基于PSR模型的四川生态系统健康时空动态研究
西南石油大学土木工程与建筑学院,成都 610500
Spatial-temporal dynamics of ecosystem health in Sichuan Province based on PSR model
School of Civil Engineering and Architecture, Southwest Petroleum University, Chengdu 610500,China
责任编辑: 张仙
收稿日期: 2019-05-17 修回日期: 2019-08-15 网络出版日期: 2020-06-15
基金资助: |
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Received: 2019-05-17 Revised: 2019-08-15 Online: 2020-06-15
作者简介 About authors
徐洲洋(1994-),男,硕士研究生,研究方向为地理信息技术的应用。Email:787090191@qq.com。 。
四川省快速的经济发展和城镇化进程,引发了许多生态环境问题,评价其生态健康状况对区域可持续发展具有重要的意义。基于2000—2016年间四川省社会、经济、农业、生态等市级数据,以及降尺度模型获取的县级数据,建立压力-状态-响应模型,分市级和县级2种尺度对四川省区域的生态系统健康进行综合评价和分析。结果表明: 在2000—2016年间,四川省生态系统健康状况整体得分从0.610上升到0.687,整体的生态状况越来越好,但区域之间的发展极不平衡,东部地区优于西部地区,成都市的优势突出,与其他地区的差距明显; 对各县的生态系统健康状况评价等级为“不健康”及“病态”的县占总数的27.9%,一半左右的县在“正常”等级以上, 等级为“病态”的县主要集中在甘孜藏族自治州和阿坝藏族羌族自治州,应对川西北部的生态健康状况引起足够的重视。
关键词:
A great many ecological and environmental problems have been caused in the course of rapid economic development and urbanization in Sichuan Province. Evaluating ecosystem health condition is of significant importance for regional sustainable development. Based on relevant city-level data in social, economic, agricultural and ecological aspects from 2000 to 2016 as well as county-level data obtained through the downscaling model, the authors built the pressure-status-response model to make comprehensive evaluation and analysis of ecosystem health of studied regions in Sichuan Province on city-level and county-level scales. The results show that the overall score of ecosystem health in Sichuan increased from 0.610 to 0.687 in 2000—2016, but the spatial distribution shows that the eastern part of Sichuan was better than the western part. The development between studied regions is extremely unbalanced. Chengdu had outstanding advantages in comparison other regions. The results of ecosystem health assessment in each county shows that 27.9% of the total counties are “unhealthy” and “sick”, while about half of the counties are above the “normal” level. The counties whose evaluation results are “sick” are mainly concentrated in Garze and Aba prefectures. The ecological health status in northwest Sichuan deserves much more attention.
Keywords:
本文引用格式
徐洲洋.
XU Zhouyang.
0 引言
自生态系统健康的概念[4]提出以来,国内外的学者围绕生态系统健康的问题开展了一系列的研究,都取得了显著的效果。目前,针对城市[5]、湿地[6]、森林[7]、海洋[8]和农业[9]等不同类型的生态系统,已有不同的模型来对其生态系统健康状况进行评价。1979年,Murray等[10]对海洋生态系统受放射性辐射影响进行评估,并研究出了一种可行的方法; Spiegel等[11]在对城市生态系统健康评估的过程中使用了驱动力-压力-状态-响应模型来进行研究,取得了不错的效果; 江香梅等[12]对鄱阳湖湿地生态系统进行了研究分析,并根据目前所面临的问题(如水域面积减小、生物多样性降低、水质水量下降等),对鄱阳湖湿地生态系统恢复从多个方面提出了可行的建议。遥感(remote sensing, RS)和地理信息系统(geographic information system,GIS)技术在生态系统健康研究方面的运用[13]推动了生态监测的发展。汪阳等[14]基于GIS系统对洪泽湖生态系统健康状况进行了综合评估; 陈鹏[15]利用压力-状态-响应(pressure-state-response,PSR)模型,在RS和GIS技术支持下获取厦门新区(翔安区)的生态健康评价指标,定量地评价了城市新区生态健康状况。
生态系统健康评价中常用的PSR模型是一种多变量的方法,它不仅关注生态系统健康的自然属性,而且在评价过程中还将这些自然属性与人类属性相结合[16]。目前,四川省经济发展较快但省内区域发展极不平衡,需要对其生态状况进行细致的评价和分析,做出有利于可持续发展的选择。本文利用PSR模型对四川省2000—2016年间的相关数据进行整理,对四川省的市级生态系统健康状况进行了评价,运用空间分析模型,对生态系统健康状况变化趋势进行了深入剖析,进而利用降尺度模型开展了更加精细化的县级尺度评价,旨在为四川省的可持续发展状态评估提供决策支持。
1 研究区概况及数据源
1.1 研究区概况
本文研究区四川省位于我国西南部,地理范围在N26°03'~34°19',E92°21'~108°12'之间(图1),面积约为48.6万km2; 共包含21个地市级行政区划单位和183个县级行政区划单位。区域内环境复杂,物种多样性高; 地势呈西高东低特点,包括山地、丘陵、平原盆地和高原等不同的地形,不同地区之间的气候、自然环境和社会经济差异较大。省会成都市地处成都平原,自然资源和环境条件优越,人口众多,在省内经济发展状况一直处于领先地位。
图1
1.2 数据源及其预处理
四川省2000—2016年间市县级相关社会经济数据来源于《四川省统计年鉴》和《区域经济统计年鉴》,少量缺失的市县级数据从《中国县级统计年鉴》中补充,最后通过拟合各指标时间序列趋势对异常和遗漏数据(其占比仅为0.72%)进行了矫正和补充。气象站站点数据从中国气象局网站下载(
2 研究方法
2.1 PSR评价模型与框架
表1 生态系统健康评价指标
Tab.1
一级指标 | 二级指标 | 三级指标 | 权重 | ||
---|---|---|---|---|---|
压力 | 自然 | 气温距平 | 0.065 | ||
降雨距平 | 0.094 | ||||
农业 | 农作物播种面积 | 0.263 | |||
化肥施用量 | 0.138 | ||||
人口 | 人口密度 | 0.216 | |||
人口自然增长率 | 0.223 | ||||
状态 | 经济 | 人均国内生产总值(gross domestic product,GDP) | 0.197 | ||
农民人均纯收入 | 0.224 | ||||
农业 | 单位面积粮食产量 | 0.183 | |||
单位面积粮食产量 | 0.232 | ||||
生态 | NDVI | 0.163 | |||
响应 | 农业 | 农业机械总动力 | 0.222 | ||
有效灌溉面积 | 0.179 | ||||
社会 | 公路总里程 | 0.174 | |||
第三产业占比 | 0.085 | ||||
人均地方财政一般预算支出 | 0.168 | ||||
人均全社会固定资产投资 | 0.171 |
式中: ki为第i种一级指标(压力、状态、响应)内的三级指标总个数; Si为压力、状态和响应的得分值; Wij为第i种一级指标内第j个三级指标的权重; Fij为第i种一级指标内第j个三级指标的归一化值; Q为区域生态系统健康综合得分。
2.2 空间演变分析
2.2.1 区域生态系统健康的全局特征
变异系数是衡量指标中各观测值变异程度的统计量。本文中则主要反映了各区域之间发展的平均程度,变异系数越大区域之间发展越不平衡。当需要比较2个或多个指标的变异程度时,如果度量单位与平均数相同,可以直接利用标准差来比较。变异系数Cv的计算公式为:
式中: σ为各地区生态系统健康得分的标准差; u为各地区生态系统健康得分的平均值。
2.2.2 区域生态系统健康的局部演化特征
本文中生态系统健康状况在空间中的迁移过程可以利用重力模型进行分析[27]。设大区域由n个小区域组成,而(Xi,Yi)为第i个小区域的重心坐标,Hi为其属性值,则大区域的重心坐标(
标准差椭圆由旋转角θ、沿x轴的标准差δx和沿y轴的标准差δy这3个要素组成。θ可以看作是笛卡尔坐标系下x轴和y轴按照点集分布的地理方位沿一定角度旋转后,正北方向与顺时针旋转的主轴之间的夹角[28]。各要素计算公式为:
式中
2.3 县级指标数据获取方法
县级评价能更加细致地对区域生态系统健康状况进行评价,为了使评价结果之间的关联性更强,评价的指标应该确保统一。但农业机械总动力和农林牧渔业总产值县级的数据不够完整,需要运用数学方法进行推算。
农业机械总动力是指用于第一产业的所有动力机械的动力的总和。农林牧渔业总产值反映了一定时期内农业生产的规模。县级统计数据获取是在市级数据的基础上通过已有的该指标数据与土地利用类型和其他社会经济农业数据的相关性分析,建立线性回归方程实现的,即
式中: Y为推算农业机械总动力和农林牧渔业总产值的县级指标系数; ai(i=1,2,…,m)为系数; xm为第m个与该指标极其相关的推算因子,例如,Y表示农业机械总动力时,通过与已有数据的相关性分析,得相关因子分别为不透水面面积、耕地面积、荒地面积和第一产业产值; YX为推算的某指标各个县的值; YS为各个市的实际值; n为该市的县级行政区的个数。
将实际数据与推算出的数据的散点图进行拟合的情况见表2。虽然农业机械总动力拟合精度偏低,但是由于数据的特殊性,只有约23.5%的县的数据缺失。部分缺失的县的数据可以用市级数据直接准确推算出。
表2 推算数据与原始数据拟合结果
Tab.2
指标 | 拟合方程 | 决定系数R2 |
---|---|---|
农业机械总动力 | y = 0.787x+5.250 | 0.82 |
农林牧渔总产值 | y = 0.989x+0.349 | 0.98 |
3 结果与讨论
3.1 市级生态系统健康的整体特征
四川省市级生态系统健康的总体趋势如图2所示。结果表明,整体上看2000—2016年期间四川省的生态系统健康总体在上升,在2000年整个研究区平均健康评分为0.610,而2016年提高到了0.687。压力得分整体变化不大,整个研究时间段内的得分都在0.72~0.73内变化。另外,研究区的状态和响应得分平均下来分别以每年0.009和0.008的速度增加。状态得分除在2001年和2005年有所下降外,整体趋势是一直在增长。响应得分在整个研究时间段内一直在增长,在2007年之前增长较为缓慢,2007年以后增长速率持续加快。
图2
图2
2000—2016年四川省生态系统健康状况
Fig.2
Ecosystem health in Sichuan Province from 2000 to 2016
图3显示了生态系统健康的首位度在2005年以后呈现出增长的趋势,而在2005年之前呈现下降趋势。2005年以后,首位度平均每年增长0.001 5,且2011—2012年间增长最快,2012年的首位度较2011年增长了56.3%。变异系数在2005年之前略有下降,之后整体上也呈现平稳向上增长的状态,个别年份有所波动。
图3
图3
生态系统首位度和变异系数变化
Fig.3
Change of ecosystem primacy and coefficient of variation
3.2 市级生态健康的空间格局演化
图4
图4
四川省市级生态系统健康评价压力,状态和响应得分
Fig.4
City ecosystem health assessment pressure, state and response scores in Sichuan Province
图5
图5
2000年与2016年四川省市级生态系统健康状况
Fig.5
Ecosystem health status of Sichuan municipal level in 2000 and 2016
图6为四川省生态系统健康标准差椭圆及重心分布。
图6
图6
生态系统健康标准差椭圆及重心分布
Fig.6
Standard deviation ellipse and center of gravity distribution of ecosystem health
3.3 县级生态系统健康
首先运用降尺度模型[34]推算出2016年的县级数据,进行标准化处理,并计算权重。研究区内共有183个县级行政区划单位,考虑到县(区)个数较多,为了针对每个县得出更细化的结果,避免由于类别较少造成各个县对比不明显,故将县级生态系统的评价结果分为6类(图7)。如图7所示,研究区生态系统压力得分在0.61~0.93之间。压力得分最高的县有8个,占比4.4%,最差的县有29个,占比15.8%。四川省由SE向NW压力得分呈逐渐降低的趋势。状态得分在0.58~0.90之间,空间上从NW向SE递增。状态得分最高的县有13个,占比7.1%,近2/3的区县得分都在0.68以上,总体状态得分较好。响应得分在0.45~0.66之间,响应得分整体都比较高,得分最低的区县有16个,占比8.7%。绝大部分地区的响应得分都较好,空间分布上没有明显的规律,得分较高的区县在川东和川西都有分布。
图7
图7
县级生态系统压力、状态和响应得分
Fig.7
Scores of pressure, state and response of county-level ecosystem
图8
由于丰富的自然资源和良好的经济基础,成都平原的区县基本保持着较为健康的经济生态环境状态。虽然这些区域面临着密集的人口、过度的资源消耗和环境污染等问题,但整体上健康状况较好(图8)。与之相反,四川西部地区虽然在人口、资源消耗和环境污染等方面的压力较小,但该地区的生态系统较为脆弱,自然环境恶劣,导致其整体的得分偏低。总的来说,虽然自然环境较差的地区会受到较多的社会关注,但是由于自身生态的脆弱,整体生态系统得分一直不高; 四川东部地区虽然面临人口密集、环境污染和资源消耗等压力,但由于自身良好的自然环境,整体的生态系统健康状况依然较好。
4 结论
1)对2000—2016年间四川省区域生态系统健康状况的时空格局进行了深入分析,生态系统健康整体得分在16 a间从0.610提高至0.687,得分年平均增长0.005左右,大部分地区生态系统状况随时间推移越来越健康。
2)对区域首位度和变异系数的研究分析表明,在2005年以后各四川省地区间的差距在逐渐扩大,成都市的领先优势越来越明显,各市(州)之间的发展不平衡性在逐渐扩大。
3)四川省区域生态系统健康重心一直位于资阳市与眉山市交界处,东部的生态健康状况优于西部地区,西部地区恶劣的自然环境导致了生态环境脆弱,经济发展落后。
4)从全省县级评价结果来看,评价等级为“健康”的地区主要集中在东部; 而西部甘孜藏族自治州和阿坝藏族羌族自治州各区县的整体生态系统健康状况都较差,这些地区的生态系统健康状况需要重点的关注和保护。
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Land ecological security assessment for Bai Autonomous Prefecture of Dali based using PSR model-with data in 2009 as case
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基于PSR模型的大丰市城市生态系统健康综合评价
[J].文章以大丰市为例,探讨了城市生态健康的内涵及评价方法.研究中综合运用压力-状态-响应(PSR)模型和模糊数学方法,评价了具有复杂特性的城市生态健康问题,对城市生态健康评价的研究工作做出了有益尝试.文章采用基于PSR模型的城市生态系统健康评价方法,建立了影响城市生态系统健康各要素之间的联系,并结合模糊数学方法,较好的解决了生态健康评价标准的问题.研究结果表明,运用PSR模型将各种要素联系起来并考虑它们之间的相互作用,可以实现对城市生态系统健康的综合评价.
Ecosystem health assessment based on PSR model:A case study of Dafeng City in Jiangsu Province
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Assessment of ecological carrying capacity on the typical resources-based cities:A case study of Tangshan City
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熵权法在草原生态安全评价研究中的应用——以甘肃牧区为例
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The application of entropy-right method to the study of ecological security evaluation of grassland:A case study at the ecological security evaluation of grassland to pastoral area of Gansu
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Spatial shift-share analysis versus spatial filtering:An application to Spanish employment data
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The aim of this work is to analyse the influence of spatial effects in the evolution of regional employment, thus improving the explanation of the existing differences. With this aim, two non-parametric techniques are proposed: spatial shift-share analysis and spatial filtering. Spatial shift-share models based on previously defined spatial weights matrix allow the identification and estimation of the spatial effects. Furthermore, spatial filtering techniques can be used in order to remove the effects of spatial correlation, thus allowing the decomposition of the employment variation into two components, respectively related to the spatial and structural effects. The application of both techniques to the spatial analysis of regional employment in Spain leads to some interesting findings and shows the main advantages and limitations of each of the considered procedures, together with the quantification of their sensitivity with regard to the considered weights matrix.]]>
2001—2010年安徽省县域经济空间演化
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DOI:10.11820/dlkxjz.2013.05.014
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G指数、经济重心、标准差椭圆以及灰色G(1, 1)模型对县域经济的空间演化进行分析预测,最后结合位序规模原理,对空间差异的机理进行分析.总体上安徽县域经济表现出微弱的空间集聚分布态势,呈现出“南北低中间高”、“西低东高”的空间分布格局.县域经济重心在117.57°~117.6°E,31.67°~31.76°N之间变动,有向东南方向移动的趋势.标准差椭圆总体上变化幅度不大,基本上以省会经济圈为核心,范围覆盖了皖江城市带大部分地区,县域经济的空间分布呈现出西北—东南格局,并且这种格局有向正北—正南方向转变的趋势.安徽县域经济满足位序规模原理,其发展状况呈低水平分散均衡型.资源禀赋与交通区位、中心城市发展状况、区域政策是导致安徽省县域经济空间差异的主要原因.]]>
Spatial evolution of county economy in Anhui Province during 2001—2010
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DOI:10.11820/dlkxjz.2013.05.014
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G index, economic gravity centre, standard deviational ellipses and G(1, 1) prediction model, this article analyzes and forecasts the evolution of county economy, and, combined with the rank-size principle, analyzes the mechanism of spatial differences. Generally speaking, the county economy of Anhui Province presents a weak clustering distribution trend and shows a spatial pattern of "low in the north and south but high in the middle" and "low in the west but high in the east". The scope of economic gravity centre is 117.569°~ 117.598°E, 31.672°~31.760°N, and has the trend moving to the southeast. The change of standard deviational ellipses is very small; basically the core is capital economic circle, covering the most areas of Wanjiang City Belt. The spatial distribution of county economy presents a "northwest-southeast" pattern, and has the trend changing to "north-south" pattern. The county economy meets the rank-size principle and performs a low-level decentralized equilibrium pattern. Regional resources endowments and location, the development of central cities, and policies are the main reasons that cause the spatial differences.]]>
Spatio-temporal evolution and the influencing factors of PM_(2.5) in China between 2000 and 2011
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DOI:10.11821/dlxb201711012
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2.5 has been universally considered as a main cause for haze formation. Therefore, it is important to identify the spatial heterogeneity and influencing factors of PM2.5 concentration for the purpose of regional air quality control and management. Using PM2.5 data from 2000 to 2011 that is inversed from NASA atmospheric remote sensing images, and employing the methods in geo-statistics, geographic detectors and geo-spatial analysis, this paper reveals the spatio-temporal evolution patterns and driving factors of PM2.5 concentration in China. The main findings are as follows: (1) In general, the average concentration of PM2.5 in China has increased quickly and reached its peak value in the year of 2006; after that, it has been maintained at around 22.47-28.26 μg/m3. (2) PM2.5 is strikingly uneven in China, with a higher concentration in North and East than in South and West, respectively. In particular, the areas with a relatively high concentration of PM2.5 are mainly the four regions including the Huang-Huai-Hai Plain, the Lower Yangtze River Delta Plain, the Sichuan Basin, and the Taklimakan Desert. Among them, Beijing-Tianjin-Hebei Region has the highest concentration of PM2.5. (3) The center of gravity of PM2.5 has shown an overall eastward movement trend, which indicates an increasingly serious haze in eastern China. Particularly, the center of gravity of high-value PM2.5 is kept on moving eastward, while that of the low-value PM2.5 moves westward. (4) The spatial autocorrelation analysis indicates a significantly positive spatial correlation. The "High-High" PM2.5 agglomeration areas include the Huang-Huai-Hai Plain, Fenhe-Weihe River Basin, Sichuan Basin, and Jianghan plain regions. The "Low-Low" PM2.5 agglomeration areas include Inner Mongolia and Heilongjiang to the north of the Great Wall, Qinghai-Tibet Plateau, and Taiwan, Hainan and Fujian and other southeast coastal and island areas. (5) Geographic detection analysis indicates that both natural and human factors account for the spatial variations of PM2.5 concentration. In particular, factors such as natural geographical location, population density, automobile quantity, industrial discharge and straw burning are the main driving forces of PM2.5 concentration in China.]]>
长白山区植被生长季NDVI时空变化及其对气候因子敏感性
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p
Spatial-temporal variation of NDVI in the growing season and its sensitivity to climatic factors in Changbai Mountains
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DOI:10.11820/dlkxjz.2012.03.003
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In order to reveal the response of mountain ecosystem to climate change, the spatial-temporal distribution of vegetation variation in the Changbai Mountains was investigated by using the 10-day SPOT/VGT NDVI data from 2000 to 2009. Combining the meteorological data, we discussed the relationship between NDVI and climatic factors and time lags of vegetation variation response to climate change. The results are shown as follows. 1) NDVI increased from 2000 to 2009 in Changbai Mountains. The NDVI increased and decreased area covered about 83.91% and 16.09% of the whole study area respectively. The increased area was mainly distributed on the northern and western slopes, while the decreased area was distributed on the southern slope. The growth rate of NDVI centralized 0 - 0.006 /a. 2) The change rate of NDVI varied by seasons and vegetation types. The peak of NDVI slope appeared in May and September, but no increase, even a little decrease was observed in July; 3) There was a significantly positive correlation between NDVI and climatic factors (temperature and precipitation), and NDVI had a closer correlation with temperature than with precipitation for the three vegetation types. The results also revealed that a correlation between NDVI and temperature in tundra zone was stronger than that in the Korean pine-broadleaved mixed forest (700-1100 m) and coniferous forest (1100-1700 m), which indicated that vegetation at higher elevation is more sensitive to temperature change; 4) The correspondence between NDVI and climatic factors had a marked time lag for 10-20 days for the whole study area. Different vegetation types had different time lags. The response of NDVI in tundra zone to climatic factors had a time lag of about 10 days, while in the two forests mentioned above, the response had a time lag of about 20 days.
空间经济学视角下成都经济区经济引力模型的构建与运用
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The construction and application of economic gravity model in Chengdu economic zone from the perspective of spatial economics
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Geospatial analysis of fisheries to improve federal enforcement
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基于PSR模型的土地生态系统健康时空变化分析——以北京市平谷区为例
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Temporal and spatial variation of land ecosystem health based on the pressure-state-response model:A case study of Pinggu District,Beijing
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基于改进TOPSIS方法的三峡库区生态敏感区土地利用系统健康评价
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土地利用系统健康评价研究能够有效引导土地合理利用,协调城市发展与自然生态保护之间的矛盾。构建基于PSR 模型的土地利用系统健康评价指标体系,并采用改进TOPSIS方法对三峡库区生态敏感区的典型区域-重庆市进行实证分析。结果表明:1)研究区土地利用系统健康综合分值整体呈现T型带状分布格局,可分为四个健康等级,即健康、临界健康、不健康、病态。2)渝东北、渝东南和重庆市西南片区部分地区因其土地生态系统脆弱敏感,土地利用风险性大和生态系统稳定性差,土地生态系统呈现病态和不健康状态,属于高风险-高压力区域;重庆市主城区环线区域因其属于城市核心拓展区和人类活动频繁区域,人口压力指数和土地利用压力指数较大,土地利用风险性较小,健康度较为良好,是低风险-中度压力区域。3)PSR模型能够较好地改变现有研究主要关注自然资源环境的状况,更准确地反映土地利用系统健康的各要素之间的关系和影响土地生态系统健康的关键因素,为三峡库区生态敏感区土地利用系统健康状态起到一定的预警作用。4)以改进TOPsis方法计算土地利用系统健康指数,消除了不同指标量纲的影响,并能充分利用原始数据的信息,能充分反映各方案之间的差距,客观真实的反映实际情况。5)为保障三峡库区生态敏感区土地利用系统的健康发展,应加强土地利用规划与调整,控制人类过度开发,维持生态系统正常功能。
Health assessment of a land use system used in the ecologically sensitive area of the Three Gorges reservoir area,based on the improved TOPSIS Method
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Changes in aridity index and reference evapotranspiration over the central and eastern Tibetan Plateau in China during 1960—2012
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[本文引用: 1]
Based on climate data from 68 meteorological stations over the Tibetan Plateau (TP) observed by the China Meteorological Administration in 1960-2012, temporal and spatial variations in aridity index (AI) and reference evapotranspiration (ET0) were comprehensively investigated. The abrupt change and the period in AI and ET0 were characterized using a comprehensive time series analysis conducted with Mann-Kendall test and Morlet wavelet. The results indicated that the regionally averaged value of AI significantly decreased by 0.04/decade during 1960-2012 period, with the maximum observed in 1972. Similarly, the regional trend for ET0 was at the rate of -9.6 mm/decade with statistically significant at the 0.01 level. Most of these stations with positive value for AI were primarily distributed at the northern southwestern TP. Moreover, a majority of stations with low values of ET0 were substantially distributed at the central and eastern TP, and amounts of the stations with high values of ET0 were mainly located at a lower elevation. Abrupt changes of both AI and ET0 primarily happened in 1980s. The major cycles of AI and ET0 were 15 y and 17 y scale over the study period with apparent periodic oscillation characteristics, respectively, and together with other different scale cycles co-existing. The significant correlations between AI and East Asian Summer Monsoon Index (EASMI) indicated that AI over the TP was related to the EASMI. (C) 2014 Elsevier Ltd and INQUA.
Downscaling socioeconomic and emissions scenarios for global environmental change research:A review
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