Evaluasi Neraca Air Pada Irigasi Kuok II

Water Balance Evaluation In Kuok II Irrigation

Abstract

[IN] Daerah irigasi kuok II memiliki luas sawah sekitar 200 hektar, sumber air irigasinya di supplay dari sungai irigasi kuok II. Permasalahan ketersediaan air didaerah irigasi ini berdasarkan pra penelitian dilapangan terindikasi kekurangan ketersediaan air, dimana lahan yang dapat diairi hanya 50% pada saat musim kemarau hal ini disebabkan menyusut nya debit air disungai irigasi Kuok II..Perhitungan neraca air ini digunakan untuk mengevaluasi ketersediaan air serta menentukan kondisi suatu daerah mengalami defisit atau surplus. Analisa dilakukan dari data sekunder yaitu analisa hidrologi hujan rata-rata daerah. Setelah itu dilakukan perhitungan analisa evapotranspirasi menggunakan pendekatan penman, dan Metode Thornwhaite & Mather. Daerah Irigasi (D,I) Kuok II terdiri dari 215,71 hektar sawah potensial, dengan perkiraan kebutuhan air sebanyak 244,59 l/hari, Kebutuhan air irigasi di hitung selama masa persiapan lahan dimana Nilai IR tertingggi terjadi pada bulan Maret periode II yaitu, 470,71 l/det/ha, kebutuhan air irigasi paling sedekit terjadi pada bulan Januari periode 1 yaitu, 12,65l /det/ha, Sedangkan ketersediaaan debit air pada irigasi Kuok II berdasarkan perhitungan Run Off, mampu memenuhi kebutuhan dengan total ketersediaan sebesar 851,94 l/dt, Besarnya perbedaan antara kebutuhan air di sawah dengan ketersediaan air disumber irigasi 381,23 l/dt. Dari hasil analisa perhitungan kebutuhan dan ketersediaan air irigasi didapatkan hasil bahwa ketersediaan air pada Daerah Irigasi Kuok II mampu mencukupi kebutuhan air untuk persawahan. Hal ini didasarkan pada besar nya nilai Run Off pada periode 2010-2020, perkiraan kebutuhan air 244,59 l/hari dan ketersediaan debit air pada irigasi Kuok II berdasarkan perhitungan RUN Off sebesar 851,94 l/hari.

[EN] The Kuok II Irrigation Area, covering approximately 200 hectares of rice fields, depends on water from the Kuok II irrigation river. Preliminary field observations indicated limited water availability, particularly during the dry season, when only about half of the land could be irrigated due to reduced river discharge. To assess this condition, a water balance analysis was conducted using secondary hydrological data, including rainfall analysis, evapotranspiration estimation with the Penman approach, and the Thornthwaite & Mather method. These methods are widely used in irrigation studies to determine crop water demand and evaluate the balance between supply and requirement. The Kuok II Irrigation Area (D.I) has a potential of 215.71 hectares of rice fields with an estimated daily water requirement of 244.59 liters. The analysis shows that irrigation needs vary throughout the year at 470.71 l/sec/ha during land preparation, while the lowest occurs in January (Period I) at only 12.65 l/sec/ha. Runoff analysis based on data from 2010–2020 indicated that the available water discharge in the Kuok II irrigation river reaches 851.94 l/sec, which exceeds the irrigation demand by 381.23 l/sec. These results suggest that despite seasonal fluctuations, the overall availability of irrigation water is sufficient to meet the needs in the Kuok II area. In conclusion, the integration of rainfall data, evapotranspiration estimation, and water balance calculations demonstrates that water resources in the Kuok II Irrigation Area are adequate to support sustainable rice cultivation, while emphasizing the need for continuous monitoring to maintain efficient and effective water management.