Infiltration characteristics of water in forest soils in the Simian mountains, Chongqing City, southwestern China

Abstract

Spearman rank-correlation analysis and grey relational grade analysis were used to study infiltration characteristics of water in different forest soils in the Simian mountains, Chongqing City. The results indicate that the soil bulk density, contents of coarse sand, and porosity of macropores were significantly correlated with saturated hydraulic conductivity. Porosity of macropores and contents of coarse sand were positively correlated with soil saturated hydraulic conductivity and soil bulk density negatively. Based on the initial infiltration rate, the stable infiltration rate, time required for infiltration to reach a stable state, and cumulative infiltration, all of which are crucial parameters determining soil infiltration capacity, the results of grey relational grade analysis showed that the grey relational grades of the different forest soils were listed from high to low as broad-leaved forest (0.8031)>Phyllostachys pubescens forest (0.7869)>mixed conifer-broadleaf forest (0.4454)>coniferous forest (0.4039). Broadleaf forest had the best ability to be infiltrated among the four soils studied. The square roots of the coefficients of determination obtained from fitting the Horton infiltration equation, simulated in our study of forest soils, were higher than 0.950. We conclude that soils of broad-leaved forests were the best suited for infiltration processes of forestry in the Simian mountains.

Keywords

Simian mountains / infiltration / Spearman rank-correlation analysis / grey relational grade analysis