Abstract
Abstract. A synergistic fusion of the Soil Moisture and Ocean Salinity (SMOS) L2 soil moisture with the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived land surface temperature (LST) and several water/vegetation indices for agricultural drought monitoring was tested. The rationale of the calculation is based on the inverse relationship between LST and vegetation condition, related in turn with the soil moisture content. All the products were time-integrated, including the lagged response of vegetation. The product aims to detect and characterize soil moisture drought conditions and, particularly, to identify potential short-term agricultural droughts among them. The new index, so-called the Soil Moisture Agricultural Drought Index (SMADI), was retrieved at 500 m spatial resolution at the Soil Moisture Measurement Stations Network of the University of Salamanca (REMEDHUS) area from 2010 to 2014 at 8-days temporal scale. SMADI was compared with other agricultural indices in REMEDHUS through statistical correlation, affording a good agreement with them, and depicting a suitable description of the drought conditions in this area during the study period.
Highlights
Drought is a normal, recurring feature of climate, and occurs in virtually all climatic regimes
Soil Moisture Agricultural Drought Index (SMADI) was based on Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI)/Normalized Difference Water Index (NDWI), together with Soil Moisture and Ocean Salinity (SMOS) surface soil moisture (SSM), all of them normalized after the maximum and minimum values across the five years of the study
The results of SMADI afforded a good agreement with other agricultural indices in the area of REMEDHUS in Spain, such as the SWDI and CMI (R=-0.75 and -0.71 respectively)
Summary
Drought is a normal, recurring feature of climate, and occurs in virtually all climatic regimes. It is a temporary anomaly, in contrast to aridity, which is a permanent feature of climate and is restricted to low rainfall areas (Wilhite, 2011). Drought indices are used for identifying, classifying and monitoring drought conditions. They allow quantitative assessment of intensity, duration and spatial extent of anomalous climatic conditions and support decision-making systems (Sánchez et al, 2016). Well-known indices such as the Standardized Precipitation Index (McKee et al, 1993) are mostly precipitation-based, even though there are water budget indices such as the Palmer Drought Severity Index, (Palmer, 1965), soil moisture indices (Martínez-Fernández et al, 2015), and many other hydrological and aridity indices, all of them meant to indicate, from different points of view, water deficit for a given area
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
