Abstract:
The aim of this study was to estimate the water footprint of selected crops in the Beles
sub-basin. To accomplish this, relevant data on the chosen crops, including crop yield,
area coverage, and meteorological data, were collected and analyzed. The CROPWAT
model version 8.0 was employed to calculate parameters like crop water requirement,
effective rainfall, and irrigation need. The CROPWAT data outputs, including effective
rainfall and irrigation requirements, were inputted into Microsoft Excel to compute the
green water footprint (GWF) and blue water footprint (BWF) of the selected crops. The
specific objectives were to determine the GWF and BWF for the chosen crops in the
study area, as well as to quantify the total yearly water volume utilized by the crops
through irrigation during the growing seasons. The findings revealed discrepancies in
irrigation water needs among the selected crops. For example, during the rainy season,
maize crops in the Pawi area required 428.3 mm of rainwater, whereas in the Dangila
area, the rainwater requirement was 404 mm. However, during the irrigated season,
maize crops in Pawi had an irrigation water requirement of 579.4 mm, while in Dangila it
was 570.3 mm. additionally; the water footprint of each crop was assessed. Maize crops
exhibited a higher GWF during the rainy season in Pawi (818.4 m3/ton) compared to
Dangila (508 m3/ton). In the irrigated season, maize crops in Pawi had a higher BWF
(506.7 m3/ton) than Dangila (348.7 m3/ton). However, the maize water footprint in
Dangila indicated a higher GWF (13.7 m3/ton) compared to Pawi (4.9 m3/ton). In terms
of onion cultivation during the irrigated season, Dangila showed a higher BWF (416
m3/ton) than Pawi (154.8 m3/ton), with Dangila also exhibiting a higher GWF (15.9
m3/ton) compared to Pawi (1.4 m3/ton). For soybean cultivation during the rainy season
in Pawi, the water footprint was determined to be 1011.1m³/ton. This study is significant
for policymakers, farmers, water management authorities, and researchers as it offers
insights to implement water-saving practices and enhance efficient water resource
management in the study area. Therefore, this study plays a crucial role in addressing and
alleviating water scarcity, especially in relation to crop cultivation.
Key words: Blue Water Footprint, Green Water Footprint, Beles Sub Basin and Crop
Yield, Water Use.