建立了适用于栅格单元系统的基于运动波理论的降尺度新安江模型(KWXAJ)。在栅格单元中采用新安江模型计算产流,运动波模型进行坡面汇流演算。模型中,为考虑上游坡地单元入流的径流入渗(run-on)效应,在进行坡地产流计算时,降雨及上游坡面流及壤中出流被同时作为来水输入新安江模型。在运动波模型中,糙率系数依据土地利用方式及洪水量级确定。选取淮河史灌河流域黄泥庄以上集水区域,作为研究区域。用流域历史上的13次洪水过程来率定和验证此模型。研究表明,run-on机制对流域产汇流预测有重要影响,其显著影响流域内土壤蓄水量时空分布,进而改变产汇流机制。数据分析还显示,不考虑run-on机制将导致模拟洪峰滞后。
In this paper, a grid-based kinematic wave Xinanjiang model is developed and the structure of the original Xinanjiang model is downscaled and modified accordingly. The basin is subdivided into raster network. The raster slope and flow vectors are extracted by the software package, DigitalHydro based on DEM. The Xinanjiang model is used for calculating runoff in each raster and the kinematic wave method is used for overland flow muting. In each grid, water input to the model includes precipitation and runoff from the upstream grids to take runoff infiltration (i. e. run-on mechanism) into account in runoff cal-culation module. In the kinematic wave model, the Manning coefficients are determined according to the land cover information and the flood grade. The Huangnizhuang sub-basin with an area of 805 km^2 in Shiguanhe basin, Huaihe River is selected as the studied area. It is shown that the run-on mechanism has an important effect on the runoff prediction and it also affects the spatio-tempomi distribution of the soil water storage. The results show that the predicted flood peak without consideration of the run-on mechanism will be lagged.