A STUDY OF THE QUALITY OF SOIL INFILTRATION AT THE DOWNSTREAM OF KURANJI RIVER, PADANG CITY.

The watershed at the downstream of Kuranji river often experience flooding. This is due to the rainfall runoff and the flat condition of the downstream area. Another factor might be due to low soil infiltration rate. The objective of this research was to analyze the quality of soil infiltration at the downstream of Kuranji River's watershed. Research methodology that had been chosen as a field survey. Soil infiltration rate was measured using double ring infiltrometer. Location of soil sample was selected by purposive random sampling and was analyzed at the Department of Soil Science Andalas University. The data was analyzed using Horton formula to identify the capacity and the cumulative soil infiltration rate. The result showed that the area which often inundated and has high soil water table had a low infiltration rate. The results showed that the bulk density factor, clay fraction and dust significantly affect the capacity of soil infiltration. Moreover, bulk density, clay fraction, and dust influence soil infiltration capacity. Areas that have high infiltration capacity are Gunung Sariek, Aie Pacah, Ampang, Kurao Pagang, and Dadok Tunggul Hitam. Other sampling locations have low infiltration rate due to the high soil water table. [ABSTRACT FROM AUTHOR]