水土保持研究

为了分析甘肃省党河流域2012—2018年土地利用类型变化及建设规划趋势,通过判读遥感影像得到了党河流域6年内土地利用类型分布。从土地利用类型时间、空间以及景观格局动态变化3个角度分析了以上趋势。结果表明:(1)从时间变化角度,6年间林地总占比减少量最大,为0.47%(82.13 km2),建设用地总占比增加量最大,为0.20%(35.10 km2)。林地下属分类中的宜林地减少量最大,为12.55%(86.36 km2)。宜林地的大幅减少是林地面积减少的主要贡献源。(2)从空间变化角度,未利用土地6年间的转入量最大,为107.76 km2,转入面积中林地为主要贡献源,转入总面积88.72 km2,林地转出量最大的时间段为2012—2014年的72.68 km2,后续2016—2018年未利用土地转出为林地50.45 km2。建设用地面积持续增加,贡献量最大的为未利用土地,转入量13.15 km2。2012—2018年土地利用类型呈现林地退化转变为未利用土地,生态建设加强后未利用土地回转为林地和向建设用地转变的大趋势。(3)从景观格局动态变化角度,6年间各地类的景观破碎度总体上呈现上升趋势,建设用地景观破碎度最大,建设用地景观形状指数较大且呈现快速上升趋势,说明人类活动较多的建设用地区域破碎度高且形状更复杂。上述研究结果对摸清并保护恢复党河流域生态环境、合理开发利用土地资源和实施土地保护利用政策具有十分重要的意义。

In order to analyze the change of land use types and the trend of construction planning in the Danghe River Basin in Gansu Province from 2012 to 2018, the distribution of land use types in the Danghe River basin in 6 years was obtained by interpreting remote sensing images. The above trends were analyzed from the three perspectives of land use type time, space and landscape pattern dynamic change. The results showed that:(1)from the perspective of time change, the total decrease of forestland was the largest, accounting for 0.47%(82.13 km2), and the total increase of construction land was the largest, accounting for 0.20%(35.10 km2); the largest reduction of suitable forest land was 12.55%(86.36 km2); the large reduction of suitable forestland is the main contribution source of forestland area reduction;(2)from the perspective of spatial change, the amount of unused land transferred in 6 years was the largest, reaching to the area of 107.76 km2; the transferred area of middle woodland was the main contribution source, and the transferred area is 88.72 km2; the maximum amount of the transferred forest land was 72.68 km2 during the period from 2012 to 2014, and the unused land transferred to forest land from 2016 to 2018 was 50.45 km2; the area of construction land continue to increase, with the largest contribution being the transfer amount of unused land of 13.15 km2; from 2012 to 2018, land use types showed a general trend of forest land degradation turning into unused land, and unused land returning to forest land and turning to construction land after ecological construction was strengthened;(3)from the perspective of dynamic changes of landscape pattern, the landscape fragmentation of each region in the past 6 years generally presented the increasing trend, with the largest landscape fragmentation of construction land and a large and rapidly increasing landscape shape index of construction land, indicating that the regional fragmentation of construction land with more human activities was high and its shape was more complex. The above research results are of great significance to understand and protect the ecological environment of Danghe River Basin, rationally develop and utilize land resources and implement policies of land protection and utilization.