汉中盆地及周边低山丘陵区土地利用变化研究

目的探究汉中盆地及周边低山丘陵区土地利用变化的时空特点及其规律。方法基于2000年、2005年、2010年和2016年四期TM影像,利用ENVI和GIS技术提取汉中盆地及其周边低山丘陵区各期土地利用现状图,分析研究区各期土地利用的时空变化及地形梯度变化特征。结果与结论1)2000—2016年汉中盆地内部土地利用类型变化明显,其中建设用地明显增加,耕地、草地、未利用地明显减少,而低山丘陵区以耕地的减少和林地的增加为主要特征。2)2000—2016年盆地区建设用地主要以城区为中心面呈环状增加和以高速公路为中轴呈条带状增加。而低山丘陵区林地主要在坡度较大和高程较高的区域增加。3)汉中盆地土地利用图谱变化类型以"耕-耕-耕-耕"为主的稳定型图谱分布面积最多,占整个汉中盆地面积的51.67%。低山丘陵区的土地利用图谱变化类型以"林-林-林-林"为主的稳定型图谱分布面积最多,占整个低山丘陵区面积的41.44%。4)汉中盆地前期变化型和稳定型的分布指数较高,土地利用类型仅局限于耕地与建设用地之间的转换,而低山丘陵区前期变化型和稳定型的分布指数较高,土地利用类型仅局限于耕地与林地之间的转换。

Research on the land use changes in Hanzhong basin and its surrounding hilly areas

Purposes—To explore the temporal and spatial characteristics and the patterns of land use changes in Hanzhoung basin and its surrounding hilly areas.Methods—Based on the T M images in the years of 2000,2005,2010 and 2016,the present land use maps of Hanzhong basin and its sur-rounding hilly areas was extracted by ENVI and GIS,respectively.The characteristics of the temporal and spatial changes in land use and the changes of terrain gradient in the study area were analyzed.Re-sults and Conclusions—1)From Year 2000 to Year 2016,there were distinct dynamic changes in the types of land-use,among which the construction land increased,the cultivated land,grassland and unused land reduced significantly,while the cultivated land decreased drastically and the forest land increased in the hilly area;2)From Year 2000 to Year 2016,the construction land increased in circu-larity with the city proper as the center in the basin area and in strip with the highway as the axis, while the forest land in the hilly area increased mainly in the area with higher slope and higher eleva-tion.3)Among the distribution pattern of land use in Hanzhong basin,the main evolution type was"tillage-tillage-tillage-tillage",which took up the largest distribution area,accounting for 51.67% of the whole area of Hanzhong basin.In the hilly areas,the main evolution type was "forest-forest-for-est-forest",accounting for 41.44% of the w hole hilly area.4)T he distribution index of early change type and stable type in Hanzhong basin was higher,and the land use type was limited to the conver-sion between cultivated land and construction land,while the distribution index of early change type and stable change type in hilly area was higher,and the land use type was limited to the conversion between cultivated land and forest land.