# Comprehensive Performance Evaluation of LID Practices for the Sponge City Construction: A Case Study in Guangxi, China

**Authors:** Li Qian, Wang Feng, Yu Yang, Huang Zhengce, Li Mantao, Guan Yuntao  
**arXiv:** [2112.10347](https://arxiv.org/abs/2112.10347)  
**Date:** 2021-12-20  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2112.10347v2/

## Key points

- Sponge city construction is a new approach to urban stormwater management in China
- It uses Low Impact Development (LID) techniques to manage stormwater at the source
- LID techniques reduce urban flooding and non-point source pollution while promoting rainwater resource utilization
- Li Qian and colleagues developed an evaluation system using the Storm Water Management Model (SWMM) and Analytical Hierarchy Process (AHP) method to quantify benefits of different combinations of LID units
- The evaluation system was applied to analyze five LID design scenarios for a sports center project in Guangxi, China with varying locations and sizes of bio-retention facilities, grassed swales, sunken green spaces, permeable pavement, and storage tanks
- The green scenario with 34.5% bio-retention facilities and 46.0% sunken green spaces had the best comprehensive performance in meeting requirements for 75% annual total runoff reduction while achieving good operation performance, rainwater utilization, landscape promotion, and ecological service functions.
- This optimal scenario was adopted for constructing the sports center project.
- The proposed evaluation system can be used not only for optimal selection but also for performance effect evaluation of LID practices in other sponge city projects.
- This study provides valuable insights into how LID techniques can be used effectively in sponge city construction projects to mitigate urban flooding while promoting sustainable water management practices.

## Summary

Sponge city construction is a relatively new approach to urban stormwater management that has gained popularity in China. It involves the use of Low Impact Development (LID) techniques to effectively manage stormwater at the source, thereby reducing urban flooding and non-point source pollution while promoting rainwater resource utilization. Li Qian and colleagues developed a comprehensive evaluation system that uses the Storm Water Management Model (SWMM) and Analytical Hierarchy Process (AHP) method to quantify the benefits of different combinations of LID units. The system was applied to analyze five LID design scenarios for a sports center project in Guangxi, China with varying locations and sizes of bio-retention facilities, grassed swales, sunken green spaces, permeable pavement, and storage tanks. The results showed that the green scenario with 34.5% bio-retention facilities and 46.0% sunken green spaces had the best comprehensive performance in meeting requirements for 75% annual total runoff reduction while achieving good operation performance, rainwater utilization, landscape promotion, and ecological service functions. This optimal scenario was adopted for constructing the sports center project. Furthermore, this proposed evaluation system can be used not only for optimal selection but also for performance effect evaluation of LID practices in other sponge city projects. This study provides valuable insights into how LID techniques can be used effectively in sponge city construction projects to mitigate urban flooding while promoting sustainable water management practices.