摘要
空间离散化是分布式水文模型构建的充要条件。在90 mm/h雨强人工降雨试验、三维激光扫描构建微地形数字高程模型(M-DEM)的基础上,基于元胞自动机(CA)模型研究了人工掏挖微地形在5种不同坡度条件下侵蚀发育过程中不同大小格网/元胞的水沙汇集和传递关系,进而提出空间离散化水文响应单元(HRU)的确定方法。结果表明:基于CA模型所确定的5°,10°,15°,20°和25°坡在溅蚀阶段的最佳HRU大小为6 mm,5 mm,6 mm,5 mm,8 mm;片蚀阶段的最佳HRU大小为6 mm,4 mm,6 mm,5 mm,5 mm,细沟侵蚀阶段的最佳HRU大小为4 mm,7 mm,5 mm,6 mm,6 mm,纳什效率系数均接近于1;综合以上,90 mm/h雨强下人工掏挖微地形水蚀模拟最佳HRU应为6 mm。研究提出了一种微地形空间离散化的方法,为微地形尺度水蚀定量化研究提供了一定的技术支撑。
Spatial discretization is a necessary and sufficient condition for the construction of distributed hydrological models.Based on the 90 mm/h rain intensity artificial rainfall test and three-dimensional laser scanning to construct the digital elevation model of micro-topography(M-DEM),and the cellular automata(CA)model,the water-sediment collection and transfer relationship of different size grids/cells in the process of erosion development in the artificially excavated micro-topography on 5 different types of slopes were studied,and then a method for determining spatial discretization hydrological response unit(HRU)was proposed.The results show that the optimal HRU sizes for the 5°,10°,15°,20°and 25°slopes determined by the CA model in the splash phase are 6 mm,5 mm,6 mm,5 mm,8 mm;the best HRU sizes at the sheet corrosion stage are 6 mm,4 mm,6 mm,5 mm,5 mm;the best HRU sizes for the rill erosion stage are 4 mm,7 mm,5 mm,6 mm,6 mm;the Nash efficiency coefficients are all close to 1.Comprehensively above,the best HRU for water erosion simulation of artificially excavated micro-terrain should be 6 mm under the rainfall intensity of 90 mm/h.This study puts forward a method for the spatial discretization of micro-topography,which can provide certain technical support for the quantitative study of water erosion at the micro-topography scale.
作者
张明浩
张鑫
王天宏
徐仪玮
张青峰
ZHANG Minghao;ZHANG Xin;WANG Tianhong;XU Yiwei;ZHANG Qingfeng(College of Natural Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China;Yangling Vocational&Teachnical College,Yangling,Shaanxi 712100,China)
出处
《水土保持研究》
CSCD
北大核心
2022年第1期86-91,99,共7页
Research of Soil and Water Conservation
基金
国家自然科学基金面上项目“微地形条件下黄土耕作坡面水蚀发育过程的三维数值模拟与机理研究”(41371273)。
关键词
空间离散化
水文响应单元
CA
微地形
坡面水蚀
spatial discretization
hydrological response unit
CA
microtopography
slope water erosion
