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1.
气候和人为因素对植被变化影响的评价方法综述   总被引:2,自引:1,他引:1  
系统评价气候变化和人为因素引起的植被退化,对有效开展生态工程建设、实现生态环境的可持续发展具有重要意义。目前绝大多研究主要分析气候因素对植被变化的影响,分析气候因素和人类活动对植被变化的双重影响少有研究。本文主要介绍这一双重影响对植被变化的贡献程度的主要研究方法——定性-半定量法、回归分析法、残差趋势法、基于净第一生产力的评价方法。综述分析了气候和人为因素对植被变化驱动的主要结论,总结目前各研究方法存在的问题,提出了未来需要重点加强气候和人为因素对植被变化驱动因素的分解研究,加强模型评价和不确定性量化研究等。  相似文献   

2.
青藏高原草地生态系统碳收支研究进展   总被引:7,自引:3,他引:4  
陆地生态系统碳收支仍然是当前全球气候变化研究的重要内容,青藏高原作为全球气候变化的敏感区,使青藏高原草地生态系统在区域碳收支平衡中占有主导地位,但研究方法等不同使得碳收支估算结果存在很大的不确定性。气候变暖在一定程度上提高了高寒草地生态系统的植被初级生产力和生物量,由此补偿了气候变暖导致的土壤有机碳分解释量,使青藏高原草地植被仍然发挥着碳汇的功能。而人类放牧活动对草地生态系统的影响较为复杂。因此,如何区分气候变化和人类活动对生态系统的影响机制,定量评价未来气候变化和人类活动影响下,青藏高原生态系统碳源/汇格局的可能变化,是一个非常重要的研究方向,也是一个极大的挑战。  相似文献   

3.
气候变化和人类活动在沙漠化过程中相对作用评价综述   总被引:5,自引:1,他引:4  
气候变化和人类活动是导致沙漠化的两大驱动力,系统评价两者在沙漠化过程中的相对作用对于深入理解沙漠化过程的驱动力作用机理以及开展防沙治沙工作具有重要的意义。本研究从定性-半定量和定量研究两个方面对目前气候变化和人类活动在沙漠化过程中相对作用评价方法进行了系统的梳理,认为目前的评价方法存在着主观性强、可重复操作性差、多基于行政单元而缺乏在连续的空间域上来评价气候变化和人类活动相对作用等不足。基于对以往研究的总结和笔者近阶段的相关研究成果,笔者认为开展气候变化和人类活动在沙漠化过程中相对作用的评价工作关键是突破两类驱动力相对作用在连续的空间域上进行评价和表达这一瓶颈的制约,并提出了以定量研究为核心,以NPP为衡量气候变化和人类活动在沙漠化过程中相对作用的公共指标,通过拆分“驱动力作用-沙漠化土地动态响应”这一生态过程为若干可能情景来构建气候变化和人类活动在沙漠化过程中相对作用评价方法的思路。此外,在进行定量评价时,还需要考虑结果验证以及评价尺度这两个重点问题对评价结果和结论的影响  相似文献   

4.
定量评价流域径流变化特征并开展其归因识别研究是应对气候变化实现水资源合理开发利用的基础.本研究以泾河流域为研究区,采用M-K检验、滑动t检验、小波分析等方法分析流域近70 a的水文气象要素变化特征,并基于Budyko假设评价气候变化和人类活动对径流变化的贡献率.结果表明:(1)泾河流域年径流深以0.41 mm·a-1的...  相似文献   

5.
流域水资源变化特征及其归因识别一直是水文研究的重要科学问题。本文以党河流域为研究区,采用线性倾向估计等方法分析了流域气象、下垫面和水文要素变化特征,基于Budyko水热耦合平衡方程量化了气候变化和人类活动对径流变化的贡献。结果表明:(1)流域内气温呈升高趋势,降水呈增加趋势,气候向暖湿化方向发展;(2)林地、草地、耕地、水域和建设用地面积增加,未利用地面积缩减;冰川退缩速率为3.86 km2·a-1;多年平均最大冻结深度平均递减速率为1.14 cm·a-1;(3)党河径流年际递增速率为0.21亿m3/10a,年内分配为“双峰型”,降水和气温对径流年内变化贡献分别为57.2%和42.8%,气候变化和人类活动对径流变化贡献分别为59.46%和40.54%。  相似文献   

6.
流域输沙量变化是水文过程的一个重要环节,同时与区域水资源、土壤管理、甚至生态系统的健康运行紧密联系,因而如何量化气候变化和人类活动对输沙量变化的相对贡献率成为水文学研究的热点问题。论文主要系统总结了流域输沙量变化归因分析的9种方法:简单线性回归分析、双累积曲线法、泥沙归因诊断分析法、库坝拦沙量法、SEDD模型、SWAT模型、弹性系数法、相似天气条件法和水保法,阐述了各方法的计算过程及其适用性,并对各种方法进行评价,同时对未来的流域输沙量变化归因分析方法进行展望:① 尝试新方法的应用,以探索更为适当的输沙量预测新方法;② 考虑流域内极端降雨事件对输沙变化的定量影响,进一步提高结果的准确度;③ 明晰各归因分析方法的局限性和差异性,进行科学的结合与相互验证。研究结果可为流域内生态水文综合治理和土地资源优化管理提供科学依据。  相似文献   

7.
景观格局变化驱动力研究进展   总被引:21,自引:0,他引:21  
吴健生  王政  张理卿  宋静 《地理科学进展》2012,31(12):1739-1746
景观格局变化驱动力研究是理解人类活动与景观格局演化关系的基础。本文概述了驱动因子的分类, 分析了主导驱动因子的时间尺度效应、空间尺度效应和主题尺度效应, 并介绍了驱动因子的相互作用、驱动机制识别、驱动系统自适应等的研究进展。驱动力识别方法正经历从简单定性分析向定量、半定量分析转变的过程, 数据获取手段也随着遥感技术等的进步得到快速发展, 多学科手段综合是景观格局驱动力研究的必然趋势。但由于驱动力研究的问题导向型特征, 目前尚缺乏对某一类景观格局变化驱动力的归纳及跨时空、多尺度对比。对景观格局变化的跨界研究, 可以加深对制度、文化等驱动力的驱动机制的理解。  相似文献   

8.
气候变化和人类活动对中国地表水文过程影响定量研究   总被引:2,自引:0,他引:2  
刘剑宇  张强  陈喜  顾西辉 《地理学报》2016,71(11):1875-1885
利用中国372个水文站月径流数据(1960-2000年)及41个水文站年径流数据(2001-2014年),采用基于Budyko假设的水热耦合平衡方程,构建气候变化和人类活动对径流变化影响定量评估模型,在Penman-Monteith潜在蒸发分析基础上,进一步分析气象因子对径流变化的弹性系数,量化气候变化和人类活动对径流变化的影响。结果表明:① 中国北方地区流域径流变化对各气象因子弹性系数明显大于中国南方地区。就全国而言,径流变化对各因子的弹性系数为:降水>土地利用/土地覆盖变化(LUCC)>相对湿度>太阳辐射>最高气温>风速>最低气温;② 1980-2000年,气候变化总体上有利于增加中国年径流量,而降水对年径流量增加的贡献最为显著;③ 1980-2000年,中国南方流域中,气候变化对年径流变化的影响以增加作用为主,而北方流域,以减少年径流作用为主。对中国大多数流域径流变化而言,人类活动的影响主要以减少年径流量为主。2001-2014年,气候变化以减少径流量为主,人类活动对径流变化的影响程度明显增强,气候变化与人类活动对径流变化的贡献率分别为53.5%、46.5%。该研究对气候变化与人类活动影响下,中国水资源规划管理、防灾减灾及保障水资源安全具有重要理论与现实意义。  相似文献   

9.
气候变化对水循环与水资源的影响研究综述   总被引:1,自引:0,他引:1  
以全球变暖为主的气候变化已成为当前世界最重要的环境问题之一。气候变化对水循环与水资源影响的研究越来越引起国内外学者的的高度关注和重视。简要回顾了国内外气候变化对水文水资源影响研究的发展历程,着重论述了目前气候变化对水文水资源影响的重点研究领域:水循环要素变化的检测与归因分析、气候变化与人类活动对水循环与水资源影响的定量评估、未来气候变化情景下水循环与水资源的演变趋势预估、气候变化对极端水文事件的影响研究和应对气候变化的水资源适应性管理策略;并介绍了气候变化对水文水资源影响研究中的气候变化情景、水文模拟及陆-气模型耦合等重要技术手段。最后,针对目前研究中存在的问题及薄弱环节,提出未来研究的发展趋势和亟需解决的关键问题。  相似文献   

10.
为定量区分退耕还林还草背景下北方典型农牧交错带植被变化过程中气候变化和人类活动的相对贡献率,以宁夏盐池县2000—2020年植被变化为研究对象,基于MODIS13Q1-NDVI数据、地表覆盖数据和气象数据,采用Thornthwaite纪念模型和CASA(Carnegie-ames-stanford approach)模型分别估算了逐年的潜在净初级生产力(Potential net primary productivity, PNPP)和实际净初级生产力(Actual net primary productivity, ANPP)。综合运用趋势分析、相关分析和差值比较法分析了2000—2020年盐池县净初级生产力(Net primary productivity, NPP)时空变化特征及其驱动力,并定量确定了气候因子和人类活动对盐池县植被变化的相对贡献率。结果表明:(1) 在2000—2020年盐池县NPP总体呈上升趋势,但存在着显著的空间异质性,主要表现为植被NPP改善区面积远大于NPP退化区面积,且改善或退化程度也存在显著的空间分异。植被改善区主要分布于荒漠、荒漠草原等退耕还林还草工程区域和灌溉区,而植被退化区则分布于荒漠和荒漠草原的边缘地带。(2) 植被变化归因分析表明,在植被改善区,气候变化和人类活动共同主导驱动了植被的改善,但气候变化的相对贡献率(59.77%)大于人类活动的相对贡献率(40.23%),而在植被退化区,人类活动的相对贡献率(91.77%)则显著高于气候变化的相对贡献率(8.23%)。(3) 驱动力分析表明,研究区植被NPP变化与降水量呈显著正相关,而与气温的相关性较弱;而人类活动是驱动植被退化区NPP下降的主要原因,但负向影响力有所减弱。总体而言,气候变化是植被改善区的主要驱动力,而人类活动是植被退化区的主要驱动因素,两者共同作用则使盐池县整体生态环境得以改善。  相似文献   

11.
It is important to study the contributions of climate change and human activities to cropland changes in the fields of both climate change and land use change. Relationships between cropland changes and driving forces were qualitatively studied in most of the previous researches. However, the quantitative assessments of the contributions of climate change and human activities to cropland changes are needed to be explored for a better understanding of the dynamics of land use changes. We systematically reviewed the methods of identifying the contributions of climate change and human activities to cropland changes at quantitative aspects, including model analysis, mathematical statistical method, framework analysis, index assessment and difference comparison. Progress of the previous researches on quantitative evaluation of the contributions was introduced. Then we discussed four defects in the assessment of the contributions of climate change and human activities. For example, the methods were lack of comprehensiveness, and the data need to be more accurate and abundant. In addition, the scale was single and the explanations were biased. Moreover, we concluded a clue about quantitative approach to assess the contributions from synthetically aspect to specific driving forces. Finally, the solutions of the future researches on data, scale and explanation were proposed.  相似文献   

12.
It is important to study the contributions of climate change and human activities to cropland changes in the fields of both climate change and land use change. Relationships between cropland changes and driving forces were qualitatively studied in most of the previous researches. However, the quantitative assessments of the contributions of climate change and human activities to cropland changes are needed to be explored for a better understanding of the dynamics of land use changes. We systematically reviewed the methods of identifying the contributions of climate change and human activities to cropland changes at quantitative aspects, including model analysis, mathematical statistical method, framework analysis, index assessment and difference comparison. Progress of the previous researches on quantitative evaluation of the contributions was introduced. Then we discussed four defects in the assessment of the contributions of climate change and human activities. For example, the methods were lack of comprehensiveness, and the data need to be more accurate and abundant. In addition, the scale was single and the explanations were biased. Moreover, we concluded a clue about quantitative approach to assess the contributions from synthetically aspect to specific driving forces. Finally, the solutions of the future researches on data, scale and explanation were proposed.  相似文献   

13.
Climate change and human activities are the two kinds of driving forces in desertification,and assessing their relative role in desertification is of great significance to deeply understanding the driving mechanisms and preventing desertification expansion.This paper has systematically reviewed the progress of the researches on assessing the relative role of climate change and human activities in desertification from qualitative,semi-quantitative and quantitative aspects respectively.The authors found that there were still some problems in the previous researches.For example,the subjectivity in assessment was obvious,the assessment cannot be easily repeated,and the assessment and its results were always based on administrative regions and less taken and expressed in a continuous space.According to the progress of previous researches and the works conducted by the authors recently,we put forward a quantitative approach by selecting NPP as a common indicator to measure the relative role of climate change and human activities in desertification and dividing the ecological process of "driving force effect-dynamic response of desertified land" into several scenarios.Meanwhile,validation and scale of assessment should be taken into account when quantitative assessment of the relative role of climate change and human activities in desertification are carried out.  相似文献   

14.
The quantitative effect of climate change on fragile regions has been a hot topic in the field of responses to climate change. Previous studies have qualitatively documented the impacts of climate change on boundary shifts in the farming-pastoral ecotone (FPE); however, the quantitative methods for detecting climate contributions remain relatively limited. Based on long-term data of meteorological stations and interpretations of land use since 1970, climate and land use boundaries of the 1970s, 1980s, 1990s and 2000s were delineated. To detect climate contributions to the FPE boundary shifts, we developed two quantitative methods to explore the spatial-temporal pattern of climate and land use boundary at the east-west (or south-north) (FishNet method) and transect directions (Digital Shoreline Analysis System, DSAS method). The results indicated that significant differences were exhibited in climate boundaries, land use boundaries, as well as climate contributions in different regions during different periods. The northwest FPE had smaller variations, while the northeast FPE had greater shifts. In the northwest part of the southeast fringe of the Greater Hinggan Mountains and the Inner Mongolian Plateau, the shifts of climate boundaries were significantly related to the land use boundaries. The climate contributions at an east-west direction ranged from 10.7% to 44.4%, and those at a south-north direction varied from 4.7% to 55.9%. The majority of the results from the DSAS were consistent with those from the FishNet. The DSAS method is more accurate and suitable for precise detection at a small scale, whereas the FishNet method is simple to conduct statistical analysis rapidly and directly at a large scale. Our research will be helpful to adapt to climate change, to develop the productive potential, as well as to protect the environment of the FPE in northern China.  相似文献   

15.
The quantitative effect of climate change on fragile regions has been a hot topic in the field of responses to climate change. Previous studies have qualitatively documented the impacts of climate change on boundary shifts in the farming-pastoral ecotone(FPE); however, the quantitative methods for detecting climate contributions remain relatively limited. Based on long-term data of meteorological stations and interpretations of land use since 1970, climate and land use boundaries of the 1970 s, 1980 s, 1990 s and 2000 s were delineated. To detect climate contributions to the FPE boundary shifts, we developed two quantitative methods to explore the spatial-temporal pattern of climate and land use boundary at the east-west(or south-north)(Fish Net method) and transect directions(Digital Shoreline Analysis System, DSAS method). The results indicated that significant differences were exhibited in climate boundaries, land use boundaries, as well as climate contributions in different regions during different periods. The northwest FPE had smaller variations, while the northeast FPE had greater shifts. In the northwest part of the southeast fringe of the Greater Hinggan Mountains and the Inner Mongolian Plateau, the shifts of climate boundaries were significantly related to the land use boundaries. The climate contributions at an east-west direction ranged from 10.7% to 44.4%, and those at a south-north direction varied from 4.7% to 55.9%. The majority of the results from the DSAS were consistent with those from the Fish Net. The DSAS method is more accurate and suitable for precise detection at a small scale, whereas the Fish Net method is simple to conduct statistical analysis rapidly and directly at a large scale. Our research will be helpful to adapt to climate change, to develop the productive potential, as well as to protect the environment of the FPE in northern China.  相似文献   

16.
 绿洲是干旱区独特的自然景观,是人们生产生活的载体。如何在保持经济发展、提高人民生活水平的基础上保护有限的耕地资源,是关系到干旱区绿洲和谐以及可持续发展的重要问题。选取干旱区典型绿洲——于田县1949\_2004年的自然与人文统计资料,首先分析了五十余年来该县耕地变化的情况。然后从自然与人文两个角度对影响耕地面积变化的因子进行分析,结果表明,自然因素往往构成一定区域绿洲发展的基本限制,人为因素在短时期内,对耕地的变化起着决定性作用,这种作用如果顺应自然因素的限制,则对绿洲发展有利,绿洲稳定性增强;反之,绿洲稳定性减弱,由于新疆绿洲外围多为戈壁及沙漠,因此,对绿洲的利用要遵循自然规律,以保护绿洲为前提,合理利用水等自然资源,否则绿洲的面积随时都有可能缩小。  相似文献   

17.
中国山区农村土地利用转型解析   总被引:39,自引:5,他引:34  
山区土地开发及其导致的资源环境问题是农业社会人地关系紧张的体现,工业化、城镇化进程中劳动力转移减轻了山区农村土地的人为扰动,由此驱动土地利用发生转型,引发一系列自然和社会经济效应。按照“土地利用转型—驱动力—效应—响应”的分析框架,剖析中国山区农村土地利用转型的特征和规律,提出山区农村土地整治的响应措施。研究表明:① 山区农村土地利用转型体现出土地利用形态在长期变化过程中的趋势性转折,显性形态转型即由农业社会的耕地扩张和林地收缩演变为城镇化进程中的耕地收缩和林地恢复性增长,隐性形态转型即伴随上述过程发生的土地边际化及生态功能恢复;② 社会经济因素主导山区农村土地利用转型过程,劳动力转移引发土地人为扰动减轻是直接驱动力,务农机会成本上升、恶劣的生存环境等引发劳动力转移的因素是更为根本的驱动力;③ 山区农村土地利用转型降低了土地生态系统脆弱性并提高了其生态安全屏障功能,其社会经济效应应聚焦山区农村发展与农户生计安全层面,并亟需实证研究的支撑;④ 当前山区农村土地利用转型是自然恢复和生态优化的良性过程,有着经济社会发展的必然规律,山区农村土地整治要顺应其土地利用转型规律,目标导向从耕地数量增加转向生态环境保护与社会经济福祉协同提升。  相似文献   

18.
滨海滩涂土壤有机碳演变驱动因子框架   总被引:1,自引:1,他引:0  
通过归纳、总结前人大量的研究成果,从土壤有机碳演变的尺度约束框架、滩涂土壤有机碳的核心控制因子以及演变的驱动因素3个方面进行总结。结果表明:①目前形成的监测技术约束下的碳库研究体系,其研究的结果忽视了机理性认识的未来需要,这对于应对未来气候变化条件下的滩涂湿地碳库变化风险稍显不足; ② 滩涂土壤有机碳演变的核心控制因子有泥沙、地貌与埋藏速率、植被与农业活动。滩涂围垦后的农业活动类型与方式是滩涂开发后影响土壤有机碳演变的核心要素,远远高于自然滩涂中的自然主导因子; ③ 不同因素在不同时空尺度上会对滩涂有机碳演变起到重要影响,其中,土地利用/覆被对于有机碳的影响机制是需要重点关注的核心命题; ④ 小尺度、长时间尺度有机碳循环机制的研究需要加强,同时,综合考量要素的时空尺度特性及其技术手段的提升,更加注重过程研究对于指导未来滩涂土壤有机碳研究更具有现实意义。  相似文献   

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