Drought monitoring in El Salvador through remotely sensed variables using the Google Earth Engine platform

O. Córdova, V. Venturini, E. Walker


Drought is a phenomenon that causes great economic losses in the society and is being observed more frequently due to climate change. In Central America this event is related to the anomalous distribution of precipitation (P) in a short period, within the rainy season. Specifically, in El Salvador, the phenomenon socalled “canícula” is associated to a significant decrease in P that lasts few days, making difficult to monitor it with P alone, as it is currently done. At present, many indicators have been developed to characterize droughts. In particular, the standardized precipitation and the condition indices proposed by Kogan (1995) that use various sources of information, stand out. In this work, five indicators of water deficit were applied - the standardized P, evapotranspiration (ET), the soil moisture condition index (HSCI), the vegetation condition index (VCI) and water stress (EH)- to assess droughts in El Salvador. For this, satellite information, climate database and the application programming interface available on the Google Earth Engine platform were used. The behaviour of the indexes in the period 2015-2019 was analysed, particularly the extremely dry year 2015, to determine the monitoring capacity of the indicators used. The results obtained suggest that the proposed set of indicators allows monitoring the drought, by identifying the onset, impact and territorial extension of it in El Salvador.


water deficit; monitoring; remote sensing; Google Earth Engine; water stress

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