Estimation of Dry Season Irrigation Water Abstraction in Lunsemfwa, Mulungushi, Mwomboshi, and Mkushi Subbasins from 2013 to 2017 in Zambia

Abstract

Water abstraction depends on many variables that include the purpose for the abstraction, the location, the policies in place, and the type of water resources available for abstraction. The overall objective of this study was to estimate irrigation water abstraction from Mkushi, Mulungushi, Mwomboshi, and Lunsemfwa subbasins in Zambia. Reference evapotranspiration was determined using FAO ETo calculator and the results ranged from 6.84 mm/day to 7.02 mm/day. For this study the soils were set as described in the soil map of Zambia and put into the soil characteristic calculator to estimate their physical properties. The results estimate that a total maximum abstraction of 119,680,200 m3 was in 2013, and a minimum estimate of 74,951,400 m3 was in 2014. Wheat abstraction volumes (which were used to represent crops with higher water demand) were compared between catchments and significant differences exist when comparing Lunsemfwa catchment to Mkushi, Mulungushi, and Mwomboshi; thus there were no chances of similarity at an alpha level of 0.05. This means that Lunsemfwa catchment abstracted most irrigation water from 2013 to 2017 than the other three catchments as a result of having the largest proportion of irrigated area in the subbasin.