【摘要】 运用水文模型DRAINMOD模拟了1988-2007年西安市城市土地利用变化对降雨径流产生的影响,通过DRAINMOD模型探讨了降低城市地表径流、增加雨水入渗的调控措施。结果表明:西安地区透水地面的年径流系数为0～0.414,不透水地面的年径流系数在0.677～0.844之间变化;土地利用类型、土壤入渗能力以及降雨强度是影响城区降雨-径流关系的重要因素;当透水与不透水地面比例接近1∶1时,城区综合径流系数达到0.8以上。分析结果显示,通过增加透水地面下凹深度的建设形式来蓄渗雨水可有效增加雨水入渗量,削减地表径流水量,但此类滞留系统对24h最大暴雨的作用有限。更多还原

【Abstract】 Based on the model of DRAINMOD for water balance calculation on the impervious surface,then the different patterns of rainfall excess on the pervious and impervious surfaces were analyzed from 1988 to 2007,and finally the viable options for reducing urban runoff and increasing rainfall infiltration through model simulation were discussed.The results showed that the annual runoff coefficients ranged from 0 to 0.414 on the pervious surface and varied from 0.667 to 0.844 on the impervious surface in Xi’an over the 55 year simulation period.The land use,soil infiltration capacity and rainfall intensity were major factors affecting the rainfall-runoff relationship.When the area ratio of permeable to impermeable surface was less than 50%,the runoff coefficient would reach above 0.8.Increasing the depth of the permeability could increase runoff infiltration,and had significant reduction of surface runoff,but it had limited effect on reducing runoff from maximum 24-hour storm.更多还原