Prediction of profile soil moisture for one land use using measurements at a soil depth of other land uses in a karst depression

Abstract

Information on root-zone soil water content (SWC) is essential for vegetation restoration, irrigation scheduling, and hydrological modeling. However, measurements of SWC within a variety of land uses may be time-consuming and labor-costing. This study tested whether SWC at a depth of a land use can be used to predict profile SWC of other land uses in terms of temporal stability analysis at a karst depression area in southwest China. A total of 30 datasets of root-zone SWC from 0.1- to 0.5-m depths were collected by time domain reflectometry probes for three typical land uses from March 12 to November 8, 2015. Results showed that the profile mean SWC and its associated standard deviation (SDP) and coefficient of variation (CVP) differed significantly (P < 0.05) among the grassland, farmland, and forestland. The profile SWC was more temporally stable according to the apparently lower CVT in comparison with CVP. The similarities of the vertical patterns of SWC were strong for the same land uses, while were relatively weak between the different land uses. The SWC measurements of the most temporally stable depth can be used to accurately predict profile SWC for both the same land use and other land uses. This study further expands the application of the temporal stability analysis and can aid water resource management in areas with diverse land uses.