| In the early stage of production and construction projects in Beijing,three items of administrative examination and approval should be carried out:"Examination and approval of water resources demonstration(evaluation)report of construction project","Examination and approval of water and soil conservation plan of production and construction project" and "Approval of flood impact assessment report of non-flood control construction project".The three systems were merged in 201 5 and the water impact assessment review system was formally launched.In order to better control the control range of each index in the process of water impact assessment and administrative examination and approval for the early stage of production and construction projects of housing construction,this research carries out the study on production and construction projects of housing construction in Beijing to obtain the data of 8 project research areas.By taking the data as the research objects,using the method of post-project evaluation and establishing a reasonable project evaluation index system.The project post-evaluation of water impact assessment was carried out to the study area,and the following conclusions were obtained:(1)8 Housing construction projects for field surveys in this study with the the total control of soil and water loss is 99%on average,the average rate of disturbed land remediation is 99%,the average slag retention rate is 98%,the average soil erosion control ratio is 1.1,the average restoration rate of forest and grass vegetation is 99%,and the average forest and grass coverage rate it's 36%,All of them meet the national first-level;The average greening rate for slopes is 99%,the average utilization rate of earth and rock is 99%,the average utilization rate of topsoil is 100%,the average ratio between temporary land occupation and permanent land occupation is 9%,the average rainwater utilization rate is 97%,and the construction rainfall is utilized The average rate is 91%.and the average rate of hardened ground control is 23.31%,which is in line with Beijing Municipality's local standards.The soil erosion in the project construction area has been basically controlled,the quality of water and soil resources,as well as the natural ecological environment in the project area have been effectively maintained and improved,which effectively protect the ecological benefits of the project area.(2)The construction areas of this investigation project are all equipped with the water gauge according to the relevant regulations in the technical specifications.The layout of rainwater sewage pipeline has been constructed basically in accordance with the relevant standards in the design of the water impact assessment report,and the project lacking reclaimed water source has reserved the corresponding reclaimed water pipeline system.Due to the difference between the actual number of occupants and the expected number of occupants,as well as the impacts of changes in the green space area after the completion of the project construction area,the actual water use will have certain discrepancy with the predicted value after completing the project construction.(3)The project construction areas are all in line with the requirements of the concave green in the green area accounting for more than 50%in" Engineering Design Specification of Rainwater Control and Utilization "(DB11/685-2013);the hardened ground penneable pavement rate is higher than 70%;each project should have the rainwater storage tanks with a capacity larger than 30m3,and the actual runoff volume of each project construction area are all in accordance with the expected standards of water impact assessment.Through the hydrological calculation,under the condition that the total amount of rainwater drainage and storage in the project construction area is constant,the micro-topography greenbelt with the function of rainwater collection of the average 1hm2 can replace the concave greenbelt of 1.15hm2 in the project construction area. |
PDF Full Text Request