Layout optimization of rural residential land based on theory of landscape security pattern

Abstract: Rural residential land layout optimization not only provides a foundation for rural land consolidation, but also plays an important role in the New Countryside Construction and Beautiful Village programs. As an important land use type, rural residential land accounts for a large proportion of construction land in China. Numerous studies have shown that the layout of rural residential land is influenced by physical, economic and social factors, whose impacts vary across different regions. Yixing city, located in the developed southern region of Jiangsu province is chosen as the study area. As economic factors are no longer the dominant factors limiting rural residential land layout in Yixing city, other factors such as ecological preservation and scenic resources conservation exert more influence instead. According to the theory of landscape security pattern, some point elements, linear elements and surface elements in space play essential roles in the formation of regional landscape, and thus combine to form the regional landscape security pattern. In this paper, the theory of landscape security pattern is applied in the optimization of rural residential land layout in Yixing city, focusing especially on consideration of ecological preservation and scenic resources conservation.Firstly, some critical plaques are selected as the sources for soil and water conservation, biodiversity protection and scenic resource conservation. Secondly, influencing factors are chosen to set up a resistance surface for the above mentioned conservation and protection objectives based on the values of influencing factors. Thirdly, an individual landscape security pattern for the three objectives is constructed via the minimum cumulative resistance model and Cost-weighted tool. Furthermore, a comprehensive landscape is obtained with four security levels. Finally, layout optimization schemes are presented after the overlaying of the rural residential land map of 2010 and the comprehensive landscape security pattern map. Rural residential land in Yixing city is divided into four types including prior remediation, expansion-control, moderate construction, and key development, which accounts for 6.79%, 17.90%, 53.18% and 22.13% of the total land area, respectively. Prior remediation land is characterized by steep slopes and is a superior ecological environment with parts being primeval forest and habitats of wildlife. It's suggested that villages on these lands should be moved. Expansion-control land is characterized by complicated topography consisting of low mountains and hills, and poor agricultural production and living conditions, and is located adjacent to the wildlife habitats. It's suggested that construction activities on these lands should be strictly controlled, and the population should be moved out gradually. Moderate construction land is characterized by gentle terrain, and superior infrastructure far away from the wildlife habitat. We suggest a reasonable layout of rural residential land on these lands. Key development land is characterized by flat terrain, convenient transportation, and superior agricultural production conditions. We suggest development activities with high intensity on these lands. With priorities focusing on the ecological environment and landscape protection, our study provides theoretical guidance not only for New Countryside Construction, but also for related planning formulation.