remote sensing Article Multi-Temporal Analysis and Trends of the Drought Based on MODIS Data in Agricultural Areas, Romania Claudiu-Valeriu Angearu 1,2 , Irina Ontel 1,* , George Boldeanu 1 , Denis Mihailescu 1 , Argentina Nertan 1 , Vasile Craciunescu 1 , Simona Catana 1 and Anisoara Irimescu 1 1 Remote Sensing and GIS Laboratory, National Meteorological Administration, 013686 Bucharest, Romania;
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[email protected]; Tel.: +40-786-044-095 Received: 9 October 2020; Accepted: 26 November 2020; Published: 1 December 2020 Abstract: The aim of this study is to analyze the performance of the Drought Severity Index (DSI) in Romania and its validation based on other data sources (meteorological data, soil moisture content (SMC), agricultural production). Also, it is to assess the drought based on a multi-temporal analysis and trends of the DSI obtained from Terra MODIS satellite images. DSI is a standardized product based on evapotranspiration (ET) and the Normalized Difference Vegetation Index (NDVI), highlighting the differences over a certain period of time compared to the average. The study areas are located in Romania: three important agricultural lands (Oltenia Plain, Baragan Plain and Banat Plain), which have different environmental characteristics. MODIS products have been used over a period of 19 years (2001–2019) during the vegetation season of the agricultural crops (April–September).