Application of Landform Arrangement and Slope Classes on Detailed Soil Resources Mapping in Transitional Volcanic Landscape. Case Study: Bompon Watershed, Magelang Regency, Central Java

Abstract

Detailed soil resources data is very importance for a development. In many sectors, information regarding the soil conditions is important, whether for civil engineering, mining, and especially agriculture. Unfortunately, despite the long history of soil studies, the cost to obtain a good soil data through soil mapping is still considerably expensive. Use of grid method for soil mapping is the reason behind the expensive cost of detailed soil mapping. In order to reduce the cost while increasing the efficiency of soil mapping, this study tries to use geomorphometry approach to simplify the soil mapping process. For this study, the geomorphology complex area, transitional volcanic landform was chosen. Transitional volcanic landform has unique soil characteristic, which are rich in clay, high erodibility, and have a depth for more than two meters. The result of this study shows that the slope has a statistical significance to the soil pH level, but the R2 value is still low due to many human activities that potentially alter the soil conditions beyond the natural rate. Despite the low R2 value, the time and cost needed to finish the soil survey is 70% lower than using a grid method. Those results shows that the geomorphometry approach still have a challenge to be implemented widely as a standard approach for soil mapping but have a great potency.