Analisis tapak untuk rehabilitasi hutan rawa gambut Kalimantan Tengah menggunakan citra spot dan sistem informasi geografis

SURYANTA, Giri, Dr. Senawi, MP

2009 | Tesis | S2 Ilmu Kehutanan

Penelitian ini bertujuan mengetahui (1) tingkat kemampuan tapak blok B eks-PLG (2) potensi restorasi blok B eks-PLG dan (3) arahan rehabilitasi hutan rawa gambut blok B eks-PLG. Kondisi tapak terkait dengan kemampuan tapak yang disusun oleh kriteria (1) kematangan gambut (2) kedalaman/ketebalan gambut dan (3) kedalaman air tanah. Potensi restorasi vegetatif secara penanaman penuh maupun suksesi alami ditentukan dengan pertampalan kerapatan vegetasi dan pola penutupan-penggunaan lahan blok B eks-PLG. Peran perangkat ArcView 3.3 dalam Sistem Informasi Geografis berupa proses penampalan/tumpangsusun berbagai kriteria tersebut sehingga diperoleh informasi baru. Perangkat ENVI 4.4. dalam kinerja penginderaan jauh berupa proses interpretasi digital citra SPOT 4 Tahun 2006 metode NDVI (Normalized Difference Vegetation Index) sehingga diperoleh informasi tingkat, sebaran dan pola kerapatan vegetasi blok B eks- PLG. Hasil penelitian menunjukkan bahwa kelas kemampuan tapak tinggi (gambut tebal, hemist/fibrist, air tanah dangkal) seluas ±103.815,42 ha, kelas kemampuan tapak agak tinggi (gambut tebal, hemist/fibrist, air tanah dalam; gambut tipis, hemist/fibrist, air tanah dangkal; gambut sedang, hemist/fibrist, air tanah sedang) seluas ±11.671,04 ha, kelas kemampuan tapak sedang (gambut sedang, hemist/fibrist, air tanah dalam; gambut tipis, hemist/mineral, air tanah dangkal) seluas ±4.091,29 ha, kelas kemampuan agak rendah (gambut tipis, hemist/mineral, air tanah sedang; gambut tipis, hemist/mineral, air tanah sedang) seluas ±14.328,55 ha sedangkan kelas kemampuan rendah (gambut tipis, hemist/mineral, air tanah dalam) seluas ±95.553,755 ha. Potensi restorasi vegetatif secara suksesi alami dan penanaman penuh pada semak belukar rawa adalah ±11.881,87 ha dan ±35.759,33 ha. Potensi restorasi vegetatif secara suksesi alami dan penanaman pada kawasan hutan adalah ±73.823,68 ha dan ±3.545,87 ha. Arahan rehabilitasi dalam rangka konservasi hutan rawa gambut blok B eks-PLG yaitu konservasi gambut tebal, konservasi hidrologi dan suksesi alami hutan galam/purun. Peruntukan padi sawah, padi sawahpalawija- hortikultura sayuran dan pemukiman direkomendasikan pada potensi tapak kurang dengan kerapatan vegetasi rendah dan tanpa-vegetasi. Peruntukan tanaman tahunan dan hortikultura buah-buahan dialokasikan pada tapak berpotensi restorasi secara penanaman penuh, terutama pada semak belukar rawa. Lahan rawa (tergenang sepanjang masa) direkomendasikan menjadi areal konservasi hidrologi.

Site – based rehabilitation planning is a key factor to the success of re-planting with indigenous species. Site factors which determine the success of rehabilitation are peat decomposition rate, peat thickness and ground water depth. The objectives of this research are to determine: (1) site capability, (2) restoration potential and (3) land and forest rehabilitation direction. Vegetative restoration potential with full plantation or natural regeneration is determined by overlaying vegetation density criteria and land use cover pattern of Block B ex-mega rice project using ArcView 3.3 Geographical Information System (GIS). While ENVI 4.4 remote sensing software was being used to conduct digital interpretation of SPOT 4 2006 image with NDVI (Normalized Difference Vegetation Index) method to determine level, distribution and pattern of vegetation density in Block B ex-mega rice project. The results showed that Block B ex mega rice project was divided into 5 classes of site capability, which were: high site capability of ±103,815.42 ha, rather high site capability of ±11,671.04 ha, medium site capability of ±4,091.29 ha, rather low site capability of ±14,328.55 ha and low site capability of ± 95,553.755 ha. The vegetative restoration potential through natural regeneration and full plantation on peat swamp shrubs were ±11,881.87 ha and ±35,759.33 ha, respectively. The vegetative restoration potential through natural regeneration and plantation on peat swamp forests were ±73,823.68 ha and ±3,545.87 ha, respectively. The rehabilitation on Block B ex mega rice project area should be directed to conserve thick peat, hydrology and natural regeneration of Galam (Melaleuca sp.) and Purun forests. Agricultural and settlements purposes were recommended to take place on low site capability class, while perennial plantation and horticulture should be allocated on peat swamp shrubs. As for swamp land (inundated all year long) was recommended to become hydrology conservation area.

Kata Kunci : Hutan rawa gambut,Eks,PLG,Rehabilitasi,Kemampuan tapak,Spot,SIG.peat swamp forest, ex-mega rice project,rehabilitation,site capability,SPOT,GIS.