Astronomy & Space Sciences
Title : | Downscaling of satellite data/model derived soil moisture and evapotranspiration products |
Area of research : | Astronomy & Space Sciences |
Focus area : | Hydrological Modeling |
Contact info : | d.chutia@nesac.gov.in |
Details
Executive Summary : | Soil moisture (SM) and Evapotranspiration (ET) arethe key hydrologic state variable for understanding hydrologic processes, including runoff, infiltration, drought, crop growth, and many other phenomena. Their estimation at a finer grid resolution is essential for water resource planning and irrigation scheduling. These data can be obtained in several ways, including in-situ measurements, remote sensing techniques, soil moisture/ET accounting models and hydrological models. Satellite remote sensingis considered as the reliable measurement to monitor SM and ET conditions on a regional scale. One major challenge in using satellite estimated data is their coarse spatial resolution and inability to resolve sub-grid scale variability. To overcome these limitations, various statistical approaches have used a downscaling framework to achieve a higher spatial resolution data. A number of studies have attempted to downscalemicrowave soil moisture and ET products with help of vegetation cover and surface temperature information obtained from optical andthermal sensors. On the basis of land surface temperature and vegetation index triangular feature space a downscaling factor is estimated which is in turn used to improve the spatial variability of the coarse resolution parameters from either satellite or model derived. The notable advantagesof this type of methods are the multi-data sources and long-term records of the optical/thermal data. This study is expected to deliver fine resolution soil moisture and evapotranspiration data considering land surface parameters and columnar soil moisture profile up to root depth. This method of downscaling has strong implication and potential for obtaininghigh-resolution soil moisture with the use of all available soil moisture products such as AMSR-E, SMOS, SMAP, and ASCAT. To achieve the actual water budgeting or planning for the field size in India this study of downscaling ET can make significant changes which is closer to the actual field condition. |
Co-PI: | Saksham Joshi, National Remote Sensing Centre (NRSC), Hyderabad |
Organizations involved