With the rapid urbanization throughout the world, urbanization has become a real or potential threat to eco-environment. How to harmonize the relationship between urbanization process and eco-environment has become one of the strategic problems for the world. As early as in 1991, the World Health Organization pointed out that the world is facing two major problems: one is that the natural environment will become seriously worsening, and the other is that the quality of urban resident’ life will accelerat to drop because of the worsening urban environment. Wally Ndow, the assistant secretary-general of the United Nations, once warned that urbanization may provide an unexampled bright prospect for the future, but also may be a knell for an unprecedented calamity, and our future is decided by what we do nowadays. A. J. Mcmichael also pointed out that urbanization will be an important form to harm the human’s survival environment and health, and urban expansion, industrial and population growth will bring great pressure to local water resources and eco-enviroment. Therefore, it is very important to study the relationship between urbanization process and eco-environmental protection, so as to accerlarate regionnal urbanization process, improve eco-environment and realize the harmonious development between urban and rural areas. Subsequently, National Natural Science Foundation of China took the research of urbanization process and eco-environmental effects as a key project in 2004.

The research group led by Professor Fang chuanglin in our institue, has completed the key project of National Natural Science Foundation of China (No.40335049) after 4 years. The project’s titlle is Study on the Urbanization Process Restricted by Water Resources in the Arid Area of Northwest China and Its Ecological Effects. The main achievements go as follows:

Firstly, this project coupled the urbanization process which follows the laws of human and the eco-environment change process which follows the laws of nature by the system integration method, and opened out the basic laws and theories of the coupling relationship between urbanization and eco-environment, the water resoureces constraint theroy during the urbanization process, and the swing and conversion theroy between the driving forces and the constraint forces of the urbanization process.

Secondly, this project chose the Hexi Corridor in the arid area of northwest China as a typical study area, summarized the dynamic characteristic of the urbanization process and the eco-environment evolvement in historical period by analysis of historiography literatures, and studied the dynamic and coupling relationship between urbanization and eco-environment in recent 50 years. Resuts show that water consumption will increase by 0.91×10⁸ m³ with the increase of urbanization bv one percent, and when the urbanization level increased at an intervals of five percent, the urban water consumption will increase at a large extend, the dificulties in getting water resources and the cost of urban water utilization will be increasing.

Thirdly, this project exppressed and validated a double-exponential changing law on the interaction between urbanization and eco-environment, analyzed the eco-enviromental effects resulting from urban expansion by GIS technology, constructed a dynamic coupling model to evaluate the coordinated devlopment degree between urbanization and eco-environment, distinguished water resource constraint intensity on urbanization, and calculated the thresholds of urbanization level under the constraint of water resources in the future 30 years by a threshold model. Resuts show that, if water transfer from other regions is not implemented, the Hexi Corridor can hold 870 thounsand peasants to go into cities, and the urbanization level threshold can reach 35.14% in 2030. If water transfer from other regions is implemented, the Hexi Corridor can obtain 15.8×10⁸ m³ water resources for urban consumption, and the urbanization level threshold can reach 47.17%.

Finally, this project put forward some healthy urbanization modes seasoned with the eco-environment and water resoureces.

This study has an important theoretic and practical meaning to urban geography in China. It can help to carry out the scientific development concept, choose an optimal urbanization mode which can protect the eco-environment and accelerate the healthy urbanization process, and construct the resource saving and environment-friendly eco-cities.