Runoff Volume Reduction Using Green Infrastructure

Exploring public attitudes toward implementing green infrastructure for sponge city stormwater management

Sponge city stormwater management (SCSM) strategy in China aims for sustainable stormwater handling. While many studies have examined the technical aspects of sponge city green infrastructure (SCGI), few have explored public perspectives. This study sought to understand public perceptions, the perceived value of SCGI's ecosystem service benefits, and the potential for diverse financial compensation methods in sponge city construction. A survey conducted in five Northeastern Chinese cities, involving 1,534 participants, was analyzed using descriptive statistics and logistic regression. The findings reveal no significant correlation between socio-demographic factors and understanding of stormwater management, indicating the concept's broad accessibility. Public valuation of ecosystem services showed clear priorities, and factors like homeownership and flood experiences significantly impacted the valuation of specific services. Moreover, the study identified a generally positive public attitude towards investing in SCSM, particularly through stormwater fees, underscoring the viability of diverse funding mechanisms. These insights are pivotal for policymakers and urban planners in formulating sustainable and resilient urban water management strategies.

Evaluation of comprehensive benefits of sponge cities using meta-analysis in different geographical environments in China

With the rapid progress in urbanization, frequent urban waterlogging and non-point source pollution are threatening the living and health of human beings. Sponge city construction has become an effective means to curb urban waterlogging. Although related studies have explored the comprehensive benefits of sponge cities, few studies have been conducted on the effects of different geographical environments on runoff control and suspended solid (SS) removal. Based on 76 cities with sponge cities in China, this study used the meta-analysis method to evaluate the relationships of climate, terrain, underlying surface conditions, and construction area with the increase in the total annual runoff control rate and SS removal rate. The results reveal that the runoff control benefit can be significantly improved by sponge cities under the combined conditions of average annual precipitation of approximately 1000 mm, high fractional vegetation cover, sufficient soil fertility, a terrain slope i of ≤2%, and a permeability coefficient of strata of 100-200 m/d, especially in northern China, where the weight representing the quantity of comprehensive benefits was calculated to be 25.5%. In addition, the study results assist in reforming unfavorable geographical environments in the construction of sponge city, thus providing more effective solutions for tackling SS pollution. The most significant benefits of SS removal were obtained in north central China, where the weight was 21.4%. This study comprehensively investigated the effects of geographical environmental factors on the comprehensive benefits of sponge city reflected by the improvement in the total annual runoff control rate and the SS removal rate. The results will provide guidance for the planning and design of global sponge cities and effectively optimize the practice, scale, and location of existing construction based on specific geographical environments.

Method of Planning Repairs of the Installation including Building Waste

Repairs of water supply, sewage and central heating installations in residential buildings should be carried out systematically. However, very often, renovation dates are postponed, which results in installation failures. The failures of water supply, sewage and central heating installations, due to the currently used methods of masking them and running them as under-plaster and under-floor installations, are always connected with the damage and necessity of reconstruction of the building elements. As a result, renovation work has to be carried out to a greater extent and the amount of construction waste is much greater. The analysis of different renovation strategies of water supply, sewage and central heating systems in residential buildings made in traditional technology has been carried out. The article presents the results of the research on the effects of the postponement of the renovation works on the changes in the technical condition of the building and on the scope of renovation works. The aim of the research is to develop a method for planning repairs of the installation taking into account optimization of the amount of construction waste. The aim of the research is also to answer the question: To what extent does the postponed repair of water and sewage installations influence the amount of construction waste? In the proposed method, the Prediction of Reliability according to Rayleigh Distribution (PRRD) model is used. The results of the research indicate the necessity of conducting the renovation works of the installation in a timely manner due to the increasing amount of construction waste and the introduced reduction of its amount with the increase of the recycling rate.

Influence of storms on the emission of pollutants from sewage into waters

During heavy precipitation, chemical and biological pollutants from urban and agricultural areas enter the waters from storm overflows as a result of infiltration and inflow, as well as via uncontrolled outflows from water treatment plants. Infiltration and inflow of rainwater into sewers is an especially popular and major worldwide problem. Climate forecasts indicate changes in climatic conditions towards an increase in the intensity and frequency of torrential rainfalls. It may therefore be assumed that the negative impact of rainwater on water quality will increase. This article attempts to address the question of the impact of pollution from wastewater introduced into water during rainy weather to the receiver. The assessment of the impact of rainfalls on a receiver was carried out on the basis of a simulation of pollution loads from sewage introduced into a river by storm overflows based on data from monitoring the amount of rainfall and simulating the operation of storm overflows using Environmental Protection Agency Storm Water Management Model (EPA SWMM). The obtained results were compared with the pollutant loads discharged at the same time from the sewage treatment plant (STP). In addition, the article assesses possible improvement solutions to reduce the negative impact of storm overflows on water.

Urban Green Space Arrangement for an Optimal Landscape Planning Strategy for Runoff Reduction

Increased impervious surfaces due to urbanization have reduced evaporation and infiltration into the soil compared with existing natural water cycle systems, which causes various problems, such as urban floods, landslides, and deterioration of water quality. To effectively solve the urban water cycle issue, green infrastructure using urban green space has emerged to reduce runoff and increase evaporation. It has the advantage of restoring the water cycle system of urban areas by complementing the failure of conventional stormwater treatment systems. However, urban areas under high-density development have limited green space for stormwater treatment. Hence, it is necessary to efficiently utilize street trees and small green spaces to improve the urban water cycle through green space. In this study, we simulated different green space distribution scenarios in the virtual domain to find the optimal strategy of green space planning. Compared to clustered scenarios, dispersed green space distribution scenarios and placing green space downstream were more effective in reducing the runoff amount. The paper provides insights into the considerations for determining green space spatial plan and zoning regulations for stormwater treatment by green infrastructure.