Publication:

Threats of sedimentation to agricultural land due to land use and degradation of watershed physical environmental

Background The Lake Lindu sub-watershed has experienced environmental damage, mainly as a result of various activities of the surrounding community who are less aware of the principles of environmental sustainability. This study aims to determine the effect of land use area and environmental physical conditions on sedimentation and water debit in the Lake Lindu sub-watershed.

Methods This research was carried out by implementing survey and non-experimental method at 3 rivers: Langko (P1), Wongkodono (P2), and Kati (P3). The dependent variable in this study is the area of land use (area of farm, shrub, paddy field, forest, and settlement) and the physical condition of the environment (the width of the catchment area and annual average rainfall). Then, the independent variables are sedimentation and water debit. Statistical analysis used is a multiple regression model.

Results The results of this study are that the wider shrub (X2) reduces the sedimentation (Y1) and increases the water debit (Y2). Each addition of one shrub unit will reduce the sediment by 0.208 mg/L and affect the water debit of 0.258 m3/ s-1. The regression equation is Y1=185.903 - 0.208X2-587.269X8 and Y2=6.854+0.258 X2 - 71.708 X8. As for the coefficient of the shape of the river (X8). The bigger the shape of the river, the smaller the average of the water debit. Thus, each reduction of one coefficient unit of the river shape will affect the water debit of 71,708 m3 /s-1.

Conclusions The significant predictor factors for sedimentation and river water debit are the shrubs and the coefficient of the river shape.