Pemanfaatan Debit Sungai Kupang untuk Keperluan Air Irigasi Daerah Pekalongan
River is the most effective for water irrigation resources, because cost in construction, operation and maintenance is lower compared with another water resources. Just like Kupang river, that is the upper of Pekalongan river usualy cousing flood in Pekalongan region, so is better if the discharge diverted for irrigation water need. To get how areal rice field can be irrigated, is depend on two component, ie, dependable flow and water requirement unit. Dependable flow can be analysed using frequency method of the annual discharge. The available data is discharge of year 1992 to 2000. Water requirement unit is analysed using Net Field Water Requirement (NFR) method, from the climatological data. Available data have length of 11 years. The analysing of given data, results the dependable flow of 80% risk is 3.77 m3/s, and for the risk of 60% is 7.90 m3/s. From the NFR analysis give a value of water requirement unit of 2.04 l/s.ha. So, the maximum irrigation area is 1848 hectare for the dependable flow of 80%, and 3872 hectare for the 60% risk. The existing irrigation rice field is less than that the maximum irrigation area, so the excess discharge can be used for another kind of water resources, eg domestic water or fresh fishpond.
keyword : irrigation, dependable flow, NFR, rice field area.
PPST DPPM Universitas Islam Indonesia