Analysis of spatiotemporal variability of water productivity in Ethiopian sugar estates: using open access remote sensing source

Abstract

ABSTRACT This study focusses on mapping the seasonal and spatial variability of agricultural water productivity of sugarcane crop in three large irrigation schemes of Ethiopia (Wonji, Fincha’a and Metahara) using remote sensing derived datasets. The datasets used in this study were acquired from WaPOR, an open access portal, and included a 100m spatial resolution 10days interval (decadal data) of Net Primary Production (NPP) and Actual Evapotranspiration and Interception (AETI). Accordingly, the average seasonal AETI was compiled for the schemes during time period of January 1/2009 to June 30/2019 and corresponding average fresh weight yields per hectare for the schemes were gathered. Using AETI (as denominator) and yield (as numerator) the water productivity could be calculated into kg/m3. The calculated crop water productivity was 7.5kg/m3 at Wonji, 7kg/m3 at Fincha’a and 4.3kg/m3 at Metahara. When spatially and temporally comparing sub-irrigation schemes with each other and the derived multi-seasonal average varying water productivity performance is visualized. Within Wonji irrigation scheme, high WP values range 7.6 – 9 kg/m3 are found in Dodota, Sodare and Wake-Tiyo during the time period of January 1/2018 to June 30/2019 and lower value of 5.7 – 7 kg/m3 was in Wonji main sub-irrigation scheme during time period of July 1/2013 to December 31/2014. For Fincha’a irrigation scheme, several plots located in the Northern part of East and West bank and the southern part of Neshie sub-schemes show a high water productivity range, from 7.3 to 11.2 kg/m3. Within Metahara irrigation scheme, plots located at southern part show high water productivity range 6.7 to 10.6 kg/m3.