1985-2015年美国坦帕湾流域土地开发利用强度时空变化分析

分析土地开发利用强度对提高土地开发利用效率和推动生态环境保护工作具有重要意义。选取美国佛罗里达州坦帕湾流域为研究区,以1985年、1995年、2005年、2015年4期Landsat TM/OLI遥感影像为数据源,采用GIS技术构建了基于行为者的土地动态度模型、转移矩阵、土地开发利用强度模型和土地利用结构模型,对坦帕湾流域土地开发利用强度时空格局进行了分析。结果表明：（1）研究期间建设用地和林地是流域主导土地利用类型;建设用地面积增加最多,主要由耕地转换而来,转换比例为53.74%。（2）各种土地利用类型相对变化率具有明显的空间差异,河流与湖泊相对变化最大;未利用地速度变化最为显著,单一动态度高达1.11%;建设用地年均增长较为平缓,每年增长0.30%左右;流域北部和南部综合动态度最高,形成极核中心,并以圈层形式向外辐射降低,同时高动态度区逐渐转换为较低动态度区。（3）信息熵均衡度呈小幅下降趋势,土地利用结构均质性下降;土地开发利用面积基本构成为建设用地>林地>耕地与牧场>河流与湖泊>未利用地>滩涂与沼泽。（4）坦帕湾沿岸皮拉尼斯县与坦帕市土地开发利用强度最高;流域土地开发利用强度发展期面积高于调整期,土地开发利用强度增强趋势明显。

Spatio-temporal analysis of land development and utilization intensity in Tampa Bay watershed from 1985 to 2015

The analysis on the intensity of land development and utilization is of great significance to improving the efficency of land development and utilization and promoting ecological and environmental protection work. Taking the Tampa Bay watershed of Florida, USA as the study area, based on the information of four TM/OLI remote sensing images of 1985, 1995, 2005 and 2015, this paper constructs a series of models of land-use dynamics, conversion matrix, land development and utilization intensity and land-use structure with GIS technology. Then, it conducts research on spatial and temporal pattern of land development and utilization intensity in Tampa Bay watershed. The results showed that: (1) Construction land and woodland are the dominant types of land use in the watershed. The area of construction land mainly converted from cultivated land increased most, with the ratio being 53.74%. (2) The relative change rates of all types of land use have obvious spatial differences and those of rivers and lakes have the greatest. The change speed of unused land is the largest, with the highest single dynamic degree of up to 1.11%. The average annual growth rate of construction land is steady at about 0.30%. The size with the highest dynamic degree was decreasing from the northern and southern polar nuclei outward, and the areas with higher dynamic degrees were gradually converted into the lower dynamic areas. (3) Information entropy slightly decreased, the land use structure heterogeneity constantly decreased. Area of the land-use composition is listed in the order of Construction Land>Wood>Cultivated Land and Pasture>Rivers and Lakes>Tidal Flat and Marsh> Unused Land. (4) The intensity of land development and utilization is the highest in the Coastal Pinellas county and Tampa city. The area of development is much larger compared with the adjustment period, and the intensity of land development and utilization was obviously strengthened.