<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>2007-2422</journal-id>
<journal-title><![CDATA[Tecnología y ciencias del agua]]></journal-title>
<abbrev-journal-title><![CDATA[Tecnol. cienc. agua]]></abbrev-journal-title>
<issn>2007-2422</issn>
<publisher>
<publisher-name><![CDATA[Instituto Mexicano de Tecnología del Agua, Coordinación de Comunicación, Participación e Información]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S2007-24222018000200210</article-id>
<article-id pub-id-type="doi">10.24850/j-tyca-2018-02-09</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Cuantificación con el SPEI de Sequías históricas y bajo cambio climático probable en la estación climatológica Zacatecas, México]]></article-title>
<article-title xml:lang="en"><![CDATA[Quantification with SPEI of historical Droughts and under probable climatic change in the climatological station Zacatecas, Mexico]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Campos-Aranda]]></surname>
<given-names><![CDATA[Daniel Francisco]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Autónoma de San Luis Potosí  ]]></institution>
<addr-line><![CDATA[ San Luis Potosí]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>04</month>
<year>2018</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>04</month>
<year>2018</year>
</pub-date>
<volume>9</volume>
<numero>2</numero>
<fpage>210</fpage>
<lpage>233</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S2007-24222018000200210&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S2007-24222018000200210&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S2007-24222018000200210&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen El SPEI (Standardized Precipitation-Evapotranspiration Index) es una variante del ampliamente difundido SPI (Standardized Precipitation Index), que tiene un mayor potencial como índice de sequías al ser sensitivo al cambio climático, debido a que usa una medida más real de la disponibilidad de agua, el balance climático. Esta medida se evalúa con la diferencia entre la precipitación y la evapotranspiración potencial mensuales. En este estudio se describe con detalle el procedimiento operativo del SPEI y se aplica a los registros históricos mensuales disponibles de precipitación y temperatura media en la estación climatológica Zacatecas, ubicada en la capital del estado de Zacatecas, México, los cuales abarcan 86 años (1930-2015). Para las sequías históricas, los resultados del SPEI definen en las sequías leves, moderadas, severas y extremas, los valores aproximados siguientes: 32.2%, 11.5%, 5.0% y 1.3%. Para esta ubicación del país, se consideró conveniente formular tres escenarios del cambio climático, el primero acepta una reducción progresiva y lineal del 20% en la precipitación anual, el segundo adopta un aumento progresivo y lineal de 4°C en la temperatura media anual y el tercero, sobrepone los dos efectos citados; por lo tanto es el más crítico. En los tres escenarios planteados, se encuentra que las sequías leves y extremas aumentan someramente en número o porcentaje y que las sequías moderadas y severas disminuyen, también de manera mesurada. Se exponen los gráficos de evolución del SPEI de duración 12 meses, histórico y del tercer escenario, en los cuales se visualiza claramente las épocas de ocurrencia de los periodos de sequía, así como de las diferencias puntuales en el valor del SPEI. Con base en los resultados de estos análisis, se recomienda la aplicación sistemática del SPEI en la caracterización de las sequías históricas y futuras. En estas últimas, los resultados tienen únicamente un carácter orientativo.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract The SPEI (Standardized Precipitation-Evapotranspiration Index) is a variant of the widespread SPI (Standardized Precipitation Index), it has greater potential as drought index since it is sensitive to climate change because it uses a more realistic measure of the water availability: the climate balance. This measure is evaluated by the difference between monthly precipitation and potential evapotranspiration. This study describes in detail the calculation of SPEI and its application to the monthly historical records of precipitation and average temperature available in the climatological station Zacatecas, located in the capital of the state of Zacatecas, Mexico. The data covers 86 years in the period from 1930 to 2015. For historical droughts, the results of SPEI indicate in light, moderate, severe and extreme droughts, the following approximate values: 32.2%, 11.5%, 5.0% and 1.3%. For this particular location, three scenarios of climatic change were proposed; the first one accepts a progressive and linear reduction of 20% in annual precipitation, the second one adopts a progressive and linear increase of 4 °C in the average temperature and finally, the third one, superimposes the two effects mentioned; being therefore the most critical. For the three proposed scenarios, results suggest that light and extreme droughts increase scarcely in number or percentage, and that moderate and severe droughts decrease, also in a slight way. Results are condensed on graphs of SPEI evolution of duration 12 months, historical and the third scenario, in which the times of occurrence of drought periods are clearly displayed, as well as the specific differences in the value of SPEI exposed. Based on these analyzes, the systematic application of SPEI in the characterization of historical and future droughts is recommended, its application on future droughts would lead to results merely indicative.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[índice SPEI]]></kwd>
<kwd lng="es"><![CDATA[distribución Log-Logística]]></kwd>
<kwd lng="es"><![CDATA[momentos de probabilidad ponderada]]></kwd>
<kwd lng="es"><![CDATA[evapotranspiración potencial]]></kwd>
<kwd lng="es"><![CDATA[homogeneidad estadística]]></kwd>
<kwd lng="es"><![CDATA[cambio climático]]></kwd>
<kwd lng="en"><![CDATA[SPEI index]]></kwd>
<kwd lng="en"><![CDATA[Log-Logistic distribution]]></kwd>
<kwd lng="en"><![CDATA[probability weighted moments]]></kwd>
<kwd lng="en"><![CDATA[potential evapotranspiration]]></kwd>
<kwd lng="en"><![CDATA[statistical homogeneity]]></kwd>
<kwd lng="en"><![CDATA[climate change]]></kwd>
</kwd-group>
</article-meta>
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