Study On Planting Soil And Vegetation Under The Optimal Control Of Rainwater Based On The New Planting House

In the process of urbanization,there are a series of problems,such as urban non-point source pollution,urban waterlogging,urban heat island effect and so on.Sponge city construction is a preferred scheme in the discussion of urban sustainable development path.In many forms of sponge city construction,planting roof is an important means.Planting roof can not only improve the pollution and waterlogging caused by rainwater,beautify the environment,but also help realize energy conservation and emission reduction,make up for the lack of urban green space,and has good ecological,economic,social and cultural benefits.The research and practice of planting roof at home and abroad can effectively promote the development and application of planting roof.However,the widely used traditional planting roof has limited the further development of roof greening due to its relatively complex structure and high maintenance and repair costs.In this study,a new planting roof module with simplified structure is proposed in order to reduce the roof load and maintenance,form an efficient water storage and pollution interception structure,configure the planting matrix suitable for the new planting roof,select the plants that are coupled with the soil and are suitable for hot summer and cold winter areas,and study and analyze the physical and chemical properties of soil and plants in the new planting roof module,as well as the impact on the rainwater amount,water consumption,water consumption and other factors Water quality control effect.In the study of planting soil,the microstructure,mineral composition,acidity and sugarcane content of soil of new type planting roof module were determined and analyzed by setting different soil a(humus soil: vermiculite: ceramsite: rural soil =5:2:1:1),soil B(humus: activated carbon: ceramsite: rural soil = 5:2:1:1),and soil C(humus: Cinder: ceramsite: rural soil = 5:2:1:1)The results showed that soil a was the most fertile,the soil pH was moderate,the plant growth was most suitable,the soil material energy metabolism,soil fertility,ecological environment quality,physical properties improvement and erosion prevention effect were the best.In the study of planting vegetation,through planting Sedum lineatum and Sedum sarmentosum in soil a,soil B and soil C of the new planting roof module,without watering for 40 days after 2 months of plant growth,the drought stress research wascarried out,and the relative water content,relative water deficit,water retention change,chlorophyll content and other indicators of plants were measured and analyzed The water content and proline content of grass leaves were higher than those of Sedum lineatum.In the same roof module,the malondialdehyde(MDA)content is higher than that of Sedum sarmentosum in the same roof module.Based on the above analysis,the adaptability of Sedum sarmentosum to arid environment was stronger than that of Sedum formosana.In the study of rainwater retention control effect,the blank control of soil a without vegetation was constructed,and artificial rainfall with return period of 10 a and50A was carried out on the new planting roof module.The conventional water quality indexes such as runoff generation delay time,runoff yield,detention rate,total nitrogen and ammonia nitrogen were measured and analyzed.For the same planting roof module,when the rainwater intensity increased,the planting roof stagnated The effect of rainwater and water purification is weakened.In soil a,soil B and soil C,when the soil ratio is the same,the rainfall runoff delay time and rainwater retention rate of Sedum chinense planting are higher than those of Sedum sarmentosum,while the rainwater runoff of Sedum chinense planting is lower than that of Sedum sarmentosum.In the study of rainwater quality control,when the return period is 10 a and 50 a,the contents of total nitrogen,ammonia nitrogen and COD in the rainwater effluent without vegetation in soil a are higher than those with vegetation.Due to the interception effect of vegetation and the coupling effect with soil,the effect of planting plants on rainwater retention and purification is better.Under the same rainstorm intensity,when planting plants,the indexes of each new planting roof module have no regular change,and the value difference is not obvious.Under the same planting soil thickness,soil proportion and plant species have no obvious influence on rainwater retention and water purification.Through the study of the new planting roof,we can conclude that the structure of the new planting roof is simplified,the load is reduced,and it is easy to assemble and maintain free.Through the research on the physical and chemical properties of soil and plants,as well as the rain control ability of the new planting roof,we can find out the most suitable soil proportion for plant growth and the most maintenance free plant species,which can provide the practical application and promotion of the new planting roof Theoretical basis.