Potential Low-impact Development Area Arid Areas Hydrological Modeling And Rainwater Resource Utilization

The construction of sponge cities,low-impact development(LID)measures and new rainwater management concepts have been integrated into the city's development,construction,planning and design.Taking the Rose Community of Guyuan City as an example,based on the measured data and SWMM model simulation,this article analyzes the improvement effect of the Rose Community on the rainwater problem before and after the construction of LID measures.A further improvement plan was proposed to clarify the effect of a specific single measure change on the rainwater problem in the community,and the utilization method and utilization potential of the rainwater resources of the Rose Garden community were determined.The main research results are as follows:(1)Analyze the precipitation characteristics of the sponge city demonstration area in Guyuan City.The 24-hour maximum precipitation in the Sponge City Demonstration Area of Guyuan City showed an insignificant upward trend;from 1985 to 2019,the annual average precipitation was 453 mm,with large inter-annual variations.The rainfall types were mainly light to moderate rain,heavy rain and storm.Occurs from July to September.(2)In the SWMM model,the dynamic wave and the low point division method of the water catchment are used for the simulation of the Rose Garden community.The model was calibrated and verified by the measured pipeline runoff data.The results showed that the Nashi-Sutcliffe efficiency coefficients(ENS)of all outlets met the model indicators,and the simulation of the Rose Garden community was reasonable.(3)Analyze the current situation of rainfall and runoff in the community before and after the construction of LID measures.The current LID measures can delay the flood peak by 0?4 min;reduce the peak flow by 1.18?14.07%;increase the runoff control rate from 23.26?48.31%to 29.12?56.24%;only improved the overflow situation of the overflow point on the southeast side of the community under the rain once every 10 years.And propose three further renovation plans:roof development,pavement renovation and grass renovation.Compared with the current development measures,roof development,pavement reconstruction and grassland reconstruction can further delay flood peaks by 0?3 min;reduce peak flow by 2.98?64.97%,0.18?36.13%and 0.18?16.54%;runoff control rate is increased to 59.04?80.04%,32.18?70.36%and 35.91?61.96%.As the rainfall return period increases,the runoff control rate keeps decreasing.(4)The utilization potential of rainwater resources under the transformation of 4 kinds of LID in Rose community is analyzed.Under the design rain conditions of different return periods,the rainwater storage capacity of the four LID transformation scenarios of Rose Community is between 71.35?491.04m3.Rainwater storage can satisfy 640 residential vehicles for washing 640 vehicles;it can save 1.50?8.22 days and 0.85?6.66 days for road spraying and green irrigation water in the community.