THE RATE OF EROSION AND EROSION HAZARD LEVELS (TBE) IN THE UPPER AREA, FARMER RIVER FLOWS (DAS) IN NORTH SUMATERA
Abstract
This study aims to determine the rate of erosion that occurs and determine the amount of permissible erosion (Edp) and how the Erosion Hazard Level (TBE) and evaluate the value of the nutrient content of Nitrogen, Phosphorus and Potassium (NPK) lost due to erosion in the upstream area of the Farmer's Sub-watershed and economic losses due to the loss of these nutrients in North Sumatra, Indonesia. Tests were carried out using a component-based SEM (Structural Equation Modeling) approach through GeSCA (Generalized Structured Component Analysis) software. The results showed that the highest prediction rate of erosion that occurred in the upstream area of the Farmer's Sub-watershed was 11,302 tonnes /ha /year (classified as very heavy) or equivalent to 941.9 mm / year in SPT-24 cultivating banana plants, which had a negative average income, namely in the amount of IDR. 805,895.75 while the lowest erosion rate prediction is 13.72 tonnes / ha / year at SPT 12 or equivalent to 1.14 mm/year (classified as very light) where SPT-12 cultivates bananas and papayas has an average income of IDR 10,820,367. Based on the results of the TBE evaluation, it can be concluded that the damaged land is 15.38 ha and the land still suitable for development for pineapple, papaya, chilli, cabbage farming is 5.38 ha.
