Analisa Perhitungan Kebutuhan Air Jaringan Irigasi Bajayu (Studi Kasus)

Abstract

In planning of water’s arrangement and utilization building, one of the important thing is the calculation of water demand. The calculation result is expected to indicate whether the river is able to fulfill the water demand and how the water balance impact to the river after used for irrigation. This research takes on the design of Bajayu Weir project in Kabupaten Serdang Bedagai and Tebing Tinggi City of North Sumatra Province. The purpose of this study isto calculate the required irrigation water demand in the irrigation area of Bajayu. The aim of this research is to analyze/assess whether the discharge of water in the river Pasture can fulfill the water demand of Irrigation in Bajayu area. The research method is done by collecting hydroclimatology data namely: rainfall climatology and river discharge data. The calculation of evapotranspiration (ETo) using a Penmann modified FAO Method. Whereas the calculation of water demand as long as preparation of irrigated land, used a method developed by Van de Goor and Zijlstra. Based on the results of the calculation of water demand irrigation, Net Farm Requirement (NFR) maximum is 1.35 liter/second/ha and water demand in intake (DR) maximum is 2.08 liter/second/ha. The results of Water balance analysis can be concluded that Padang River can fulfill the water demand for irrigation