DIMENSI SPASIO EKOLOGIKAL PEMANFAATAN LAHAN PERBUKITAN-PEGUNUNGAN DI KECAMATAN KOKAP, GIRIMULYO DAN PENGASIH KABUPATEN KULONPROGO DAERAH ISTIMEWA YOGYAKARTA

Juhadi, Drs.,M.Si., Prof. Dr. Hadi Sabari Yunus, MA

2013 | Disertasi | S3 Geografi

Penelitian ini memfokuskan pada studi pemanfaatan lahan oleh petani kawasan perbukitan-pegunungan di Kecamatan Girimuyo, Kokap dan Pengasih Kulonprogo, dikaji dalam dimensi spasio-ekologikal, dengan tujuan: (1) mengkaji sebaran spasial tipologi pemanfaatan lahan pertanian dari aspek pola, proses, struktur dan kecenderungan spasial, (2) mengkaji faktor-faktor yang berpengaruh terhadap kerusakan lahan, dan (3) menemukan model penilaian status keberlanjutan pemanfaatan lahan pertanian secara multidimensional. Metode penelitian utama yang digunakan adalah survei, dengan unit analisis satuan bentuklahan dan rumahtangga tani. Variabel penelitian terdiri atas aspek geobiofisik lahan, aspek sosioekonomi, dan aspek sosiobudaya. Sampel penelitian diperoleh secara acak proposional pada setiap satuan bentuklahan. Pendekatan kuantitatif dan kualitatif digunakan dalam penelitian ini, sifat uraian selain deskriptif juga dianalisis dengan model RApALU (Rapid Appraisal for Agricultural Land Utilization) berbasis statistik MDS (multi dimensional scaling). Hasil penelitian menunjukkan (1) pola spasial pemanfaatan lahan kebun campuran tersebar pada sebagian besar wilayah penelitian; ladang/tegalan tersebar di antara kebun dan permukiman; sawah tersebar di lembah-lembah dan dataran kirikanan sungai. Proses perkembangan pemanfaatan kebun campuran relatif konstan dari tiga titik tahun yang diteliti; terdapat kecenderungan penurunan luas sawah irigasi dan kenaikan luas pada sawah tadah hujan dan semak/belukar. Daerah lereng atas dan tengah didominasi oleh kebun campuran dan sebagian tegalan, sedang lereng kaki perbukitan untuk sawah tadah hujan dan permukiman. Pemanfaatan lahan belukar/semak menunjukkan kecenderungan spasial adanya penambahan luas sekalipun masih relatif kecil. Demikian sebaliknya kebun, sawah irigasi dan ladang/tegalan cenderung mengalami penurunan luas area. (2) Faktor penyebab kerusakan lahan selain faktor geobiofisik lahan, juga dampak dari implementasi kebijakan tata ruang wilayah oleh pemerintah lokal yang kurang konsisten yaitu penggunaan kawasan lindung menjadi kawasan budidaya dan pembukaan akses jalan yang melebihi kapasitas kemampuan daya dukung tanah sehingga memicu terjadinya erosi dan longsor lahan. Namun demikian tingkat kerusakan lahan potensial tidak selalu berbanding lurus dengan tingkat kerusakan lahan aktual. (3) Model RApALU menghasilkan nilai Indek Keberlanjutan Pemanfaatan Lahan (IKPL) pada setiap satuan bentuklahan cukup baik dengan rentang nilai IKPL antara 57.89 – 76.89. Temuan utama penelitian adalah model RApALU berbasis MDS yang dapat digunakan untuk penilaian status keberlanjutan pemanfaatan lahan secara lebih holistik dan implementatif.

This study focuses on investigating the land utilization by farmers in the hillymountain at Kulonprogo, in terms of spatial-ecological dimensions, with the aim of: (1) assessing the spatial distribution of agricultural land utilization typology based on the aspects of patterns, processes, structures and spatial trends, (2 ) examining the factors that influence land degradation and, (3) finding out a multidimensional assessment model of sustainability status in the utilization of agricultural land. The main research method used was a survey with landforms and domestic farms as the units of analysis units. Research variables consisted of land geo-biophysical, socio-economic and socio-cultural aspects. Samples were obtained at proportional random to each unit of landforms. Quantitative and qualitative approaches were employed in this study. In addition to the descriptive nature the model was also analyzed by RApALU (Rapid Appraisal for Agricultural Land Utilization) statisticsbased MDS (multi-dimensional scaling). The findings show that (1) spatial patterns of mixed utilization of land farms were among major parts of the research sites; agricultural sites were available among farm land and housing settlement; rice fileds were at valleys and both banks of rivers; the proses of mixed utilization was relatively constant in three years under study; the area of irrigated rice fields tended to decrease, and rainfall rice fields and bushes tended to increase. Upper and middle slopes of the area were dominated by mixed farms and partly moor, while the slope foothills for rain fed and settlements. Utilization of shrubs/bushes indicated to broaden the farm space though it was still relatively small. On the other hand, gardens, irrigated fields and fields /moor tended to decrease the area. (2) The causes of land degradation in addition geo-physical factors, was the impact of spatial policy implemented by local governments that were less consistent in the utilization of protected areas to be cultivated area, and the opening of access roads exceeding the carrying capacity had thus caused soil erosion and landslides. However, the levels of potential land degradation did not show the extent of damage directly proportional to the actual utilization of land. (3) RApALU model generated the value of Land Utilization Sustainability Index (IKPL) on each unit of landforms being relatively good to excellent with a range of values IKPL ranging from 57.89 to 76.89. The main finding of the study is that MDS-based RApALU model can be used to appraise sustainability status of land utilization in a holistic and implementative.

Kata Kunci : pendekatan spasio ekologikal, kerusakan lahan, RApALU.