海岸带城镇空间扩展情景模拟及其生态风险评价

Scenario Simulation of Urban Spatial Expansion and its Ecological Risks Assessment in Coastal Zones

海岸带城镇扩展及土地利用变化在很大程度上影响着海岸带生态安全。本文以滨海城市-烟台市为例,基于1990年-2009年间的遥感监测历史数据,将城市扩展动态模拟方法与区域生态风险评价方法相结合,模拟和评估三种海岸带政策管理预案条件下烟台市区2010年-2040年间的城镇扩展与土地利用变化过程,以及城镇扩展导致的海岸带资源损失和区域生态风险空间差异性。结果表明:烟台市区未来城镇化过程加速,开发区、莱山-牟平一带区域生态风险明显加大;若不加约束将有更多的耕地资源和近岸海域被侵占;鼓励海岸带开发利用与适度围填海的城镇发展政策,加速了岸线资源的损失,使得海岸带区域生态风险增大,需要采取强有力的海岸带保护和围填海建设监管措施,降低高强度开发给海岸带地区带来的生态风险。

Yantai,situated on the northern coast of the Shandong Peninsula,has achieved great development in industrialization and urbanization since the reform and opening up.In recent years,coastal tourism and maritime transportation increasingly have contributed to local economic development.As a result,the urban area of Yantai has expanded drastically,which resulted in massive threat to coastal ecological integrity.In this study,urban distribution maps of Yantai in five years（1990,1995,2000,2004,and 2009）were obtained from Landsat Thematic Mapper（TM）and Enhanced Thematic Mapper Plus（ETM＋）satellite imageries.Then,the spatial-temporal process of urban expansion and land use changes over the period 2010-2040 under three kinds of coastal policy management scenarios were simulated with the SLEUTH urban growth model.The three urban growth policy management scenarios included history trend scenario（HT）,coastal protection scenario（UP）,and coastal growth scenario（CG）.Under scenario HT,there are no extra management for urban growth.Policies protecting coastal resources and guaranteeing ecological security are applied under scenario UP.Scenario CG could promote the exploitation and utilization of coastal resources.On the basis of the simulation results and a combination of GIS spatial analysis with regional ecological risk assessment methods,differences in urban development patterns as well as coastal resource losses and the regional ecological risk spatial-temporal distribution were analyzed.Conclusions are given as follows.1）After the year 2000,the urbanization rate of Yantai has speeded up.Under the HT scenario,the urban area in 2040 was estimated to be 607.36 km2,increasing by 388.04 km2 compared to that in 2009.About 205.39 km2 of cultivated lands would be lost and the annual loss would come up to 743.88 ha.There were 34.75 km2 of land reclaimed from the sea which became urban and public facilities.The ratio of high-risk ecological zones would go up and the local ecological risks would apparently increase in Laishan district,the economic and technological development zone,as well as the areas of 15 km from the coast;2）The CG scenario would promote urban expansion along coastline;however,it aggravated losses of cultivated land,shelter forest,and natural resources in the coastal zone,causing higher ecological risks.Under the management condition,strong reclamation regulatory measures for urban development should be taken to prevent tourists and industrial constructions from being close to the sea and to increase the intensive land and sea use in coastal zones.The measures also include increasing ecological spaces and wetland,reducing geological disasters and ecological risks resulted from the high-intensity development in the sea area of the Yantai west port and near the Yangma Island;3）Scenario UP would protect resources of coastal areas to some extent and effectively reduce ecological risks along the coastline from Laishan to Muping by restricting the rates of urban expansion.Under this condition,the connotation development policies should be taken to adjust the land use structure and make urban land use more intensive.This study could help governments to develop coastal urban areas and manage coastal land use reasonably.