Effects of karst vegetation-soil-rock composite structure on soil and water flow/leakage processes and driving factors at the micro-plot scale

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research Pub Date : 2024-11-23 DOI:10.1016/j.still.2024.106370

Rui Li , Jun Jing , Zhengyi Tang , Ling Xiong

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引用次数: 0

Abstract

Intense land degradation had created a special vegetation-soil-rock complex structure (VCS) on karst slopes, which altered regional soil and water processes. In this study, we investigated the combined effects of heterogeneous VCS on soil erosion/leakage, rainwater transformation and hydrodynamic characteristics at the microplot scale by simulating the karst dichotomous structure slopes with steel tanks and indoor artificial rainfall. The analysis showed that the surface runoff rate decreased with the increase of VCS and the subsurface runoff rate decreased with the increase of VCS. When the rainfall intensity increased to 60–120 mm/h, there was obvious surface runoff yield on the VCS slope. When the rainfall intensity exceeded 60 mm/h, the VCS showed obvious surface sediment yield with an initial rate ranging from 0 to 4.03 g·min⁻¹. VCS showed obvious underground runoff and sediment yield under different rainfall intensities, and the initial rate was greater than 0.45 L·min⁻¹ or 0.13 g·min⁻¹. This suggests that soil and water leakage from the karst rocky desertification slopes may be generalized. All the erosion flow regimes of VCS slopes were rapid laminar flow or slow laminar flow. The drag coefficient and flow shear increased with the increase of VCS, and the flow power showed a trend of increasing, then decreasing and then increasing. The water flow shear and water flow power showed a power function relationship with the sediment yield rate (R² ≥ 0.2293, P < 0.05). In terms of direct effects, hydrodynamic characteristics had the strongest influence on surface sediment yield (β = 0.68, P < 0.05), and rock exposure rate had the strongest influence on subsurface sediment yield (β = 0.56, P < 0.05). In terms of total effect, rainfall intensity was the dominant driver of surface/subsurface sediment yield (β = 0.75/0.72, P < 0.05). This study provides insights into understanding the mechanism of hydraulic erosion on rocky decertified slopes and provides a theoretical basis for decision-making on soil erosion management in karst areas.

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岩溶植被-土壤-岩石复合结构对水土流失/渗漏过程的影响以及微地块尺度上的驱动因素

强烈的土地退化在喀斯特斜坡上形成了特殊的植被-土壤-岩石复合结构（VCS），改变了区域水土过程。本研究通过钢槽和室内人工降雨模拟岩溶二分结构斜坡，在微地块尺度上研究了异质VCS对土壤侵蚀/渗漏、雨水转化和水动力特征的综合影响。分析表明，地表径流量随 VCS 的增加而减少，地下径流量随 VCS 的增加而减少。当降雨强度增加到 60-120 mm/h 时，VCS 坡面的地表径流量明显增加。当降雨强度超过 60 mm/h 时，VCS 坡面出现明显的地表沉积物产流，初始速率为 0 至 4.03 g-min-1。在不同降雨强度下，VCS 均有明显的地下径流和泥沙产出，初始速率大于 0.45 L-min-1 或 0.13 g-min-1。这表明岩溶石漠化边坡的水土渗漏可能具有普遍性。岩溶石漠化边坡的侵蚀流态均为快速层流或慢速层流。阻力系数和水流切变随 VCS 的增加而增大，水流功率呈先增大后减小再增大的趋势。水流剪切力和水流功率与泥沙产率呈幂函数关系（R2≥0.2293，P <0.05）。在直接效应方面，水动力特征对表层泥沙产率的影响最大（β = 0.68，P < 0.05），岩石裸露率对地下泥沙产率的影响最大（β = 0.56，P < 0.05）。就总效应而言，降雨强度是表层/次表层沉积物产率的主要驱动因素（β = 0.75/0.72，P < 0.05）。这项研究为了解岩石陡坡的水力侵蚀机制提供了见解，并为岩溶地区水土流失治理决策提供了理论依据。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Soil & Tillage Research 农林科学-土壤科学

CiteScore

13.00

自引率

6.20%

发文量

266

审稿时长

5 months

期刊介绍： Soil & Tillage Research examines the physical, chemical and biological changes in the soil caused by tillage and field traffic. Manuscripts will be considered on aspects of soil science, physics, technology, mechanization and applied engineering for a sustainable balance among productivity, environmental quality and profitability. The following are examples of suitable topics within the scope of the journal of Soil and Tillage Research: The agricultural and biosystems engineering associated with tillage (including no-tillage, reduced-tillage and direct drilling), irrigation and drainage, crops and crop rotations, fertilization, rehabilitation of mine spoils and processes used to modify soils. Soil change effects on establishment and yield of crops, growth of plants and roots, structure and erosion of soil, cycling of carbon and nutrients, greenhouse gas emissions, leaching, runoff and other processes that affect environmental quality. Characterization or modeling of tillage and field traffic responses, soil, climate, or topographic effects, soil deformation processes, tillage tools, traction devices, energy requirements, economics, surface and subsurface water quality effects, tillage effects on weed, pest and disease control, and their interactions.