SCIENTIA GEOGRAPHICA SINICA ›› 2018, Vol. 38 ›› Issue (7): 1189-1197.doi: 10.13249/j.cnki.sgs.2018.07.021

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Parameter Estimation of Soil Water Retention Curve Based on Soil Physical and Chemical Properties of Van Genuchten Model

Shuang Li1(), Xiangjie Zhao1, Yun Xie1(), Junrui Zhai1, Gang Liu1, Xiaofei Gao1, Jing Li1, Yan Gao2   

  1. 1. Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
    2. Songliao Water Resources Commission, Ministry of Water Resources, Changchun 130021, Jilin, China
  • Received:2017-06-20 Revised:2017-09-12 Online:2018-07-20 Published:2018-07-20
  • Supported by:
    National Natural Science Foundation of China (41371271), the Public Welfare Industry Special Funds for Scientific Research from Ministry of Water Resources (201501012)

Abstract:

The soil water retention curve (SWRC) is the basic parameter of soil hydraulics to study soil water movement and soil water balance, which is closely related to soil physical and chemical properties. But the parameters of model is difficult to estimate. In this study, black soil samples with different erosion intensity were collected in the black soil region of Northeast China, and soil moisture under 7 soil water suction, mechanical composition, organic matter and bulk density were measured. We used Rosetta model to estimate the parameters of Van Genuchten (VG) model and compared the estimated soil moisture with the measured soil moisture. And then the simulation accuracy of different soil physical and chemical indexes and the suitability of the method to the black soil in Northeast China were evaluated. The results showed that there had little effect for the residual water content (θr) and saturated water content (θs) between 4 or 6 soil properties index, but had large difference for the scale parameter (α) and shape parameter (n). When the 6 indexes were used, shape parameter n decreased with the increased of scale parameter α. The relationship between the shape parameters m and n of the VG model was further modified, which improved the accuracy of model fitting obviously. The results of the 6 indexes were better than the 4 indexes. But the estimated values were different from the measured values and the estimated values were larger than the measured, which means soil moisture estimation need to be corrected according to the estimated value of relatively large degree. The fitting precision of Rosetta model for lightly and moderately erosion black soil was higher, and the precision of severely erosion black soil was lower. The model was suitable for sand content less than 46%, the clay content more than 28% of black soil in Northeast China.

Key words: soil water retention curve, soil physical and chemical properties, black soil, Rosetta model, Van Genuchten model

CLC Number: 

  • S152.7