Rehabilitasi Lahan Kawasan Das Wai Ruhu Berbasis Konservasi Tanah Dan Air

Pattiselanno, SteanlyRR (2013) Rehabilitasi Lahan Kawasan Das Wai Ruhu Berbasis Konservasi Tanah Dan Air. Magister thesis, Universitas Brawijaya.

Abstract

Daerah aliran sungai (DAS) Wai Ruhu, merupakan DAS yang terdapat di Kota Ambon, secara topografi dibatasi oleh punggung-punggung gunung yang menampung dan menyimpan air hujan, kemudian menyalurkannya ke laut melalui sungai utama. Kondisi riil DAS saat ini, telah mengalami kondisi degradasi lahan, akibat konversi lahan tangkapan yang diubah fungsinya menjadi pemukiman warga. Sehingga berdampak pada debit air sungai Wai Ruhu yang semakin berkurang dan tingkat sedimentasi yang tinggi serta banjir. Berdasarkan kondisi tersebut, maka diperlukan identifikasi lebih detail terhadap faktor degradasi lahan akibat perubahan fungsi kawasan, melalui pemetaan fungsi lahan eksisting yang berbasis sumber daya air (konservasi tanah dan air). Dari proses identifikasi, diharapkan dapat diketahui tingkat kerawanan longsor, dan bahaya erosi serta bisa menentukan arahan rehabilitasi lahan berbasis konservasi tanah dan air pada DAS Wai Ruhu Metode yang digunakan adalah metode deskriptif melalui proses survey pada DAS Wai Ruhu. Selain survey, data sekunder dari lapangan yang diperoleh juga dipakai untuk mengklasifikasikan tingkat kerawanan longsor, menghitung tingkat bahaya erosi dan menentukan fungsi kawasan sesuai arahan BRLKT. Hasilnya, menunjukkan ada tingkat kerawanan bencana longsor pada DAS Wai Ruhu, termasuk dalam kategori tinggi (58.88% area DAS) dan sedang (41.12% area DAS). Rencana rehabilitasi lahan kawasan DAS Wai Ruhu pada indikator aspek aktifitas manusia (tingkat resiko) terhadap bahaya longsor, penataan kawasan pemukimannya antara lain pada indikator “pola tanam” (penanaman tanaman yang bisa membantu menstabilkan tanah, khususnya pada kawasan berlereng seperti jenis bambu, tanaman berakar tunjang, dll), indikator “penggalian dan pemotongan lereng” (memperkuat lereng bekas dipotong dengan memberikan talud/dinding penahan. Mewajibkan pembuatan s truktur penguat lereng untuk bangunan yang ada di lereng), indikator “drainase” (pembuatan, perbaikan sistem drainase yang terencana dengan lebih baik dari sisi kapasitas maupun kualitas, perawatan dari sumbatan akibat sampah maupun sedimentasi) , dan indikator “usaha mitigasi” (perbaikan koordinasi mitigasi bencana dan pola penanganannya antara seluruh stakeholder misalnya pemerintah, masyarakat, pihak lainnya). Dengan perbaikan indikator ini mampu menekan tingkat resiko pada luas guna lahan pemukiman (10.47%) dari total skor resiko 2.6 (kelas tinggi) menjadi 2.1 (kelas sedang). Sesuai kriteria BRLKT, maka pengembalian fungsi kawasan untuk tingkat bahaya erosi (TBE) dan rencana perbaikan tingkat bahaya erosi, dengan rencana pelaksanaan perbaikan masing-masing kawasan hasil rehabilitasi antara lain yaitu, pada fungsi kawasan lindung (reboisasi, hutan rakyat, perlindungan sungai, mata air, jurang, p engetatan pengawasan, dll), fungsi kawasan penyangga (reboisasi, hutan campuran, hutan rakyat, dengan seresah), fungsi kawasan budidaya tanaman tahunan (reboisasi, perkebunan, hutan/kebun rakyat, dengan seresah), dan terjadi peningkatan dengan klasifikasi “sangat ringan” sebesar 53.52% area DAS, dan penurunan TBE klasifikasi “sangat berat” sebesar 39.41% area DAS.

English Abstract

Wai Ruhu Watersheds (DAS) is located in the City of Ambon. It`s limited by the topography of the mountain ridges that accommodate and store rain water, and then distribute it to the sea through the main river. The latest condition of the watershed at this time has experienced a degradation conditions, due to land conversion of catchment area converted into the residential areas. That impact on the river, as decrease in the level of water, sedimentation and flooding. Under these conditions, it would require a more detailed identification of the factors of land degradation due to changes in the function of the region, through the mapping function of existing land-based water resources (soil and water conservation). By the identification process, it expected to know the level of vulnerability to landslides, and erosion hazard and could determine the direction of the rehabilitation, based on land and water conservation at Wai Ruhu watershed. The method that used is descriptive method through the survey process at Wai Ruhu watershed. In addition to the survey, secondary data obtained from the field is also used to classify the level of vulnerability to landslides, calculate and determine the degree of erosion hazard and re function area by BRLKT terms of condition. The results, showed a level of vulnerability to landslides in Wai Ruhu watershed, including in the high category (58.88% of watershed area) and moderate (41.12% of watershed area). Rehabilitation plan of Wai Ruhu watershed area on aspects of human activity indicator (risk level) of the avalanche danger, the arrangement of settlement areas, such as the indicator "cropping pattern" (planting crops that could help stabilize the soil, especially on sloping areas such as bamboo, plant trees, etc.), the indicator "excavation and slope cutting" (slope strengthen the former cut to give retaining wall. Requiring the build of structures for slope reinforcement of existing buildings on the slopes), indicators of "drainage" (build, repair drainage system that planned better in terms of capacity and quality, treatment of obstruction due to waste and sedimentation), and indicators of "mitigation efforts" (improved coordination of disaster mitigation and treatment patterns among all stakeholders such as the government, civil society, and other parties). With the improvement of this indicator is able to reduce the level of risk on the extensive land settlement (10.47%) of the total risk score of 2.6 (high grade) to 2.1 (medium grade). In accordance BRLKT criteria, then the function returns to the level of erosion hazard areas (TBE) and erosion rate remediation plans, the implementation of improvement plans of each area of rehabilitation outcomes among others, in the function of protected areas (reforestation, forest people, the protection of rivers, springs water, ravines, tightening supervision, etc.), the function of the buffer zone (reforestation, mixed forests, community forests, the litter), the function of the annual crop cultivation area (reforestation, plantations, forest / garden people, with litter), and an increase in the classification "very light" 53.52% of the watershed area, and decrease erosion potential classification of "very heavy" 39.41% of the watershed area.

Item Type: Thesis (Magister)
Identification Number: TES/333.73/PAT/r/041311823
Subjects: 300 Social sciences > 333 Economics of land and energy > 333.7 Land, recreational and wilderness areas, energy
Divisions: S2/S3 > Magister Teknik Sipil, Fakultas Teknik
Depositing User: Budi Wahyono Wahyono
Date Deposited: 23 May 2014 08:15
Last Modified: 23 May 2014 08:15
URI: http://repository.ub.ac.id/id/eprint/155838
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