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1.
基于GIMMS NDVI 3g v1.0数据集和日值气象数据，结合极端气温指数，辅以极点对称模态分解、趋势分析、Mann-Kendall趋势检验、相关分析等方法，探讨中国北方生长季植被覆盖及极端气温的变化特征，研究植被覆盖对气温极值的响应状况。结果表明：① 1982—2015年中国北方生长季NDVI以0.002·（10a）-1的速率上升（P<0.05），ESMD（极点对称模态分解方法）显示生长季NDVI波动上升；针叶林、灌丛、荒漠植被、草地以及栽培植被呈增长趋势，栽培植被增速最快，针阔混交林、落叶阔叶林和高山植被呈不显著减少趋势。② 空间上，NDVI显著增加区域超过全区的33%，主要分布在天山、塔里木盆地北部、祁连山、陇南山区、黄土高原、河套平原、吕梁山和太行山、大别山以及辽西丘陵地区；显著下降区域仅占12%，主要分布在大兴安岭、小兴安岭和长白山区。③ 极端气温指数中，除TNmean（日最低气温平均值）和TNn（日最低气温极低值）呈上升趋势外，其余冷极值指数均呈下降趋势；所有暖极值指数均呈上升趋势；其他指数中，DTR（气温日较差）呈减小趋势，GSL（生长季日数）呈增加趋势。④
中国北方NDVI与极端气温指数的相关性表明，冷极值指数中NDVI与FD0（霜冻日数）、TN10p（冷夜日数）、TX10p（冷昼日数）呈显著负相关（P＜0.05），与TNmean呈显著正相关（P＜0.01）；NDVI与所有暖极值指数呈正相关，与TR20（热夜日数）、TXmean（日最高气温平均值）、TX90p（暖昼日数）以及TN90p（暖夜日数）存在显著相关性（P＜0.05）；NDVI与GSL呈显著正相关（P＜0.05）。⑤ 天山、塔里木盆地北缘、祁连山区、河套平原、黄土高原、太行山和吕梁山区等NDVI显著增加区域对极端气温指数的响应强烈。NDVI显著增加区主要对FD0、TNmean、TN90p、GSL等指数响应较强。NDVI显著减少区域对指数的响应各异，主要与SU25（夏季日数）呈显著负相关（P＜0.05）。 相似文献
2.
基于GIMMS NDVI 3g v1. 0数据集和日值气象数据,结合极端气温指数,辅以极点对称模态分解、趋势分析、Mann-Kendall趋势检验、相关分析等方法,探讨中国北方生长季植被覆盖及极端气温的变化特征,研究植被覆盖对气温极值的响应状况。结果表明:①1982-2015年中国北方生长季NDVI以0. 002·(10a)^-1的速率上升(P <0. 05),ESMD(极点对称模态分解方法)显示生长季NDVI波动上升;针叶林、灌丛、荒漠植被、草地以及栽培植被呈增长趋势,栽培植被增速最快,针阔混交林、落叶阔叶林和高山植被呈不显著减少趋势。②空间上,NDVI显著增加区域超过全区的33%,主要分布在天山、塔里木盆地北部、祁连山、陇南山区、黄土高原、河套平原、吕梁山和太行山、大别山以及辽西丘陵地区;显著下降区域仅占12%,主要分布在大兴安岭、小兴安岭和长白山区。③极端气温指数中,除TNmean(日最低气温平均值)和TNn(日最低气温极低值)呈上升趋势外,其余冷极值指数均呈下降趋势;所有暖极值指数均呈上升趋势;其他指数中,DTR(气温日较差)呈减小趋势,GSL(生长季日数)呈增加趋势。④中国北方NDVI与极端气温指数的相关性表明,冷极值指数中NDVI与FD0(霜冻日数)、TN10p(冷夜日数)、TX10p(冷昼日数)呈显著负相关(P <0.05),与TNmean呈显著正相关(P <0.01);NDVI与所有暖极值指数呈正相关,与TR20(热夜日数)、TXmean(日最高气温平均值)、TX90p(暖昼日数)以及TN90p(暖夜日数)存在显著相关性(P <0. 05);NDVI与GSL呈显著正相关(P <0.05)。⑤天山、塔里木盆地北缘、祁连山区、河套平原、黄土高原、太行山和吕梁山区等NDVI显著增加区域对极端气温指数的响应强烈。NDVI显著增加区主要对FD0、TNmean、TN90p、GSL等指数响应较强。NDVI显著减少区域对指数的响应各异,主要与SU25(夏季日数)呈显著负相关(P <0.05)。 相似文献
3.
文中应用2000～2011年期间的MODIS NDVI数据对比了山东半岛和辽东半岛植被覆盖的时间变化以及空间自相关特征。结果表明:山东半岛和辽东半岛植被覆盖状况均较好,其中辽东半岛植被覆盖相对更好;2000～2011年间两个半岛NDVI均呈显著上升趋势,山东半岛的上升趋势更明显。两半岛NDVI的全局Moran's I分别为0.896和0.778,均表现为正的全局空间自相关,植被覆盖均呈空间集聚状态,且山东半岛植被覆盖的集聚特征更突出。局部空间自相关上,山东半岛大部分地区,辽东半岛千山山脉以东和辽河流域的ND-VI表现为高-高自相关,这些区域植被覆盖较好;而山东半岛西北部的黄河三角洲湿地区域以及莱州湾,辽东半岛千山山脉以西和半岛南端大连市的NDVI呈低值区集聚状态,植被覆盖较差。总的来说,该研究有助于了解山东半岛和辽东半岛植被覆盖的空间聚集规律和关联模式,从而为认识研究区植被覆盖状况以及生态保护提供依据。 相似文献
4.
近10 a来祁连山植被覆盖变化研究 总被引：7，自引：1，他引：6
NDVI作为植被生长状况及植被覆盖度的最佳指示因子,被认为是监测地区或全球植被和环境变化的最有效指标。基于2000-2011年250 m分辨率的MODIS NDVI数据并结合气候资料,采用最大值合成法、均值法、斜率分析法、相关分析法,研究祁连山生长季植被覆盖的时空变化及其与气候因子的相关性。结果表明：祁连山植被覆盖总体上自西向东递增,呈现东多西少的分布格局;植被覆盖变化存在明显的空间差异,表现为中西部植被覆盖增加,增加面积为79 149 km2,占祁连山总面积的52.93%;东部植被覆盖减少,减少面积为22 865 km2,占祁连山总面积的11.09%。近10 a来植被覆盖整体上呈增加趋势,生长季各月植被覆盖整体上呈增加趋势,全球气候变暖导致的降水增加是祁连山植被覆盖增加的主要原因。NDVI与气温、降水的相关性较高并存在一定的滞后性,6、7月NDVI分别与前期1月和前期2月的降水显著相关,相关系数分别为0.788和0.684;8、9月NDVI分别与当月、前期1月的气温极显著相关,相关系数分别为0.825和0.829。 相似文献
5.
中国西北干旱区1981～2001年NDVI对气候变化的响应分析 总被引：6，自引：1，他引：5
气候变化在不同的区域有着不同的特征,对植被也带来不同的影响,对不同地区气候变化特征的认识及植被变化的相应分析,可使我们对全球变化对干旱区的影响有更深入的认识。本文通过定量分析西北干旱区1981~2001年NOAA/AVHRR数据和同期的气象资料,借助于遥感技术和数理统计知识,分析了1981~2001年我国西北干旱区NDVI变化及其与气候变化的关系。结果显示:1981-2001年间西北干旱区年际最大NDVI的变化与气候变化具有明显的相关性,尤其是对新疆的南、北疆来说,NDVI的变化受到年降水量、年均温和空气相对湿度的影响比较显著,NDVI与年降水量和相对湿度的相关程度要明显比与年均温的相关程度高。甘肃内蒙古的河西走廊和青海的柴达木地区NDVI没有明显的变化趋势,同时这两个地区也是年降水量变化最小的地区。从而得出一个结论:降水资源是我国西北干旱区植被生长和生态建设的最重要气象因子,只有充分、合理地利用"降水"这种天然水资源才能最终实现中国西北干旱区环境、社会与经济的可持续发展。 相似文献
6.
基于SPOT VEGETATION数据的榆林地区土地覆盖变化研究 总被引：11，自引：0，他引：11
榆林地区位于我国农牧交错带,能源富集区,生态环境脆弱。建国以来的土地整治工作取得显著成效。本文利用1998-2004年SPOT VEGETATION NDVI分析了榆林地区植被变化情况。并且利用多年气象数据分析了降水和温度变化情况。结果表明榆林地区植被状况有明显改善,改善集中于8、9、10月份。而且植被覆盖变化具有明显的区域差异,北部植被覆盖改善趋势明显,且变化平稳;南部增加趋势不明显,有的地方还呈下降趋势,变化幅度大。 相似文献
7.
LIU Yifeng 《干旱区科学》2023,15(1):91-108
Under the combined influence of climate change and human activities, vegetation ecosystem has undergone profound changes. It can be seen that there are obvious differences in the evolution patterns and driving mechanisms of vegetation ecosystem in different historical periods. Therefore, it is urgent to identify and reveal the dominant factors and their contribution rates in the vegetation change cycle. Based on the data of climate elements (sunshine hours, precipitation and temperature), human activities (population intensity and GDP intensity) and other natural factors (altitude, slope and aspect), this study explored the spatial and temporal evolution patterns of vegetation NDVI in the Yellow River Basin of China from 1989 to 2019 through a residual method, a trend analysis, and a gravity center model, and quantitatively distinguished the relative actions of climate change and human activities on vegetation evolution based on Geodetector model. The results showed that the spatial distribution of vegetation NDVI in the Yellow River Basin showed a decreasing trend from southeast to northwest. During 1981-2019, the temporal variation of vegetation NDVI showed an overall increasing trend. The gravity centers of average vegetation NDVI during the study period was distributed in Zhenyuan County, Gansu Province, and the center moved northeastwards from 1981 to 2019. During 1981-2000 and 2001-2019, the proportion of vegetation restoration areas promoted by the combined action of climate change and human activities was the largest. During the study period (1981-2019), the dominant factors influencing vegetation NDVI shifted from natural factors to human activities. These results could provide decision support for the protection and restoration of vegetation ecosystem in the Yellow River Basin. 相似文献
8.
1982-2006年华北植被指数时空变化特征 总被引：3，自引：0，他引：3
利用1982-2006年GIMMS/NDVI数据,研究华北近25 a来植被指数在时间和空间上的变化。结果表明:①植被指数的年内变化呈单峰型,最大值出现在夏季,其中北京市NDVI最大,森林NDVI比农田和草地NDVI大;②华北年平均NDVI呈增加趋势,河北省植被指数增加最快,北京市次之,不同土地覆盖类型中,农田NDVI增加最快,草地次之,森林最小;③空间趋势分析结果显示,华北植被指数改善的面积占整个地区面积的15.96%,退化面积占11.86%,其中,河北省改善面积最大,内蒙古退化较明显,不同土地覆盖类型中,农田植被改善最明显;④基于华北近年暖干化发展趋势下,人类活动对该区域NDVI变化起到了重要作用。 相似文献
9.
基于SPOT/NDVI华北地区植被变化动态监测与评价 总被引：4，自引：0，他引：4
利用1998-2011年SPOT NDVI数据反映华北地区植被覆盖变化情况,结合该地区土地覆盖数据以及1982-2011年84个气象站点的气温和降水数据,分别从时间和空间两个方面对其进行植被动态监测与评价,并简要分析其变化原因。结果表明:1)从时间上来看,华北地区NDVI在1998-2011年总体呈增长趋势,表明该地区植被覆盖情况整体上得到改善,其中,森林和农田NDVI增长最快;2)从空间上来看,华北地区地表植被覆盖得到改善的区域比退化区域面积要大,其中,森林和农田的恢复效果最为明显,而灌丛、草地、沙漠退化面积均超过改善面积,表明华北地区水土流失和荒漠化现象依然严峻;3)在华北地区气候长期趋于暖干化的背景下,华北植被变化与降水变化关系比与气温变化关系密切,表明植被覆盖变化受降水影响较大,此外,人类活动也是引起植被覆盖变化的重要驱动因子。 相似文献
10.
近20年来祁连山区植被变化特征分析 总被引：10，自引：2，他引：8
利用1982-2003年8 km分辨率的 NDVI数据集,分析了祁连山区植被覆盖的年、年际、年代变化特征.结果表明:祁连山区植被覆盖总体上自东向西递减,其年变化NDVIm都为单峰型;祁连山区各段植被覆盖的年际NDVIy、年代变化NDVIn趋势有所不同:祁连山西中段植被的NDVIy 变化趋势基本相似,20世纪80年代变化较平稳,90年代变化幅度最大,1995年以后植被明显开始增加,祁连山东段植被的 NDVIy 从1982年开始呈增加趋势,直到1997年以后下降;祁连山西中段1982-1985,1986-1990,1991-1995,1996-2000,2001-2003年5个阶段植被的 NDVIn最大值出现在2001-2003年,最小值出现在1991-1995年,而祁连山东段最大值出现在1996-2000年,最小值出现在1982-1985年;祁连山各段5～9月植物生长期植被的NDVIpy,NDVIpn变化与年的NDVIy,NDVIn变化相似. 相似文献
11.
2000-2010年祁连山植被MODIS NDVI的时空变化及影响因素 总被引：3，自引：0，他引：3
利用2000-2010年间的MODIS/NDVI数据和对应的气候资料,研究了近10年来祁连山植被的时空变化及影响因素。结果表明:1)10年来,祁连山年最大化NDVI(MNDVI)增加了2.4%,植被改善、无变化和退化的面积分别占总面积的26.32%、66.42%和7.26%。植被改善的区域分布在冷龙岭、拉脊山、大通山、达坂山、青海南山、走廊南山、托来山等山地以及西宁盆地、湟水谷地周边地区,减少的区域分布在乌鞘岭、庄浪河、古浪河、大通河、石羊河、黑河、疏勒河等河流河谷。2)祁连山不同植被类型MNDVI的年际变化趋势不同。灌丛地、荒漠草原、高寒稀疏草甸MNDVI呈快速增加趋势,高山草原、高山灌丛草甸和高寒草甸MNDVI呈增加趋势,落叶阔叶林、针阔混交林、常绿针叶林MNDVI呈快速下降趋势。3)影响祁连山植被生长的主要因子是气温和降水,局部地区密集的人类活动也能成为影响植被生长的关键因子。 相似文献
12.
较全面地综述了西北干旱地区表土孢粉与植被和气候关系的研究进展, 讨论了部分有指示意义的花粉,如云杉、杨、桦、禾本科、豆科等代表性花粉以及花粉浓度、A/C(蒿属Artemisia/藜科Chenopodiaceae)比值等问题.并提出了自己的一些见解和未来进一步开展工作的方向:如,在新疆某些地区很少发现桦属花粉可能属个别现象;可以根据藜科的生理习性解释草原区植被的A/C值较低即表明草原植被退化严重;进一步开展杨属(Populus)和桦属(Betula)花粉在林中的代表性、西北地区Ch(藜科Chenopodiaceae)/Po(禾本科Poaceae)值的研究,以及草原带与森林带之间的过渡地带的孢粉组合研究;今后需要将整个中国西北干旱区作为一个整体来研究,以深入了解孢粉-植被-气候的关系. 相似文献
13.
基于GIMMS/NDVI数据对诺敏河流域1982-2006年间植被覆盖的时空演变特征进行了研究,并结合SCS模型模拟地表径流,在流域和像元尺度分析植被NDVI变化与径流的关系。研究表明:诺敏河流域植被NDVI值较高,但25a间整体呈下降趋势,NDVI减少的区域占总面积的82.5%,植被覆盖有所降低;NDVI空间差异明显,NDVI的高值区主要分布在中上游林区,而耕地分布较多的下游地区NDVI值相对较低。流域尺度上植被NDVI与径流不具有明显的相关性。但从像元尺度来看,植被NDVI和径流的正相关和负相关共存,流域不同空间位置的植被变化与径流的关系并不一致。 相似文献
14.
天山北坡气候因子对植被影响的空间分异性研究 总被引：2，自引：1，他引：1
天山北坡经济带作物品种多且品种间差异大,气候变化对区域作物结构布局的影响研究对新疆农牧业生产具有积极的指导作用。文中利用2002～2007年天山北坡生长季逐月MODIS归一化植被指数（ND-VI）数字影像,计算了NDVI动态变化与气温、降水变化的相关关系,分析了NDVI变化的区域分异规律,探讨了气温、降水对植被NDVI... 相似文献
15.
Spatial distribution of vegetation and the influencing factors in Qaidam Basin based on NDVI 总被引：1，自引：0，他引：1
The spatial distribution of vegetation in Qaidam Basin was analyzed using GIMMS(Global Inventory Modeling and Mapping Studies) /NDVI(Normalized Difference Vegetation Index) data set from January 1982 to December 2006.Based on the data of precipitation,terrain,stream systems,land use and the map of vegetation distribution in Qaidam Basin,we studied the factors influencing the spatial distribution of vegetation.The results showed that the vegetation was generally low in Qaidam Basin and there was a clear semi-ring structure from southeast to northwest.In some areas,the existence of rivers,lakes and spring belts turned this semi-ring structure into a non-continuous state and formed distinct bright spots and continuous linear features.There were four main factors that affected the spatial distribution of vegetation coverage in Qaidam Basin,i.e.,precipitation,hydrological conditions,altitude and human activities.Precipitation and altitude have a correlation and determine the basic pattern of vegetation distribution in Qaidam Basin.The impacts of hydrological conditions and human activities were mainly embodied in partial areas,and often broke the pattern of vegetation distribution dominated by precipitation and altitude. 相似文献
16.
YANG Zhenjing ZHANG Yun REN Haibao YAN Shun KONG Zhaochen MA Keping NI Jian 《干旱区科学》2016,8(5):799-810
To provide information on vegetation patterns and altitudinal distributions of pollen assemblage in surface soil layers,their complicated relationships in a dryland mountain-basin system in northwestern China and a realistic basis for paleovegetational reconstruction,we investigated 86 vegetation quadrats and analyzed 80 soil samples from the surface soil layers along an altitudinal transect on the north slope of the Middle Tianshan Mountains from alpine cushion vegetation at 3,510 m near glacier to desert vegetation at 460 m in the Gurbantunggut Desert.According to surface pollen assemblages and the results of the detrended correspondence analysis,the transect can be divided into six major altitudinal pollen zones as alpine cushion vegetation,alpine and subalpine meadows,montane Picea forest,forest-steppe ecotone,Artemisia desert and typical desert,which basically reflect the characteristics of the mountainous vegetation patterns on the north slope of the Middle Tianshan Mountains.However,Picea pollen also exists outside the spruce forest,Chenopodiaceae and Artemisia pollen appeared above the elevation of 1,300 m,indicating that most of them might be introduced from lower elevations by upslope winds.Airborne pollen researches from three regions at different elevations further suggest that a high-frequency northwest anabatic wind has a remarkable influence on the transportation and dispersion of surface pollen in the area. 相似文献
17.
基于SPOT NDVI的中国东北地表植被覆盖动态变化及其机理研究 总被引：8，自引：4，他引：4
为了分析东北地表植被覆盖动态变化及其变化机理,选取该地区1998-2007年的SPOT/NDVI时间序列数据进行研究,并利用时间序列谐波分析(HANTS)算法对旬合成的NDVI数据进一步去云处理,根据处理后的结果,用一元线性回归趋势法定量描述了东北地表植被覆盖的动态变化。结果表明:近10年来中国东北地表植被覆盖整体得到改善的区域远比植被覆盖退化的区域面积大,其中严重退化的区域主要是内蒙古的东四盟地区,尤其是呼伦贝尔和科尔沁地区。 相似文献
18.
Grassland degradation is influenced by climate change and human activities, and has become a major obstacle for the development of arid and semi-arid areas, posing a series of environmental and socio-economic problems. An in-depth understanding of the inner relations among grassland vegetation dynamics, climate change, and human activities is therefore greatly significant for understanding the variation in regional environmental conditions and predicting future developmental trends. Based on MODIS (moderate resolution imaging spectroradiometer) NDVI (normalized difference vegetation index) data from 2000 to 2020, our objective is to investigate the spatiotemporal changes of NDVI in the Xilin Gol grassland, Inner Mongolia Autonomous Region, China. Combined with 12 natural factors and human activity factors in the same period, the dominant driving factors and their interactions were identified by using the geographic detector model, and multiple scenarios were also simulated to forecast the possible paths of future NDVI changes in this area. The results showed that: (1) in the past 21 a, vegetation cover in the Xilin Gol grassland exhibited an overall increasing trend, and the vegetation restoration (84.53%) area surpassed vegetation degradation area (7.43%); (2) precipitation, wind velocity, and livestock number were the dominant factors affecting NDVI (the explanatory power of these factors exceeded 0.4). The interaction between average annual wind velocity and average annual precipitation, and between average annual precipitation and livestock number greatly affected NDVI changes (the explanatory power of these factors exceeded 0.7). Moreover, the impact of climate change on NDVI was more significant than human activities; and (3) scenario analysis indicated that NDVI in the Xinlin Gol grassland increased under the scenarios of reduced wind velocity, increased precipitation, and ecological protection. In contrast, vegetation coverage restoration in this area was significantly reduced under the scenarios of unfavorable climate conditions and excessive human activities. This study provides a scientific basis for future vegetation restoration and management, ecological environmental construction, and sustainable natural resource utilization in this area. 相似文献
19.
Qinli XIONG 《干旱区科学》2019,11(5):637-651
Climate change and human activities can influence vegetation net primary productivity (NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural values, is one of the most susceptible regions to climate change and human disturbancesin the world. To assess the impact of climate change and human activities on vegetation dynamics in the grassland ecosystems ofthe northeastern Qinghai-Tibet Plateau, we applied a time-series trend analysis to normalized difference vegetation index (NDVI) datasets from 2000 to 2015 and compared these spatiotemporal variations with trends in climatic variables over the same time period. The constrained ordination approach (redundancy analysis) was used to determine which climatic variables or human-related factors mostly in?uenced the variation of NDVI. Furthermore, in order to determine whether current conservation measures and programs are effectivein ecological protection and reconstruction, we divided the northeastern Qinghai-Tibet Plateau into two parts: the Three-River Headwater conservation area (TRH zone) in the south and the non-conservation area (NTRH zone) in the north. The results indicatedan overall (73.32%)increasing trend of vegetation NPP in grasslands throughout the study area. During the period 2000-2015, NDVI in the TRH and NTRH zones increased at the rates of 0.0015/aand 0.0020/a, respectively.Specifically, precipitation accounted for 9.2% of the total variation in NDVI, while temperature accounted for 13.4%. In addition, variation in vegetation NPP of grasslands responded not only to long- and short-term changes in climate, as conceptualized in non-equilibrium theory, but also to the impact of human activities and their associated perturbations. The redundancy analysis successfully separated the relative contributions of climate change and human activities, of whichvillage populationand agricultural gross domestic product were the two most important contributors to the NDVI changes, explaining 17.8% and 17.1% of the total variationof NDVI (with the total contribution >30.0%), respectively. The total contributionpercentages of climate change and human activitiesto the NDVI variation were27.5% and 34.9%, respectively, inthe northeastern Qinghai-Tibet Plateau. Finally, our study shows that the grassland restoration in the study area was enhanced by protection measures and programs in the TRH zone, which explained 7.6% of the total variation in NDVI. 相似文献
20.
近10年甘南牧区草地净初级生产力变化研究 总被引：2，自引：0，他引：2
以改进的CASA模型为基础,结合MODIS NDVI数据、气象资料,估算了甘南牧区草地2000、2005、2008年牧草生长旺季7月净初级生产力,并分析了其时空动态.结果显示:(1)甘南牧区草地净初级生产力(NPP)的空间分布基本格局是西南偏西和东北两区域最低,然后由西南-东北方向为轴心逐渐向内陆中心部分递增,该分布规... 相似文献