Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith Equation

To achieve sustainable development and to ensure water availability in hydrological basins, water managers need tools to determine the actual evapotranspiration (ET) on a large scale. Field energy balances from irrigated and natural ecosystems together with a net of agro-meteorological stations were...

Full description

Bibliographic Details
Main Author: Antônio H. de C. Teixeira
Format: Article
Language:English
Published: MDPI AG 2010-05-01
Series:Remote Sensing
Subjects:
Online Access:http://www.mdpi.com/2072-4292/2/5/1287/
id doaj-e4cb4115eb1143a9b333d9312a5b359c
record_format Article
spelling doaj-e4cb4115eb1143a9b333d9312a5b359c2020-11-25T01:18:36ZengMDPI AGRemote Sensing2072-42922010-05-01251287131910.3390/rs0251287Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith EquationAntônio H. de C. TeixeiraTo achieve sustainable development and to ensure water availability in hydrological basins, water managers need tools to determine the actual evapotranspiration (ET) on a large scale. Field energy balances from irrigated and natural ecosystems together with a net of agro-meteorological stations were used to develop two models for ET quantification at basin scale, based on the Penman-Monteith equation. The first model (PM1) uses the resistances to the latent heat fluxes estimated from satellite measurements, while the second one (PM2) is based on the ratio of ET to the reference evapotranspiration (ET0) and its relation to remote sensing parameters. The models were applied in the Low-Middle São Francisco river basin in Brazil and, after comparison against field results, showed good agreements with PM1 and PM2 explaining, respectively, 79% and 89% of the variances and mean square errors (RMSE) of 0.44 and 0.34 mm d−1. Even though the PM1 model was not chosen for ET calculations, the equation for surface resistance (rs) was applied to infer the soil moisture conditions in a simplified vegetation classification. The maximum values of rs were for natural vegetation—caatinga (average of 1,937 s m−1). Wine grape and mango orchard presented similar values around 130 s m−1, while table grape presented the lowest ones, averaging 74 s m−1. Petrolina and Juazeiro, in Pernambuco (PE) and Bahia (BA) states, respectively, were highlighted with the biggest irrigated areas. The highest increments are for vineyards and mango orchards. For the first crop the maximum increment was verified between 2003 and 2004 in Petrolina-PE, when the cultivated area increased 151%. In the case of mango orchards the most significant period was from 2005 to 2006 in Juazeiro-BA (129%). As the best performance was for PM2, it was selected and used to analyse the regional ET at daily and annual scales, making use of Landsat images and a geographic information system for different soil moisture conditions. Considering the daily rates of the regional ET, pixels with values lower than 1.0 mm d−1 occurred outside the rainy season, representing the caatinga species. Values from 1.0 to 5.0 mm d−1 during the driest conditions of the year coincided with irrigated crops, being the highest values for table grapes. The highest accumulated ET values during 2006 were for mango orchards, being around 500–1,300 mm yr−1. Vineyards presented lower values, ranging from 450–800 mm yr−1, while in caatinga they were between 200 and 400 mm yr−1. It could be concluded that irrigated mango orchards and vineyards in that year consumed more water than caatinga by factors of 3 and 2, respectively. The mango orchards and vineyard areas, representing 19.4 and 8.2% of the total irrigated area, respectively, resulting in a total evaporative depletion of 0.22 km3 yr−1 in the growing regions comprised of the agro-meteorological stations. http://www.mdpi.com/2072-4292/2/5/1287/energy balancemodelinglatent heat fluxwater managementsatellite measurements
collection DOAJ
language English
format Article
sources DOAJ
author Antônio H. de C. Teixeira
spellingShingle Antônio H. de C. Teixeira
Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith Equation
Remote Sensing
energy balance
modeling
latent heat flux
water management
satellite measurements
author_facet Antônio H. de C. Teixeira
author_sort Antônio H. de C. Teixeira
title Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith Equation
title_short Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith Equation
title_full Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith Equation
title_fullStr Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith Equation
title_full_unstemmed Determining Regional Actual Evapotranspiration of Irrigated Crops and Natural Vegetation in the São Francisco River Basin (Brazil) Using Remote Sensing and Penman-Monteith Equation
title_sort determining regional actual evapotranspiration of irrigated crops and natural vegetation in the são francisco river basin (brazil) using remote sensing and penman-monteith equation
publisher MDPI AG
series Remote Sensing
issn 2072-4292
publishDate 2010-05-01
description To achieve sustainable development and to ensure water availability in hydrological basins, water managers need tools to determine the actual evapotranspiration (ET) on a large scale. Field energy balances from irrigated and natural ecosystems together with a net of agro-meteorological stations were used to develop two models for ET quantification at basin scale, based on the Penman-Monteith equation. The first model (PM1) uses the resistances to the latent heat fluxes estimated from satellite measurements, while the second one (PM2) is based on the ratio of ET to the reference evapotranspiration (ET0) and its relation to remote sensing parameters. The models were applied in the Low-Middle São Francisco river basin in Brazil and, after comparison against field results, showed good agreements with PM1 and PM2 explaining, respectively, 79% and 89% of the variances and mean square errors (RMSE) of 0.44 and 0.34 mm d−1. Even though the PM1 model was not chosen for ET calculations, the equation for surface resistance (rs) was applied to infer the soil moisture conditions in a simplified vegetation classification. The maximum values of rs were for natural vegetation—caatinga (average of 1,937 s m−1). Wine grape and mango orchard presented similar values around 130 s m−1, while table grape presented the lowest ones, averaging 74 s m−1. Petrolina and Juazeiro, in Pernambuco (PE) and Bahia (BA) states, respectively, were highlighted with the biggest irrigated areas. The highest increments are for vineyards and mango orchards. For the first crop the maximum increment was verified between 2003 and 2004 in Petrolina-PE, when the cultivated area increased 151%. In the case of mango orchards the most significant period was from 2005 to 2006 in Juazeiro-BA (129%). As the best performance was for PM2, it was selected and used to analyse the regional ET at daily and annual scales, making use of Landsat images and a geographic information system for different soil moisture conditions. Considering the daily rates of the regional ET, pixels with values lower than 1.0 mm d−1 occurred outside the rainy season, representing the caatinga species. Values from 1.0 to 5.0 mm d−1 during the driest conditions of the year coincided with irrigated crops, being the highest values for table grapes. The highest accumulated ET values during 2006 were for mango orchards, being around 500–1,300 mm yr−1. Vineyards presented lower values, ranging from 450–800 mm yr−1, while in caatinga they were between 200 and 400 mm yr−1. It could be concluded that irrigated mango orchards and vineyards in that year consumed more water than caatinga by factors of 3 and 2, respectively. The mango orchards and vineyard areas, representing 19.4 and 8.2% of the total irrigated area, respectively, resulting in a total evaporative depletion of 0.22 km3 yr−1 in the growing regions comprised of the agro-meteorological stations.
topic energy balance
modeling
latent heat flux
water management
satellite measurements
url http://www.mdpi.com/2072-4292/2/5/1287/
work_keys_str_mv AT antoniohdecteixeira determiningregionalactualevapotranspirationofirrigatedcropsandnaturalvegetationinthesaofranciscoriverbasinbrazilusingremotesensingandpenmanmonteithequation
_version_ 1725141616713269248