or social engagement) with capacity to boost economic and territorial development from different fields of creativity.First, the economy itself includes various activities not easily quantifiable but which help to shape the tissue of the "creative economy". Second, we should distinguish the culture itself of those other cultural expressions that, by adding a "plus" creative seek economic development, attracting visitors and improving the quality of urban life through festivals, art walks and exhibitions. Finally, in the field of social movements can be found initiatives which, without losing their initial characteristics (social inclusion, claimand demands, otherness...) seek approaching economic activities to allow a livelihood to its protagonists (André y Réis, 2009; Leslie y Rantisi, 2010).These ideas are transferred to a case study in the city of Madrid, after a first critical reflection on the distribution of employment in the creative sectors and their recent evolution. In the case study, several entrepreneurs belonging to existing social movements in the city, saw the possibility of creating alternative business in a traditional market, recovering from the lethargy in which he found himself.Since alternative funding ways (cooperatives, crowdfunding, etc.) they opened new activities, aiming for a new trade in closeness well in line with the character of the neighborhood. The purpose was not to displace the traditional trade but to integrate it into the same project. The space has also become a new leisure and meeting point because the project includes other recreational and cultural offerings. In this case, as Margulies (2013) notes creativity has spread to other, traditional sectors which has added an extra creativity to boost activities in principle fall outside the statistics released by traditional studies. From the case study of Market San Fernando, it can be said that although the "official" discourse on the creative economy can provide some insights on the distribution and the weight of these sectors and their impact on other economic activities, the emergence of certain theoretical and methodological concerns and their inability to show a much more complex reality require its combination with other approaches and other analysis techniques, especially when it descends to more specific territorial levels, which tend to emphasize the richest range of possibilities and broader definitions offered by the concept of creativity. <![CDATA[Caracterización del peligro por inundaciones en el oasis La Purísima, Baja California Sur, México]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200076&lng=es&nrm=iso&tlng=es ResumenEn el estado de Baja California Sur existen solo cuatro oasis con extensiones mayores a 2.0 km2; La Purísima (2.25 km2) representa el tercero en extensión. En el pasado el oasis fue frecuentemente afectado por inundaciones resultantes de los eventos extremos de precipitación, que generaron graves daños en la cuenca.Se realizó un diagnóstico del oasis La Purísima, con respecto a posibles inundaciones como consecuencia de lluvias extremas, lo cual incluye el análisis estadístico de la precipitación para la elaboración de un modelo hidrológico e hidráulico, con el fin de calcular el caudal máximo, el volumen y la frecuencia de crecidas en los cursos del arroyo Cadegomo bajo diferentes escenarios de lluvias extremas. Finalmente se elaboró un mapa de peligro por inundación según los escenarios elaborados.Se efectuó un análisis de la ocurrencia de inundaciones en el pasado y sus efectos en el oasis por medio de evidencias históricas de inundación de la zona, para verificar su posible aplicación en la calibración de los modelos.Los caudales resultantes de los eventos de precipitación extremos generan un incremento importante de los niveles en el drenaje de la cuenca. La respuesta del arroyo es un incremento en el área de inundación de hasta 14% respecto al tiempo de retorno de 20 años. Un evento de 1 000 años generaría un incremento en el área de inundación de 67% y bajas, afectando las zonas de la región urbana, así como todos los lotes de cultivo.<hr/>AbstractIn the Mexican state of Baja California Sur there are only four oasis of more than 2.0 km2; La Purísima (2.25 km2) is the third largest of them. In the past this oasis was frequently affected by flooding, resulting from extreme rainfall events, which in several occasions generated severe destruction in the oasis. The first permanent settlement in the oasis of La Purísima was the foundation of a Jesuit mission at Cadegomó River in 1720. Since then the oasis repeatedly has been affected by floods; for example hurricanes caused severe damages in 1770 and in 1828, when finally the mission was abandoned. It took ten years to revive the mission, which remained in operation for several years after independence of Mexico. After its secularization, La Purísima became village in 1858. Major inundations occurred in 1957 and 1959, as well as in 2008 and 2009 which affected all farmers in the oasis. Parts of garden areas were lost, many fields covered with sand and the irrigation channels were severely damaged. The destruction included plantations of avocado, mango, guava, banana, plum, apple, black fig, orange trees, sugar cane and severe livestock losses.The mayor part of the La Purísima watershed, with a total area of 1,728.6 km2 is dominated by a very arid, warm climate (BWh (x') after Köppen), with an average annual temperature between 18° and 20° C, whereas the lowlands, near the Pacific Ocean are influenced by a very dry and warm weather (BW (h&gt;) (x&gt;)), with a higher annual average temperature of 22° C.The main extreme weather events that aífect the area are the tropical cyclones that originate in the Northeast Pacific, and aífect the peninsula of Baja California during the months May to November. In the last decade there has been an increase of extreme rain events in the area, caused by tropical cyclones.A hydrological analysis was conducted, regarding to possible flooding levels, caused by extreme rainfall events. This included a statistical analysis of precipitation data in order to define the relation between rainfall intensity and return period. The data were entered into hydrologic and hydraulic models, using HEC-1 and HEC-RAS software in combination, which permitted to calculate the volume and impact of floods in the Cadegomo River under diíferent scenarios of extreme rainfall events. According to the evaluated scenarios of extreme runoíf events, a hazard map of flooding areas under diíferent return periods was elaborated.The results indicate a significant rise in the water levels of the drainage basin, caused from extreme rainfall events with an increase in the flooded area by 14%, estimated for the return period of 20 years and a 1 000 year event would generate an increase in the flooded area by 67%, which would aífect important areas of the urban region, as well as nearly all gardens of the oasis.The occurrence of floods in the past and their eífects on the oasis La Purísima were analyzed through historical evidences which permitted to verify the scenarios and calibrate the models. In three occasions runoíf volumes of higher magnitude were documented at the hydrological station "Ojo de Agua", run by the National Water Commission (CONAGUA): in September 1962, December 1972 and September 1974. The rainfall recorded in 1972 was 69 mm, which caused a total runoíf of 29.48 million cubic meters, observed during the next 230 hours; this is comparable to a model event with a return period of 10 years.In Baja California Sur, due to the lack of direct runoíf measurements, it is of utmost importance to continue ela-borating climate and hydraulic models to quantify the local eífects that could be expected before the end phenomenon of runoíf, in order to install measures to limit the economic damage and impacts on society. <![CDATA[Identificación de asentamientos irregulares y diagnóstico de sus necesidades de infraestructura en Ciudad Juárez, Chihuahua, México]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200088&lng=es&nrm=iso&tlng=es ResumenMás de la mitad de la población mundial vive desde el 2007 en ciudades, provocando que uno de los más grandes retos de esta transición demográfica, el cual ocurre principalmente en los países en desarrollo desde la década de 1970, sea el de proveer vivienda digna a una creciente población urbana. Este fenómeno, aunado a las particularidades de los mercados del suelo, produce asentamientos espontáneos que ocurren en las ciudades de una manera informal y con grandes deficiencias tanto en la infraestructura como en la calidad de la vivienda.Aproximadamente mil millones de personas alrededor del mundo viven en condiciones deplorables de vivienda, servicios básicos urbanos e infraestructura. En el 2000 la organización UN-HABITAT de las Naciones Unidas (ONU) emitió la "Declaración del Milenio" cuyos objetivos primordiales fueron adoptados por los principales líderes del mundo para mejorar las condiciones de vida de la población que habita en los asentamientos irregulares (AI).A pesar de que la ocupación irregular del suelo es un fenómeno frecuente en las ciudades, en la actualidad no se cuenta con técnicas de estimación confiable que permitan conocer su extensión y características de forma confiable y expedita. Es a partir de esta problemática que surge la necesidad de elaborar una propuesta de análisis que permita identificar y delimitar los AI a escala urbana y realizar un diagnóstico de sus necesidades de infraestructura urbanas.Este trabajo de investigación presenta así una alternativa para identificar de forma oportuna, confiable y eficaz los AI, para que las diferentes instancias del gobierno puedan brindar respuesta ágil a los problemas de regularización, falta de infraestructura y servicios urbanos. El trabajo consiste en el desarrollo de un modelo de análisis basado en la integración de atributos físicos, socioeconómicos y de organización espacial del entorno urbano, utilizando técnicas de percepción remota, análisis espacial e información censal. Los atributos físicos incluyen las condiciones del terreno, disección vertical y zonas de riesgo geológico y de inundación. Los atributos socioeconómicos incluyen, polígonos de pobreza, cobertura de agua potable y drenaje, nivel de hacinamiento, relación centro-periferia y valor del suelo. Los atributos de organización espacial y tipo de materiales de construcción, fueron recabados de imágenes satelitales de alta resolución y métricas de paisaje. Estos tres grupos de variables fueron integrados en un modelo multicriterio para la identificación de AI en Ciudad Juárez, Chihuahua, México. El modelo permite no solo la identificación de dichos AI sino también la realización de un diagnóstico de sus necesidades de infraestructura y servicios urbanos contando con un nivel de exactitud del 97.66%. Esta investigación presenta un método nuevo y confiable para la identificación de AI y a su vez los resultados obtenidos proveen una importante herramienta para los responsables del desarrollo urbano en la toma de decisiones.<hr/>AbstractSince 2007, more than half of the world popula-tion lives in cities, causing that one of the biggest challenges of this demographic transition, which occurs mainly in developing countries since the 1970s, is providing decent housing to a growing urban population. This phenomenon, coupled with the particularities of land markets, triggers spontaneous settlements that occur in cities in an informal way and with major deficiencies in both the infrastructure and the quality of housing.Approximately one billion people worldwide live in deplorable housing conditions, lack of basic urban services and infrastructure. Most of this population lives in irregular settlements with extreme poverty within the major developing countries. The expansion of this type of settlement is considered as a visual manifestation of poverty itself. In 2000, the UN-HABITAT, organization of the United Nations, issued their "Millennium Declaration" in which primary goals were adopted by major world leaders to improve the living conditions of the population living in informal settlements.Although irregular land occupation is a frequent occu-rrence in the cities, currently there are no reliable estimation techniques to determine its extent and characteristics reliably and expeditiously. It is from this issue, that there is a need to develop a proposal for analysis to identify and delineate the irregular settlements to an urban scale and make a diagnosis of urban infrastructure needs.This dissertation presents an alternative to identify in a timely, reliable and effective manner irregular settlements, so that different levels of government can provide quick res-ponse to regularization problems, lack of infrastructure and urban services. This research work involves the development of a model of analysis based on the integration of physical attributes, socioeconomic attributes and the spatial organization of the urban environment, using remote sensing techniques, spatial analysis and census data. These physical attributes include terrain conditions, cooperative, flood, and risk zones. Socioeconomic attributes include income levels, sewage and adaptable water coverage, overcrowding level, center- periphery relationship and land value. The attributes of spatial organization and type of building ma-terials were collected from high-resolution satellite imagery and landscape metrics. These three groups of variables were integrated into a multi-criteria model for irregular settlement identification at Ciudad Juarez, Chihuahua, Mexico with a 97.66% of accuracy. The contribution of this research is to present a new reliable method to identify irregular settlements. The achieved results can provide a great asset to help urban development officials in decision making. <![CDATA[Diseño de un indicador de necesidad socio-espacial para el análisis y la formación de decisiones sobre servicios sociales urbanos. Un estudio de caso]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200102&lng=es&nrm=iso&tlng=es ResumenLa toma de decisiones sobre servicios sociales requiere, como paso previo, un conocimiento de las necesidades y de su distribución en el espacio, cuestión singularmente acuciante en ámbitos menos desarrollados o en periodos de crisis económica, cuando la cohesión socio-territorial se ve más amenazada. La cuestión de medir esas necesidades sociales ha sido tratada con métodos variados, por ser aquéllas muy diversas en naturaleza y porque en ciertos casos resultan elusivas. Incorporar la dimensión espacial supone un reto adicional, pero añade utilidades significativas de cara a la planificación socio-espacial.En línea con esa preocupación en este trabajo se aborda el problema de estimar las necesidades a atender por los centros de servicios sociales municipales (CSS). A tal fin se plantea el diseño de un indicador estadístico original por zonas intraurbanas, en cuya fórmula se integran los principales componentes generadores de la demanda real observada y también la renta per cápita, con el propósito de tomar en cuenta el relevante principio de equidad espacial. El indicador se ha aplicado experimentalmente, con el apoyo de un sistema de información geográfica (SIG) a la ciudad de Madrid para cuantificar la necesidad de CSS en dos tipos de unidades espaciales, distritos y secciones censales, que aportan utilidades complementarias. Los resultados desvelan las desiguales intraurbanas de ese tipo de necesidades y pueden servir de apoyo para la formación de decisiones públicas sobre dotación y localización de recursos sociales. Adicionalmente el trabajo incluye un ensayo preliminar de examinar estadísticamente las potencialidades y limitaciones del indicador propuesto para ambos tipos de unidades espaciales.<hr/>AbstractDecision-making regarding social services requires, as a preliminary step, a knowledge of the needs and their spatial distribution, a particularly pressing need in under-developed areas or during periods of economic crisis. It must also be borne in mind that, having established such needs, proposals should involve and be inspired on major principles such as socio-territorial equity and efficiency, as well as those of social cohesion and socio-demographic sustainability which are often violated or sidestepped.The task of measuring these social needs has been addressed from various disciplines (e.g. political science and public administration, economics, sociology, geography, marketing, urban planning, etc.) and with a variety of methods, owing to the wide diversity in the nature of such needs and because, in certain cases, they are elusive. Incorporating the spatial dimension adds a further challenge, but at the same time proves significantly useful for socio-spatial planning.In line with this endeavour, this work examines the problem of estimating the needs that must be met by the municipal social service centres (CSS) of Madrid, which are set up as a civic facility to provide free assistance with social problems. Basically, they deliver information, guidance and help to resolve citizens' requests. Among their most conspicuous functions we can mention: a) Information on resources and social benefits: pensions, public grants, scholarships, infant schools, elderly people's homes, adult day-care centres, drug addiction treatment centres, minors, etc.; b) Management of social benefits, both financial (e.g. integration/insertion income), and service related (e.g. home assistance and tele-assistance); c) Social intervention, both individual and in groups; and d) Advisory services for organisations and associations operating in the field of social welfare.For this purpose, an original statistical indicator for intraurban areas has been designed that is in keeping with the logic behind current use of the CSS and with the objectives for their provision. In short terms, it is assumed that the indicator should respond to the sum of several components generating current demand: on the one hand, the whole population, and on the other, the demographic segments most likely to have social needs: young people, the elderly and immigrants from less developed countries. The formal starting point for what we shall call the need-related or potential demand synthetic index (ISD) is the expression:ISD = f (population, young people, the elderly and immigrants)Each of the above components has been weighted. The weights of population groups are based on the proportion of actual users registered in one year. For the total population weight we have sought to take into account the important principle of spatial equity. As social needs, and by extension the propensity to use the CSS, spring up unevenly depending on socioeconomic status, we have postulated weighting the total population according to personal income. Consequently, the weight wpd, for a given area has been treated as a proportion of municipal income per capita with respect to that area, which may be a district or a small census unit (called census section). In formal terms:Where RPCM = Income per capita in Madrid, and RPCd = Income per capita in the spatial unit d.The formula finally adopted for the potential demand synthetic index for any spatial unit d, ISDd, is as follows:Where:Pd = Population of the spatial unit d,wpd = Weight for population in zone d, according to its level of income per capita, as described above,Jd = Number of young people in the spatial unit d,Ad = Number of elderly people in the spatial unit d,Id = Number of immigrants in the spatial unit d,wjd = weight for the young people group (0.10),wad = weight for the elderly people group (0.42),wid = weight for the immigrants group (0.27).The indicator has been applied experimentally, with the support of a geographical information system, to the city of Madrid in order to quantify the need for CSS in two types of spatial units, namely districts and census sections that provide complementary utilities for political actions.The results reveal intraurban inequalities in this type of needs, and may serve to support public decision-making on the provision and location of these social resources. This work further includes a preliminary statistical study of the potentials and limitations of the indicator proposed for both spatial unit types. <![CDATA[La zonificación morfotectónica-volcánica en el análisis morfoestructural del relieve: el caso del municipio de Managua, Nicaragua]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200118&lng=es&nrm=iso&tlng=es Con base en la relación entre las estructuras geológicas y formas de relieve, se definieron doce unidades morfotectónico-volcánicas (UMTV) que caracterizan el relieve resultante de la fragmentación de la cadena volcánica nicaragüense y la formación del graben de Managua. Se elaboró un mapa (escala 1:50 000) considerando criterios asociados a elementos y atributos lito-estratigráficos, morfotectóni-cos y morfoestructurales, así como a elementos morfométricos. Los criterios considerados incluyeron el análisis de la orientación estructural del relieve, la evaluación morfo-métrica integral de las categorías geomorfológicas, la identificación e interpretación de los rasgos estructuro-geológicos, el análisis de los morfoelementos lineales y anulares, el análisis estructural correlativo con las relaciones litoestratigráficas del sustrato y la interpretación de los patrones estructurales de la red hidrográfica. Las UMTV identificadas sintetizan de manera geosistémica la expresión de la estructura y constitución geológicas, y reconocen la importancia de la actividad neotectónica en la formación y diferenciación del relieve.<hr/>AbstractThe modern Geomorphology has one of the scientific objectives: the morphostructural analysis, which is the set of methods oriented to reveal the structural-tectonic conditions of the earth's crust and its role in the shaping and consolidation of the actual landforms.Having into account the above mentioned, the main objective in this research is to create a Morpho-Tectonics Volcanic Unit (UMVT) of the Municipality of Managua, Nicaragua, which is represented in a topographic Map to a 1:50 000.00 scale, having as a base, the relationship between the geologic structures and the resulting relief shapes originated by the fragmentation of the Nicaraguan Volcanic Chain and the Graben Formation of Managua.The following research methods were applied in order to conduct this study: a) Creation of a digital model of elevation and shapes, b) morphometrics analysis, c) interpretation of air photographs to a 1:40 000,00 scale, d) analysis of the lineal morpho-elements and annular relief in order to complement the failure systems and morpho-lineal, e) a correlative structural analysis with the relief litostratigraphy and its lying conditions and the precision between the tectonic-volcanic units, f) interpretation of the structural patterns of the hydrographic network.The findings obtained from the morphometrics Analysis were: a) the altimeter map that allowed identifying altimetry differences between the main tectonic structures and the volcanic formations of the area. b) The creation of a dissection deep map that identified in a general way, a relationship between the slope and the dissection deep values in the territories: areas with a great number of slopes involves a major dissection and vice versa. c) The slope map which identified that the most important features appreciated, in a general way, were the escarps, which coincide with the mountain sides and erosive deforestation. The minor values are observed in the plains and middle foothills.In according to the geological-geomorphologic conditions, and the specific criteria stated previously, the Municipality of Managua was divided in twelve zones or morphotectonic volcanic units (UMVT), which are mentioned below:UMT I: Cuajachillo. This zone is represented by a low plain; UMTV II. Ticomo Los Martínez: This is a crustal weakness zone; UMTV III. San Judas-Tiscapa: This is a zone represented with middle-high plains with notable internal fissures; UMTV IV. San Juan-Unidad de Propósito: This unit is characterized with middle high plains, with presence of low foothills and with notable disjunctives structures; UMTV V. Barrio Nuevo-Esquipulas: In this zone it is middle and high plains are observed with presence of moderate fissures; UMTV VI. Graben el Aeropuerto: This zone is represented by the presence of the Graben Aeropuerto; UMTV VII. Los Madrigales: Low Foothills Zone, form volcanic origin with few presences of notable structural elements; UMTV VIII. Las Cuchillas: It is geomorphologically classified in pre-mountains with some elliptical features in its configuration; UMTV IX. San Isidro: From the geo-morphological perspective, it is classified as a high foothill, with structural evidences of the recent tectonic activity; UMTV X. Cedro Galan-Monte Tabor: This zone is represented by low foothills with some plain sectors; UMTV XI. Berlin: It is characterized by pre-mountain features; UMTV XII. Costa del Lago: This zone is characterized by a low plain.This classification is a regional characterization and its morphotectonic zoning is constituted from the scientific point of view: as a geo-systemic vision of the structure expression and the geological constitution and the neotectonic activity in the formation, consolidation and differentiation of the tectonic-volcanic relief in Nicaragua, showing the individual characteristics of each of the 12 space units.In this sense, the morphotectonic-volcanic zoning has a significant holistic strength that allows it to understand the space relationship between the composition of the geological substratum, its structures, and tectonics deformities, and at the same time its role in the relief differentiated formation in complex genetics conditions related with the recent and quaternary volcanism. The definition of the twelve units of this morphotectonic volcanic zoning represent an important input for further studies of the seismic dangerous, volcanic and extreme hydro-meteorological in different weakness sceneries and for designing the suitable programs for an adequate management of its risks.These aspects are considerably related with the UMTV, for that reason, its analysis in the weakness context due to flooding and its corresponding affections as well as the economic value of the tangible potential damages provoked by a flooding are clear examples of the relevance presented in this research (Velásquez, 2011). <![CDATA[Cuatro siglos de variabilidad hidroclimática en el noroeste de Chihuahua, México, reconstruida con anillos de árboles]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200141&lng=es&nrm=iso&tlng=es En el noroeste de Chihuahua, sitio Mesa de las Guacamayas, catalogada como "Área Natural Protegida" (ANP) para anidamiento de la cotorra serrana, se desarrolló una serie dendrocronológica con abeto Douglas (Pseudotsuga menziesii) con una extensión de 409 años (1600-2008). La cronología de anillo total mostró asociaciones significativas (r&gt;0.40, p=0.000) con cronologías vecinas (no separadas más de 200 km), particularmente las ubicadas en la misma vertiente de la Sierra Madre Occidental (SMO), lo que implica la influencia de patrones climáticos comunes, cuyos frentes húmedos impactan simultáneamente una extensa área del noroeste de México. Un análisis espectral de potencia indicó que los índices dendrocronológicos estuvieron afectados por ENSO y por otros patrones circulatorios, como se deduce de los picos espectrales dominantes (&lt;10 años) presentes en la cronología; también mostraron asociación significativa (r=0.52, n=111, p&lt;0.000) con registros del PDSI para el suroeste de los Estados Unidos. Una reconstrucción de precipitación acumulada enero-julio para la misma región, mostró sequías prolongadas en los periodos 1772-1782, 1793-1803, 1999-2008 y periodos húmedos en 1742-1751 y 1809-1818. La proporción de años secos detectados en la reconstrucción, sugiere que existe 50% de probabilidad de su ocurrencia a nivel anual.<hr/>A Douglas-fir chronology with a length of 409 years (1600-2008) was developed for northwestern Chihuahua in Mesa de las Guacamayas, a "Natural Protected Area" known as an important nesting habitat for the thick-billed parrot (Rhynchopsitta pachyrhyncha) an endangered neotropical bird. Increment cores and cross-sections from selected Douglas-fir trees (Pseudotsuga menziesii) in a mixed conifer forest were obtained with an increment borer and a chain-saw. Standard dendrochronological techniques were used to process and date each one of the rings to their exact year of formation. The quality of dating of the measured series was analyzed with the COFECHA program, while biolo-gical trends not related to climate (age differences, stem-size increases, and disturbances) were removed by standardiza-tion procedures in the ARSTAN program. Tree ring series of earlywood, latewood and total ring width were developed for the last four centuries. The total ring-width chronology was significantly associated (r&gt;0.40, p=0.000) with nearby chronologies, particularly those located &lt;200 km apart along the western slopes of the Sierra Madre Occidental (SMO) observing correlations as high as 0.69 (p&lt;0.001). Association between chronologies decreased for those sites in the state of Durango along the SMO but separated more than 200 km in straight line and also for sites in nearby borderline in the USA side. The similar climatic response among distant chronologies implies the influence of common atmospheric circulatory patterns affecting a large portion of land simultaneously. ENSO is one of the most important factors in determining inter-annual and multiannual hydroclimatic variability in northern Mexico, increasing winter-spring precipitation in its warm phase and causing extreme droughts in its cold phase. A negative relationship (r = -0.4, n= 106, p&lt;0.0000) was found between average January-May Southern Oscillation Index (SOI) and earlywood indices corroborating the significant influence of ENSO in cool season precipitation for this region. A power spectral analysis of the seasonal winter-spring precipitation reconstruction detected the presence of significant peaks (p&lt;0.05) &lt;10 years (5, 10 years) commonly associated to ENSO. Significant frequencies at 50 and near 100 years have also been related to the ENSO influence. 50-year frequency droughts historically have caused intense and prolonged droughts in northern and central Mexico, particularly those in the periods 1613-1617, 1666-1673, 1728-1733, 1752-1761, 1840-1845, 1862-1866, 1934-1939, 1944-1951, and 1953-1957. The ring-width index values were significantly associated (r=0.52, n=1 11, p&lt;0.000) with PDSI values recorded for the Southwestern region of the USA. The PDSI integrates precipitation and temperature data and is a measure of the availability of moisture for tree growth as related to average moisture conditions. The relationship between PDSI data from Arizona and New Mexico and ring-width indices from Mesa de las Guacamayas, Chihuahua is an indication that extreme climatic events extend from the Southwestern USA to northern Chihuahua and even further down in the Durango state. This behavior highlights the im-portance of developing a network of three ring chronologies at basin or watershed level to have a better understanding of climate dynamics. A seasonal January-July precipitation reconstruction detected intense and prolonged droughts for the periods1772-1782, 1793-1803, and 1999-2008, where 1633 and 1954 stand out as the driest years of the reconstruction. Wet episodes were detected from 1742 to 1751 and from 1809 to 1818. Pluvials are less recorded in historical documents and tree rings are less sensible to wet episodes given that much of the precipitation for this region takes place in the summer months when earlywood formation that makes most of the ring size has ceased. In addition, much of the rain is lost by runoffas its intensity exceeds soil infiltration rate and water holding capacity of the soil is overridden. Historical droughts have had a seve-re impact in food production, reducing grain availability, increasing livestock mortality, and producing famine. The drought documented for the period 1613 to 1626 has been detected in Durango, Chihuahua and New Mexico. Later droughts like one in the 1720's, end of the 1730's and early part of the 1740 's produced grain scarcity and famine in a great portion of northern Mexico. The drought of the 1950 s extended all over northern Mexico and southwestern USA producing economical crisis in rural areas and greatly increased immigration and movement of migrant farm workers (braceros) to the USA. The proportion of dry years detected in the reconstruction suggests a 50% probability of occurrence of below average precipitation for a given year, implying that the development of a more extensive network of climate sensitive tree-ring chronologies will allow us a better understanding of climate variability in this region which is important for the management of limited water resources and for the conservation of endangered wildlife species. <![CDATA[América Latina: caminos de la integración regional]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200154&lng=es&nrm=iso&tlng=es En el noroeste de Chihuahua, sitio Mesa de las Guacamayas, catalogada como "Área Natural Protegida" (ANP) para anidamiento de la cotorra serrana, se desarrolló una serie dendrocronológica con abeto Douglas (Pseudotsuga menziesii) con una extensión de 409 años (1600-2008). La cronología de anillo total mostró asociaciones significativas (r&gt;0.40, p=0.000) con cronologías vecinas (no separadas más de 200 km), particularmente las ubicadas en la misma vertiente de la Sierra Madre Occidental (SMO), lo que implica la influencia de patrones climáticos comunes, cuyos frentes húmedos impactan simultáneamente una extensa área del noroeste de México. Un análisis espectral de potencia indicó que los índices dendrocronológicos estuvieron afectados por ENSO y por otros patrones circulatorios, como se deduce de los picos espectrales dominantes (&lt;10 años) presentes en la cronología; también mostraron asociación significativa (r=0.52, n=111, p&lt;0.000) con registros del PDSI para el suroeste de los Estados Unidos. Una reconstrucción de precipitación acumulada enero-julio para la misma región, mostró sequías prolongadas en los periodos 1772-1782, 1793-1803, 1999-2008 y periodos húmedos en 1742-1751 y 1809-1818. La proporción de años secos detectados en la reconstrucción, sugiere que existe 50% de probabilidad de su ocurrencia a nivel anual.<hr/>A Douglas-fir chronology with a length of 409 years (1600-2008) was developed for northwestern Chihuahua in Mesa de las Guacamayas, a "Natural Protected Area" known as an important nesting habitat for the thick-billed parrot (Rhynchopsitta pachyrhyncha) an endangered neotropical bird. Increment cores and cross-sections from selected Douglas-fir trees (Pseudotsuga menziesii) in a mixed conifer forest were obtained with an increment borer and a chain-saw. Standard dendrochronological techniques were used to process and date each one of the rings to their exact year of formation. The quality of dating of the measured series was analyzed with the COFECHA program, while biolo-gical trends not related to climate (age differences, stem-size increases, and disturbances) were removed by standardiza-tion procedures in the ARSTAN program. Tree ring series of earlywood, latewood and total ring width were developed for the last four centuries. The total ring-width chronology was significantly associated (r&gt;0.40, p=0.000) with nearby chronologies, particularly those located &lt;200 km apart along the western slopes of the Sierra Madre Occidental (SMO) observing correlations as high as 0.69 (p&lt;0.001). Association between chronologies decreased for those sites in the state of Durango along the SMO but separated more than 200 km in straight line and also for sites in nearby borderline in the USA side. The similar climatic response among distant chronologies implies the influence of common atmospheric circulatory patterns affecting a large portion of land simultaneously. ENSO is one of the most important factors in determining inter-annual and multiannual hydroclimatic variability in northern Mexico, increasing winter-spring precipitation in its warm phase and causing extreme droughts in its cold phase. A negative relationship (r = -0.4, n= 106, p&lt;0.0000) was found between average January-May Southern Oscillation Index (SOI) and earlywood indices corroborating the significant influence of ENSO in cool season precipitation for this region. A power spectral analysis of the seasonal winter-spring precipitation reconstruction detected the presence of significant peaks (p&lt;0.05) &lt;10 years (5, 10 years) commonly associated to ENSO. Significant frequencies at 50 and near 100 years have also been related to the ENSO influence. 50-year frequency droughts historically have caused intense and prolonged droughts in northern and central Mexico, particularly those in the periods 1613-1617, 1666-1673, 1728-1733, 1752-1761, 1840-1845, 1862-1866, 1934-1939, 1944-1951, and 1953-1957. The ring-width index values were significantly associated (r=0.52, n=1 11, p&lt;0.000) with PDSI values recorded for the Southwestern region of the USA. The PDSI integrates precipitation and temperature data and is a measure of the availability of moisture for tree growth as related to average moisture conditions. The relationship between PDSI data from Arizona and New Mexico and ring-width indices from Mesa de las Guacamayas, Chihuahua is an indication that extreme climatic events extend from the Southwestern USA to northern Chihuahua and even further down in the Durango state. This behavior highlights the im-portance of developing a network of three ring chronologies at basin or watershed level to have a better understanding of climate dynamics. A seasonal January-July precipitation reconstruction detected intense and prolonged droughts for the periods1772-1782, 1793-1803, and 1999-2008, where 1633 and 1954 stand out as the driest years of the reconstruction. Wet episodes were detected from 1742 to 1751 and from 1809 to 1818. Pluvials are less recorded in historical documents and tree rings are less sensible to wet episodes given that much of the precipitation for this region takes place in the summer months when earlywood formation that makes most of the ring size has ceased. In addition, much of the rain is lost by runoffas its intensity exceeds soil infiltration rate and water holding capacity of the soil is overridden. Historical droughts have had a seve-re impact in food production, reducing grain availability, increasing livestock mortality, and producing famine. The drought documented for the period 1613 to 1626 has been detected in Durango, Chihuahua and New Mexico. Later droughts like one in the 1720's, end of the 1730's and early part of the 1740 's produced grain scarcity and famine in a great portion of northern Mexico. The drought of the 1950 s extended all over northern Mexico and southwestern USA producing economical crisis in rural areas and greatly increased immigration and movement of migrant farm workers (braceros) to the USA. The proportion of dry years detected in the reconstruction suggests a 50% probability of occurrence of below average precipitation for a given year, implying that the development of a more extensive network of climate sensitive tree-ring chronologies will allow us a better understanding of climate variability in this region which is important for the management of limited water resources and for the conservation of endangered wildlife species. <![CDATA[Names, Ethnicity and Population]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200156&lng=es&nrm=iso&tlng=es En el noroeste de Chihuahua, sitio Mesa de las Guacamayas, catalogada como "Área Natural Protegida" (ANP) para anidamiento de la cotorra serrana, se desarrolló una serie dendrocronológica con abeto Douglas (Pseudotsuga menziesii) con una extensión de 409 años (1600-2008). La cronología de anillo total mostró asociaciones significativas (r&gt;0.40, p=0.000) con cronologías vecinas (no separadas más de 200 km), particularmente las ubicadas en la misma vertiente de la Sierra Madre Occidental (SMO), lo que implica la influencia de patrones climáticos comunes, cuyos frentes húmedos impactan simultáneamente una extensa área del noroeste de México. Un análisis espectral de potencia indicó que los índices dendrocronológicos estuvieron afectados por ENSO y por otros patrones circulatorios, como se deduce de los picos espectrales dominantes (&lt;10 años) presentes en la cronología; también mostraron asociación significativa (r=0.52, n=111, p&lt;0.000) con registros del PDSI para el suroeste de los Estados Unidos. Una reconstrucción de precipitación acumulada enero-julio para la misma región, mostró sequías prolongadas en los periodos 1772-1782, 1793-1803, 1999-2008 y periodos húmedos en 1742-1751 y 1809-1818. La proporción de años secos detectados en la reconstrucción, sugiere que existe 50% de probabilidad de su ocurrencia a nivel anual.<hr/>A Douglas-fir chronology with a length of 409 years (1600-2008) was developed for northwestern Chihuahua in Mesa de las Guacamayas, a "Natural Protected Area" known as an important nesting habitat for the thick-billed parrot (Rhynchopsitta pachyrhyncha) an endangered neotropical bird. Increment cores and cross-sections from selected Douglas-fir trees (Pseudotsuga menziesii) in a mixed conifer forest were obtained with an increment borer and a chain-saw. Standard dendrochronological techniques were used to process and date each one of the rings to their exact year of formation. The quality of dating of the measured series was analyzed with the COFECHA program, while biolo-gical trends not related to climate (age differences, stem-size increases, and disturbances) were removed by standardiza-tion procedures in the ARSTAN program. Tree ring series of earlywood, latewood and total ring width were developed for the last four centuries. The total ring-width chronology was significantly associated (r&gt;0.40, p=0.000) with nearby chronologies, particularly those located &lt;200 km apart along the western slopes of the Sierra Madre Occidental (SMO) observing correlations as high as 0.69 (p&lt;0.001). Association between chronologies decreased for those sites in the state of Durango along the SMO but separated more than 200 km in straight line and also for sites in nearby borderline in the USA side. The similar climatic response among distant chronologies implies the influence of common atmospheric circulatory patterns affecting a large portion of land simultaneously. ENSO is one of the most important factors in determining inter-annual and multiannual hydroclimatic variability in northern Mexico, increasing winter-spring precipitation in its warm phase and causing extreme droughts in its cold phase. A negative relationship (r = -0.4, n= 106, p&lt;0.0000) was found between average January-May Southern Oscillation Index (SOI) and earlywood indices corroborating the significant influence of ENSO in cool season precipitation for this region. A power spectral analysis of the seasonal winter-spring precipitation reconstruction detected the presence of significant peaks (p&lt;0.05) &lt;10 years (5, 10 years) commonly associated to ENSO. Significant frequencies at 50 and near 100 years have also been related to the ENSO influence. 50-year frequency droughts historically have caused intense and prolonged droughts in northern and central Mexico, particularly those in the periods 1613-1617, 1666-1673, 1728-1733, 1752-1761, 1840-1845, 1862-1866, 1934-1939, 1944-1951, and 1953-1957. The ring-width index values were significantly associated (r=0.52, n=1 11, p&lt;0.000) with PDSI values recorded for the Southwestern region of the USA. The PDSI integrates precipitation and temperature data and is a measure of the availability of moisture for tree growth as related to average moisture conditions. The relationship between PDSI data from Arizona and New Mexico and ring-width indices from Mesa de las Guacamayas, Chihuahua is an indication that extreme climatic events extend from the Southwestern USA to northern Chihuahua and even further down in the Durango state. This behavior highlights the im-portance of developing a network of three ring chronologies at basin or watershed level to have a better understanding of climate dynamics. A seasonal January-July precipitation reconstruction detected intense and prolonged droughts for the periods1772-1782, 1793-1803, and 1999-2008, where 1633 and 1954 stand out as the driest years of the reconstruction. Wet episodes were detected from 1742 to 1751 and from 1809 to 1818. Pluvials are less recorded in historical documents and tree rings are less sensible to wet episodes given that much of the precipitation for this region takes place in the summer months when earlywood formation that makes most of the ring size has ceased. In addition, much of the rain is lost by runoffas its intensity exceeds soil infiltration rate and water holding capacity of the soil is overridden. Historical droughts have had a seve-re impact in food production, reducing grain availability, increasing livestock mortality, and producing famine. The drought documented for the period 1613 to 1626 has been detected in Durango, Chihuahua and New Mexico. Later droughts like one in the 1720's, end of the 1730's and early part of the 1740 's produced grain scarcity and famine in a great portion of northern Mexico. The drought of the 1950 s extended all over northern Mexico and southwestern USA producing economical crisis in rural areas and greatly increased immigration and movement of migrant farm workers (braceros) to the USA. The proportion of dry years detected in the reconstruction suggests a 50% probability of occurrence of below average precipitation for a given year, implying that the development of a more extensive network of climate sensitive tree-ring chronologies will allow us a better understanding of climate variability in this region which is important for the management of limited water resources and for the conservation of endangered wildlife species. <![CDATA[Paisaje y Territorio. Articulaciones teóricas y empíricas]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200158&lng=es&nrm=iso&tlng=es En el noroeste de Chihuahua, sitio Mesa de las Guacamayas, catalogada como "Área Natural Protegida" (ANP) para anidamiento de la cotorra serrana, se desarrolló una serie dendrocronológica con abeto Douglas (Pseudotsuga menziesii) con una extensión de 409 años (1600-2008). La cronología de anillo total mostró asociaciones significativas (r&gt;0.40, p=0.000) con cronologías vecinas (no separadas más de 200 km), particularmente las ubicadas en la misma vertiente de la Sierra Madre Occidental (SMO), lo que implica la influencia de patrones climáticos comunes, cuyos frentes húmedos impactan simultáneamente una extensa área del noroeste de México. Un análisis espectral de potencia indicó que los índices dendrocronológicos estuvieron afectados por ENSO y por otros patrones circulatorios, como se deduce de los picos espectrales dominantes (&lt;10 años) presentes en la cronología; también mostraron asociación significativa (r=0.52, n=111, p&lt;0.000) con registros del PDSI para el suroeste de los Estados Unidos. Una reconstrucción de precipitación acumulada enero-julio para la misma región, mostró sequías prolongadas en los periodos 1772-1782, 1793-1803, 1999-2008 y periodos húmedos en 1742-1751 y 1809-1818. La proporción de años secos detectados en la reconstrucción, sugiere que existe 50% de probabilidad de su ocurrencia a nivel anual.<hr/>A Douglas-fir chronology with a length of 409 years (1600-2008) was developed for northwestern Chihuahua in Mesa de las Guacamayas, a "Natural Protected Area" known as an important nesting habitat for the thick-billed parrot (Rhynchopsitta pachyrhyncha) an endangered neotropical bird. Increment cores and cross-sections from selected Douglas-fir trees (Pseudotsuga menziesii) in a mixed conifer forest were obtained with an increment borer and a chain-saw. Standard dendrochronological techniques were used to process and date each one of the rings to their exact year of formation. The quality of dating of the measured series was analyzed with the COFECHA program, while biolo-gical trends not related to climate (age differences, stem-size increases, and disturbances) were removed by standardiza-tion procedures in the ARSTAN program. Tree ring series of earlywood, latewood and total ring width were developed for the last four centuries. The total ring-width chronology was significantly associated (r&gt;0.40, p=0.000) with nearby chronologies, particularly those located &lt;200 km apart along the western slopes of the Sierra Madre Occidental (SMO) observing correlations as high as 0.69 (p&lt;0.001). Association between chronologies decreased for those sites in the state of Durango along the SMO but separated more than 200 km in straight line and also for sites in nearby borderline in the USA side. The similar climatic response among distant chronologies implies the influence of common atmospheric circulatory patterns affecting a large portion of land simultaneously. ENSO is one of the most important factors in determining inter-annual and multiannual hydroclimatic variability in northern Mexico, increasing winter-spring precipitation in its warm phase and causing extreme droughts in its cold phase. A negative relationship (r = -0.4, n= 106, p&lt;0.0000) was found between average January-May Southern Oscillation Index (SOI) and earlywood indices corroborating the significant influence of ENSO in cool season precipitation for this region. A power spectral analysis of the seasonal winter-spring precipitation reconstruction detected the presence of significant peaks (p&lt;0.05) &lt;10 years (5, 10 years) commonly associated to ENSO. Significant frequencies at 50 and near 100 years have also been related to the ENSO influence. 50-year frequency droughts historically have caused intense and prolonged droughts in northern and central Mexico, particularly those in the periods 1613-1617, 1666-1673, 1728-1733, 1752-1761, 1840-1845, 1862-1866, 1934-1939, 1944-1951, and 1953-1957. The ring-width index values were significantly associated (r=0.52, n=1 11, p&lt;0.000) with PDSI values recorded for the Southwestern region of the USA. The PDSI integrates precipitation and temperature data and is a measure of the availability of moisture for tree growth as related to average moisture conditions. The relationship between PDSI data from Arizona and New Mexico and ring-width indices from Mesa de las Guacamayas, Chihuahua is an indication that extreme climatic events extend from the Southwestern USA to northern Chihuahua and even further down in the Durango state. This behavior highlights the im-portance of developing a network of three ring chronologies at basin or watershed level to have a better understanding of climate dynamics. A seasonal January-July precipitation reconstruction detected intense and prolonged droughts for the periods1772-1782, 1793-1803, and 1999-2008, where 1633 and 1954 stand out as the driest years of the reconstruction. Wet episodes were detected from 1742 to 1751 and from 1809 to 1818. Pluvials are less recorded in historical documents and tree rings are less sensible to wet episodes given that much of the precipitation for this region takes place in the summer months when earlywood formation that makes most of the ring size has ceased. In addition, much of the rain is lost by runoffas its intensity exceeds soil infiltration rate and water holding capacity of the soil is overridden. Historical droughts have had a seve-re impact in food production, reducing grain availability, increasing livestock mortality, and producing famine. The drought documented for the period 1613 to 1626 has been detected in Durango, Chihuahua and New Mexico. Later droughts like one in the 1720's, end of the 1730's and early part of the 1740 's produced grain scarcity and famine in a great portion of northern Mexico. The drought of the 1950 s extended all over northern Mexico and southwestern USA producing economical crisis in rural areas and greatly increased immigration and movement of migrant farm workers (braceros) to the USA. The proportion of dry years detected in the reconstruction suggests a 50% probability of occurrence of below average precipitation for a given year, implying that the development of a more extensive network of climate sensitive tree-ring chronologies will allow us a better understanding of climate variability in this region which is important for the management of limited water resources and for the conservation of endangered wildlife species. <![CDATA[VI Congreso Iberoamericano de Estudios Territoriales y Ambientales]]> http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0188-46112015000200161&lng=es&nrm=iso&tlng=es En el noroeste de Chihuahua, sitio Mesa de las Guacamayas, catalogada como "Área Natural Protegida" (ANP) para anidamiento de la cotorra serrana, se desarrolló una serie dendrocronológica con abeto Douglas (Pseudotsuga menziesii) con una extensión de 409 años (1600-2008). La cronología de anillo total mostró asociaciones significativas (r&gt;0.40, p=0.000) con cronologías vecinas (no separadas más de 200 km), particularmente las ubicadas en la misma vertiente de la Sierra Madre Occidental (SMO), lo que implica la influencia de patrones climáticos comunes, cuyos frentes húmedos impactan simultáneamente una extensa área del noroeste de México. Un análisis espectral de potencia indicó que los índices dendrocronológicos estuvieron afectados por ENSO y por otros patrones circulatorios, como se deduce de los picos espectrales dominantes (&lt;10 años) presentes en la cronología; también mostraron asociación significativa (r=0.52, n=111, p&lt;0.000) con registros del PDSI para el suroeste de los Estados Unidos. Una reconstrucción de precipitación acumulada enero-julio para la misma región, mostró sequías prolongadas en los periodos 1772-1782, 1793-1803, 1999-2008 y periodos húmedos en 1742-1751 y 1809-1818. La proporción de años secos detectados en la reconstrucción, sugiere que existe 50% de probabilidad de su ocurrencia a nivel anual.<hr/>A Douglas-fir chronology with a length of 409 years (1600-2008) was developed for northwestern Chihuahua in Mesa de las Guacamayas, a "Natural Protected Area" known as an important nesting habitat for the thick-billed parrot (Rhynchopsitta pachyrhyncha) an endangered neotropical bird. Increment cores and cross-sections from selected Douglas-fir trees (Pseudotsuga menziesii) in a mixed conifer forest were obtained with an increment borer and a chain-saw. Standard dendrochronological techniques were used to process and date each one of the rings to their exact year of formation. The quality of dating of the measured series was analyzed with the COFECHA program, while biolo-gical trends not related to climate (age differences, stem-size increases, and disturbances) were removed by standardiza-tion procedures in the ARSTAN program. Tree ring series of earlywood, latewood and total ring width were developed for the last four centuries. The total ring-width chronology was significantly associated (r&gt;0.40, p=0.000) with nearby chronologies, particularly those located &lt;200 km apart along the western slopes of the Sierra Madre Occidental (SMO) observing correlations as high as 0.69 (p&lt;0.001). Association between chronologies decreased for those sites in the state of Durango along the SMO but separated more than 200 km in straight line and also for sites in nearby borderline in the USA side. The similar climatic response among distant chronologies implies the influence of common atmospheric circulatory patterns affecting a large portion of land simultaneously. ENSO is one of the most important factors in determining inter-annual and multiannual hydroclimatic variability in northern Mexico, increasing winter-spring precipitation in its warm phase and causing extreme droughts in its cold phase. A negative relationship (r = -0.4, n= 106, p&lt;0.0000) was found between average January-May Southern Oscillation Index (SOI) and earlywood indices corroborating the significant influence of ENSO in cool season precipitation for this region. A power spectral analysis of the seasonal winter-spring precipitation reconstruction detected the presence of significant peaks (p&lt;0.05) &lt;10 years (5, 10 years) commonly associated to ENSO. Significant frequencies at 50 and near 100 years have also been related to the ENSO influence. 50-year frequency droughts historically have caused intense and prolonged droughts in northern and central Mexico, particularly those in the periods 1613-1617, 1666-1673, 1728-1733, 1752-1761, 1840-1845, 1862-1866, 1934-1939, 1944-1951, and 1953-1957. The ring-width index values were significantly associated (r=0.52, n=1 11, p&lt;0.000) with PDSI values recorded for the Southwestern region of the USA. The PDSI integrates precipitation and temperature data and is a measure of the availability of moisture for tree growth as related to average moisture conditions. The relationship between PDSI data from Arizona and New Mexico and ring-width indices from Mesa de las Guacamayas, Chihuahua is an indication that extreme climatic events extend from the Southwestern USA to northern Chihuahua and even further down in the Durango state. This behavior highlights the im-portance of developing a network of three ring chronologies at basin or watershed level to have a better understanding of climate dynamics. A seasonal January-July precipitation reconstruction detected intense and prolonged droughts for the periods1772-1782, 1793-1803, and 1999-2008, where 1633 and 1954 stand out as the driest years of the reconstruction. Wet episodes were detected from 1742 to 1751 and from 1809 to 1818. Pluvials are less recorded in historical documents and tree rings are less sensible to wet episodes given that much of the precipitation for this region takes place in the summer months when earlywood formation that makes most of the ring size has ceased. In addition, much of the rain is lost by runoffas its intensity exceeds soil infiltration rate and water holding capacity of the soil is overridden. Historical droughts have had a seve-re impact in food production, reducing grain availability, increasing livestock mortality, and producing famine. The drought documented for the period 1613 to 1626 has been detected in Durango, Chihuahua and New Mexico. Later droughts like one in the 1720's, end of the 1730's and early part of the 1740 's produced grain scarcity and famine in a great portion of northern Mexico. The drought of the 1950 s extended all over northern Mexico and southwestern USA producing economical crisis in rural areas and greatly increased immigration and movement of migrant farm workers (braceros) to the USA. The proportion of dry years detected in the reconstruction suggests a 50% probability of occurrence of below average precipitation for a given year, implying that the development of a more extensive network of climate sensitive tree-ring chronologies will allow us a better understanding of climate variability in this region which is important for the management of limited water resources and for the conservation of endangered wildlife species.