Đánh giá trữ lượng nước mưa thu gom từ mái nhà cao tầng phục vụ bổ sung nhân tạo nước dưới đất cho khu vực Hoàng Mai, Hà Nội

Abstract

Urbanization and rapid population growth have put pressure on water resources and the environment in Hoang Mai District, Hanoi. Increased water demand leads to a decline in groundwater levels, leading to increased ground subsidence and urban flooding. The above problems are also amplified in the context of urbanization and abnormal rainfall due to reduced infiltration supply and increased surface runoff. This study focuses on evaluating the amount of rainwater that can be collected from the roofs of high-rise buildings in Hoang Mai district and used to artificial groundwater recharge. The study methods include: Identifying and calculating the roof area of ​​high-rise buildings in the study area using Google Earth; Conducting survey and fieldsite measurements to verify the results of calculating the roof area on Google Earth; Calculating the total amount of rain collected from the roof. The results show that 151 buildings with a total roof area of ​​147,544 m2 can be used for collecting rainwater. The amount of rainwater collected from the roofs of 151 high-rise buildings in Hoang Mai calculated according to the average rainfall in the 2013-2022 period is 258,497m3/year, equivalent to 708m3/day. In addition, the amount of rainwater collected from the 151 roofs during a 2-hour rain on May 11, 2021 up to 6197 m3/2h. Therefore, the study proposes a solution to harvest rainwater from rooftops for artificial groundwater recharge using wells to inject rainwater down into the Pleistocene aquifer, which contributes to increasing of groundwater resource for main aquifer, reducing urban flooding and mitigating land subsidence.