Abstract:
Planning and managing new irrigation expansion projects necessitates a systematic
assessment of irrigable land, which is typically linked to available water supplies. The
objective of this study was to assess the Kola river water resources availability and surface
irrigation potential using integration of Soil Water Assessment Tool (SWAT) and geographic
information system (GIS). A CROPWAT model was used to determine crop water requirements
of important crops that grow in the area. The identification of potentially irrigable land was
assess using Analytic Hierarchy process (AHP) along with GIS and Arc SWAT model was used
to estimate the water resources available in the watershed. When identifying potentially
suitable irrigable land, irrigation suitability characteristics such as soil physical features,
slope, land use/land cover, and distances from the water supply (sources) are considered.
According to the irrigation suitability analysis show that; 93.97% of the soil in the study area,
94.81% of the LULC, 93.5% of the slope, and 90.02% of the river proximity are highly to
marginally suitable for irrigation. According to the final irrigation land suitability results,
69.2% of the land is highly suitable (S1), 28.2% of the land is moderately suitable (S2), and
2.6% of the land is unsuitable (N) for surface irrigation development. The calibrated and
validated SWAT model show that; 26.23m3/s per annual/month the minimum simulated stream
flow and to determine water availability for irrigation. The irrigation water demand, for five
major crops grown in the study area, was determined to be 64.19m3/s throughout the growing
season. The available water could irrigate 3287 ha (23%) of highly suitable land.
