宁夏原州区生态移民村生境景观连接度变化及其驱动因素

目的]分析生态移民土地利用过程中生境景观连接度变化及其驱动因素,为生态移民的生态风险管理及移民可持续性提供科学依据。方法]以宁夏原州区"十二五"时期4个生态移民村(丰泽、金轮、和润及泉港)为例,基于2016年高分影像数据,同时参考移民前谷歌地球2010年数据和第二次全国土地调查数据(2010年),经野外GPS校验,通过计算障碍影响指数和生境景观连接度指数,分析生态移民村土地利用生境景观分异。结果]丰泽村和金轮村的生境景观连接度呈下降态势,和润村和泉港村呈上升态势。4个生态移民村的变化趋势明显,但极高连接度和高连接度比例很小。生态移民村生境景观变化驱动力主要为人为因素,建设用地占用耕地、园地普遍,其中泉港村与和润村建设用地面积年均增长率分别高达27.49%和21.28%,同时金轮村、和润村、泉港村无后备土地资源,生态压力突出。结论] 4个生态移民村人口密度增大导致建设用地占用耕地明显,生态用地被分割,移民的非农活动比重大造成耕地撂荒,景观破碎化和孤岛化现象明显,生境景观呈现出不稳定状态,生态压力增加。

Changes of Habitat Landscape Connectivity and Driving Factors of Ecological Migration Villages in Yuanzhou District of Ningxia Hui Autonomous Region

Objective] The changes of habitat landscape connectivity and its driving factors in the process of land use of ecological migration were analyzed, in order to provide scientific basis for ecological risk management and sustainability of ecological migration. Methods] Four eco-migration villages (Fengze, Jinlun, Herun and Quangang) in Yuanzhou District of Ningxia Hui Autonomous Region during the 12th five-year plan period were taken as examples. Based on the high-resolution image data of 2016, Google Earth data (2010) and the second national land survey data (2010)before migration, the landscape differentiation in ecological immigrant village was analyzed by calculating the barrier impact index and the landscape connectivity index, after field verification by GPS. Results] The landscape connectivity of Fengze and Jinlun villages was declining, while that of Herun and Quangang village was on the rise. The change trend of each immigration village was obvious, but the proportion of extremely high and high connectivity was very small. The driving forces of the landscape connectivity change in ecological immigration villages were mainly human factors. Construction land occupied cultivated land and garden land widely in general, and the average annual growth rate of construction land area in Quangang village and Herun village were up to 27.49% and 21.28%, respectively. In addition, Jinlun, Herun and Quangang village had no reserve land resources, and thus, the ecological pressure was prominent. Conclusion] The increase of population density in the four eco-migration villages resulted in the obvious occupation of cultivated land for construction and the division of ecological land. The ratio of non-agricultural activity of immigrants was significant, resulting in the abandonment of cultivated land, the fragmentation and isolation of landscape, the instability of habitat landscape and the increase of ecological pressure.