Comparative Evaluation of Simplified Surface Energy Balance Index-Based Actual ET against Lysimeter Data in a Tropical River Basin

Abstract

In the past decades, multispectral and multitemporal remote sensing has been popularly used for estimating actual evapotranspiration (ETc) across the globe. It has been proven to be a cost-effective tool for understanding agricultural practices in a region. Today, because of the availability of different onboard sensors on an increasing number of different satellites, land surface activity can be captured at fine spatial and time scales. In the present study, three multi-date satellite imageries were used for the evaluation of remote sensing-based estimation of actual evapotranspiration in paddy in the command area of the tropical Kangsabati river basin. A surface energy balance model, the Simplified-Surface Energy Balance Index (S-SEBI), was applied for all three dates of the Rabi season (2014–2015) for the estimation of actual evapotranspiration. The crop coefficient was calculated using the exhaustive survey data collected from the command area and adjusted to local conditions. The ETc estimated using the S-SEBI-based model was compared with the Food and Agriculture Organization Penman–Monteith (FAO-56 PM) method multiplied by the adjusted local crop coefficient and lysimeter data in the command area. The coefficient of determination (r2) was applied to examine the accuracy of the S-SEBI model with respect to lysimeter data and the FAO-56 PM-based ETc. The results showed that the S-SEBI model performed well with the lysimeter (r2 = 0.90) in comparison with FAO-56 PM, with an r2 of 0.65. In addition to this, the S-SEBI-based ET estimates correlated well with the FAO-56 PM, with r and RMSE values of 0.06 and 1.13 mm/day (initial stage), 0.85 and 0.48 mm/day (development stage), and 0.77 and 0.52 (maturity stage) for paddy, respectively. The S-SEBI-based ETc estimate varied with different stages of crop growth and successfully captured the spatial heterogeneity within the command area. In general, this study showed that the S-SEBI method has the potential to calculate spatial evapotranspiration and provide useful information for efficient water management. The results revealed the applicability and accuracy of remote sensing-based ET for managing water resources in a command area with scarce data.

Optimal allocation of agricultural water resources in Yanghe watershed considering blue water to green water ratio

“…The meteorological data include temperature, precipitation, wind speed, sunshine time, and humidity. The Penman-Monteith formula recommended by the FAO is generally used to calculate the crop evapotranspiration 23 :…”

Seasonal variation of surface energy balance over Mubi northeastern Nigeria during 2000-2020

“…For the past decade, SEB has become a standard tool to study the exchange of energy between the Earth's surface and atmosphere. The research of SEB is often carried out in different places such as Jakarta and Neighboring regions by Ilhamsyah [30], metropolitan cities of India during the 2000-2018 winter seasons by Sultana and Satyanarayana [28], Greenland ice sheet by Liu [31], Naqu region of Qinghai-Tibet Plateau during 2005-2016 by Wang and Ma [32], lake Huron by Petchprayoon [33], tilled and nontilled bare soils by Akuoko [34], tropical river Basin by Kumar et al [35], semiarid environments by Small and Kurc [36], Storglacia¨ren, Sweden by Hock and Holmgren [37], urban park and its surroundings by Bäckström [38], two Sahelian surfaces by Verhoef et al [39]. These studies motivated us to carry out such research in Mubi, Northeastern Nigeria, to benefit from the resources that SEB is disclosing.…”