ANALYSIS OF EROSION USING HYDROSEEDING ON POST COAL MINING IN MELAK SITE

Abstract

After the mining process, Melak coal mining conducts reclamation. One of the
problems is the steep slope caused by the coal exploitation process. The slope is difficult to be replanted
and the soil is easily eroded by rainwater. The hydroseeding combined with jute net method has been
applied in this area, but the effectiveness and success of using that method have not been measured
accurately. Therefore, this study aims to examine explicitly the effectiveness of hydroseeding combined
with jute net method on the amount of erosion in this Melak Coal Mining site especially at the disposal
slopes and low wall in pit. The observation was done by making two square area models in separate
locations, which applied jute net and without jute net combined with hydroseeding technique. The seeds
used were Centrosema Pubescens, Pueraria Javanica, and Calopogonium Mucunoides. Next, the actual
erosion was compared to erosion prediction using the USLE. The average results of the actual erosion
were: at jute net disposal 471.59 ton/acre and at non-jute net disposal 510.19 ton/acre; and at jute net in
pit 896.23 ton/acre and at non-jute net in pit 974.43 ton/acre. The results of USLE calculation method
were: at jute net disposal 944.56 ton/acre and at non-jute net disposal 1016.81 ton/acre; and at jute net in
pit 1805.31 ton/acre and at non-jute net in pit 1917.10 ton/acre. The results indicated that the method was
able to reduce about 89.57% of the sediment accumulation at disposal and about 96.62% at low wall.