From field soil sampling to watershed model: Upscaling by integrating information entropy and interpolation method

Lei Chen; Weichen Wang; Chengcheng Wang; Xiaoman Yan; Yuhan Zhang; Zhenyao Shen

doi:10.1016/j.jenvman.2024.121119

From field soil sampling to watershed model: Upscaling by integrating information entropy and interpolation method

J Environ Manage. 2024 May 10:360:121119. doi: 10.1016/j.jenvman.2024.121119. Online ahead of print.

Authors

Lei Chen¹, Weichen Wang², Chengcheng Wang³, Xiaoman Yan², Yuhan Zhang², Zhenyao Shen²

Affiliations

¹ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, PR China. Electronic address: chenlei1982bnu@bnu.edu.cn.
² State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, PR China.
³ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, PR China; Shanghai Investigation, Design & Research Institute Co., Ltd., Shanghai, 200335, PR China.

PMID: 38733849
DOI: 10.1016/j.jenvman.2024.121119

Abstract

Soil property data plays a crucial role in watershed hydrology and non-point source (H/NPS) modeling, but how to improve modeling accuracy with affordable soil samplings and the effects of sampling information on H/NPS modeling remains to be further explored. In this study, the number of sampling points and soil properties were optimized by the information entropy and the spatial interpolation method. Then the sampled properties were parameterized and the effects of different parameterization schemes on H/NPS modeling were tested using the Soil and Water Assessment Tool (SWAT). The results indicated that the required sampling points increased successively for soil bulk density (SOL_BD), soil saturated hydraulic conductivity (SOL_K) and soil available water capacity (SOL_AWC). Compared to the traditional database (Harmonized world soil database), the NSE and R² performance by new scheme increased by 22.8% and 10.5%, respectively. The entropy-based optimization reduced the sampling points by 13.2%, indicating a more cost-effective scheme. Compared to hydrological simulation, sampled properties showed greater effects on NPS modeling, especially for nitrogen. This proposed method/framework can be generalized to other watersheds by upscaling field soil sampling information to the watershed scale, thus improving H/NPS simulation.

Keywords: Information entropy; Model parameterization; Nonpoint source pollution; Soil and water assessment tool; Soil sampling.