摘要
为进一步揭示分布式水文模型子流域划分对径流和输沙量模拟的影响,以东南沿海桃溪流域为研究区,构建日尺度产流产沙的AnnAGNPS模型,基于9种不同临界源面积(critical source area,CSA),分析了不同子流域划分对输入参数空间聚合的影响,并设置7种组合情景,分别从年和日尺度,定量区分了地形与土壤/土地利用参数的空间聚合对产流产沙过程的影响。结果表明:1)随着CSA取值的增加,地形、土壤和土地利用类型在空间上存在明显的聚合。2)土壤/土地利用参数空间聚合导致年平均径流量和输沙量减少,且对输沙量影响更显著;地形参数的空间聚合导致年输沙量减少,但对年平均径流量无显著影响。3)地形参数的空间聚合造成的洪峰流量增加、峰现时间提前,是影响日径流过程变化的主要因素。4)土壤/土地利用参数的空间聚合对多年平均最大1 d、连续最大5 d输沙量的影响随着聚合程度的增加而显著下降,而地形参数的空间聚合造成日输沙过程峰值的出现时间提前。
The parameter spatial aggregation has significant impacts on the results of Annualized Agricultural Nonpoint Source Pollution model (AnnAGNPS). Parameter spatial aggregation mainly includes spatial aggregation of topographic (T) parameters and soil & land use (SL) parameters. The previous studies mainly focused on the coupling impacts of the 2 kinds of parameters’ spatial aggregation on the hydrologic process, lacking the separate impacts of the 2 kinds of parameters’ spatial aggregation on the hydrologic process in different time scales, and the comparison of the impacts of 2 kinds of parameters’ spatial aggregation on hydrologic process. The objective of this study was to distinguish the impacts of T parameters aggregation and SL parameters aggregation on the simulation results of the AnnAGNPS. Taoxi watershed which is located in the southeast of China was selected as the study area. Based on the sensitivity analysis of parameter by differential sensitivity analysis (DSA) method, the AnnAGNPS model with the daily time step was set up. Nine discretization scenarios including 15, 30, 50, 70, 100, 150, 200, 250 and 300 hm2 were established, and 6 topographic indices (i.e., channel length, slope length of subbasin, average slope of channel, maximum gradient of channel, average slope of subbasin and maximum gradient of subbasin) and the areas of different soil and land use types were calculated to evaluate the impact of cell division on the parameter aggregation. And then 7 combination scenarios were carried out to evaluate the impact of T and SL parameters spatial aggregation on runoff and sediment yield at annual and daily time scale, the scenarios T15SL15, T15SL50, T15SL100 and T15SL300 with the same T parameters aggregation were used to analyze the effect of SL parameters spatial aggregation on hydrologic process, and the scenarios T15SL300, T50SL300, T100SL300 and T300SL300 with the same SL parameters aggregation were used to analyze the effect of T parameters spatial aggregation on sediment yield and run
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2016年第8期127-135,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(41301031)
福建省科技厅重点项目(2013N0013)
