Research On Urban Comprehensive Carrying Capacity In Arid And Semi-arid Region Based On The Sustainable Development

At the present, along with the rapid growth of the world’s population, the contradiction between resource consumption, environmental pollution and the population growth is intensifying. The phenomenon of food shortage, ecological destruction and environmental pollution is serious worldwide, and the lack of arable land and water resources has become a universal problem. How to coordinate the relationship between economic development and environment protection is grave challenge to mankind. At the same time, China steps into a rapid developmental period of urbanization, and the rapid expanding of city also brings the natural environment and public facilities a heavy pressure.In 2014 the national new urbanization planning (2014-2020) pointed out that "The distribution and scale of urban space structure are unreasonable, and does not match the resources and environment carrying capacity. Some crowd cities in the east faced with resources and environment constraints, and some cities of central and western China need to explore development potential of carrying capacity."According to the national development policies, the central and western China where the carrying capacity is strong will become the rapid urbanization regions in the future. So how to promote the urbanization process, the coordination, and the sustainable development of the cities within the scope of carrying capacity reasonably will become the main research topic in this area in the future.In the background of the new national strategic security pattern "One Belt And One Road", the central and western regions which are the important parts of "the Silk Road Economic Belt" will be faced with new opportunities in the future. And these regions are located in China’s arid and semi-arid climate zones where ecological environment is fragile and the population carrying capacity is low due to the dry climate, evaporation, desertification, soil erosion and some other natural reasons. Therefore, under the limitation of natural conditions and environmental conditions, economic and population development of the arid and semi-arid regions must respect the laws of nature fully. Especially under the condition of new important opportunities, we must consider the comprehensive carrying capacity of the city fully, and avoid excessive population urbanization, and other behaviors conflicted with resources and environment. Considering the fragile ecological environment in these regions, the destruction once occurs, the contradiction between human and nature will aggravate. This will cause irreversible consequences.Considering the above comprehensively, this article attempts to study urban comprehensive carrying capacity of arid and semi-arid areas in China through constructing the model to explore how to realize the sustainable development and promote urbanization orderly in the arid and semi-arid regions. In view of the current research on the carrying capacity of arid and semi-arid areas, many researches are mainly concentrated in the aspect of water resources bearing capacity singly, combining. So in according to the special conditions in arid and semi-arid areas, the paper constructs the comprehensive bearing capacity model suitable for the region using the Analytic Hierarchy Process (AHP). It gives different weights to adapt to the development characteristics of arid and semi-arid regions. It selected 31 indicators to form six elements (water resources capacity, land resource capacity, traffic capacity, environmental capacity, economic capacity, social capacity) of urban comprehensive capacity. In order to evaluate the comprehensive capacity of Urumqi synthetically from 2000 to 2012, the paper also used some other index, such as pressure index, coordinated index, sustainable index. The purpose is to find out the problems existing in the urban development, and put forward some suggestions to promote the sustainable development of Urumqi.This article selects Urumqi as a case study in the arid and semi-arid regions. The research purpose is to construct scientific evaluation index system of urban comprehensive carrying capacity, and use the index system to evaluate the comprehensive capacity, state of bearing capacity, coordination in the process of development, sustainable development status and so on. Then it tries to find disadvantages restricting urban carrying capacity, and look for specific solutions to promote the urbanization process. It is also hoped to provide certain experience of urban sustainable development for other cities in arid and semi-arid regions.In this paper, the main conclusions are the following:Water resources carrying capacity is the first factor of comprehensive carrying capacity in arid and semi-arid regions, and the economic and social factors also beyond other natural factors gradually. In the future improving the water resources bearing capacity of Urumqi is in a top priority, and the promotion of social and economic bearing capacity can make up the defects of water resources carrying capacity in a certain extent. Decline of the water resources carrying capacity becomes the main factor influencing the urban comprehensive carrying capacity promotion in arid and semi-arid regions. The main reasons for decline in water resources carrying capacity are shortage of water resources, population growth, and insufficient water supply capacity. The coordination of the city need each capacity develops synchronously. Improving the coordination of urban cannot ascend the sustainability of the city. It must promote the key short board factors, and realize the coordination of all the elements. Only by this way can we promote the sustainable development of city.