基于GIS和CA-Markov模型的乌江下游地区土地利用变化情景模拟与生态环境效应评价

发布时间：2018-01-10 10:30

本文关键词：基于GIS和CA-Markov模型的乌江下游地区土地利用变化情景模拟与生态环境效应评价　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：当前,人类活动深刻影响着土地利用格局及其变化。因此,探究土地利用变化原因和机理、模拟未来土地利用格局分布对当前土地政策、土地规划具有重要意义。以乌江下游的涪陵等六个区县为研究区,基于1995年、2005年、2015年的Landsat影像解译数据,综合运用GIS空间分析技术、CA-Markov模型和MCE模型,实现研究区土地利用时空格局模拟。结合情景分析方法,探讨在“快速城镇化情景”、“规划情景”和“生态保护情景”三种模式下研究区2020年、2030年、2050年的土地利用格局。参考其他学者制定的生态服务价值当量因子,结合研究区实际情况,利用植被净初级生产力、降水、土壤数据对研究区的单位面积生态系统服务功能价值当量加以校正,然后通过生态系统服务价值估算方法,计算研究区未来不同情景下的生态系统服务功能价值。研究结果表明:(1)研究区以耕地和林地为主,两者之和占总面积的86%及以上,20年来,耕地经历了“先减后增”的过程,前10年减少了451.85km2,占耕地总面积(1995)的6.84%,后10年耕地面积略有增加,但增幅较缓;与此相反,林地在20年内持续增加,2015年比1995年增加了894.49 km2,年均增幅达0.4%。此外,草地和未利用地面积20年间持续减少,尤其是未利用地,减少了590.61 km2,占未利用地总面积(1995)的80%,且主要转化为耕地和林地。水域面积变化虽略有起伏,但总体上幅度不大。(2)20年间研究区土地利用的动态度差异比较明显。就单一土地利用动态度而言,未利用地的变化幅度最大,1995-2015年间达到-8%;其次是建设用地,前10年比后10年变化幅度要大,总体呈逐年增加趋势;耕地和林地的年动态度均小于1%,而前者呈现先减少后缓慢增加的趋势,后者则呈现轻微增加的趋势;草地呈现逐年减少的趋势,且后10年变化幅度更大;水域总体上变化比较平稳。就综合土地利用动态度而言,三个时段各地类综合动态度都小于2%,其中,耕地、林地、水域和建设用地的综合动态度都小于1%,而草地和未利用地的综合动态度基本上介于1%-2%之间,这说明研究区土地利用变化的总体幅度或强度不大,但个别地类变化比较明显。(3)1995-2005年间耕地转出量最大,为783.26 km2,是转入总量的2.36倍,耕地面积的大幅度减少不容忽视。从耕地转出类型来看,位居第一的是转换为林地,数量为627.93 km2,占转出总面积的80.17%。其次是建设用地,在此期间有112.38 km2的耕地转为了建设用地,占转出总面积的14.35%。从转入类型来看,未利用地和林地转为耕地数量最多,分别为140.00 km2和116.09 km2。2005-2015年各地类之间的转换大致与上一阶段相同。1995-2015年研究区各土地类型相互转入转出量较大,土地类型转移变化十分明显,且呈“三增三减”的变化趋势,即林地、水域和建设用地增加,耕地、草地和未利用地减少。(4)在“快速城镇化情景”下,建设用地急剧扩张,35年间其面积增加了一倍,达到1 390.46 km2,且主要来源为耕地,约占转出耕地面积的一半;林地增长十分缓慢,草地和未利用地持续减少,到2050年分别减少了186.58 km2和69.40 km2,未利用地减少了一半。在“规划情景”下,建设用地增长仍然较快,2050年增加了347.92 km2,增幅达37.92%;耕地减幅有所下降,林地增加也比“快速城镇化情景”要快,但草地和未利用地仍在持续减少,35年间分别减少了25.9%和44.3%。而在“生态保护情景”下,林地、草地、未利用地等生态用地不断恢复和增加,到2050年,生态用地总面积占研究区64%;建设用地无序扩张得到限制,到2050年其总面积为1 171.42 km2,比同期“快速城镇化情景”减少了219.04 km2;耕地虽有减少,但逐渐趋于平衡,始终保持在6 000 km2以上。(5)研究区未来不同情景下土地利用变化的生态系统服务价值变化与各土地利用类型面积变化密切相关,即当生态系统服务功能单价一定时,土地利用类型面积的增加或减少直接导致其对应的生态系统服务总价值的增加或减少。未来三种情景下,由于研究区土地利用变化呈现“三减、两增、一平”的趋势,即耕地、草地和未利用地持续减少,林地和建设用地持续增加,水域总体上变化不明显,其对应的生态系统服务价值也呈现相同的变化趋势。但从生态系统服务总价值的变化幅度来看,生态保护情景下的生态系统服务价值变化幅度最小,且林地、草地、水域等生态用地的生态系统服务价值比同期“快速城市化情景”、“规划情景”都要大,其产生的生态环境效应也比较明显。因此,“生态保护情景”是研究区未来经济、社会和环境协调发展较为理想的模式。研究结果可为该地区土地规划、区域可持续发展提供科学参考。
[Abstract]:At present, human activities affect the land use pattern and its change. Therefore, to explore the cause and mechanism of land use change, simulation of the future land use pattern of the current land policy, has important significance to Fuling land planning. The lower reaches of Wujiang six counties as the research area, based on 1995, 2005, 2015 Landsat image solution the data, using GIS spatial analysis technology, CA-Markov model and MCE model, realize the spatio-temporal patterns of land use simulation. Combined with scenario analysis method on "rapid urbanization scenario", "scenario planning" and "ecological protection scenario" under the three modes of the study area in 2020, 2030, 2050, the land use pattern equivalent factor of ecosystem services value. Making reference to other scholars, combined with the actual situation in the study area, using the net primary productivity of vegetation, rainfall, soil data in the study area of the single Area ecosystem service function value equivalent to correction, and then through the ecosystem service value estimation method, the calculation of ecosystem services under different scenarios of the future research area. The results show that: (1) the study area is mainly farmland and woodland, and both accounted for 86% of the total area and more than 20 years. The process of farmland has experienced first decrease and then increase ", 10 years before the reduction of 451.85km2, the total area of cultivated land (1995) of the 6.84%, after 10 years of cultivated land area increased slightly, but the growth rate is relatively slow; on the contrary, woodland continued to increase in 20 years, an increase of 894.49 km2 in 2015 than in 1995, an average annual increase in addition to 0.4%., the area of grassland and unused land 20 years continue to decrease, especially the unused land decreased 590.61 km2, accounting for the total unused land area (1995) of the 80%, and mainly converted to farmland and woodland. Water area change is slightly undulating, but on the whole Amplitude. (2) the difference of land use dynamic degree of 20 years of the study area are obvious. The single land use dynamic degree, not use change greatly the maximum, 1995-2015 years to reach -8%; followed by the construction land, 10 years ago than 10 years after the change to be big, the overall trend is increasing year by year; the annual dynamic degree of cultivated land and woodland were less than 1%, while the former has slowly increased after the first reduction trend, the latter showed a slight increasing trend; grassland showing a decreasing trend, and the change of amplitude 10 years more; the overall water change is steady. The comprehensive dynamic degree of land use, three time around the comprehensive dynamic degree is less than 2%, among them, farmland, woodland, water area and construction land use dynamic degree is less than 1%, and the grassland and unused land between the comprehensive dynamic degree basically is 1%-2%, which shows that the study area land use change The overall magnitude or intensity, but the individual changes obviously. (3) the largest amount of cultivated land during the period of 1995-2005, 783.26 km2, 2.36 times to the total cultivated area is greatly reduced, can not be ignored. From the view of cultivated land types, ranked first is converted to woodland, the number is 627.93 km2. Transfer accounted for 80.17%. of the total area followed by the construction land, during which there is 112.38 km2 the conversion of cultivated land to construction land, accounting for 14.35%. of the total area to turn out from the type of view, unused land and forest to farmland were the largest number of conversion between 140 km2 and 116.09 km2.2005-2015 around the class of general and a the same year.1995-2015 land types in the study area are transferred into a large amount of land transfer type change obviously, and a three increase three decrease in the trend, namely, woodland, waters and the increase of construction land, Cultivated land, grassland and unused land decreased. (4) in the "rapid urbanization scenario", construction land expansion, 35 years the area has doubled, reaching 1390.46 km2, and the main source of cultivated land, accounting for about half of arable land transfer; forest growth is very slow, grassland and unused land continued to decline, to 2050 were reduced by 186.58 km2 and 69.40 km2, the unused land decreased by half. In the "Planning scenario", construction land is still growing rapidly, in 2050 increased 347.92 km2, an increase of 37.92%; reduction of cultivated land decreased, woodland increased than the "rapid urbanization scenario" to be fast, but grassland and unused land continues to decrease, 35 years were reduced by 25.9% and 44.3%. in the "ecological protection scenario", woodland, grassland, unused land and ecological land to recover and increase, by 2050, the ecological land total area of 64% building; A land sprawl is limited to 2050, the total area is 1171.42 km2, 219.04 km2 less than the same period of "rapid urbanization situation"; cultivated land has reduced gradually, but the balance remained above 6000 km2. (5) the study area under different scenarios of land use change of ecosystem services the value and the land utilization type area is closely related to the changes, i.e. when the ecosystem services unit when land area increase or decrease in the total value of ecosystem services directly lead to the corresponding increase or decrease in the future. Three scenarios, due to the presentation of "minus three, two increase of land use change in the study area, a flat trend, namely arable land, grassland and unused land decreased, woodland and construction land continued to increase, the overall water change is not obvious, the ecosystem service value also showed the same The change of trend. But the variation in the total value of ecosystem services of grassland ecological protection scenario of the changes of ecosystem service value was the smallest, and woodland, waters, and other ecological land ecosystem service value than the same period of "fast city scene", "Planning scenario" should be large, ecological and environmental effects it is also more obvious. Therefore, the "ecological protection scenario" is the research area of future economic, social and environmental coordinated development pattern is ideal. The research results can be used for land planning in the region, and provide scientific reference for regional sustainable development.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：F301.2;P208

【参考文献】