Research And Application On Calculation Model Of Urban Water Logging Water Accumulation

The whole model of runoff producing,conflux and water accumulationof urban inland inundation,the model is the basic theory of the city flood controlplanning, design theory drainage network, water accumulation pointsgovernance.According to the national conditions of our country,to solve urbanwater accumulation need to replace the urban drainage system is unrealistic, theregional flood control capacity of the city is different, a city of wateraccumulation formed mainly in the local point region, study area water depth ofthese points, has great significance for the treatment of urban wateraccumulation.Aiming at this situation, in the runoff calculation model on the basis ofprevious studies, the addition of water accumulation calculation model, theestablishment of hydrocephalus and other aspects of the model of the theory ofurban storm water runoff,conflux and water accumulation proceedingcalculation and analysis. By testing and application of theoretical arguments andmodels, take the following major findings:(1) Through the analysis of a variety of urban storm runoff calculationmethod of comparison, the city for the impervious surface area by a variety ofunderlying surface composition, can be used to calculate runoff coefficientmethod, different underlying surfaces corresponding to different factor. Runoff coefficient method to calculate runoff urban impervious surface area calculationmethod is simple and the results more accurate; permeable surface area of thecity for the calculation using infiltration equation method.(2) By the confluence of urban storm calculation method of surfaceanalysis and comparison, we use the instantaneous unit hydrograph method tocalculate the confluence of urban surface. Instantaneous Unit net method meansrain on the infinitesimal time evenly distributed watershed basin formed by theoutlet section of the surface runoff, reflects the convergence characteristics ofbasins, the number of parameters is littlel, easy to theoretical studies andregional relations storm flood comprehensive.(3) The computational complexity of network the confluence, we usecalculate and consult the results of previous studies, the coefficients arecalculated by intercepting rainfall storm water inlet, closure efficiency andrainfall intensity, width, and vertical gradient of the road, cross slope, surfaceroughness, roads length, gullies form and size. Beyond gullies called Beyondrainfall in low-lying downstream together to form water accumulation.(4) The amount of water accumulation is equivalent to a smallreservoir volume calculations, more than just water drainage capacity of storagein the ground into depression but is not stored in the reservoir, here is the gulliesdraining flood.(5) The establishment of a calculation by surface runoff, surface theconfluence, network the confluence, urban water accumulation constitute amodel. Validation and application of the model, the results show that thestructure of the model is reasonable and realistic calculation results, not only canmore truly reflect the urban runoff hydrograph, but also to calculate the wateraccumulation depth of the water area of the city water accumulation governanceprovide a theoretical basis, so that the entire city of water accumulationgovernance, from whole city governance becomes water accumulation points, saving the economy.