ANALYSIS OF LAND EROSION AT LOMAYA WEIR WATERSHED GORONTALO PROVINCE

• Main Author: CAMELIA IBRAHIM (NIM 95006018), MISKA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/10899
• Institution: Institut Teknologi Bandung

Lomaya weir is an outlet of Bolango Watershed, where Bolango watershed represent as one of watershed which located at Gorontalo Province, nowadays still in optimum condition where most of its region still be consisted of forest. nevertheless tendency of there are various of resident activity such as cleared away of forest, illegal logging, mobile dry rice field and land processing can result the happening of erosion, sedimentation and also reduction of quality and supporting of nature resource. Bolango watershed at Lomaya Weir outlet has width of 397,83 km2. From thet there are forest as much as 81%. Bushes 12,432%, mixture garden 4,968% and its remain is dry rice field. Topographical condition of Lomaya weir watershed dominated by Slope Class III/Rather Steep (25-40%) that is for width 172,59 km2 (43,38%) from width total DAS Lomaya Weir. Method used to analyze the erosion changes using calculation based on USLE Method (Universal Soil Loss Equation). As for sedimentation analysis of Lomaya Weir using value of SDR (Sediment Delivery Ratio). Based on land erosion calculation of existing condition with using maximums rainfall input daily during 5 years obtained land erosion as much 4.636.448 ton/year with area wide 39.783 Ha equivalent with 116,54 ton/ha/year. This meaning that Lomaya Weir watershed include in category of Erosion Class III/ very heavy. With very optimum forest condition that is 81%. This matter caused by high rainfall, slope degree more than 40% and there are new land what susceptible to erosion. For that needed land simulation existence with conservation existing land by ways bench terrace system or even with distance crop. <br />