一种消减内涝的新方法——城市绿地吸纳

A new method for reduction of waterlogging hazard——soaking with green area

为缓解城市内涝日益频发的困境,减轻由此引起的经济损失,提高城市生活水平,以城市内涝的研究现状为基础,提出一套在城市绿地区域设置多孔吸附层进行消减城市内涝的新方法。推导了该方法消减内涝的潜能模型,并对该方案的关键设计技术参数进行了研究。利用有限元方法模拟了10 m自然水头作用下吸附层对雨水的吸附和解吸能力,并以煤渣为例,研究了其对水分和磷等污染物的吸附能力,从细观孔隙结构角度揭示了煤渣吸附雨水和污染物的机理。结果表明,160 m3的吸附层的稳定吸附量约为28 m3,其吸水过程约为0.8 h,煤渣吸附层可以达到35 m3/h的消减能力,而且对污染物具有较强的吸附能力,不仅能有效的减小城市内涝发生的可能性,而且能避免含磷雨水流入地下水使地下水富营养化,从而论证了通过改造绿地消减城市内涝的方法的可行性和创新性。

In order to ease the plight of increasingly frequent city waterlogging, reduce the economic losses and improve the living standards of people, based on present waterlogging research, a new waterlogging reduced method which sets one porous adsorption layer in the green area region is put forward. A waterlogging-reducing model is proposed, and the key design parameters are determined. The water adsorption and desorption process in the adsorption layer under 10 m natural water head is simulated using the finite element method. In addition, taking coal residue as an example, its ad- sorption capacity for moisture and phosphorus pollutants is studied, and the absorbing mechanism of water and pollutants is revealed from the microscopic pore structure aspect. The results show that 160 cubic meters coal residue layer can absorb 28 cubic meters of water steadily in 0. 8 hours at the speed of 35 mZ/h to reduce the possibility of city waterlogging, and it has the long-term adsorption capacity for pollutants to keep out rainwater that could carry phosphorus into the water table, which proves that it is feasible and innovative to reduce waterlogging by green area.