ANALYSIS OF WATER AVAILABILITY AND WATER DEMAND IN PEMATANG PANJANG AGRICULTURAL AREA

Sungai Tabuk district is one of the areas in South Kalimantan where most of the population has a livelihood as a farmer. Sungai Tabuk district has several sub-districts including Pematang Panjang sub-district. This area has a problem, which is the source of irrigation water is only rain-fed so local farmers' profits are not maximized.In this study, secondary data were used in the form of rain data, climatological data, and river discharge data. These data were analyzed using several methods including the Weibull method to obtain effective rainfall, the Penman-Monteith method to obtain evapotranspiration values, and the F.J. Mock method to obtain dependable flow or water availability.From this study, the average value of irrigation water demand was 0,2384 m3/sec. In addition, it is also known that the dependable flow or maximum water availability occurs in the first half of February, which is 1,961 m3/s, while the lowest dependable flow occurs in the first half of August, which is 0,103 m3/s. Keywords: Penman-Monteith, F.J. Mock, Evapotranspiration, Dependable Flow, Pematang Panjang.