Perubahan Tutupan Lahan dan Stok Karbon Permukaan di Daerah Aliran Sungai (DAS) Blega

Abstract

ABSTRAK 

Emisi karbon merupakan isu yang sangat berdampak pada pemanasan global, peningkatan bencana hidrometeorologi dan penurunan sumberdaya alam. Salah satu cara mengurangi emisi karbon adalah mencegah perubahan tutupan lahan terutama hutan pada daerah tropis seperti Kawasan DAS Blega. Penelitian ini bertujuan untuk melihat perubahan tutupan lahan dan dan pengaruhnya terhadap stok karbon permukaandi DAS Blega tahun 1990-2020. Penelitian dilakukan di area DAS Blega melalui 6 tahapan, yaitu koreksi geometric, komposit band, training sample pada Area of Interest (AoI), uji Training sample, klasifikasi tutupan lahan dan menghitung stok karbon. Hasil analisis menunjukkan rata - rata tutupan lahan pada tahun 1990, 2000, 2010 dan 2020 terluas berturut-turut adalah pertanian lahan kering (69%), hutan tanaman (11.2%), sawah (8.77%), hutan tanaman (4.59%), tambak (2.65%), pertanian lahan kering campur (1.56%), hutan mangrove sekunder (0.87%), pemukiman (0.70%), belukar (0.63%) dan sisanya tanah terbuka. Perubahan tutupan lahan 1990-2000 dari belukar rawa menjadi pertanian lahan kering (8,819.81 ha), sawah (2,629.13 ha) dan pemukiman (152.57 ha). Periode 2000-2010 terjadi perubahan tutupan lahan pada pertanian Lahan Kering Campur-Pemukiman sebesar 654.14 ha. Periode 2010-2020 terjadi konversi lahan tertinggi pada sawah - tambak dengan luas 4,571.08, belukar - sawah, dan hutan mangrove sekunder - tambak masing - masing luas 343.12 dan 316.13 ha serta sebagian kecil penutup lahan lainnya. Selanjutnya, periode 2010-2020 tutupan lahan sawah mengalami penurunan sebesar 4,302.7 ha. Perubahan tutupan lahan tersebut berpengaruh pada perubahan stok karbon di DAS Blega, yakni selama periode tahun 1990-2020 mengalami penurunan sebesar 25.98%. Tahun 1990-2000 mengalami penurunan 19.41%, tahun 2000-2010 dan 2010-2020 mengalami penurunan masing-masing sebesar 1.55% dan 5.02%.

Kata kunci: emisi karbon, karbon permukaan, madura

ABSTRACT

Carbon emissions are a strategic issue because of the impact on global warming, increased hydrometeorological disasters, and decreased natural resources. One way to reduce carbon emissions is to prevent land cover change, especially forests for other uses in tropical areas such as forests in the Blega watershed area. This study aims to look at land cover change and its effect on surface carbon stock in the Blega watershed from 1990-2020. This research was conducted in the Blega watershed area through 6 stages, namely: 1) Geometric correction, 2) Band composite, 3) Training sample on Area of Interest (AoI), 4) Training sample test, 5) Land cover classification and 6) Carbon stock calculation. The results of image analysis of the Blega watershed area show that the average land cover in 1990, 2000, 2010, and 2020 are dry land agriculture (69%), plantation forest (11.2%), rice fields (8.77%), plantation forest (4.59%), ponds (2.65%), mixed dry land agriculture (1.56%), secondary mangrove forest (0.87%), settlements (0.70%), shrubs (0.63%) and the remaining open land. The land cover changed 1990-2000 from swamp scrub to dry land agriculture (8,819.81 ha), paddy fields (2,629.13 ha), and settlements (152.57 ha). The period 2000-2010 saw land cover change in Mixed Dryland Agriculture-Settlement of 654.14 ha. The 2010-2020 period saw the highest land conversion in paddy fields - ponds with an area of 4,571.08, scrub - paddy fields, and secondary mangrove forest - ponds with an area of 343.12 and 316.13 ha respectively, and a small portion of other land covers. Furthermore, in the 2010-2020 period, rice field land cover decreased by 4,302.7 ha. The change in land cover affects the change in carbon stock in the Blega watershed, which during the 1990-2020 period decreased by 25.98%.1990-2000 experienced a decrease of 19.41%, 2000-2010 and 2010-2020 experienced a decrease of 1.55% and 5.02% respectively.

Keywords: carbon emissions, surface c stock, madura