Authors : Chay Asdak and Sudradjat Supian
Abstract: The assessment of important factors affecting runoff and erosion was carried out by collecting runoff and soil loss from runoff/erosion plots. The runoff/erosion plots were set up in sloping areas of about 40% slope in two different places of the upper parts of Citarum and Cimanuk Watersheds, West Java, Indonesia. The plots (6×10 m) at the upper Citarum were established in the following four sets of conditions: bamboo garden, mixed garden, small shrub and agricultural crops with different species and stand structures. After 20 rainfall events, a treatment in the form of removing undergrowth and litter were applied to bamboo and mixed garden plots. The results of this before and after treatment are the following: runoff from bamboo garden was increased from 0.40-1.02 L/m2 and erosion was increased from 1.47-11.65 g/m2. While the runoff and erosion in mixed garden were increased from 0.36-1.65 L/m2 and from 1.36-10.88 65 g/m2, respectively. When this compared to the runoff and soil loss in the agricultural plot, the soil erosion is much higher, 50.5 65 g/m2 (about 50 times higher). These results will then be compared to the similar field-plot based measured in the upper Cimanuk watershed for a comparative study purpose. For both cases, stand/canopy structure appeared to be the important factors that determine the magnitude of soil erosion. While the role of these factors were less significant compared to rainfall in determining the magnitude of runoff.
Chay Asdak and Sudradjat Supian, 2017. Hydrological Implication of Traditional Farming Systems: A Case Study in the Upper Citarum and Cimanuk Watersheds, West Java. Journal of Engineering and Applied Sciences, 12: 4415-4419.