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The study presented herein characterizes climate for historical series of average temperature and precipitation, also including future projections for the Province of Santa Elena, westernmost point of continental Ecuador, which presents desert environment in the intertropical belt. The historical analysis shows increasing temperatures (0,038 ºC/year) and precipitation (0,196 mm/year). Comparison of historical and generated (65 climate models) climate determines scenario ECHOG A2 as the most appropriate to reproduce the climate of the zone. This model predicts increases in temperature (+2,7 ºC), precipitation (+8,2%), and in maximum annual rain values, at the end of the XXI century. Evolution of temperature and precipitation does not lead to changes in annual climate characteristics, which is maintained as Semiarid, but the aridity index decreases monthly, from January to April.Keywords: Temperature, precipitation; aridity index; climate models; trend. Evolución climática en la costa de Ecuador por efecto del cambio climáticoResumen Este trabajo caracteriza el clima de la serie histórica de temperatura media y precipitación y sus proyecciones futuras (2012-2099) en la Provincia de Santa Elena, región más occidental del Ecuador continental con características desérticas en el cinturón intertropical. El análisis histórico muestra aumentos de temperatura (0,038 ºC/año) y precipitación (0,196 mm/año). La comparación del clima histórico y generado por 65 modelos climáticos determina al escenario ECHOG A2 como más adecuado para reproducir el clima de la zona. Dicho modelo predice a final del siglo XXI aumentos en la temperatura media (+2,7 ºC), precipitación (+8,2%) y en los valores máximos de lluvia anual. La evolución de la temperatura y precipitación no lleva cambios en las características de clima anual que se mantiene como Semidesértico árido, si bien mensualmente disminuye la aridez de enero a abril.Palabras clave: Temperatura; precipitación; índice de aridez; modelos climáticos; tendencia. IntroducciónEl grupo intergubernamental de expertos sobre el cambio climático (IPCC) pone de manifiesto que el calentamiento global debido a la emisión de gases de efecto invernadero es un hecho constatado con el que se prevén importantes cambios en gran cantidad de variables climáticas [1]. Entre ellas, destacan precisamente la temperatura, en la que se detecta una tendencia creciente de 0,74 ºC entre 1901-2005, y las precipitaciones, en las que a pesar de su alta variabilidad espacial puede evidenciarse un aumento generalizado en regiones septentrionales y una reducción en las más How to cite: García-Garizábal, I., Romero, P., Jimenez, S. and Jordá, L., Evolución climática en la costa de Ecuador por efecto del cambio climático DYNA, 84(203), pp. 37-44, December, 2017. meridionales.El IPCC recoge la necesidad de establecer medidas de adaptación y mitigación de cara al cambio climático, si bien, dada la complejidad del sistema Tierra, es imposible detallar actuaciones a nivel mundial y resulta necesario desarrol...

The generation of quality climatic series is the first step in the analysis of climate characteristics and behaviour in any region of the world. This article approaches the construction of homogeneous average temperature series for the period 1982-2011, for the study of spatial distribution and temporal evolution in the Province of Santa Elena, in the most western point of continental Ecuador in South America. Despite the low variability registered in the temperatures of the Province, these were higher and more homogeneous in the inland region than on the coast and almost 3 ∘ C higher in the trimesters of the rainy season December-January-February (DJF) and March-April-May (MAM) than in the trimesters of the dry season June-July-August (JJA) and September-October-November (SON). Trend analysis detected positive increasing rates for the temperature of the province, with values three times higher during DJF and MAM in comparison with SON and annual average trend of 0.33 ∘ C decade −1 in the region. The construction of homogeneous average temperature series in the Province of Santa Elena has been an important step towards the spatial-temporal characterization of this peculiar climatic zone. These series can also be employed as base scenarios for the development of climate change studies in the region.

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Mining environmental liabilities (MEL) are of great concern because of potential risks to ecosystems and human health. In this research, the environmental risk (RI) related to MEL existing in three artisanal and small-scale gold-mining areas of Ecuador was evaluated. For this purpose, data of 167 MEL including landfills, mining galleries, tailing deposits, and mineral processing plants from Macuchi, Tenguel–Ponce Enriquez, and Puyango mining areas, were analyzed. The risk assessment related to the presence of waste deposits was carried out based on the methodology proposed by the Spanish Geological Survey. Moreover, the procedure outlined in the Environmental Risk Assessment Guide of the Ministry of Environment of Peru for nonwaste deposits was applied. The highest RI values were identified in Puyango and Tenguel–Ponce Enriquez. Thus, they were both categorized as priority control areas requiring intervention and rehabilitation plans. The MEL that require a high level of intervention include waste deposits and mine entrances associated with potentially toxic elements. Moreover, the point risk maps showed that rivers in the studied areas have a potential pollution risk. This study provides risk levels associated with MEL in mining areas from Ecuador. This information could be used for environmental management and pollution mitigation.

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Groundwater is a strategic resource, which is experiencing a growing threat of contamination worldwide. This study aimed to assess the vulnerability of the groundwaters in the basins of the rivers Gala, Tenguel, and Siete in the Ponce Enriquez mining area, considering as a hypothesis that anthropogenic activities (mainly mining and agricultural) conducted in the area generate a high risk of contamination. Vulnerability to contamination was quantified using the DRASTIC and GOD methods. In addition, the risk of contamination (Rc) was calculated considering the vulnerability index (IV) and the danger index (IP). Geographic information system (GIS) environment was used for the spatial analysis and the generation of vulnerability maps. The DRASTIC method showed that the negligible-to-low vulnerability category was predominant (50.7% of the area), followed by moderate vulnerability (25.6%), and high-to-extreme vulnerability (23.7%). Regarding the GOD method, the low and medium vulnerability categories were predominant in 41.4% and 27.5% of the area, respectively. Both methods agree that the center area, where the mining activities are located, has a vulnerability ranging from negligible to moderate. The IP was low in the eastern zone (58.7 km2) and ranged from moderate (426.2 km2) to high in the central and western zones (371.1 km2), where mining activities predominate. The RC revealed that 20% of the study area corresponded to a high contamination index; from which, 87% comes from agricultural activities, 9% from mining activities, and 4% due to shrimp farms and urban areas. This is the first study that evaluates the vulnerability to the contamination of groundwater in a mining area of Ecuador. The results of this research can serve as a baseline for future research, since the methodology used provides information on the priority areas for the protection of aquifers, considering the current land use in the study area.