Chongqing to Chengdu on the Yangtze river
A giant megacity looking for water
Chongqing is a huge megacity of more than 30 million people, the largest of the four direct-controlled municipalities of the People's Republic of China. The City is the largest one located upstream the Three Gorges Dam in the Eastern edge of Sichuan Basin, it covers a large area crossed by rivers and mountains. Chongqing is known as a "mountain city" and a "city on rivers", the Yangtze River and the Jialing River meets in the Central City. Here, the climate is subtropical humid, with monsoons influence.
On the Yangtze River, each day, large containers are loaded on cargo ships and sent from Chongqing to various destinations. With abundant natural resources, large deposits of coal, natural gas, and more than 40 kinds of minerals such as strontium and manganese, the area has a long history of heavy industries and manufactures development coupled with a galloping growth in the past decades. The city fostered millions of farmers and migrant workers, and the demand for water supply grew at an average rate of 14% per annum. As a consequence of large-scale industries development, coal burning power plants, and transportation related issues, the city suffered from severe air pollution. Rivers too were polluted because of poor waste management, industries, domestic development and agricultural runoffs dramatically increased the discharges of wastes in the Yangtze River, leading to water supply issues and river water severe pollution.
Since 2004 the Three Gorges Dam 660 Km downstream Chongqing was gradually filled and the situation noticeably worsened. If in the huge reservoir eutrophization threatens surface water quality, the damming reduces the velocity of the Yangtze River upstream, and alters the natural flow regime in the rivers and its tributaries. Because of inappropriate treatment of wastes and wastewater, severe pollution problems aroused in Chongqing area: conflicts between water supply for the City’s needs and polluted effluent discharges in the river. Of course, all this affected the river’s ecology and biodiversity on one hand, and induces frequent water shortages and bottlenecked sustainable development on the other hand.
The municipality, with the help of the World Bank, took radical steps in order to tackle these major environmental issues. They decided to relocate heavy industries - major polluters - to the outskirts in industrial parks with tighter environmental controls. They implemented a new wastewater treatment initiative in the region to radically improve the treatment of both domestic and industrial wastewaters and invested in Waste Water Treatment Plants (WWTP). They implemented an integrated solid waste management and planned to construct modern sanitary landfill areas.
Since 2002, the Sino French Water Development, a Suez Environment subsidiary, and Chongqing national water companies created joint ventures - 5 innovative treatment plants have been built in the area on behalf of joint ventures. EnvIM students visited two Waste Water treatment plants in Chongqing, welcomed by the Sino French Ventures:
- Jiangjiatou WWTP, operating since 2009, the plant treats wastewater from around a million inhabitants. The sludge produced, up to 240 tons per day, after drying is converted into alternative fuel, for use within the plant itself.
- Located 50 km from Chongqing, downstream Yangtze river, the Chongqing Waste water treatment plant is located in the Industrial Park Chongqing Chemical Industrial Park. Fresh Water is pumped from Yangtze, treated for the industrial park water needs in the Water Treatment Plant, the industries waste water is sent back to the WWTP on the same location. Water is discharged 6km downstream compared to the intake of water. The Government encourages the use of bricks from sludge for building industry. In the WTP, a specific process is added for domestic water production (disinfection process after the clean water tank).
Even if, thanks to the costly efforts engaged, the situation is improving in Chongqing, and the Yangtze water quality has improved, pollution in the river and its tributaries in this area remain high and water management improvements are still a priority for the province.
After having spent some times in Chongqing, EnvIM students crossed the Sichuan plain by train to reach Chengdu. This city is located on the Minjiang River, a tributary of the Yangtze River. The Yangtze River and its tributaries flows through the mountains of western Sichuan forming the Eastern part of the Qinghai-Tibet Plateau, and the Sichuan Basin; the province is upstream the great cities that stand along the Yangtze River further to the east; The mild weather is rainy, often overcast and humid in winter, the climate being monsoon-influenced humid subtropical, a perfect place for bamboo and panda ! The giant pandas are a Chinese national treasure and are found only in Sichuan, Shaanxi and Gansu provinces. Students visited the breeding center for giant pandas the “Research Base of Giant Panda” situated a few kilometers from downtown, a rare opportunity to meet baby pandas and other rare and protected animals.
They discovered the famous Dujiangyan irrigation system: 2200 year ago this Dam has been built to preventfloods that threaten the city of Chengdu, flooding the rich and fertile plains. Today it is still draining off floodwater, irrigating farms and providing water resources for more than 50 cities in the province. Mount Qingcheng was the birthplace of Taoism, which is celebrated in a series of ancient temples.
Last stop Haikou
Last but not least, they spent some time in Haikkou, in Hainan Island. This sunny part of China was the main destination of EnvIM 2014 fieldtrip. You can find more information about this trip here.
Past field trips