Analysis Of Rainwater Collection,Storage And Utilization In Suburban Areas

In recent years,due to the rapid development of society and economy,the contradiction between the supply and demand of water resources in China has become increasingly prominent,especially the problems of large agricultural water consumption and low efficiency.Precipitation is an important source of replenishment of terrestrial water resources,so rainwater resources have irreplaceable characteristics,and it is necessary to study the efficient use of rainwater resources.Aiming at the problems of shortage of water resources and low rainfall utilization rate in Hecun Village,Lingjingdian Township,Yangqu County,Shanxi Province,this paper studies the rainwater accumulation and utilization in agriculture,analyzes the precipitation characteristics of Yangqu County,and calculates the Lingjing of Yangqu County.Rain collection potential of Hexiang,Lingjingdian Township;and the water demand of crops under different years was calculated using facility tomatoes as an example.The purpose is to provide guidance and theoretical basis for improving the utilization rate of precipitation resources in experimental areas and similar areas,and conserving the rational allocation of groundwater sources and water resources,so as to form an efficient utilization model of rainfall accumulation in dry areas.This article mainly draws the following conclusions:（1）The annual average precipitation in Yangqu County is 441.3mm,which has a certain potential for rainwater collection.Inter-annual precipitation changes frequently,with a trend of increasing year by year,but it is not obvious.It is found from the run-length analysis that the drought and flood in this area are persistent,and the frequency of continuous high years is higher than that of continuous dry years.The year 2006 was a sudden change in rainfall from less to more,and the period of change between high and low in 45 years was about 11years.（2）May to October is the best time for rainwater collection.75.9%of the year’s precipitation is concentrated in June to September,with the most precipitation in August,and the largest rainfall in mid-August,at 40mm.There is very little precipitation in winter.The precipitation in Yangqu County changes seasonally and is distributed.It is more concentrated,but the heterogeneity is decreasing year by year.On average,there are 68 rainy days per year,and heavy rains occur on average every 5 years.（3）The greenhouse water in the test area meets the farmland irrigation water quality standards in terms of the measured indicators,and is more suitable for farmland irrigation.The theoretical potential of the rainwater harvesting project in the experimental area during the dry season（P=75%）is 3.64×10⁵m³,the achievable potential is 2.29×10⁴m³,the actual potential is 1.68×10⁴m³,and the field crop water demand is 3.26×10⁴m³.The theoretical scale of the calculated sedimentation tank is 254m³,and the theoretical volume of the reservoir is 8842m³.The forecast model and query table for the rainwater harvesting project in the greenhouse have been established.The design elements of each project can be determined through inquiry and calculation.（4）The daily reference crop evapotranspiration ET₀outside the shed and the reference crop evapotranspiration ET_0棚inside the shed are calculated,and the relationship between the two is cubic:Y=-0.087X³+1.130X²-3.487X+4.606;the long series tomato early and full growthET_0棚it showed a trend of decreasing first and then increasing,showing a slight downward trend in the middle period of growth,and showing a slight upward trend in the later period of birth.The water consumption of greenhouse tomato Aoguan 8 in each growth period is greater than that of Tomato Yijia Fanwang,and the output is more than Yijia Fanwang,but the water utilization rate is lower than that of Yijia Fanwang.The crop coefficients of tomato in the greenhouse under film drip irrigation were0.34,0.91 and 0.48,during and after the growth of the tomato,respectively.（5）Under the condition of long series full irrigation,the satisfaction rate of water harvesting in greenhouse tomato is 0.77,0.66 and 1,respectively during the growth period of tomato,and each greenhouse can store at least about 12m³ of water in advance,which can also appropriately reduce the irrigation quota in the middle growth period.If the rainwater collected from all the collecting surfaces in the test area is used for greenhouse cultivation,it can fully meet the local tomato planting stubble.