Study And Research Of City Boundary’s Determinacy

Since the beginning of the reform and opening, China has developed with an amazing speed. Many scholar thought many cities in China unfortunate choose the wrong way of western cities to expand. With the development, more and more people flooded into the the city, this caused a lot of pressing problems. The problems, which big cities are facing, is based on the situation of over expanded or damaged the environment while developing. How to solve these pressing problems is a big task to the generations of planners. This paper redefined and researched the city boundary, at the background of city development.And made a general description of city boundary. By representing the forming and changing of city boundary from standpoint of history,territory and resources, I analyzed the different types of city boundary from different view. Then I introduced a new point of view to study city boundary:an area exist with the expansion of city. At meantime, I find a new way of using the model of biological semipermeable membrane and calculate the landscape features inside to calculate the boundary of city. Using this scientific discipline to plan and control the usage of land, planner can build a more powerful ecosystem system, as big as possible, to study the effect of the result to city development, and to discuss the use to city planning.The development of city can be well under control, while the development density has been set by factors as city scale or populations. Especially when dealing with the abuse of cheap boundary land in politics of market economy, the scale and structure need to accept landscape background. We should protect biological green lands more positive when using land, and make the development more acceptable to local environment, to develope the feature of city and help it to last. This can make biological green lands relate to each other, and the relation is based on the natural biological development.The goal to certain the city boundary is to make city plan more biological, and to make the plan more useful to human sustainable development and natural environment protection, not only to human needs.In short, it is to help build a organic,healthy and sustainable city.