SECONDARY CHANNEL PLANNING TECHNICAL ANALYSIS BATANG ALAI, BARABAI, SOUTH KALIMANTAN

Abstract

The Batang Alai Irrigation Area has a potential area of ± 8000Ha, located to the left and right of the Batang Alai river, where 5000Ha is to the left 3000Ha to the right of the river. In this area, a study was carried out on the Analysis of Calculation of Water Needs in fields on the Secondary Profile of the Tanah Alang Habang Channel. Research and calculation will be carried out on the secondary channel profile. This research and analysis are done to determine the performance of secondary channels in irrigating water needs in paddy fields. Whereas in the current era, the government has a goal for food self-sufficiency. So research and calculations are carried out so that agriculture can know the discharge of the channel that can rinse, and the solution so that the flow of water in the channel can irrigate rice fields to the maximum.

The research method used was the Irrigation Planning Criteria published by the Ministry of Public Works of the Republic of Indonesia and the Penman Method to obtain evapotranspiration value. The initial step in writing this thesis is the analysis of Rainfall Hydrology from Batang Alai and Batu Tangga Station with 29 years of data from 1978–2006, evapotranspiration calculations calculating irrigation water requirements to determine the dimensions of irrigation channels.

Based on the analysis of the calculation of water requirements for Group I Planting Patterns (Penman Method), the following results were obtained: Water demand for the biggest corn plant in June was 0,722 lt/sec/ha while the smallest in April was 0,254 lt / sec / ha . The biggest water demand for Variety I Rice in October was 1,302 lt/sec/ha while the smallest in February was 0,165 lt/sec/ha. The highest water demand for Rice Variety II in May was 1,120 lt/sec/ha while the smallest in August was 0,671 lt/sec/ha. Secondary Channel Tanah Habang: 1) B.BT.2–BTh.1, Wet Cross-sectional Area (Ao) = 3,04 m2, Wet Section Cross-Section (P) = 4,78 m, Hydraulic Radius (R) = 0,64 m and Channel Discharge (Q) = 1,393 m3/s. 2) BTh.1–BTh.2, Wet Cross-sectional Area (Ao) = 2,93 m2, Wet Cross Section (P) = 4,70 m, Hydraulic Radius (R) = 0,62 m and Channel Discharge (Q) = 1,336 m3/s. 3) BTh.2–BTh.3, Wet Cross-sectional Area (Ao) = 1,14 m2, Wet Section Cross-section (P) = 2,89 m, Hydraulic Radius (R) = 0,39 m and Channel Discharge (Q) = 0,345 m3/s. 4) BTh.3–BTh.4, Wet Cross-sectional Area (Ao) = 1,04 m2, Wet Section Cross-section (P) = 2,77 m, Hydraulic Radius (R) = 0,38 m and Channel Discharge (Q) = 0,313 m3/s. 5) BTh.4–Kehakan, Wet Cross-sectional Area (Ao) = 0,76 m2, Wet Section Cross-Section (P) = 2,36 m, Hydraulic Radius (R) = 0,32 m and Channel Discharge (Q) = 0,217 m3/s.

Keywords: Irrigation, irrigation channels in Batang Alai Barabai, irrigation water needs.