河南省典型样区地形对城镇建设用地多样性的影响

The Influence of Topography on the Diversity of Urban Construction Land in Typical Sample Areas of Henan Province

为揭示城镇建设用地扩张变化在地形差异上的演变过程,选取河南省北部、中部、南部的部分县、市作为典型样区。首先,采用最大似然分类法对不同样区2001年、2007年、2017年的遥感影像进行监督分类,建立土地利用信息数据库并从中获取相应的城镇建设用地数据;然后,运用改进的仙农熵测度方法探索3个研究样区的地形空间分布多样性、城镇建设用地的面积和空间分布离散性格局特征的变化;最后,探讨不同地形下城镇建设用地在空间分布特征上的差异性。研究结果表明:3个研究样区均以平原地形为主,其占不同研究区总面积的比例均在53%以上,且其空间分布多样性平均值(0.95)也均高于丘陵地形(0.85)和山地地形(0.72);2001—2017年,豫北、豫中和豫南样区不同研究时期建设用地总面积豫北样区>豫中样区>豫南样区,且随时间推移其面积均处于上升趋势呈正相关关系,但其上升幅度存在差异;就城镇建设用地空间分布多样性而言,豫北样区和豫中样区其值均大于0.80,说明两个地区城镇建设用地在研究区内的空间分布较为均匀,而豫南样区的城镇建设用地发展潜力较大;就不同地形下分布的城镇建设用地多样性而言,平原上分布城镇的均匀程度高于丘陵和山地,且随时间推移3个研究样区的城镇建设用地多样性呈上升趋势,其分布越来越均匀。综上,在研究样区内,城镇建设用地与平原空间分布多样性关系密切,同时也有沿寄托于丘陵、山地发展的趋势。地形要素与城镇建设用地相互影响,应当坚持可持续发展的原则。

Three case study areas from north,central and south Henan Province were selected by means of maximum likelihood classification method to get the supervised classification from the remote sensing images in 2001,2007 and 2017 for the different case areas.First,a land use information database is established based on the evolution process of urban construction land expansion.Thus,urban construction land data can be obtained from it.Then,a modified Shannon diversity measure method is used to explore spatial distribution diversity of the terrain conditions,the area changes and spatial distribution diversity of urban construction land use for the three case study areas.Finally,the differences in spatial distribution characteristics of urban construction land use under different terrains are discussed.Results showed that:(1)the three case areas are dominated by plain terrain.The plain area accounts for more than 53%of the total area of the study area.The average spatial distribution diversity(0.95)of plain terrain is also higher than that of hilly terrain(0.85)and mountainous terrain(0.72).(2)From 2001 to 2017,the total area of construction land in different research periods in the north,central and south case study areas was ordered as north Henan case area>central Henan case area>south Henan case area.As time goes by,these areas also increase with a positive correlation between them.(3)In terms of the spatial distribution of urban construction land use,the value of spatial distribution diversity in north Henan case area and central Henan case area are all more than 0.80.It shows that the spatial distribution of urban construction land in the two regions is relatively uniform in the study area.The development potential of urban construction land in the south Henan case area is relatively high.(4)For the spatial diversity of urban construction land use distributed under different topography,Towns are more evenly distributed on the plains than on the hills and mountains.And the diversity of urban construction land in the three case study areas is growing over time.Besides,its distribution is getting more and more uniform.In summary,in the sample areas,the urban construction land is closely related to the spatial diversity of the plain.At the same time,there are also trends to develop the land along the hills and mountains.The topographical elements and the urban construction land interact with each other.Therefore,we should adhere to the principle of sustainable development.