Publications

Shekar, NCS; Raju, BCK (2022). Modeling bulk surface resistance and evaluation of evapotranspiration using remote sensing and MATLAB. WATER SUPPLY, 22(4), 4109-4119.

Abstract
In developing countries, computation of Actual Evapotranspiration (AET) is challenging due to the lack of ground-based flux measurement data. The estimation of AET is crucial for water resources management involving the allocation of water for different land cover (LULC) classes. The study's novelty was mapping pixel-by-pixel spatial variations of bulk surface resistance and evaluating the derived actual evapotranspiration in a sub-humid tropical river basin where flux tower data was lacking for validation. This study aimed to map bulk surface resistance and evaluate the estimated AET by global evapotranspiration data product (MOD16A2). MODIS data products, including Land Surface Reflectance (LSR), Land Surface Temperature (LST) and Leaf Area Index (LAI) data, were used as input in the MATLAB for mapping pixel-wise variations to analyze the seasonal variations in bulk surface resistance (r(s)) and actual evapotranspiration in pre-monsoon and post-monsoon seasons during the years 2019 and 2012. The years 2019 and 2012 were selected because 2019 experienced a relatively wet pre-monsoon and post-monsoon, whereas 2012 experienced the opposite conditions, which proved useful when interpreting variations that are influenced by wetness conditions. Overall the results indicated significant variability in the r(s) and AET for different LULC classes. MOD16A2 AET was determined to be slightly higher than the LULC classes estimated AET. This study's Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data products provided information on surface characteristics at a reasonable resolution. This permitted the identification of differences in LULC classes and changes in surface characteristics by season and wetness conditions, which are helpful when estimating AET.

DOI:
10.2166/ws.2022.036

ISSN:
1607-0798