陕南汉江水源地土地利用时空动态与生态效应测评

发布时间：2018-04-06 04:08

本文选题：陕南汉江水源地　切入点：土地利用动态　出处：《陕西师范大学》2014年博士论文

【摘要】：中国是一个严重缺水的国家,人均水资源占有量仅有世界平均水平的四分之一,空间分布的巨大差异又使北方地区缺水更为严重,南水北调中线工程承担着北方地区水资源调配的重任。陕南汉江流域上游是南水北调中线工程的重要水源区,其土地利用及其变化关系着水源地自身的生态环境及安全,更对我国北方地区的用水安全及社会经济发展产生深远影响。土地利用及其覆被变化时全球变化研究的重点问题之一,土地利用变化的生态效应测评是目前研究的热点问题。本文以南水北调中线工程重点水源区——汉江上游陕南段为研究对象,基于GIS和RS支持,收集与处理遥感、气象、植被、土壤、统计等多源数据,建立Geodatabase数据库对空间数据和属性数据进行一体化管理,从对土地利用变化的现状分析入手,基于土地利用动态度、土地利用转移矩阵、景观格局指数等定量评估该区域的土地利用变化状况,继而估算土地利用变化所引起的植被净第一性生产力效应、保土效应和水源涵养效应,最后对保持的物质量进行价值量转换,得到生态效应价值量。本研究对优化汉江水源区土地利用格局,提升水源涵养能力,对水源地为涵养水源而实施的土地利用变化的机会成本补偿依据提供参考,实现国家水资源优化配置具有重要理论和现实意义。主要结论如下： (1)生态用地持续增加,土地利用变化活跃区集中在河谷盆地及低山丘陵区。耕地和林地面积变化最大,研究时段,耕地减少484.44km2,林地增加425.54km2,耕地和林地的转移量占到总转移量的43%,主要表现为耕地向林地的转化；增幅最大的是水域和建设用地,年均动态度分别达到1.19%和0.98%,但是比重较低,生态影响不大；土地利用变化的活跃区主要集中在河谷盆地及低山丘陵区,这是土地利用变化的重点监控区。 (2)土地破碎化程度高,景观格局空间差异大,连通性有增强趋势。林地斑块面积最大,为364.28hm2,连通性最高,其中高山区斑块数量少,面积大,而低山丘陵和河谷盆地区,林地破碎,斑块数量众多。耕地斑块数量最多,达55647块,其中,河谷盆地连通性较好,斑块数量少且面积大,而从低山丘陵至中山区,斑块数量虽倾向于减少,耕地零散分布,破碎化程度相当高,反映出秦巴山地区耕地分布的宏观特点。CA、CONTAG、AI、TE、ED等景观指数动态变化显示出研究区类型斑块有聚集度增大、连通性增强的变化趋势。 (3)土地利用变化的生态效应物质量增加显著、空间差异较大。2000、2006、2012植被第一性生产力达6.05×107t,7.25×107t,7.42×107t/a,保持土壤量达到3.85×108t/a、2.53×108t/a和4.20×108t/a,总涵养水源量达到14.23×108t/a、15.41×108t/a、16.38×108t/a,数量巨大,生态效应显著且持续增加,生态环境物质生产能力和保土保水能力快速提升。生态效应保持物质量的低值区集中于河谷盆地,高值区集中于南北两侧山地。空间分布表明随高程增加,自然植被覆盖度增加而带来的生态效应显著。但从动态变化角度来看,增幅最大的区域集中在海拔1000m以下的河谷盆地和低山丘陵区,河谷盆地为研究区主要工农业生产生活集中区域,土地利用方式改变难度大,生态效应物质量提升潜力较小,因此,低山丘陵区成为未来提升生态效应物质保持量的重点区域。 (4)土壤侵蚀强度和程度空间差异巨大,河谷盆地与低山丘陵区为土壤保持工作的重点区域。但从土壤实际侵蚀系数来看,低山丘陵区和河谷盆地区的实际侵蚀程度均较高,侵蚀程度可达40%以上,是土壤保持和治理工作的的重点区域。 (5)地利用变化生态效应价值总量巨大且不断增加,水源涵养机会成本高。2000、2006和2012年生态总效益依次为723.97、855.23和882.57亿元；12年增加了158.60亿元。生态系统总价值中,固碳释氧价值量的贡献率最高,其次为干物质生产价值。NPP干物质价值、固碳释氧价值、保持土壤价值、涵养水源价值的高值区均在两侧山区,低值区均在河谷盆地,低山丘陵为过渡区,反映着自然植被随高程增加而增加所带来的环境效应,但是从生态总价值变化幅度来看,总价值量较低的河谷盆地和低山丘陵区增幅较大,反映出此区域土地利用变化生态效应价值量变化最大的区域,也是应进行生态补偿的重点区域。 (6)论文创新点： ①南水北调中线工程水源区承担着我国北方缺水地区水资源调配的重任,水源涵养问题至关重要。以往的研究多就水论水,但水源涵养是一个涉及气候、地形、植被、土壤、人类活动等多要素的复杂问题,需要进行系统研究。本研究首次基于系统思维,对南水北调中线工程水源区汉江上游陕南段进行lucc变化的水土保持效应研究。 ②在前人土壤侵蚀通用方程基础上,利用土壤保持措施因子P和植被覆盖与经营管理因子C,得到土壤实际侵蚀系数,可有效的反映土壤侵蚀程度,更加准确地说明人类活动对土壤侵蚀的影响程度。
[Abstract]:China is a serious water shortage in the country, the per capita water resources is only 1/4 of the world average, huge differences in spatial distribution and the northern region of water shortage is more serious, the South-to-North Water Transfer Project plays an important role in water resources in the north of Shaanxi. The deployment of the upper reaches of the Hanjiang River is an important water source area of the middle route of South to north water diversion project the land use change, and the relationship between the ecological environment and the safety of water itself, more far-reaching impact on northern China's water security and social and economic development.
Land use and land cover change is one of the key issues of global change research, land use change ecological effect evaluation is a hot topic of current research. Based on the South-to-North Water Diversion Project of key water area in the upper reaches of the Hanjiang River as study object, based on GIS and RS to support, collection and processing of remote sensing, meteorological, vegetation. Soil, multi-source data statistics, establish Geodatabase database integrated management of spatial data and attribute data, starting from the analysis of present situation of land use change, based on the dynamic degree of land use, land use transfer matrix, land use changes in the regional assessment of landscape pattern index and quantitative estimation of vegetation net primary productivity effect due to the change of land use, soil conservation effect and water conservation effect, to maintain the quality of the final value conversion, get the ecological effect of price The amount of value. This study on the optimization of land use pattern of water source area of Hanjiang River, improve water conservation capacity of water sources for water conservation and the implementation of the reference of land use change in the opportunity cost compensation basis, realize the optimal allocation has important theoretical and practical significance of national water resources. The main conclusions are as follows:
(1) the ecological land continued to increase, the land use change active area concentrated in the river basin and hilly area. The change of cultivated land and forest land area, study period, the decrease of cultivated land 484.44km2, woodland increased 425.54km2, the transfer amount of cultivated land and forest land accounted for the total transfer amount of 43%, mainly for the conversion of farmland to forestland is the largest increase; water area and construction land, the annual dynamic degree reached 1.19% and 0.98%, but the proportion is low, the ecological impact of land use change; active area mainly concentrated in the river basin and hilly area, which is the key monitoring area of land use change.
(2) a high degree of fragmentation of land, landscape spatial pattern, connectivity has increased. Forest land area is the largest, 364.28hm2, the highest connectivity, including the number of mountain area, and less plaque, hilly and valley basin area, woodland fragmentation, patch number. Many cultivated land had the largest number. Up to 55647, among them, the valley basin better connectivity, the number of patches and area, and from the hills to the Zhongshan area, although the number of patches tend to reduce the amount of arable land, scattered distribution, a high degree of fragmentation, reflect.CA, macroscopic characteristics of Qinba mountain area of cultivated land distribution of CONTAG, AI, TE, ED the dynamic change of landscape index shows the types of plaque aggregation increased, enhanced connectivity trends.
(3) the ecological effect of land use change in quality increased significantly. The spatial difference of.200020062012 vegetation is 6.05 * 107t, 7.25 * 107t, 7.42 * 107t/a, keep the soil volume reached 3.85 * 108t/a, 2.53 * 108t/a and 4.20 * 108t/a, the total water conservation quantity is 14.23 * 108t/a, 15.41 * 108t/a. 16.38 * 108t/a, a huge number, the ecological effect of a significant and sustained increase, rapid promotion of ecological environment material production capacity and soil water holding capacity. The ecological effect of keeping the quality of the low value area concentrated in the valley basin, the high value area focused on the two sides of North and South mountain. The spatial distribution shows that with increasing elevation, the natural increase of vegetation coverage. But the ecological effect caused by the significant. But from a dynamic point of view, the biggest increase in regional concentration at an altitude of 1000m valley basin and hilly area, river basin as the research area is mainly industrial and agricultural production and living in In the middle region, land use change is very difficult, and the quality of ecological effects is little. Therefore, hilly area will become a key area to enhance the material holding amount of ecological effects in the future.
(4) the difference of soil erosion intensity and the degree of space is huge, and the valley basin low mountain and hilly areas for soil conservation work in key areas. But from the actual soil erosion coefficient, the actual degree of erosion in hilly area and river basin area were higher, the degree of erosion is more than 40%, is the key area of soil conservation and management the.
(5) land use change and ecological effects of the total value of the huge and growing, water conservation and ecological high opportunity cost.20002006 2012 total efficiency were 723.97855.23 and 88 billion 257 million yuan; 12 years increased 15 billion 860 million yuan. The total value of ecosystem, carbon fixation and oxygen release value of the highest contribution rate, followed by dry matter production value of.NPP dry matter value, carbon fixation and oxygen release value, soil conservation value, high values are on both sides of the mountain water conservation value, low value area in the valley basin, low mountains and hills for the transition area, reflects the natural vegetation and environmental effect caused by the increase with the elevation increased, but from the total value of ecological change rate the total value of low growth, valley basin and hilly area is larger, this value reflects the regional variation of regional land use change and ecological effects of the largest, but also should focus on regional ecological compensation.
(6) the innovation of the paper:
The water source area of the South-to-North Water Diversion Project plays an important role in water resources in the north of China water allocation, water conservation is very important. Previous studies on water on the water, but the water conservation is related to climate, topography, vegetation, soil, human activities and other factors of complex problems, the need for system research. This is the first study based on systematic thinking, study on Soil and water conservation effect of LUCC change on the upper reaches of Hanjiang River water source area of the South-to-North Water Transfer Project in southern Shaanxi section.
Secondly, based on the general equation of soil erosion, soil erosion factors were obtained by soil conservation measures P and vegetation cover and management factor C, which can effectively reflect the degree of soil erosion, and more accurately explain the impact of human activities on soil erosion.

【学位授予单位】：陕西师范大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P208;F301.24

【参考文献】