Analysis Of Rain Water Conservancy Usage In Typical Situations In Xi’an

According to the actual characteristics of Xi’an, four different areas was chosen in this study, analyzed and calculated rainfall which collected by rainwater collection facilities using Xi’an rainfall data in four different regions, The main contents and conclusions are as follows:1. A typical household in the New Rural was selected as the research object. A typical four-person household with water-collecting area of 200 square meters as example, with daily rainfall data in Central Shaanxi Plain,based of the equilibrium model of day water volume, calculates the feasibility and reliability of household collected garden rainwater as a water source in the new rural. The results show that the optimal volume of rain accumulation tank is 25m3.2. A residential area was selected as the research object to collect the rainwater using green and rainwater storage tanks. The results show that the runoff control rate can reach 80% by using the green to collect rainwater when the green rate reach 36%. A rainwater tank of 500m3 for a 40000m2 residential area can better,which runoff control rate reach 86%.3. Using sunken lawn as the rainwater harvesting facilities to collect the road rainwater In Xi’an. The results show that the infiltration storage efficiency of municipal roads can be influenced by the concave depth of green sunken, width ratio and so on. with the increase of the concave depth of green sunken and the width ratio increases, the infiltration storage efficiency of municipal roads increases. In built-up area of Xi’an municipal road area as example, with the width ratio of 30% and the concave depth 50 mm case, penetration and storage rate can reach 86.27%, average permeability reservoir about 144 million cubic meters of rain a year.4. Collected rainfall in ecological parking. Without changing soil, the cover rate of practices was 7%~30% under different permeability coefficient. In the condition of changing soil, the cover rate of practices was 2%~17% under different permeability coefficient(with controlling 20 mm, concave depth was 5 to 15 cm). The relationship between design rainfall and control rate of total rainfall was calculated in different afforestation rate. Selected a parking as example, the cover rate of practices was 4.8%, the results show that controlled rainfall is 22 mm, runoff control rate is 81%.