Evaluating soil-water conserving performance of land management strategies for spoil tips on the Chinese Loess Plateau

Letao Zhang; Qingyuan Wang; Yiyuan Wei; Mengzhen He; Junwu Dong; Hongwei Tian; Zhaoliang Gao

doi:10.1016/j.jenvman.2022.115701

Evaluating soil-water conserving performance of land management strategies for spoil tips on the Chinese Loess Plateau

J Environ Manage. 2022 Oct 1:319:115701. doi: 10.1016/j.jenvman.2022.115701. Epub 2022 Jul 11.

Authors

Letao Zhang¹, Qingyuan Wang², Yiyuan Wei², Mengzhen He², Junwu Dong², Hongwei Tian³, Zhaoliang Gao⁴

Affiliations

¹ National Demonstration Center for Environmental and Planning, College of Geography and Environmental Science, Henan University, Kaifeng, Henan, 475004, PR China. Electronic address: zhangletao10@mails.ucas.ac.cn.
² National Demonstration Center for Environmental and Planning, College of Geography and Environmental Science, Henan University, Kaifeng, Henan, 475004, PR China.
³ Changjiang Institute of Survey, Planning, Design and Research Co., Ltd., Wuhan, Hubei, 430010, PR China.
⁴ Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi, 712100, PR China.

PMID: 35834848
DOI: 10.1016/j.jenvman.2022.115701

Abstract

Surface runoff decrease (SRD) and sediment concentration change (SCC) are accountable for sediment reduction by anti-erosion strategies. Using a design of horizontal stages, contour trenches, fish-scale pits, as well as their combinations, this study evaluated the two components for sediment reduction after the implementation of various land management strategies on steep spoil tips. The study highlighted the interactions between SRD and SCC in reducing sediment, and characterized the temporal variations of sediment-reducing capacity by SRD and SCC. Results showed that slope erosion was well controlled with control ratios of sediment yield ranging from 0.4 to 0.59, 0.2 to 0.22, for horizontal stage- and contour trench-based strategies, respectively. Sediment-reducing benefit by SRD accounted for 52%-77% of the total sediment reduction and highly determined the performance of SCC. Quadratic relationships between sediment-reducing capacity by SCC and that by SRD were observed. The function of SCC only operated when the sediment-reducing capacity by SRD reached a certain threshold. These thresholds varied greatly in the range of 0.75 kg m^-3-0.91 kg m^-3 and 0.61 kg m^-3-0.66 kg m^-3 for horizontal stage- and contour trench-based strategies, respectively. The upper limits for sediment-reducing capacity by SCC varied in the range of 0.32 kg m^-3-0.44 kg m^-3 and 0.63 kg m^-3-0.76 kg m^-3 for horizontal stage- and contour trench-based strategies, respectively. An efficiency coefficient of 55% and an M-N ratio of 1:1 indicated that sediment-reducing benefits by SRD and SCC were effectively exerted by combining contour trenches and fish-scale pits. The findings emphasized that the application of land management strategies must be considered based on particular goals to restore spoil tips. In practice, if targeted to enhancing sediment-reducing efficiency, contour trenches and fish-scale pits should be primarily considered. However, if the aim is to decrease water consumed for sediment control, then horizontal stages should be principally considered.

Keywords: Land management strategies; Sediment concentration change; Sediment-reducing capacity; Spoil tips; Surface runoff decrease.

MeSH terms

China
Conservation of Natural Resources / methods
Environmental Monitoring
Geologic Sediments
Soil*
Water*

Substances

Soil
Water