Analisis Morfometri dan Hipsometri di Sub DAS Belayan, Kutai Kartanegara, Kalimantan Timur

Abstract

Sub Daerah Aliran Sungai (DAS) Belayan merupakan salah satu Sub DAS Mahakam yang sering terdampak banjir dikarenakan perluasan lahan kritis. Oleh karena itu perlu adanya pemantauan dan evaluasi pengelolaan DAS melalui analisis morfometri dan hipsometri menggunakan Sistem Informasi Geografis. Morfometri yang dianalisis berupa aspek linier, relief, dan areal, sedangkan hipsometri berupa integral dan kurva hipsometri. Penelitian ini bertujuan menghitung hingga menganalisis karakterisitik morfometri dan hipsometri Sub DAS Belayan menggunakan DEM HydroSHEDS, dan hubungan spasial parameter pengontrolnya seperti tutupan lahan, kemiringan lereng, formasi batuan, dan jenis tanah melalui pemeringkatan dan overlay. Hasil penelitian menunjukkan Sub DAS Belayan memiliki 4 tingkat orde sungai; bentuk sangat memanjang; kemiringan landai hingga datar; kenaikan dan penurunan muka air banjir cepat; vegetasi lebat; tekstur sungai sangat kasar; panjang aliran darat besar; penyimpanan air yang rendah; dan geomorfik dewasa yang didukung melalui analisis spasial di order ketiga hulu dan order keempat hilir.

The Belayan Sub-Watershed (DAS) is one of the Mahakam Sub-DAS that is often affected by flooding due to the expansion of critical land. Therefore, monitoring and evaluation of watershed management through morphometric and hypsometric analysis using Geographic Information Systems is necessary. The morphometric aspects analyzed include linear, relief, and areal features, while hypsometric aspects include integrals and hypsometric curves. This study aims to calculate and analyze the morphometric and hypsometric characteristics of the Belayan Sub-DAS using HydroSHEDS DEM, and the spatial relationships of its controlling parameters such as land cover, slope gradient, rock formation, and soil type through ranking and overlay. The results of the study show that Belayan Sub DAS has four river order levels; a very elongated shape; gentle to flat slopes; rapid rises and falls in floodwater levels; dense vegetation; very coarse river texture; long landflow; low water storage; and mature geomorphology supported by spatial analysis in the third order upstream and fourth order downstream.