1985年以来江苏省土地利用变化对人类活动程度的响应

利用1985、1995、2005和2008年4期遥感影像解译获取的土地利用变化数据,从土地利用变化速度、转移方向和土地利用程度方面,借助GIS空间分析和图谱分析技术及Ucinet社会网络分析软件,全面定量分析江苏省1985年以来人类活动作用下土地利用时空变化规律。研究表明:(1)1985~1995、1995~2005、2005~2008年3个时段江苏省的土地利用综合动态分别为12.95%、17.17%、15.03%,反应了人类活动对江苏省土地利用变化的影响程度呈现出"缓慢影响—剧烈影响—影响减缓"的倒U型曲线规律;(2)1985年以来,耕地、建设用地和水域之间的空间转移是江苏省土地利用转移的关键,也是人类影响土地利用最主要的表现形式,3种地类的相互转移占所有土地转移流的80%以上,其中耕地转为建设用地所占比例最大,主要分布苏锡常及南京4市的市辖区,以及昆山、江阴等经济发达的县市及苏北的宿迁市、淮安市、徐州市;(3)1985年以来,追求净产出(利润)的增长是土地利用变化的内在动力,导致建设用地增加及耕地减少,使得全省土地利用程度整体水平不断升高;受可驱动的有效资本量控制,经济发达的苏南地区一直是人类活动影响土地利用最为剧烈的区域,而苏北地区随着经济实力的不断提升土地利用受人类活动影响的程度也在逐渐增强。

RESPONSE OF LAND USE CHANGES TO HUMAN ACTIVITIES IN JIANGSU PROVINCE SINCE 1985

Based on the remotely sensed data of land use/land cover in Jiangsu Province in 1985, 1995, 2005 and 2008, a combined spatial analysis using GIS, Ucinet social network analysis software and atlas analysis were conducted to comprehensively and quantitatively study the spatial-temporal variations of land use change in Jiangsu Province during 1985 to 2008, including the variations of land use change rate, land use transformation direction and land use intensity. Results showed that: 1) The integrated dynamic degree of land use dynamics during 1985-1995, 1995-2005, 2005-2008 was 12.95, 17.17 and 15.03, respectively, suggesting that the impact of human activities on land use change followed a rule of inverted U-shape curve starting from slight to intense impacts and then to slowing-down impacts. This phenomenon seems to be closely related with regional socioeconomic transformation process, yet other case studies and more rigorous mechanism studies are needed. 2) Since 1985, the land use interchange flows between cultivated land, built-up land and water area have been dominant in the land use dynamics of Jiangsu Province. They reflected the main manifestations of the impacts by human activities on land use dynamics, accounting for more than 80% of all land use change flows. In addition, the flow of cultivated land into built-up land ranked as the top land use change type, mainly distributed in the metropolitan areas of Suzhou, Wuxi, Changzhou, and Nanjing as well as in the developed county-level cities such as Kunshan and Jiangyin, and also in part of the North Jiangsu of including Suqian, Huaian and Xuzhou. These conclusions are in line with existing findings of previous case studies, indicating that the comparative economic advantages between various land use types have driven those land use changes along with regional development process. 3) As land use intensity is an indicator closely related with capital input and economic output per unit land, its spatial-temporal variations gave other hints of the dynamics of human activities. Since 1985, the pursuit of direct economic output prompted the increasing of built-up land and the decreasing of cultivated land, leading to the ascending growth of overall land use intensity degree in Jiangsu. This impact of human activities on land use change was most obvious in South Jiangsu all the time while it was ever-increasing in North Jiangsu. Our findings provided novel insights into land resource sustainability in Jiangsu Province, suggesting new possibilities to better manage land resources in accordance with regional socioeconomic development stage.