近四十年来冀津海岸带土地利用时空变化及驱动因素

冀津海岸带是国内港口和围填海工程集中分布区之一,高强度开发活动对土地利用变化产生深远影响。本研究基于中科院土地利用遥感监测数据,在原有分类系统基础上增加了养殖盐田用地、待利用地、滨海滩涂、浅海海域等4类利用类型,分析了改革开放以来土地利用时空变化特征及其驱因素。结果表明：（1）近40 a内土地利用总体动态度可达0.48%,土地利用强度不断上升,土地类型的主要转移方向为建设用地、养殖盐田用地及待利用地;（2）土地利用变化的峰值时段为2000-2010年,变化区域在空间上集中分布在距离海岸带3~8 km范围内,即黄骅、滨海新区、曹妃甸围填海区域及乐亭沿海陆域。地理加权回归结果显示,地形、中心城市、GDP、人口、港口等因素是对土地利用强度产生主要影响的因素,且人口及港口建设的驱动效应有所增强。土地财政依赖、过度超前规划是待利用地激增的主要政策性驱动因素,近10 a来的基本农田和滨海湿地保护政策降低了耕地和滩涂的缩减量。当前,冀津沿海地区应进一步提高待利用地使用效率,加强土地利用高强度变化区域的生态环境监测与修复。

Spatiotemporal changes and the drivers of coastal land use in Hebei and Tianjin in recent 40 years

The coastal zones of Hebei and Tianjin, China, have a concentration of ports and reclamation projects, and these high-intensity development activities have a profound impact on their land-use patterns. In this study, based on the land-use remote-sensing data and classification system by the Chinese Academy of Sciences, we investigated land-use changes and their drivers since 1978. On the basis of the aforementioned classification system, four new land-use types were added:tidal flats, shallow seas, aquaculture land, and salt pan. The results show the following. (1) In the past 40 years in this area, land-use patterns have undergone significant spatiotemporal change and increased continuous utilization, with a total dynamic extent reaching 0.48%. (2) The peak period of land-use change occurred in the 2000-2010 period. Areas of high-intensity change are mainly concentrated 3-8 km from the coastal zone, especially in Huanghua, Binhai New District, Caofeidian, and Laoting. Based on the results of geographical weighted regression analysis, the geomorphology, urban area, GDP, population, and port were identified as the main divers of the variation in land use utilization, with the driving effect of the latter two having increased in 2010. Reliance on land revenue and over-planning were identified as the main policy drivers for the surge in the "land to be used" category. Thanks to corresponding protection policies, the reduction of cultivated land and coastal wetlands was effectively curbed. Currently, to optimize the land-use model, a number of measures should be taken. The utilization efficiency of the land to be used must be improved, and the ecological and environmental monitoring and restoration of areas that have or are undergoing high-intensity changes in land use must be strengthened.