Penelitian ini dilakukan di Daerah Irigasi Rawa Pasang Surut Karang Agung Hilir yang berada di dalam wilayah Kabupaten Banyuasin dan Kabupaten Musi Banyuasin. Tujuan dilakukannya penelitian ialah untuk menganalisis pengaruh pasang surut terhadap pola tata tanam, kebutuhan air dan ketersediaan air eksisting. Berdasarkan data rencana tata tanam dari Dinas PSDA Provinsi Sumatera Selatan terdapat dua kali masa tanam yang dapat ditanami padi-padi, palawija-palawija dan tanaman keras (kelapa). Pada penelitian ini dilakukan analisis berdasarkan kondisi eksisting dan analisis hidrotopografi dengan menggunakan Arc-Map dan MOD-LSQ. Pada kondisi eksisting ketersediaan airnya hanya dipengaruhi oleh curah hujan sehingga mengalami defisit sedangkan berdasarkan hasil analisis hidrotopografi, Daerah Irigasi Rawa Karang Agung Hilir terbagi menjadi tiga tipe yaitu A, B dan C. Melalui neraca air dapat diketahui bahwa lahan pasang surut tipe A dan B terjadi surplus karena dipengaruhi oleh tinggi muka air dari pasang surut Muara Sungai Lalan. Sementara itu, untuk lahan pasang surut tipe C terjadi defisit karena lahan tidak terluapi air pasang sepanjang tahun dan tanah di D.I.R Karang Agung Hilir mengandung gambut sebesar 50≤100 cm dan tergolong masam hingga sangat masam karena memiliki kisaran pH 3,50-5,45. Kedalaman piritnya termasuk kedalam kategori dangkal hingga sedang.

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This research was conducted in the Karang Agung Hilir Tidal Swamp Irrigation Area which is located in the Banyuasin Regency and Musi Banyuasin Regency. The purpose of the study was to analyze the effect of tides on cropping patterns, water requirements and water availability. Based on the data cropping-pattern plan from the Dinas PSDA Sumatera Selatan, There are two planting periods that can be planted with paddy-paddy, palawih=ja-palawija and coconut. In this study, analysis was carried out based on existing conditions and hydrotopographic analysis using Arc-Map and MOD-LSQ. In the existing condition, the availability of air is only influenced by rainfall so that it experiences a deficit based on the results of hydrotopographic analysis, the Karang Agung Hilir Swamp Irrigation Area is divided into three types, namely A, B and C. Through the water balance it can be seen that the tidal land types A and B are surplus. because it is influenced by the water level from the ebb and flow of the Lalan River Estuary. Meanwhile, for tidal land type C, there is a deficit because the land is not flooded with tidal water throughout the year and the soil in Karang Agung Hilir DIR contains peat of 50-100 cm and is classified as acidic to very acidic because it has a pH range of 3.50-5.45. . The depth of the pyrite belongs to the shallow to medium category.