UPAYA KONSERVASI LAHAN BERDASARKAN INDIKATOR EROSI DAN SEDIMEN DI DAS JRAGUNG

Abstract

ABSTRAK: Daerah Aliran Sungai (DAS) Jragung terletak pada Wilayah Kerja Balai Besar Wilayah Sungai Pemali Juana. Pertambahan penduduk di DAS Jragung wilayah hulu menyebabkan perubahan pada fungsi lahan. Studi Upaya Konservasi Lahan Berdasarkan Indikator Erosi dan Sedimen di DAS Jragung sangat diperlukan untuk meminimalkan permasalahan di DAS Jragung. Pendugaan laju erosi dan sedimentasi dihitung dengan model AVSWAT 2000. Hasilnya menunjukkan besarnya limpasan permukaan, erosi dan sedimentasi sebesar 707,519 mm/thn, 168,51 ton/ha/th dan 229.806,089 ton/th. DAS Jragung memiliki indeks bahaya erosi rendah sebesar 40,19%, sedang sebesar 25,66%, tinggi sebesar 14,63%, dan sangat tinggi sebesar 19,52% terhadap luas DAS jragung Upaya konservasi secara vegetatif dapat mereduksi erosi sebesar 38,19% dan secara mekanis dapat mereduksi sedimen sebesar 48,09%. Â Kata-kata kunci: Limpasan permukaan, erosi, sedimentasi, AVSWAT 2000 Â ABSTRACT: Jragung Watershed (DAS) located in BBWS Pemali Juana. The population increase that occurred in the upper reaches Jragung watershed cause many changes in land use. The study of land conservation efforts based on indicators of erosion and sediment in Jragung watershed is necessary to minimize the problems that exist in Jragung watershed. The estimation of the rate of erosion and sedimentation is calculated by the model approach AVSWAT 2000. The results showed that the amount of surface runoff, erosion and sedimentation on the current state of each of 707.519 mm / yr, 168.51 tons / ha / year and 229.806,089 tons / year. Jragung watershed have erosion hazard index was lower by 40.19%, currently at 25.66%, higher by 14.63%, and was very high at 19.52% of the area jragung watershed. Conservation efforts for vegetatif erosion can reduce the amount of 38.19% and mechanically reduce sediment of 48.09%. Â Key words: surface runoff, erosion, sedimentation, AVSWAT 2000