Experimental Study On Impact Of Landscape Structure Of City Underlying On Rainfall Infiltration In Different Precipitation Time Condition

Urban underlying surface is essential to the existence and development of our human being, and it is also the summation of urban surface. But with quick development of economy, city underlying surface is changing profundity, too. In all, manifold of city building behave most evidently, which straightly affect rainfall infiltration of city. On one hand, which bring conflux time shorten and the earth's surface track events increase, and bring a great many stress, in rainstorm season, make lake and river flow; on the other hand, valuable water resource go directly into river, city can't use, make many cities be short of water in our country; Besides, lead to the earth's surface water condition different from nature condition's, and affect on the earth's surface heat characteristic and increase city heat island probability. But rainfall time is an important factor to infiltration of city underlying surface. So city with different rainfall time how to seek the best city underlying surface space structure have far-reaching realistic significance.In this paper, the author use lab simulation rainfall equipment to simulate landscape structure of city underlying surface and rainfall, study on the relationship of landscape structure and rainfall infiltration on different rainfall time condition. The author make rainfall time 1min,1.25min,1.5min,2min,2.8min,3min,3.3min,4min,5min,6min .Changing density,shape,evenness and separation of staunch patch , menstruate rainfall and calculate rainfall infiltration. Analyze data come out conclusion: when rainfall time is same ,density,shape,evenness and separation of staunch patch all have effect on rainfall infiltration, but effect of density is most, shape,evenness and separation take second place. When rainfall time is different, at the beginning of rainfall, infiltration is 100%; when rainfall time go on larger, rainfall infiltration distinctly cut down; after rainfall time is a certain given numerical value, infiltration don't change with extending of time, but tend to given steady numerical value.