The Available Water Capacity in Landslide Area

Abstract

Available water capacity (AWCA) is very important for agriculture and recovery of degraded area resulting from landslide and surface soil loss affected soil water storage. Maepoon sub-district is an area that affected by landslide in 2006. This study conducted with the aim at 1) measurement of the volume and the difference of AWCA 2) analyzing of the relationship and grouping of the major component between soil property variables and AWCA using Principle component analysis (PCA) 3) analyzing of the factors that affect the AWCA using the General linear models (GLMs). The experiments were done in two ecosystems, Bamboo Mixed deciduous forest (BN) and Mixed fruit tree-based agroforestry (FN), at normal condition and landslide occurrence in 2006. The results showed that BN had the highest AWCA with an approximate mean of 16.76% by volume in all depths of soil followed by Mixed fruit tree-based agroforestryLandslide (FS), Bamboo Mixed deciduous forest -Landslide (BS) and FN with mean AWCA of 12.50, 12.36 and 8.32%, respectively. The BN showed highest AWCA, the AWCA correlated positively with field capacity, root ratio, air ratio, porosity, soil pH and cation exchange capacity, while negatively correlating with solid phase ratio, bulk density and clay particles. Furthermore, results of PCA showed that soil with high AWCA also had high air ratio but low permanent wilting point (PWP) and water ratio. The specific properties of BN are including high air ratio and infiltration rate (Unsaturated soil but low moisture at PWP and water ratio. These results indicated that BN has highest AWCA and GLMs clearly indicates that the landslide occurrence can affect the available water capacity.