KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 中亚阿姆河三角洲景观生态风险时空特征分析 | |
| Alternative Title | Spatial and Temporal Characteristics of Landscape Ecological Risks in the Amu Darya Delta, Central Asia |
| 于涛 | |
| Subtype | 硕士 |
| Thesis Advisor | 包安明 |
| 2020-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学硕士 |
| Keyword | 景观生态风险评价 空间自相关 地理加权回归 阿姆河三角洲 Landscape Ecological Risk Assessment Spatial Autocorrelation Geographic Weighted Regression Amu Darya Delta |
| Abstract | 一个稳定的生态系统是自然与社会和谐发展的基础。然而，随着人类活动的加剧和区域环境的变化，生态系统受到的干扰越来越强，面临的生态风险逐渐加大。生态风险反映了生态系统在受到外界压力干扰时功能发生退化的可能性。近年来，随着景观生态学的发展，一些学者基于景观格局与生态系统之间的相互作用，从景观生态学的角度提出了景观生态风险评价的研究方法。 与传统生态风险评价方法不同，景观生态风险评价主要突出了景观格局变化对生态系统功能以及生态进程带来的影响，能够从不同的尺度对生态风险进行空间分析，综合反映生态风险在时空上的变化特征。 因此， 对区域景观生态风险进行评价，并在此基础上分析其变化特征与驱动力之间的关系，可以为区域生态风险防范以及开展可持续的景观生态规划工作提供决策依据，具有重要意义。在最近几十年，由于受人类活动、全球气候变化以及“咸海危机” 的影响，阿姆河三角洲出现了土壤盐渍化、植被退化、沙尘暴等严重的生态环境问题，区域景观的结构和功能遭到破坏，生态系统稳定性逐渐降低，景观生态风险有升高的趋势。在此背景下，分析阿姆河三角洲景观生态风险变化特征及其驱动力具有重要意义，可以为阿姆河三角洲景观生态规划和环境保护以及推进“一带一路”沿线国家生态文明建设与经济可持续发展提供理论参考和决策依据。本文以中亚阿姆河三角洲为例，基于景观格局指数，构建了阿姆河三角洲景观生态风险评价体系，并利用空间自相关与地理加权回归分析的方法，对 2000年和 2015 年研究区景观生态风险进行了时空特征与驱动力分析。主要研究结论如下：（1）在研究期间，阿姆河三角洲主要的景观类型为耕地，其次为未利用地和草地。林地、水域和湿地面积较小，占据的面积不到三角洲的 7％； 从景观类型面积的变化情况来看， 2000-2015 年耕地、建设用地和未利用地面积有所增加，而湿地、水域、草地和林地的面积则出现不同程度的减少，其中减少幅度最大的是林地和草地，面积分别减少了 37.55％和 32.70％。（2）景观生态风险的时序变化表明， 2000-2015 年阿姆河三角洲景观生态风险整体上呈增加趋势，高风险等级区域在原来基础上增加了 86.55%； 研究区大部分区域处于低生态风险和较低生态风险等级，占据的面积大约为三角洲的 55%左右； 此外与 2000 年相比， 2015 年中度与较高生态风险等级的面积均有所下降，下降比例分别为 7.92％和 5.06%。（3）从景观生态风险的空间格局来看， 2000 年与 2015 年阿姆河三角洲景观生态风险等级在空间分布上具有较强的一致性：风险等级从三角洲的外围到内部均呈现出下降的趋势； 研究期间中度和高生态风险等级主要分布在阿姆河三角洲的外围和努库斯市附近； 而具有较高生态风险等级的区域则主要分布在阿姆河三角洲的下游； 此外，大多数低生态风险和较低生态风险区域主要位于三角洲的西部和中部； 同时从景观生态风险空间分布的变化情况看， 2000-2015 年高生态风险等级在三角洲的下游有明显扩张的趋势； 此外 2000-2015 年生态风险等级在三角洲的土库曼斯坦区域有下降趋势，而在乌兹别克斯坦则呈现上升趋势。（4）空间自相关分析的结果表明 2000 年和 2015 年景观生态风险的莫兰指数值分别为 0.669 和 0.719，均为正值，这说明景观生态风险在空间上的聚类现象明显，同时存在很强的正相关性； 空间聚类分析的结果显示 2000 年与 2015 年阿姆河三角洲景观生态风险在空间上主要为“高-高” 和“ 低-低” 型的空间聚类模式，其中“高-高” 型主要分布在三角洲外围和下游， “低-低” 型则主要分布在三角洲的中部和上游。（5）景观生态风险的驱动力研究表明，地理加权回归（Geographic WeightedRegression, GWR） 比普通最小二乘回归（Ordinary Least Square, OLS） 模型在评估本研究驱动因子对景观生态风险时的效果要好； GWR 模型的结果显示，在阿姆河三角洲的大部分区域归一化植被指数 NDVI（ Normalized DifferenceVegetation Index） 与景观生态风险呈负相关关系，这说明植被的增加对景观生态风险有抑制作用，而地表温度 LST（Land Surface Temperature） 和 DEM 则与景观生态风险有较强的正相关关系； 同时在阿姆河三角洲的中部，农作物产量与景观生态风险呈正相关关系，这表明频繁的农业活动可能会加剧该区域的景观生态风险； 在城市和道路节点区域，道路密度与景观生态风险呈正相关关系，在这些区域道路密度的增加会导致较高的景观生态风险； 此外人口密度与景观生态风险的正相关系显著，且与 2000 年相比，这种正相关关系在 2015 年已经扩展到了阿姆河三角洲的下游。 |
| Other Abstract | A stable ecosystem is the basis for the harmonious development of nature andsociety. However, with the intensification of human activities and the changingenvironment, many serious disturbances have occurred in natural ecosystems, whichhave led to many ecological risks. Ecological risk reflects the possibility of degradationwhen an ecosystem is subjected to external pressures. As an important branch ofecological risk, compared with traditional ecological risk assessment, it emphasizes theimpact of landscape patterns on specific ecological functions or processes, and paysmore attention to the spatiotemporal heterogeneity and scale effects of risks. Landscapeecological risk emphasizes the spatial scale effect of ecological risks and provides away to spatially represent multi-source ecological risks. Therefore, landscapeecological risk assessment can provide a theoretical basis and technical support forlandscape ecological construction.In recent decades, due to the impact of human activities, global climate change,and the “Aral Sea Crisis”, the Amu Darya Delta (ADD) has experienced seriousecological and environmental problems such as soil salinization, vegetation degradation,and dust storms. The structure and function of regional landscapes have been damaged,the stability of ecosystems has gradually decreased, and landscape ecological risks haveincreased. Therefore, it is important to analyze the characteristics and driving factors oflandscape ecological risk changes in the ADD, which can provide theoretical referencesfor the ecological planning and environmental protection of the ADD and to promotethe ecological civilization construction and sustainable economic development ofcountries along the “Belt and Road”.In this study, the ADD was selected to construct landscape ecological risk index(LERI) values for 2000 and 2015. And the spatial and temporal characteristics anddriving forces of LERI in the study area in 2000 and 2015 were analyzed by using themethods of spatial autocorrelation and geographical weighted regression (GWR),respectively. The conclusions are as follows：(1) During the study period, the main landscape type was farmland, followed byunused land and grassland. The areas of forest land, water and wetland were small,occupying less than 7% of the ADD. From the perspective of the change in the area oflandscape types in the ADD, the area of farmland, construction land and unused landincreased from 2000 to 2015, while the areas of wetland, water, grassland and woodforest land declined, among of them forest land and grassland decreased by 37.55% and 32.70%, respectively.(2) The temporal changes of LERI showed that the levels of landscape ecologicalrisk in ADD had an increased trend from 2000 to 2015, and the area of high-risk areasincreased by 86.55%. In addition, compared with 2000, the proportion of moderateecological risks and sub-high risks in the ADD decreased in 2015, with the decline ratesof 7.92% and 5.06%, respectively.(3) The spatial pattern of LERI revealed that LERI decreased from the peripheryof the ADD to the central and that high-risk areas were distributed in the ADD’sdownstream region. During the study period, the medium risk and high-risk areas weremainly located in the periphery of the ADD and near the city of Nukus; the sub-highrisk areas were mainly distributed in the lower reaches of the ADD; most of the lowrisk regions were mainly located in the western and central parts of the ADD.Meanwhile, from 2000 to 2015 in the lower reaches of the ADD, the high-risk areashad a significant expansion trend.(4) The Moran’s I index values for 2000 and 2015 were 0.669 and 0.719,respectively, indicating pronounced spatial aggregation of the LERI. The risk “hot spot”areas were mainly distributed in the periphery and downstream regions of the ADD,whereas the “cold spot” areas were mainly concentrated in the middle of the ADD.(5) The GWR model indicated that crop yield and the LERI exhibited significantpositive correlations in the middle of the ADD. In the most part of the ADD, NDVI hada significant and negative impact on the LERI. Road density was positively correlatedwith the LERI in cities and roads, and in most areas of the ADD, the LST and DEM hadpositive impacts on the LERI. In 2000 and 2015, the population density wassignificantly positively correlated with the LERI in the densely populated cities of thecentral delta and ADD’s surrounding areas. Moreover, the positive impact of populationdensity on the LERI gradually extended from 2000 to the downstream regions of theADD in 2015. |
| Subject Area | 地图学与地理信息系统 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15467 |
| Collection | 中国科学院新疆生态与地理研究所 研究系统 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 于涛. 中亚阿姆河三角洲景观生态风险时空特征分析[D]. 北京. 中国科学院大学,2020. |
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