Quota Restrictions on Land Use for Decelerating Urban Sprawl of Mega City: A Case Study of Shanghai, China
The mega cities of China are faced with great pressure from conflict between huge land demand for construction use and limited resources. To improve this situation, it is necessary to slow the increasing rate of built-up land and even reduce the existing built-up land by improving land use efficiency. Herein, land use planning with urban sprawl deceleration is proposed. Land quotas are important tools for the control of land use planning in China, but the current quotas are mainly in the form
... ainly in the form of increment, thus cannot support land use planning with urban sprawl deceleration. To address these issues, we developed a model named "current-plan-requirement response (CPRR)", to optimize the land quotas. With this model, we investigated the current status of land use, the process of land use planning, and the requirements of land use planning with urban sprawl deceleration in Shanghai. It was found that the current land quotas have provided somewhat inhabited conversion of arable land to built-up land, but scarcely any regulation of land use efficiency or protection of natural environment. Then, the land quotas were optimized and quota management recommendations were made. The optimized land quotas included four aspects of quotas: arable land protection, ecological conservation, scale constraint on built-up land and economical and intensive land use. These new land quotas could be used to guide reduction of built-up land and increase ecological land in China's mega cities. It might also be beneficial for easing conflict between supply and demand of built-up land, for building an eco-friendly city land-use structure. of large-scale urban land use for intensive and sustainable development is very important in China's mega cities. In China, the land quotas have become important tool of land resource management. The land quotas used by China nowadays aim to protect arable land and constrain built-up land    . The land quotas are determined according to the trend of social and economic development, and are allocated from top to bottom. The central government determines the land quotas of each province, and each provincial government determines the land quotas of each city in its administrative area. When land use planning is made, land quotas for about 15 years are set for each administrative area. During the implementation of land use planning, the upper level of governments will issue the annual land quotas to the lower governments at the beginning of every year. This means that the amount of each land quota is divided into the amount for every year during the planning period [18, 19] . By quantitatively studying the development targets of land use, and guiding the structure and distribution of land use with quotas, limited land resources can be allocated both temporally and spatially. The land resources in China are extremely limited and governmental administrative power is highly centralized, making allocative planning that focuses on mandatory quotas more suitable for the national conditions of China [20, 21] . However, local governments want to strive for land quota to expand built-up areas and do not fully comply with regulations that control urban sprawl. In such cases, the effect of land use planning is lower than anticipated, and the sustainability of land use is threatened [22, 23] . Given this situation, China's mega cities, such as Shanghai, Shenzhen, and Beijing, have all proposed land use planning with urban sprawl deceleration. The cities attempt to lower the increasing rate of built-up land, and encourage the change of land use mode from continuous increase of built-up land to renewing the inefficient built-up land    . The indices and their values of current land quotas are determined at the time of making land use planning and are static during the planning period. It cannot adapt to the change of new situation. Thus, it is necessary to re-examine and rethink the effects of the current land quotas, and to seek a method to evaluate the status of planning implement and adjust land quotas if necessary. In this study, the city of Shanghai was taken as a case. By comprehensively considering the current status of land use, the process of land use planning, and the requirements of land use planning with urban sprawl deceleration, a "current-plan-requirement response (CPRR)" model was developed. Using this model, the effectiveness of current land quotas for Shanghai was evaluated and their weakness summarized. Then, a new land quota system that is more suitable for land use planning with urban sprawl deceleration was proposed. From the perspective of protection (ecological resource) and control (built-up land scale), we designed four categories of land quotas with respect to arable land protection, ecological conservation, scale constraint on built-up land, and economical and intensive land use. The management of land quotas for land use planning with urban sprawl deceleration was explored to guide land use for mega cities.