Evapotranspiration Estimates at High Spatial and Temporal Resolutions from an Energy–Water Balance Model and Satellite Data in the Capitanata Irrigation Consortium

Chiara Corbari,Josè Sobrino,Marco Mancini,Drazen Skokovic Jovanovic,Luigi Nardella

doi:10.3390/rs12244083

Chiara Corbari, Josè Sobrino + Show 3 more

Open Access

https://doi.org/10.3390/rs12244083

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Journal: Remote Sensing	Publication Date: Dec 13, 2020
Citations: 17	License type: CC BY 4.0

Affiliation: Politecnico di Milano, University of Valencia

Abstract

The feasibility of combining remotely sensed land surface temperature data (LST) and an energy–water balance model for improving evapotranspiration estimates over time distributed in space in the Capitanata irrigation consortium is analysed. The energy–water balance FEST-EWB model (flash flood event-based spatially distributed rainfall–runoff transformation—energy–water balance model) computes continuously in time and is distributed in space soil moisture (SM) and evapotranspiration (ET) fluxes solving for a land surface temperature that closes the energy–water balance equations. The comparison between modelled and observed LST was used to calibrate the model soil parametres with a newly developed pixel to pixel calibration procedure. The effects of the calibration procedure were analysed against ground measures of soil moisture and evapotranspiration. The FEST-EWB model was run at 30 m of spatial resolution for the period between 2013 and 2018. Absolute errors of 2.5 °C were obtained for LST estimates against satellite data; while RMSE around 0.06 and 40 Wm−2 are found for ground measured soil moisture and latent heat flux, respectively.

Highlights

Distributed pixelwise knowledge of evapotranspiration (ET) and soil moisture (SM) is of extreme importance for a wide range of applications, especially for estimates of irrigation water needs in agricultural areas
This procedure improves the traditional calibration based on local soil moisture or discharge data, which allows a global calibration of the parametres that are modified by a single factor over the entire basin [29]
The paper showed the feasibility of the combined advantage of satellite data and distributed hydrological model for improving water resources assessment, in particular evapotranspiration estimates at high temporal and spatial resolution

Summary

Introduction

Distributed pixelwise knowledge of evapotranspiration (ET) and soil moisture (SM) is of extreme importance for a wide range of applications, especially for estimates of irrigation water needs in agricultural areas. Their direct measurement at large scale is still not feasible; there exist several estimates from modelling and remote sensing data that are affected by intrinsic errors. In the last 40 years, several satellites data from passive or active microwave sensors are available for the retrieval of superficial soil moisture (few centimetres) [1,2,3], which is nowadays used for a wide range of applications, even in agriculture water management [4]. SM estimates from active radars can be affected by problems linked to the saturation of the retrieval algorithms [7] and their ability to detect soil moisture over vegetated surfaces [8]

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Discussion

Conclusion