Shaw L. Yu

Advances in LID BMPs research and practice for urban runoff control in China

China is at present experiencing a very rapid urbanization process, which has brought a number of adverse impacts upon the water environment. In particular, urban runoff quantity and quality control have emerged as one of the key concerns for municipal officials. One of the strategies being considered is the use of a Low Impact Development type of Best Management Practices (LID BMPs) for urban storm water runoff quantity and quality control. In this paper, the situation surrounding urban runoff control in China is reviewed first. Then the conventional strategy and technologies for the construction and management of urban drainage systems are discussed, while exploring their inherent dilemmas. The LID BMPs are then introduced to control urban runoff in the context of urban sustainable water systems. After the comprehensive analysis of the various LID BMPs, the advances in LID BMPs research and practice for urban runoff control in China are investigated and summarized. At last, the difficulties of implementing LID BMPs in China are discussed, and a direction for the future is proposed.

LID-BMPs planning for urban runoff control and the case study in China

Low Impact Development Best Management Practices (LID-BMPs) have in recent years received much recognition as cost-effective measures for mitigating urban runoff impacts. In the present paper, a procedure for LID-BMPs planning and analysis using a comprehensive decision support tool was proposed. A case study was conducted to the planning of an LID-BMPs implementation effort at a college campus in Foshan, Guangdong Province, China. By examining information obtained, potential LID-BMPs were first selected. SUSTAIN was then used to analyze four runoff control scenarios, namely: pre-development scenario; basic scenario (existing campus development plan without BMP control); Scenario 1 (least-cost BMPs implementation); and, Scenario 2 (maximized BMPs performance). A sensitivity analysis was also performed to assess the impact of the hydrologic and water quality parameters. The optimal solution for each of the two LID-BMPs scenarios was obtained by using the non-dominated sorting genetic algorithm-II (NSGA-II). Finally, the cost-effectiveness of the LID-BMPs implementation scenarios was examined by determining the incremental cost for a unit improvement of control.

Development of a multi-criteria index ranking system for urban runoff best management practices (BMPs) selection

Low impact development best management practices (LID-BMPs) are considered to be cost-effective measures for mitigating the water quantity and quality impact of urban runoff. Currently, there are many types of LID-BMPs, and each type has its own intrinsic technical and/or economical characteristics and limitations for implementation. The selection of the most appropriate BMP type(s) for a specific installation site is therefore a very important planning step. In the present study, a multi-criteria selection index system (MCIS) for LID-BMP planning was developed. The selection indexes include 12 first-level indices and 26 second-level indices which reflect the specific installation site characteristics pertaining to site suitability, runoff control performance, and economics of implementation. A mechanism for ranking the BMPs was devised. First, each individual second-level index was assigned a numeric value that was based on site characteristics and information on LID-BMPs. The quantified indices were normalized and then integrated to obtain the score for each of the first-level index. The final evaluation scores of each LID-BMP were then calculated based on the scores for the first-level indices. Finally, the appropriate BMP types for a specific installation site were determined according to the rank of the final evaluation scores. In order to facilitate the application of the MCIS BMP ranking system, the computational process has been coded into a software program, BMPSELEC. A case study demonstrating the MCIS methodology, using an LID-BMP implementation planning at a college campus in Foshan, Guangdong Province, is presented.

China’s Sponge City construction: A discussion on technical approaches

Since 2014, China has been implementing the Sponge City Construction initiative, which represents an enormous and unprecedented effort by any government in the world for achieving urban sustainability. According to preliminary estimates, the total investment on the Sponge City Plan is roughly 100 to 150 million Yuan (RMB) (

Urban watershed management under rapid urbanization

15 to

FIELD EVALUATION OF A STORMWATER BIORETENTION FILTRATION SYSTEM

22.5 million) average per square kilometer or 10 Trillion Yuan (RMB) (

Low impact development and sponge city construction for urban stormwater management

1.5 Trillion) for the 657 cities nationwide. The Sponge City Plan (SCP) calls for the use of natural processes such as soil and vegetation as part of the urban runoff control strategy, which is similar to that of low impact development (LID) and green infrastructure (GI) practices being promoted in many parts of the world. The SCP includes as its goals not only effective urban flood control, but also rainwater harvest, water quality improvement and ecological restoration. So far, the SCP implementation has encountered some barriers and challenges due to many factors. The present paper presents a review of those barriers and challenges, offers discussions and recommendations on several technical aspects such as control goals and objectives; planning/design and construction of LID/GI practices; performance evaluation. Several key recommendations are proposed on Sponge City implementation strategy, Site-specific regulatory framework and technical guidance, Product innovation and certification, LID/GI Project financing, LID/GI professional training and certification, public outreach and education. It is expected that the successful implementation of the SCP not only will bring about a sustainable, eco-friendly urbanization process in China, but also contribute enormously to the LID/GI research and development with the vast amount of relevant data and experiences generated from the Sponge City construction projects.

Hydrologic and water quality performance of a laboratory scale bioretention unit

Recent years have witnessed a trend of rapid urban growth, accompanied by a significant impact on the environment, in many parts of the world. For example, in China, an extraordinary urbanization process has exerted enormous pressures on water resources and the urban environment as well as ecological systems. Protecting the water environment is now one of the most important and pressing issues that demand great attention. Urban watershed management is therefore critically important to the sustainable use of water resources and the protection of valuable eco-systems. The objective of the International Conference on Urban Watershed Management (ICUWM), inaugurated in 1997 at the University of Virginia, is to provide a forum for international professionals to share research and experiences in watershed management practices. The 8th ICUWM was organized and hosted by the School of Environment at Tsinghua University in Beijing, China during September 6–8, 2011 as part of the university’s Centennial celebration activities. Co-organizers and sponsors included the Urban Water Resources Research Council (UWRRC) of the American Society of Civil Engineers (ASCE) Environmental and Water Resources Institute (EWRI), the Urban Watershed Management Branch (UWMB) of the US Environmental Protection Agency (USEPA), the University of Virginia, and the H2-O China. In addition, the Asian Development Bank (ADB) sponsored a parallel “Workshop on Water-Food-Energy Security”, which is a subject of critical importance that intertwined with subjects of the ICUWM. Specific topics for the 8 ICUWM ranged from urban water environment management, such as water sustainable urbanization, lake/river restoration; water environment research, such as planning/design/monitoring of best management practices (BMPs), low impact development (LID), to regulatory and institutional aspects of urban water management. A total of seven keynote speeches and sixty-eight papers from many parts of the world were presented at the Conference. In order to make the significant presentations available to a broader readership; a number of papers were selected and, after the normal peer-review process, published in this issue of Frontiers of Environmental Science & Engineering (FESE). The FESE Editorial Office’s assistance is much appreciated.

A storm event-based approach to TMDL development

A field evaluation of the Filterra ® Stormwater Bioretention Filtration System was performed to: 1) determine removal efficiency information based on field data, which is inherently more variable than laboratory data, and 2) compare the observed field efficiency with the efficiency determined in the laboratory. Inlet and outlet pollutant concentrations from a Standard 6’ × 6’ Filterra ® System (manufactured by the Filterra Division of Americast, Inc.) were monitored between October 19, 2004 and November 22, 2005. The pollutants of interest were total suspended solids (TSS), total phosphorus (TP), total Kjeldahl nitrogen (TKN), and the heavy metals cadmium, copper, lead and zinc. Monitoring data were then evaluated to determine appropriate efficiency ratios. Raw data were first evaluated to determine if they were normally distributed. If so, the efficiency ratio was determined based on the event mean concentrations (EMCs) of the influent and effluent samples. If the raw data were not normally distributed, the efficiency ratio was calculated using the EMCs. Results show the following average efficiency ratios: TSS 85%; TP 55%; TKN 20%; Cu 16%, and Zn 50%. Statistical significance and seasonal variations of the removal efficiency were also examined.

A Planning Tool for Watershed LID-BMP Implementation

Low Impact Development and Sponge City Construction are new paradigm for Urban Stormwater Management. It has become a hot focus in urban water resources research and practices globally. In this context, in order to provide an international forum for stormwater management professionals to present the latest developments, technologies and case studies related to low impact development (LID) and green infrastructure (GI) technology, the 2016 International Low Impact Development Conference was organized and held. The Conference was jointly sponsored by the Water Industrial Society of the Chinese Society of Civil Engineers, the Water Environment Research Institute of the American Society of Civil Engineers and the Chinese Academy of Engineering. Organizers included Tsinghua University, Peking University and Beijing University of Civil Engineering and Architecture. The conference was the very first major gathering of LID/GI professionals in China. It was a timely event, as China had just initiated a monumental effort in sustainable urban development. The Sponge City Construction Plan, released in 2014, announced a new paradigm that calls for the use of natural systems such as soiland vegetation as part of the urban runoff control strategy.The principles of the Sponge City approach are similar to those of the LID/GI technology. Recognizing the limitation of LID/GI facilities in controlling large or less frequentstorm events, the government mandates the integration of green and gray infrastructure. During 2015 and 2016, the Chinese government selected 30 cities as pilot sites under the Sponge City Plan. Each city is to receive 400 to 600 million RMB (