Spatial pattern of sediment transport for analysis of precipitation direction and magnitude in the upper Lematang river sub-basin

The high level of erosion that occur in Musi river basin has improved a tremendous impact on sedimentation in downstream areas and has resulted in many infrastructure of water is disturbed, such as silting of irrigation channels, siltation of rivers which disrupt the flow of transport stream and increasing the risk of flooding, high sedimentation in the port basin, low quality of water and the rising costs of water treatment. This study utilizes techniques terrain models Digital (Digital Elevation Model/DEM) to analysis the spatial distribution of the potential for erosion and sources of sedimentation, as well as the direction of the flow of sediment into channels as well as its relationship with outlet in branching river as the supplies to be sediment to the river flow. The method used in this study using a spatial model analysis with the help of GIS in analysing and presenting the level of erosion and deposition by utilizing modelling slope and kinetic energy of rainfall to estimate the index erosivity and distribution pattern of sediment into the river channel. This research was conducted at the upper Lematang river sub basin with area 412,638 Ha, which are classified into 11 sub-chatments with the highest altitude is 3.159 m above sea level (Dempo Valley) and the lowest is 126 m above sea level (Talang tinggi Valley). Analytical results have been tested by taking a fine sediment sampling in each sub-watershed in the analysis and is taken along the channel network and compare the observed patterns with the results predicted by the model analysis of soil erosion. Overall, erosion by high intensity tends to occur in the relationship between the different vegetation coverage, the barren land and open land used for farms and land used for mining. Approximately 45-65.5% slope bad condition because the vegetation has been open, so it can be seen the amount of erosion in the area is 2.139 ton/ha/year, at the sloping is 1.8239 ton / ha / year