Professor Yang Changming, Tongji University
Prepared by Zhang Jiefeng, Nanyang Technological University
UniversityChaohu Lake is located in the center of Anhui Province of China, lying between the Yangtze and Huai rivers. With a surface area of about 770 km2 and an average depth of 2.69 m, it is one of China’s five largest freshwater lakes. There are 33 rivers that directly or indirectly flow into the Chaohu Lake, making the entire lake basin a rich water resource (~ 53.6 × 108 m3).
Prof. Yang pointed out that the population living within the lake basin area goes beyond its optimum environmental capacity. Fueled by rapid urbanization, the water quality in Chaohu Lake has been markedly deteriorating (IV-Grade level) during the last decades. Water pollution in the lake was mainly attributed to urban construction, industrial development and agricultural discharge. The total phosphate and total nitrogen were detected as two major pollutants in the lake. Cyanobacteria blooms break out during summer and autumn nearly every year. In 2013, for example, the phytoplankton density was found to vary from 17.2× 107 to 47.9× 107cell/L, containing 118 different species including diatoms, dinoflagellates, cyanobacteria, green algae, euglena and cryptomonas. A total of 24 species of zooplankton rotifer and 32 species of crustacean plankton were also found in the lake, and the average biomass of benthic animals was 19.5 g/m3.
In the ascent of water shortage and health awareness, local government has begun to make efforts to improve the current water resource management practice in a more sustainable way. An ultimate goal has been set to restore the environmental capacity and ensure water safety within the Chaohu Lake basin area. These efforts mainly include scientific urban planning and industrial structural adjustment and upgrade. New wastewater treatment plants have been built or upgraded to protect the rivers from being polluted. Integrated prevention and control approaches have also been adopted to control non-point pollution in rural area. From a holistic perspective, the local government also promotes “low-impact development” (LID) and emphasizes eco-prevention and restoration along with economic growth.