A Study On The Method Of Improving The Urban Green Space System In The Old Town Of County-level City

County-level city has the great potentialities in contrast to the other medium-sized cities now,he is the main carrier of urbanization,also an important node of urban and rural planning,But along with the rapid development of city,various urban problems arise increasingly,especially in the old city.This paper take the old city of Tianchang in Anhui Provinceas the research object,focus on the methods of transformation of old city green system.The main research results are as follows:1、On the basis of the studies of the planning and construction of urban green system of domestic and foreign cities,then analyze the transformation process of the urban green space system when study the planningof it,it reveal out the rule: Each period of the urban green system is based on the current situation in that time and it develops between balance and imbalance.2、Aim at the urban problems of county-level city,for example: densepopulation,poor living environment,imperfect infrastructure and so on,the paper propose the construction goals: improving the old city landscape spatial structureto ensure the sustainable development of the old city;preventing the disordered expansion of urban spaceto ensure the healthy development of county-level cities;continuing the history cultural heritage of the old city to ensure the power function of the old city.3、Through the study of the structure of the urban green system of some typical county-level cities,the paper summed up the basic characteristics of the urban green system structure of the old city as follows: the dotted-distribution greenbelt is the main forms of layout;as the structure of green space is not completedlead to the whole network is not formed;the old city green rate is low and the ecosystem is fragile;the greenbelt layout mainly in the from of small and medium-sized plaques,the characteristic of this kind of forms is likely to lead to serious fragmentation;construction of corridor green space is not enough,it lead to the connection of the is seriously poor;the green structure is relatively simple and the stability is poor;all kinds of greenbelts are unevenly distributedand it’s function is poor.4、On the premise of following the principles as systemic,holistic,sustainability and so on,the paper propose the general methods of the planning of the green space system of the old city: determine the nature of urban land and reconstruct the urban landscape structure;protect the original green space and ensure the continuation of urban green space pattern;excavate thecapacities of the construction of green space and improve the green area of the old city;increase the park green space construction and perfect the urban recreation system;strengthen the road greening construction and build green space network system;optimize configuration of green plants and enrich city natural landscape.5、Taking the promotion of the green system of the old city of Tianchang in Anhui Provinceas the example,analysis of the status of the old city of Tianchang deeply,and put forward the method to enhance the transformation of the old city of Tianchang green space system,then verify and perfect results,all the work aim at providing guidance to enhance the transformation of the green space system of county-level city.