植被对坡面汇流时间影响的试验研究
Experimental Study on the Flow Concentration Influenced by Vegetation
作者：彭清娥(四川大学 水力学与山区河流开发保护国家重点试验室, 四川 成都 610065)；刘兴年(四川大学 水力学与山区河流开发保护国家重点试验室, 四川 成都 610065)；黄尔(四川大学 水力学与山区河流开发保护国家重点试验室, 四川 成都 610065)；杨克君(四川大学 水力学与山区河流开发保护国家重点试验室, 四川 成都 610065)；赵明辉(四川大学 水力学与山区河流开发保护国家重点试验室, 四川 成都 610065)
Author：PENG Qing'e(State Key Lab. of Hydraulics and Mountain River Eng., Chengdu 610065, China)；LIU Xingnian(State Key Lab. of Hydraulics and Mountain River Eng., Chengdu 610065, China)；HUANG Er(State Key Lab. of Hydraulics and Mountain River Eng., Chengdu 610065, China)；YANG Kejun(State Key Lab. of Hydraulics and Mountain River Eng., Chengdu 610065, China)；ZHAO Minghui(State Key Lab. of Hydraulics and Mountain River Eng., Chengdu 610065, China)
收稿日期：2018-02-28 年卷（期）页码：2018,50(3):185-192
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：植被种类;植被覆盖度指数;坡面汇流时间;人工模拟降雨
Key words：vegetation type;vegetation coverage index;slope flow concentration time;artificial rainfall
基金项目：国家自然科学基金资助项目（51539007）； 国家重点研发计划资助项目（2016YFC0402302）
中文摘要
引发暴雨山洪的主要因素除大气降水特性以外还与下垫面森林植被状况有着密切的关系，流域植被对坡面汇流时间有着直接的影响。目前应用最为广泛的坡面汇流时间公式，以坡面长度、综合糙率、有效降雨强度及坡度的恒定指数形式表征其对汇流时间的影响，而植被对汇流时间的影响是隐含在综合糙率之中，从而无法直接利用有关植被的高精度遥感资料。本研究基于不同下垫面情况下不同坡度、不同雨强的坡面汇流系列试验，深入分析植被对坡面汇流时间的影响，引入植被覆盖度因子，结合统计分析方法，建立植被与坡面汇流时间的关系。研究结果表明：植被的种类（草或灌木）对坡面汇流时间影响存在一定差异，草植被下的坡面汇流时间大于相应条件灌木植被下的坡面汇流时间；植被覆盖度（草或灌木）对坡面汇流时间存在显著影响，坡面汇流时间随植被覆盖度的增大出现明显的增加；降雨强度、坡度对坡面汇流时间的影响也较为显著，坡面汇流时间随雨强及坡度的增大而出现明显的减小；草及灌木植被覆盖度指数随坡度及雨强变化规律基本相似，总体上草植被覆盖度指数略大于灌木植被覆盖度指数。随着雨强增大，植被覆盖度指数减小趋势较为明显；随着坡度变缓，植被覆盖度指数有所增大。本研究将植被因子从综合糙率中剥离出来，便于融合植被遥感数据，从而提高坡面汇流时间的计算精度。
英文摘要
Due to the steep slope of mountainous watersheds and large changes in vegetation,flood responses to rainstorms are complicated.At present,the most widely used formula is the constant index of slope length,effective roughness,effective rainfall intensity and slope.However,the effect of vegetation on the confluence time is implicit in the effective roughness,which makes impossible to directly use the high-precision remote sensing data of vegetation in calculation.In this study,a series of heavy rainfall induced confluence tests under different slopes and vegetation coverage were carried out.By introducing the vegetation coverage factorCand employing the statistical analysis method,the relationship between the flow confluence time on a slope and the vegetation coverage is established.The results showed that the influence of vegetation coverage on the flow confluence time was significant.The flow confluence time increased with the increase of vegetation coverage,and decreases with the increase of rainfall intensity and slope.The flow confluence time under turf vegetation was slightly larger than that under shrubs vegetation.In this study,the vegetation factor was separated from the effective roughness to facilitate the more effective use of vegetation remote sensing data.The calculation accuracy of the flow confluence time on the slope is improved.
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