Estimation of irrigation water abstraction in the upper reaches of Lunsemfwa, Mulungushi, Mwomboshi and Mkushi sub-basins.
Date
2018
Authors
Tshenyego, Lamong
Journal Title
Journal ISSN
Volume Title
Publisher
The Univeristy of Zambia
Abstract
Water abstraction is achieved by many means, and for many purposes. Abstraction depends on many variables that include the purpose for the abstraction, the location, the type of laws in place regarding the procedure, and the type of resources available for the abstraction process. The overall objective of the study was to estimate the abstraction for irrigation water from the upper reaches of Mkushi, Mulungushi, Mwomboshi and Lunsemfwa sub-Basins. For the years 2013–2017 Landsat (L8OLI/TIRS), QGIS and AquaCrop packages were used to generate water abstraction estimates. Field and climate data was obtained from the internet and literature as well as weather stations under Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSACAL) project closer to the sub-catchments.
Reference evapotranspiration was determined using FAO ETo calculator and ranged from 6.84 mm/day to 7.02mm/day. The QGIS software was used to delineate the catchments areas. Mwomboshi had a smallest catchment area of 3043 km2, while Lunsemfwa had largest area of 7794 km2. Classified estimates of irrigated areas within each sub basin under the study were for the period 2013 to 2017. The least recorded irrigated area was in Mkushi in 2016 (12 km2) while highest being 167 km2 in Lunsemfwa in 2013. For the five years period (2013 to 2017) Mkushi has irrigated a sum of 103.83 km2, Lunsemfwa 692.00 km2, Mulungushi 136.00 km2 and Mwomboshi with the sum of 115.17 km2. For this study the soils were set as described by in the soil map of Zambia and put into the soil Characteristic calculator to estimate their physical properties.
The results show that maximum volume of water abstracted in all the catchment was estimated at 120,203,800 m3 in 2013, while the minimum was in 2014 estimated at 73,366,400 m3. The results show that for maximum volume abstracted for irrigation had a significant difference when comparing Lunsemfwa catchment to Mkushi. Mulungushi and Mwomboshi show no chances of being the same at alpha of 0.05 level.
Description
Thesis of Master of Engineering in Agricultural Engineering