Water Productivity Modeling by Remote Sensing in the Semiarid Region of Minas Gerais State, Brazil

Abstract

This chapter aimed to demonstrate the potential of monitoring water and vegetation parameters by combining weather and satellite measurements in mixed agroecosystems in the semiarid region of the northern Minas Gerais state, Southeast Brazil. Soil moisture indices and water productivity components were quantified with Landsat 8 images under different hydrological conditions along the year 2015. The surface resistance to the water fluxes (r s) performed better than the ratio of actual to the reference evapotranspiration (ET r) to detect soil moisture conditions. The mean pixel values for actual evapotranspiration (ET), biomass production (BIO), and water productivity based on evapotranspiration (WP), for irrigated crops (IC), ranged respectively from 2.5 ± 1.3 to 4.1 ± 1.6 mm d −1 ; 78 ± 62 to 132 ± 64 kg ha −1 d −1 ; and from 2.2 ± 0.8 to 3.3 ± 0.9 kg m −3. The corresponding ranges for natural vegetation (NV) were 0.1 ± 0.2 to 1.9 ± 1.3 mm d −1 ; 1 ± 1 to 44 ± 42 kg ha −1 d −1 , and 0.6 ± 0.3 to 1.8 ± 0.8 kg m −3. The incremental values, resulting from the replacement of natural species by agricultural crops, were respectively 2.7 mm d −1 and 83 kg ha d −1. However, this replacement increased water productivity based on evapotranspiration (WP) by 264% during the studied year, what should be considered in land use and climate change studies in the Brazilian semiarid region.

Monitoring environmental indicators by coupling remote sensing and weather data: applications to the Brazilian biomes

“…The ETf average values ranged between 0.14 in CT from October to December (Q4) and 1.15 in PP from April to September (Q3), averaging respectively 0.29 and 0.94 at the annual scale. In agreement with our results, Teixeira et al (2018) found ETf values between 0.04 and 0.34 in the CT biome through SAFER applications with Landsat 8 images, while Rubert et al (2018) also reported ETf of 0.83 and 0.92 in two distinct ecosystems of PP, throughout eddy covariance measurements from 2014 to 2016. As for P and ET, spatial and temporal variations on BIO pixel values among quarters and geographic regions are strong, with the highest ones in S during Q1, with 32% of the area covered by the PP biome and the lowest in NE during Q3, with 53% of its area with the CT biome (Table 1).…”

Water productivity assessments for dwarf coconut by using Landsat 8 images and agrometeorological data

“…Under different agro-climatic zones in India, simulated average BIO values ranged from 93 to 100 kg ha −1 d −1 for irrigated coconuts (Naresh Kumar et al, 2008), little higher than those for the current study. In the agricultural growing region of the North of Minas Gerais state, semi-arid conditions of Southeast Brazil, Teixeira et al (2018), reported BIO values between 78 ± 62 and 132 ± 64 kg ha −1 d −1 , for different irrigated crops. The similarity between these last values and those from the current study brings confidence of the applied models for WP coconut assessments in the coastal zone of the Northeast Brazil.…”

“…The ET f images were multiplied by ET 0 to retrieve the daily ET values. (Franco et al, 2016;Nuñez et al, 2017;Silva et al, 2018a,b;Teixeira et al, 2018):…”

“…For BIO calculations, the Monteith's RUE model (Monteith, 1972) was used, introducing the moisture effect through ET f (Teixeira et al, 2018):…”

“…After elaboration and validations in the Northeast Brazil, its applications in mixed Brazilian agroecosystems has been contributing to better knowledge of the WP components and other agrometeorological indices. These knowledges can subsidize water conservation practices without losing agricultural yield (Franco et al, 2016;Nuñez et al, 2017;Silva et al, 2018aSilva et al, , 2018bTeixeira et al, 2018).…”