摘要
采用间隔覆盖技术,利用室内人工模拟降雨实验对间隔覆盖塿土坡面产流动态变化过程进行研究。选取对坡面产流影响的主要因素坡度、降雨强度、覆盖面积比,通过正交试验设计,采用人工降雨的方法,探讨各因素对坡面产流的作用效应。结果表明,起始产流时间在各坡度间差异不明显;起始产流时间随雨强增大而减小,不同覆盖面积比条件下产流起始时间不稳定。当降雨强度和覆盖面积比一定时,累积径流量随坡度增加的趋势呈现一定不连续性,存在一个临界坡度;当覆盖面积比和坡度一定时,累积径流量不仅随雨强增大,而且与降雨历时呈现显著的线性关系,不同降雨强度条件下产流过程存在明显差别。不同覆盖面积比条件下坡面产流情况主要表现为累积径流量和径流速率均随覆盖面积比的增加而增加;雨水利用率与覆盖面积比及降雨强度等因素密切相关,降雨强度和覆盖面积比越大,雨水利用率越低。间隔覆盖法在降雨强度较小的情况下应用效果会更好。
Alternative coverage strategies were investigated in orthogonal experiments using indoor artificial rainfall. Three main factors（ slope, rainfall intensity and coverage ratio） were selected to analyze variations in runoff dynamics for a Lou soil surface and to obtain a theoretical foundation for practical application. The results indicated that there was no obvious relationship between decreasing runoff initiation time and increasing slope. The runoff initiation time significantly decreased with increasing rainfall intensity. For a fixed slope, the runoff initiation time decreased with increasing rainfall intensity according to a power law relationship. Different coverage ratios influenced the runoff initiation time in a variable manner. For a fixed rainfall intensity and coverage ratio, a critical slope close to 26.8% was observed. The cumulative runoff volume increased with the slope which less than the critical value. Conversely, the cumulative runoff volume decreased with increasing slope which greater than the critical value. For a fixed coverage ratio and slope, a significant linear relationship was observed between the cumulative runoff volume and rainfall duration. The cumulative runoff volume also increased with the rainfall intensity. There were obvious differences in runoff occurrence according to the rainfall intensity. Overland flow varied with the coverage ratio and it could be attributed to increase in the cumulative runoff volume and runoff velocity with increasing coverage ratio. The rainwater utilization efficiency was closely related to the coverage ratio and rainfall intensity, the greater rainfall intensity and coverage ratio was, the lower utilization efficiency was. The simulation results demonstrated that an alternative coverage strategy was better under low rainfall intensity.
出处
《水土保持学报》
CSCD
北大核心
2014年第1期73-78,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(40801100
50179035
50609022)
黄土高原土壤侵蚀与旱地农业国家重点实验室基金项目(10501-177
10501-220)
关键词
覆盖面积比
径流
起始产流时间
雨水利用率
间隔覆盖技术
mulch coverage ratio
runoff
runoff initiation time
rainwater utilization
alternative coverage strategies
