Monitoring of crop water consumption changing based on remotely sensed data and techniques in North Sinai, Egypt

Abstract

This paper aims to approximate and verify crop water use based on satellite results. Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) were used as the critical parameters derived from NOAA/AVHRR and landsat8 satellite data. Reference evapotranspiration (ETo) was determined using FAO-Penman-Monteith (FPM) agrometeorological data as a standard process. Based on data from remote sensing, the ETo was calculated based on the Hargreaves (Har) process. ETo-FPM has been used to calibrate ETo-Har under the same conditions for five years (2002-2006). Landsat8 data was obtained on 25 June 2013 and 28 June 2014 and used to estimate the crop coefficient (Kc) based on satellite data (Kc-Sat). The LST was used to predict the maximum, minimum, and mean Tair (oC) levels in June 2013 and 2014. ETo was calculated using the expected maximum, minimum, and mean Tair according to the Har method and was used with Kc-Sat to estimate ETc-Har. ETo-FPM is used to measure ETc-FPM with Kc-Sat. LST and NDVI have been used to measure the Water Deficiency Index (WDI). WDI incorporated ETc to measure the actual evapotranspiration of the crop (ETa). ETa-FPM was used for the evaluation of ETa-Har. The relationship between ETa-FPM and ETa-Har was high, where R2 was 0.99 in 2013 and 2014. ETa determined by Hargreaves based on remotely sensed data was overestimated at about 0.8 (mm/day) compared to the FPM process.