摘 要

本研究以裸地、狗牙根、香根草、伞房决明四个小区为研究对象, 基于水量平衡原理，以2018年1月至2018年12月一年内降雨数据为依据，利用数据采集法，分析研究区一年内降雨天数、降雨量、降雨类型分布情况，选取中雨、大雨、暴雨事件为典型日，对比草本植物覆盖下径流、产沙特征，以裸地为对照，形成了降雨-产流-产沙的水文过程的体系，并依据研究内容对比分析不同草本植物覆盖及不同降雨类型下的地表径流、产沙规律，提出不同的草本植物对地表径流、产沙控制的作用，总结各草本植物的水土保持效益。结果表明，不同草本植物对地表径流的影响存在共同点，其地表径流是随降雨量的增加而增加。降雨量到达峰值时，四块植被样地的径流深及径流量也达到峰值；在中雨及大雨的环境条件下，当降雨强度为2时，除对照组外的植被样地削减率达到峰值；在暴雨环境条件下，当降雨强度为0.4时，除对照组外的植被样地削减率达到峰值。香根草对径流的削减效果最好，其次为伞房决明、狗牙根，说明在不同降雨条件下香根草与伞房决明和狗牙根相比，可以促进水分下渗，减少地表径流的流失。由此提出降雨特征与径流、产沙、径流削减率、产沙量的相关性和回归关系。

关键词：降雨特征；地表径流；产沙效益；削减效应

Study on the effects of three herbaceous plants on reducing runoff and sediment

ABSTRACT

In this study, four plots of bare land, foxtail, bermudagrass and ovary were used as research objects. Based on the principle of water balance and the rainfall data from January 2018 to December 2018, the data collection method was used to analyze the rainfall in the study area within one year. The distribution of days, rainfall, and rainfall types is dominated by moderate rain, heavy rain, and heavy rain events. The surface runoff and sediment yield of bare land are used as a control, and a hydrological process system of rainfall-flow-sand production is formed. According to the research contents, the effects of different herbaceous plant cover and different rainfall types on surface runoff and sediment yield were analyzed. The effects of different herbaceous plants on surface runoff and sediment yield control were proposed, and the soil and water conservation benefits of each herb were summarized. The results showed that the effects of different herbaceous plants on surface runoff have in common, and the surface runoff increases with the increase of rainfall. When the rainfall reaches the peak, the runoff depth and runoff of the four vegetation plots also peak. Under the conditions of moderate rain and heavy rain, when the rainfall intensity is 2, the vegetation plot reduction rate peaks except for the control group. In the heavy rain environment, when the rainfall intensity is 0.4, the vegetation plot reduction rate except the control group peaks. Vetiver has the best effect on reducing runoff, followed by Cassia Cassia and Bermudagrass, indicating that vetiver can promote water infiltration and reduce surface runoff compared with Cassia and Bermudagrass under different rainfall conditions. Loss. The relationship between rainfall characteristics and runoff, sediment yield, runoff reduction rate, sediment yield and regression relationship are proposed.

Key words： rainfall characteristics ; runoff; sand production benefit; reduction effect

目 录

1 引言....................................................................1

1.1 研究目的和意义........................................................1

1.2 植被对产沙影响研究进展...............................................2

1.3 降雨特征对地表径流影响研究进展........................................3

1.4 植被对地表径流影响研究进展........................................4

1.5 本研究主要解决的问题........................................4

2 研究方法................................................................... 5

2.1 研究区概况...................................................7

2.2 研究方法...................................................9

3 结果与分析.................................................................10

3.1 全年降雨特征.......................................................10

3.2 典型日降雨特征......................................................12

3.3 不同降雨条件下产流过程随降雨的响应..................................13

3.4 不同降雨条件下不同植被对径流的削减分析..............................14

3.5 产沙过程对降雨的响应................................................15

3.6 植被对产沙效益的响应.................................................16

3.7 产沙量和降雨强度相关性分析...........................................17

3.8 不同降雨条件下不同植被对径流的整体削减效益...........................17

4 结论与讨论.................................................................18

4.1 结论.......................................................18

4.2 讨论......................................................18

致谢........................................................................19

参考文献.....................................................................20

1. 引言

1.1研究目的和意义

土壤水是指自地面向下至地下自由水面以上的土壤层中的水分，处于地球表层大气圈、水圈、岩石圈和生物圈交界处，是联系大气降水、地表径流和地下水的纽带，在“四水”转换过程中起重要作用，是陆地水文循环的一个重要变量土壤水分的研究是研究降雨入渗产流过程的关键，作为降雨入渗产流这一过程的重要变量，在降水分配中起决定性作用。土壤水作为土壤的重要组成成分，是植物生长的必要条件之一，并影响着土壤特性，同时土壤水也是水资源的重要组成部分之一，对地表径流的产生、土壤侵蚀、植物生长、洪水的发生及地表物质再分配的过程具有重要影响。

伞房决明、香根草、狗牙根均是多年生但根系长短不同的植被，具有优良的水土保持效益，本研究在南京市溧水白马实验基地的径流小区进行，以伞房决明、香根草和狗牙根为研究对象，有助于揭示天然降雨对土壤侵蚀的作用方式、产流与产沙的之间的相互作用与联系，本课题来源于《基于水量平衡的不同深浅根系草本植物对径流组分影响机制研究》 (16KJA220003)，该研究不仅有助于丰富溧水地区土壤水力侵蚀研究的内容，而且还能深化对该地区坡面土壤水力侵蚀规律的认知，为建立土壤水力侵蚀预报的模型提供了一定的数据基础，同时对为当地坡面水土流失的防治有重要科学价值。