Estimation of soil heat flux in a neotropical Wetland region using remote sensing techniques

Abstract

The direct estimation of the soil heat flux (G) by remote sensing data is not possible. For this, several models have been proposed empirically from the relation of G measures and biophysical parameters of various types of coverage or not vegetated in different places on earth. Thus, the objective of this study was to evaluate the relation between G/Rn ratio and biophysical variables obtained by satellite sensors and evaluate the parameterization of different models to estimate G spatially in three sites with different soil cover types. The net radiation (Rn) and G were measured directly in two pastures at Miranda Farm and Experimental Farm and and Monodominant Forest of Cambará. Rn, G, and G/Rn ratio and MODIS products, such as albedo (α), surface temperature (LST), vegetation index (NDVI) and leaf area index (LAI) varied seasonally at all sites and inter-sites. The sites were different from each other by presenting different relation between measures of Rn, G and G/Rn ratio and biophysical parameters. Among the original models, the model proposed by Bastiaanssen (1995) showed the best performance with r = 0.76, d = 0.95, MAE = 5.70 W m -2 and RMSE = 33.68 W m -2 . As the reparameterized models, correlation coefficients had no significant change, but the coefficient Willmott (d) increased and the MAE and RMSE had a small decrease. Keywords: Mato Grosso, pasture, monodominant forest, orbital sensors. RESUMO: PARAMETRIZAÇÃO DE MODELOS PARA ESTIMAR O FLUXO DE CALOR NO SOLO EM TRÊS REGIÕES DO PANTANAL DO MATO GROSSO USANDO SENSORIAMENTO REMOTOA estimativa do fluxo de calor no solo (G) diretamente por dados de sensores remotos não é possível. Para isso, diversos modelos foram proposto relacionando empiricamente medidas de G e parâmetros biofísicos de diversos tipos de cobertura vegetada, ou não, em diferentes locais do planeta. Sendo assim, o objetivo deste trabalho foi avaliar a relação entre G/Rn e variáveis biofísicas obtidas por sensores orbitais e avaliar a parametrização de diferentes modelos de estimativa de G espacialmente em três sítios experimentais com distintos tipos coberturas do solo. O saldo de radiação (Rn) e G foram medidos diretamente em duas áreas de pastagens na Fazenda Miranda e na Fazenda Experimental e em uma Floresta Monodominante de Cambará. Rn, G, razão G/Rn e os produtos MODIS, tais como albedo (α), temperatura da superfície (LST), índice de vegetação da diferença normalizada (NDVI) e índice de área foliar (LAI) variaram sazonalmente em todos os sítios experimentais e entre os sítios experimentais. Os sítios experimentais mostraram-se diferentes entre si por apresentar distintas relações entre as medidas de Rn, G e a razão G/Rn e os

Assessment of actual evapotranspiration over a semiarid heterogeneous land surface by means of coupled low-resolution remote sensing data with an energy balance model: comparison to extra-large aperture scintillometer measurements

“…These empirical methods are suitable for specific conditions; therefore, estimating G, especially in this type of environment where NDVI values are low and thus G/R n values are large, is a critical issue. The approach adopted here was drawn on Danelichen et al (2014), who evaluated the parameterization of these different models in three sites in Mato Grosso state in Brazil and found that the model proposed by Bastiaanssen (1995) showed the best performance for all sites, followed by the model from Choudhury et al (1987) and Jackson et al (1987): Bastiaanssen (1995):…”

Estimation of Irrigation Water Pumping by Remote Sensing: Application of the SAMIR Model to Citrus under Mediterranean Climate Conditions

“…Estimating the energy balance at the soil surface to provide continuous information on evapotranspiration and the monitoring of hydric balance of the plant is not sufficient (Bastiaanssen, 2000;Danelichen et al, 2014), modeling the interpolation of evapotranspiration using a model that integrates plant characteristics is indispensable. SVAT models such as BUDGET and GAPS can calculate the hydric balance of the crops, but inputting their data is complex compared to the that of the FAO CROPWAT model (Clarke et al, 1998).…”

Assessment of actual evapotranspiration over a semi-arid heterogeneous land surface by means of coupled low resolution remote sensing data with energy balance model: comparison to extra Large Aperture Scintillometer measurements

“…In order to estimate the G/Rn ratio, several methods have been tested for various types of surfaces at different locations (Bastiaanssen, 1995;Burba et al, 1999;Choudhury et al, 1987;Jackson et al, 1987;Kustas and Daughtry, 1990;Kustas et al, 1993;Ma et al, 2002;Payero et al, 2001). 275 Danelichen et al(2014) evaluated the parameterization of these different models in three sites in Mato Grosso state in Brazil and found that the model proposed by Bastiaanssen (2005) showed the best performance for all sites, followed by the model from Choudhury et al (1987) and Jackson et al (1987). Hence to estimate G, we tested three methods:…”