NATIONAL SCIENCE FOUNDATION
TOKYO REGIONAL OFFICE
The National Science Foundation's (NSF) Tokyo Regional Office periodically receives and disseminates reports on research developments in Japan that are related to the Foundation's mission. It also provide occasional reports on developments in other East Asian Countries.
These reports present information for the use of NSF program officers and policy makers; they are not statements of NSF policy.
Special Scientific Report #02-12 (November 21, 2002)
The following report was prepared by William Y.B. Chang, Senior Program Manager, East Asia and Program in the National Science Foundation's Office of International Science and Engineering. Dr. Chang was an Embassy Fellow at the American Consulate General in Shanghai, China from July 29, 2002 to October 8, 2002. Dr. Chang may be reached at wychang@nsf.gov.
Abstract
Regional urbanization in the Yangtze River Delta has altered the level and type of water use by people in the Delta. This has led to the changes in water quality and quantity, regional employment as a result of the shift in rural resources, and health concerns. These changes will pose challenges as well as render opportunities for water resource management and uses in the Delta. Below is a synopsis of water related impacts, challenges, and opportunities resulting from regional urbanization.
Introduction
Lake Tai and the cluster of other lakes and waterways in the Yangtze River Delta have not only been serving as a source for drinking water, fish, and aquatic food production, but also play an important role in transportation, flood control and waste disposal. They have been providing generous life support to the people in the Yangtze River Delta for centuries, and have nurtured this area as a historical, cultural and civil center in China. They are now facing pressures as never before, as they struggle to survive in the face of rapid regional urbanization.
Impacts of Regional Urbanization
Urban renovation, infrastructure development, and social, economic and spatial structures are experiencing great changes in the Yangtze River Delta. Population density has been increasing greatly as the rural population enters this delta for employment. Urban spread and construction have been taking over what once were farmlands, as industrial enterprises gradually replace farming as the key sector for providing employment. Uncontrolled and untreated wastes have increased substantially in regional waterways and Lake Tai.
These wastes have made the water in Lake Tai and the cluster of lakes in the Delta eutrophic or hyper-eutrophic. The construction of dams and weirs for water resources and flood control further reduces water exchanges and increases the frequency of water reuse in the lakes. Rural industry, while helping the growth of regional industrial enterprises, adds to the spread of deadly pollutants from urban centers to rural waterways. These rural wastes generally receive no treatment, and inflict great damage on waterways, lake ecosystems and human health. High levels of metals and toxic organics have now been found in the lake sediments and benthic fishes. These contaminants include mercury, arsenic, phenol, copper, cyanide, zinc, lead, chromium and various forms of toxic organics. These changes degrade the water quality, making finding and transporting level III drinking water (the minimum acceptable level for drinking water in China) a challenging task for most large city water supply companies surrounding the lake.
Areas formerly occupied by small farms and wetlands are rapidly being replaced by urban spread and construction. In addition, large fishing farms and animal husbandry industries have come to occupy areas previously serving as wetland and littoral zones. This has significantly reduced the lake size, the nutrient uptake ability of the wetlands, and spawning area for fishes. Aquatic vegetation in wetland and littoral zones is important for nutrient uptake and needed by many littoral species for spawning, foraging and protection during maturation. As a result, the water quality continues to deteriorate, and many species that depend upon this environment have been declining and disappearing.
The construction of dams and weirs has brought benefits in terms of flood control and water resources, but has had deleterious effects on water quality, fisheries resources and aquatic life, especially with respect to those species which migrate from lakes to rivers in order to spawn. Recruitment is prevented by dam construction, and reductions in fisheries stocks have become apparent. Fish-stocking programs are now the major means of maintaining lake fisheries in Lake Tai. These programs have also led to changes in trophic relationships in fish communities, and have significantly affected the indigenous lake species. Both fish species and the abundance of the fish upon which many fishermen depend have decreased greatly. This further contributes to the excessive labor force in rural communities in the Delta, and adds to the number of migrants seeking employment in regional cities.
Effects on Quality Drinking Water
The expanding urbanization has created insatiable demands for quality drinking water. At the same time, however, it has accelerated water pollution, which further shrinks the clean water supplies available to area communities. The burgeoning urban population, combined with certain weather-related events, is causing severe shortages. Megacities such as Shanghai are continuously searching for ways to provide quality drinking water for their populations. Abundant, inexpensive drinking water provided by Lake Tai and transported by the regional waterways has been taken for granted for generations, yet in the foreseeable future residents in major cities in the Delta may have to adjust to life without this unless a coherent management solution is found to reverse the current trend of growing pollution.
Inexpensive quality drinking water is becoming increasingly difficult to obtain for average households living in the delta. As new water plants are constructed, and municipalities search for ways of providing quality water, the price of drinking water has been rising in the cities. One wouldn’t think of drinking orange juice out of a pipe, and the same is becoming increasingly true of water as well. The cost of drinking water in large Chinese cities, especially bottled water, may soon be typical of the cost for other beverages. Uneven supply and low grade of drinking water in some cities have left people in the Delta with limited choices. Many city and rural residents are now resorting to buying bottled waters for daily consumption, which was unthinkable one or two decades ago. Bottled water is rapidly becoming a household essential and bottled water industries have sprung up in the cities and townships of the delta.
This move toward daily use of bottled water has widened the gap between haves and have-nots. This gap is likely to increase even further, since some gated communities in Shanghai are now looking into ways to supply clear drinking water themselves for their residents, using updated technologies. Clean inexpensive water has long been an essential resource provided by nature to all residents in the Delta. Increasingly, this resource is no longer available. Unless new initiatives are undertaken to assure the availability of quality drinking water to all, disparities in water service are expected to increase. Such initiatives should therefore be greatly encouraged, in order to assure access to this essential resource, so necessary to the quality of life, for all residents of the delta.
Social Impacts
Because wetlands and farmlands are rapidly being replaced by urban spread and construction in the Delta, fish resources in the lake are diminishing at an unprecedented rate. For some rural communities of the Delta, the ability to earn a living based on the area’s natural resources is increasingly being challenged. At the same time, farming incomes are trailing behind wages in the industrial and service sectors in the cities. Many surplus laborers have flocked into cities in the Delta from rural communities as migrants, creating one of the social issues of greatest concern in China. As industrial enterprises gradually replace farming as the key sector for providing employment, transitions in employment patterns have created significant social impacts within the Delta.
Health Concerns
Increased levels of uncontrolled and untreated wastes entering the lakes and the waterways in the Delta can also increase the incidence in water-borne disease; the frequency of such occurrences is directly correlated to the inputs of human and animal wastes to the water. As urbanization continues, population density (registered population plus migrant population) is sure to increase continuously; thus, contaminated water could be a major contributor to the outbreak of infectious diseases in the Delta.
Changes have also been noted in the species of microbes present in the waters, as these become more eutrophic. The new dominant microbe species can pose challenges for public health professionals seeking to control their spread and impact, and for water supply companies seeking to minimize their biomass. Control of outbreaks is likely to be a constant concern for regional governments. This is especially true in view of the recently reported increases in the level of viral species in the enriched waters.
Opportunities
Higher tax revenues as a result of regional urbanization have enabled some cities and governments to undertake new programs and to experiment with new technologies for abating pollution and untreated wastes. This also provides companies with added opportunities to research and develop new technologies for improving water quality and for providing safe drinking water. The challenges originating from the human impact as a result of urbanization require human solutions. Integrated regional plans in water management are badly in the Yangtze River Delta. A plan which takes into consideration the needs of the majority of the population, local jurisdictional differences, human conflicts and local concerns will have a better chance to be respected and implemented. Sustainable regional development for water resources requires participation by all concerned to assure access to inexpensive quality drinking water for all residents of the delta.