基于Markov模型的三峡上游消落带土地利用变化预测

Land use Change Prediction of Subsidence Zone in the Upper Reaches of Three Gorges Based on Markov Model

三峡水库蓄水后形成高程差30 m的消落带,以蓄满水位175 m为基准水平外扩150 m得到交错缓冲区。缓冲区土地利用情况较复杂,本研究通过研究库区上游缓冲区近20年土地利用的变化情况,分析前20年上游发展模式。通过马尔可夫函数来预测未来20年的土地利用变化可能,为上游区域未来规划发展方向提出建议。研究表明:(1)上游在发展过程中持续紧抓农业用地,可按目前的模式继续发展;(2)生态方面,森林、灌丛、草地等与生态环境相关的地类占比是有所提高的,目前发展政策是有利生态环境的,但由于水域面积增长导致裸岩增加,水土流失风险增加,需更加重视水土流失的防治;(3)经济发展与城镇化密切相关,城乡建设用地与道路占比不断上升,上游经济形势一片大好。综合来说,可按照2000~2020年的发展模式继续开发建设,但应在此基础上更加重视经济与环境的协同发展,尽量建设森林城市,通过工程护坡、生态护坡等技术来加强两岸土地的水土保持力度。

After Three Gorges Reservoir is impounding,a fall-off zone with an elevation difference of 30 m is formed,and a staggered buffer zone is obtained by horizontal expansion of 150 m based on the full water level of 175 m.The land use of buffer zone is complicated.This study analyzes the development model of the upstream buffer zone in the past 20 years by studying the land use change of the upstream buffer zone in the past 20 years.The possibility of land use change in the next 20 years is predicted by Markov function,and some suggestions are put forward for the future planning and development direction of the upstream region.The results showed that:①The upstream continues to grasp the agricultural land in the development process and could continue to develop according to the current development trend;②In terms of ecology,the proportion of forest,scrub,grassland and other land types related to the ecological environment had increased.The current development policy was favorable to the ecological environment.However,due to the increase of water area,bare rock has increased and the risk of soil erosion has increased.③Economic development were closely related to urbanization.The proportion of urban and rural construction land and roads is on the rise,and the upstream economic situation was promising.In general,development and construction can continue according to the development mode from 2000 to 2020,but on this basis,more attention should be paid to the coordinated development of economy and environment,the construction of forest city as far as possible,and the soil and water conservation of land on both sides of the strait should be strengthened through engineering slope protection,ecological slope protection and other technologies.