Primanto, Fauzi Rahmadi (2019) Pendugaan Erosi Menggunakan Metode USLE Sebagai Dasar Rehabilitasi Hutan dan Lahan di DAS Opak-Oyo, Jawa Tengah. Sarjana thesis, Universitas Brawijaya.
Abstract
Daya dukung DAS mempunyai peran dalam menjaga kualiatas air. Namun, dengan pemanfaatan lahan yang berlebihan dan pengolahan lahan yang kurang tepat dapat menurunkan daya dukung DAS. DAS Opak-Oyo merupakan DAS yang terletak di Daerah Istimewa Yogyakarta, diklasifikasikan dipulihkan daya dukungnya. Dalam upaya meningkatkan daya dukung DAS, dapat dilakukan dengan menghitung sebaran erosi yang terjadi. Perhitungan sebaran erosi bertujuan untuk menentukan arahan konservasi yang dilakukan dalam upaya meningkatkan daya dukung di wilayah DAS Opak-Oyo. Penelitian ini bertujuan untuk 1) mengetahui sebaran Tingkat Bahaya Erosi (TBE) di DAS Opak-Oyo, 2) menentukan luas lahan yang perlu dilakukan tindakan konservasi untuk upaya memperbaiki daya dukung di DAS Opak-Oyo. Penelitian ini telah dilaksanakan mulai dari Desember 2018 hingga Mei 2019. Dalam penelitian ini, pendugaan erosi dihitung menggunakan metode USLE oleh Wischmeier dan Smith (1978). Terdapat beberapa tahapan yang dilakukan, antara lain kegiatan persiapan, pengumpulan data, pemrosesan data, dan analisis hasil. Kegiatan persiapan yaitu mengetahui kondisi umum wilayah penelitian seperti wilayah administrasi,kondisi geologi, bentuk lahan, iklim, curah hujan, jenis tanah, kemiringan lahan, penggunaan lahan, dan kedalaman solum. Kegiatan pengumpulan data meliputi pengumpulan bahan dasar pembuatan peta yang dibutuhkan dalam perhitungan sebaran erosi antara lain data curah hujan, peta jenis tanah, Digital Elevation Model , dan Landsat 8. Kegiatan pemrosesan data meliputi pembuatan peta-peta dasar yang dibutuhkan dalam perhitungan erosi seperti peta erosivitas hujan (R), peta erodibilitas tanah (K), peta panjang dan kemiringan lereng (LS), peta vegetasi dan pengolahan lahan (CP), dan peta kedalaman solum. Kegiatan analisis hasil meliputi analisa sebaran Tingkat Bahaya Erosi wilayah penelitian, penentuan kawasan fungsi lahan, serta penentuan tindakan konservasi yang dilakukan berdasarkan Rehabilitasi Hutan dan Lahan (RHL) dalam upaya memperbaiki daya dukung DAS. Hasil penelitian menunjukan bahwa DAS Opak-Oyo mempunyai nilai erosivitas hujan (R) 1.342,31 sampai 1.714,63. Mempunyai nilai erodibilitas (K) tanah 0,09 sampai 0,29. Mempunyai nilai panjang dan kemiringan lereng (LS) 0,1 sampai 38,2397. Mempunyai nilai vegetasi dan pengolahan lahan (CP) 0,0000012 sampai 1. DAS Opak-Oyo didominasi oleh Tingkat Bahaya Erosi kelas berat dengan laju erosi 180-480 ton/ha/tahun dengan luas 58.814 Ha. DAS Opak-Oyo mempunyai empat fungsi kawasan lahan, diantaranya Kawasan Lindung, Kawasan Penyangga, Kawasan Budidaya Tahunan, dan Kawasan Budidaya Semusim. Luas sebesar 132.746 Ha dari luas DAS Opak-Oyo perlu dilakukan tindakan konservasi berdasarkan Rehabilitasi Hutan dan Lahan (RHL). Kegiatan RHL yang dilakukan berupa tindakan konservasi vegetatif dan mekanik.
English Abstract
The carrying capacity of watershed has a role in keeping the water quality. However, with excessive land utilization and less precise land processing can reduce the carrying capacity of watershed. Opak-Oyo watershed is a watershed located in Special Region Yogyakarta, classified restored its carrying capacity. In an effort to increase the carrying capacity of watershed, it can be by calculating the erosion distribution. The calculation of erosion distribution to determine the direction of conservation carried out in an effort to increase the carrying capacity in Opak-Oyo watershed. The research aims to 1) Know the distribution of erosion Hazard at Opak-Oyo watershed, 2) Determine the area of land to be carried out conservation measures for efforts to improve the carrying capacity of Opak-Oyo watershed. This research has been implemented from December 2018 to May 2019. In this research, estimation of erosion was calculated using USLE menthod by Wischmeier and Smith (1978). There are several stages, such as preparation, data collection, data processing, and results analysis. The preparation are to know the general conditions of the research areas such as administrative area, geological conditions, landforms, climate, rainfall, soil type, land slope, land use, and solum depth. Data collection include the collection of the necessary materials making map needed in the calculation of erosion distribution such as rainfall data, soil type maps, Digital Elevation Model, and Landsat 8. Data processing include the creation of basic maps needed in erosion calculations such as rain (R) erosivity maps, soil erosive maps (K), long and slope maps (LS), vegetation maps and land processing (CP), and maps Solum depth. The results of the analysis include the analysis of hazard level erosion rate of research area, determination of land function area, and the determination of conservation measures conducted based on forest and land Rehabilitation in efforts to improve the support watershed. The results showed that Opak-Oyo watershed had a value of precipitation erosivity (R) 1,342.31 to 1,714.63. Has an value eroibility value (K) of land 0.09 to 0.29. Has long and slope value (LS) 0.1 to 38.2397. has an value of vegetation and land processing (CP) from 0.0000012 to 1. Opak-Oyo watershed is dominated by heavyweight erosion rate with a rate of 180-480 tons/ha/year with an area of 58,814 Ha. Opak-Oyo watershed has four functions of land area, including protected area, buffer area, annual cultivation area, and season cultivation area. Area of 132,746 Ha of Opak-Oyo watershed area needs to be carried out conservation measures based on forest and land rehabilitation. Forest and land rehabilitation activities conducted in the form of vegetative and mechanical conservation measures.
| Item Type: | Thesis (Sarjana) |
|---|---|
| Identification Number: | SKR/FP/2019/208/051906951 |
| Uncontrolled Keywords: | - |
| Subjects: | 600 Technology (Applied sciences) > 631 Specific techniques; apparatus, equipment materials > 631.4 Soil science > 631.45 Soil erosion |
| Divisions: | Fakultas Pertanian > Agroekoteknologi |
| Depositing User: | Endang Susworini |
| Date Deposited: | 24 Aug 2020 07:18 |
| Last Modified: | 24 Aug 2020 07:18 |
| URI: | http://repository.ub.ac.id/id/eprint/173574 |
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