Abstract:
Management of land and water resources are very important through assesment practice
for future irrigation development. However, the irrigation potential of Gololcha river
watershed has not been assessed yet. Thus, it was difficult to identify and know land and
water resources potential of the watershed for sustainable management. The current study
was conducted to assess the potential of land and available water of river for surface
irrigation in Gololcha river watershed for the development of surface irrigation. The study
employed Geographical information System_based multi criteria analysis method
considering seven factors such as soil texture, soil drainage, soil depth, Slope, LULC,
distance from the main river and road to find suitable land for surface irrigation. Using
the Analytical Hierarcy process, the values of each dataset were weighted and combined
to find the most suitable land for irrigation using the ArcGIS environment. The results of
the study revealed that about 2508ha (7.27 % of the watershed area) highly suitable,
16420 ha (47.65 % of the watershed area) moderately suitable, 1502 ha (4.35 % of the
watershed area) marginally suitable and 14029 ha (40.71 % of the watershed area) not
suitable. Three (Maize, Wheat and Potato ) major crops which are mainly grown in the
area were selected under identified irrigable area and their gross irrigation demand were
calculated by using nearby climatic stations. The results revealed that irrigation
requirements of identified command area varies according to nearby climatic stations and
type of crops selected. The discharges at un-gauged sites were estimated from gauged
sites on the same river by applying area-ratio method and results were obtained on
monthly bases. By associating gross irrigation demand of irrigable land with available
flow in rivers, the total surface irrigation potential of the study area was obtained as
4872.58ha. Potential suitable land for surface irrigation is very small due to the scarcity of
water. Therefore, it is possible to increase surface irrigation potential by increasing
available water using storage structure.
