共查询到17条相似文献，搜索用时 93 毫秒
1.
京津冀地区NDVI变化及气候因子驱动分析 总被引：3，自引：0，他引：3
植被覆盖动态监测及与气候变化的响应,是陆地生态系统研究的重要内容。本文以2001-2013年间京津冀地区MOD13A 3月合成NDVI数据,结合生长季的降水和气温资料,运用偏相关和复相关分析、趋势分析方法,研究了该区域NDVI的变化特征和空间分布,以及其区域植被覆盖变化的气候驱动力。结果表明,该区域NDVI最大值在13a间缓慢增加,植被覆盖呈现改善趋势;NDVI和生长季降雨量及平均气温的平均偏相关系数分别为0.20和-0.14,表明在年际变化水平上,京津冀地区NDVI总体与降水量呈正相关,与平均气温呈负相关,且降水对NDVI的影响大于温度对NDVI的影响。对植被覆盖驱动分区得出,降水和气温驱动型占区域面积的5.68%;单独降水驱动型和气温驱动型分别占4.51%、0.18%;区域内植被覆盖变化主要受非气候因子驱动型为主,所占比例为89.63%,表明人类活动对植被变化的影响巨大。 相似文献
2.
基于2000-2013年三江源MODIS NDVI数据,本文系统地分析了三江源植被生长季累计NDVI的时空变化特征,并结合三江源生态保护与建设工程实施的相关统计数据,探讨了人类活动对三江源植被变化的影响,最后通过气候因子与生长季累计NDVI的相关性分析,揭示了影响三江源不同地区植被变化的主要气候限制因素。结果表明,2000-2013年三江源植被NDVI整体上呈增加趋势,NDVI明显增加的区域面积比例达17.84%,主要分布于研究区的西部和北部;明显减少的区域仅占0.78%,多零星分布于研究区中部;NDVI变化稳定或没有显著变化趋势的区域面积比例为59.64%,主要位于研究区东部和南部。三江源生态保护与建设工程的实施虽然促进了植被恢复,但对区域植被整体变化的影响有限,研究时段内区域植被整体好转主要受气候因素控制。西部长江源区的植被生长主要受气温影响,东北部黄河源区主要受降水制约,南部澜沧江源区降水和气温的限制性均不明显。 相似文献
3.
10年来锡林郭勒盟草原植被长势变化及其影响因子分析 总被引：2，自引：0，他引：2
对草原植被长势变化的监测,及其与气候因子关系的分析,对生态环境治理及保护具有重要意义。本文利用250m的MODIS-NDVI数据,构建草原植被长势指数(MGI),分析了16天间隔的植被长势变化及其与降水、气温的相关性和对降水响应的滞后性。得到锡盟3种草原类型区2001-2010年草原长势变化情况,及降水、气温在草原生长不同阶段对草原长势的影响。研究结果表明:(1)在空间上长势东部变化好于中部与西部,北部好于南部;时间上2003年长势最好、2001年长势最差。(2)锡盟内3种草原类型区MGI均与降水关系明显,与气温相关性不显著,降水对温性草原区长势变化的影响最大。(3)在草原生长的不同阶段,影响因子不同,前期与后期主要受气温影响,中期主要受降水影响,草原生长对降水存在明显的滞后,一般在32-48天,同时指出草原植被在不同时间段对降水响应的滞后时间。 相似文献
4.
新疆NDVI时空特征及气候变化影响研究 总被引：1，自引：0，他引：1
基于新疆50个气象测站2003-2010年逐日降水、气温资料,结合逐月归一化植被覆盖影像资料,利用趋势分析、R/S分析、模糊C均值聚类、图像处理等方法,系统分析了全疆NDVI时空变化特征及其可持续性,并探究NDVI与气候因子（气温、降水）之间的相关性。研究表明：植被覆盖及气象因子年际间差异不大,呈现出整体稳定的态势,但年内变化明显。北疆/天山北坡水热条件优良、植被长势最好,且植被长势对气候因子的滞后效应并不明显且滞后时间短。天山南坡/天山东段次之,而南疆植被覆盖程度最差,南疆/天山南坡植被长势对气候因子（降水、气温）存在明显的滞后效应,植被生长受气温、降水限制性更大,且气温作为主要因子,对天山南坡植被生长的限制作用表现得更为突出。总体上,新疆植被覆盖呈持续性变化,现有植被覆盖情况基本保持不变,但呈退化趋势的面积大于得到改善的面积,在一定程度上与人类活动有很大关系,探查植被长势的变化趋势并及时做出相应调整,不仅能为新疆地区的植被保护以及植被恢复工作提供一定的科学依据,更能够为合理有效地安排农作物生产提供重要的理论指导。 相似文献
5.
在全球气候变化背景下,植被动态变化以及植被对气候变化的响应方式已经成为生态学和地理学领域的热点。本文对比分析了南方亚热带季风区将乐县不同类型森林植被对不同时间尺度的干旱响应的差别。基于2000-2017年MODIS-EVI数据及气象站点数据,用最大值合成法、趋势分析法以及相关分析法,分析了森林植被及气象因子的动态变化特征,并对比不同森林植被对气候变化响应的差别。研究表明：① 2000-2017年,研究区植被覆盖度、EVI和降水均显著增加,区域内湿度增加,森林长势渐趋良好;② EVI在生长季初期和末期与同期的降水、温度均显著正相关（P<0.1）,初期森林受降水因子的影响更大,末期受温度因子的影响大;③ 1-3月和周年的气候变化对森林的生长至关重要,长时间尺度的湿度增加对森林生长具有显著的促进作用,SPEI的时间尺度越长与EVI的相关性也越大;④ 针阔混交林与同期温度、降水的相关系数最高,并且与不同时间尺度的SPEI相关性均比较高,属于气候敏感型林型,在生产经营中要谨慎预防气候变化对该林型带来的伤害;⑤ 森林覆盖度变化与降水和SPEI_24的相关性极显著,长时间尺度的降水变化是影响森林植被覆盖率变化的重要因素之一。 相似文献
6.
利用1997-2006年的AvHRR NOAA遥感资料,对陕西省陕北地区(榆林市、延安市和铜川市部分地区)地表植被指数的空间变化和时间变化进行了分析,并对相应时段的气候因子与植被指数之间的关系,以及气候因子对该地区植破的影响进行了分析.结果表明:近10a陕北大部地区平均植被有增加的趋势,但部分地区有减少的趋势.四季平均NDVI呈上升趋势,春季是陕北季平均NDVI上升趋势最为显著,上升速度最快的季节.降水量对地表植被的变化起重要的作用,特别是对农业用地植被和草地植被的影响;对于常绿针叶林和落叶阔叶林植被,降水的年际变化对地表植被的影响较小;温度的变化对地表植被的变化影响显著. 相似文献
7.
青藏高原脆弱的高寒植被对外界干扰十分敏感,使其成为研究植被对气候变化响应的理想区域之一。青藏高原气候变化剧烈,在较短的合成时间研究气候变化对植被的影响十分必要。因此,本文利用GIMMS NDVI时间序列数据集,研究了1982-2012年青藏高原生长季月尺度植被生长的时空动态变化,探讨了其与气温、降水量和日照时数等气候因子的响应关系。结果表明：在区域尺度上,除8月外,其他各月份植被均呈增加趋势,显著增加多发生在4-7月和9月;大部分月份的NDVI增加速率随着时段的延长显著减小,表明NDVI增加趋势放缓;在像元尺度上,月NDVI显著变化的区域多呈增加趋势,但显著减少范围的扩张多快于显著增加。4月和7月植被生长主要是受气温和日照时数共同作用,6月和9月受气温的控制,而8月则主要受降水量的影响。长时间序列NDVI数据集的出现为采用嵌套时段研究植被生长变化趋势奠定了前提,而植被活动变化趋势的持续性则有助于形象表征植被活动变化过程、深入理解植被对气候变化的响应和预测植被未来生长变化趋势。由此推测,青藏高原月NDVI未来增加趋势总体上趋于缓和,但在像元尺度显著变化的区域趋于增加。 相似文献
8.
植物生长季的变化反映了全球气候变化对生态环境的影响。本研究以2000-2006年间MODIS-NDVI影像数据集,使用TIMESAT软件从归一化植被指数（NDVI）时间序列中,分别提取福建省不同森林植被的生长季开始日期（Start of Season,SOS）、生长季结束日期（End of Season,EOS）和生长季长度（Length of season,LOS）等物候参数,并与全省尺度的气温与降水量进行相关分析。结果表明：不同森林类型NDVI与当月月均气温之间具有较显著的相关性（R2为0.72-0.79,p<0.01）,同期温度变化对植被生长的影响相对于降水量更重要;而植被生长对降水量的响应存在大约2个月的时滞效应（R2为0.54-0.75,p<0.01）,说明前期的降水累积对于后续植被生长有较显著影响。福建省森林植被生长季持续时间约213~223 d,开始于每年4月初到4月中旬（第98~103 d）,结束于11月中旬前后（第316~321 d）。其中,南亚热带森林生长季长于中亚热带森林,相同气候条件下的阔叶林生长季时间略长于针叶林。另外,春季（2-4月）气温变化是导致福建省内2个气候带森林生长季开始时间、生长季结束时间及生长季长度变化的关键因素,而伴随春季温度升高,植被生长季开始时间提前（R2为0.83,p<0.01）,同时生长季长度延长（R2为0.80,p<0.01）。7 a间,生长季持续时间呈现微弱延长趋势,总体延长幅度为2.4~3.1 d。 相似文献
9.
川西高原植被特征及其气候变化的相关分析 总被引：1，自引：0，他引：1
利用常规气象资料及NOAA-AVHRR的归一化植被指数（NDVI）资料和趋势系数、皮尔逊相关、Morlet小波分析等统计诊断方法,分析了1982年1月-2002年12月川西高原植被和气候因子（气温和降水）的变化特征及其相关关系和周期特征。结果表明：川西高原地区植被覆盖良好,大部分区域植被覆盖增加,局部退化（高原南部和东部）;气温总体呈增加趋势,降水量总体少变,局部有所减少;NDVI与气温和降水有一定相关性,其中与气温的相关性比与降水相关性大;NDVI周期约为5和10年左右,与降水和气温周期相同。川西高原地区植被及气候特征的分析为川西高原旅游和经济的发展规划提供依据,为研究川西高原的生态、气候资源提供参考。 相似文献
10.
内蒙古中部MODIS植被动态监测分析 总被引：12，自引：0，他引：12
对中分辨率成像光谱仪(MODIS)250m空间分辨率的每8天NDVI卫星遥感数据,利用年平均NDVI及一元线性回归方法,分析了2000-2008年内蒙古中部地区植被变化趋势。结果表明,近9年内蒙古中部地区79.60%地区的植被总体上保持稳定,17.33%的地区得到了明显改善,3.06%的地区仍存在较强的退化或沙化趋势。退化或沙化地区主要分布在内蒙古农牧交错带北部边缘,成条带状分布,反映了农牧交错带地区生态仍然较为脆弱,需要进一步关注和保护,东南部地区的植被恢复明显。植被年际动态主要受该地区暖干化气候影响,气候变暖造成植被NDVI增加,而降水波动导致NDVI随之变化,降水的作用是气温的2.8倍,有些地区可达到11倍之多。 相似文献
11.
Examining the direct and indirect effects of climatic factors on vegetation growth is critical to understand the complex linkage between climate change and vegetation dynamics. Based on the Moderate Resolution Imaging Spectroradiometer(MODIS) Normalized Difference Vegetation Index(NDVI) data and meteorological data(temperature and precipitation) from 2001 to 2012, the trend of vegetation dynamics were examined in the Ziya-Daqing basins, China. The path analysis was used to obtain the information on the relationships among climatic factors and their effects on vegetation growth. It was found that the trends of growing season NDVI were insignificant in most plain dry land, while the upward trends were significant in forest, grass and dry land in Taihang Mountains. According to the path analysis, in 23% of the basins the inter-annual NDVI variation was dominated by the direct effect of precipitation, in 5% by the direct effects of precipitation and temperature, and in less than 1% by the direct effect of temperature or indirect effects of these two climatic factors. It indicated that precipitation significantly affected the vegetation growth in the whole basins, and this effect was not regulated by temperature. Precipitation increase(especially in July, August and September) was favorable to greenness enhancement. Summer temperature rising showed negative effect on plant productivity enhancement, but temperature rise in April was beneficial for the vegetation growth. When April temperature increases by 1℃, the onset date of greenness for natural vegetation will be 2 days in advance. There was a lag-time effect of precipitation or temperature on monthly NDVI for all land use types except grass. 相似文献
12.
Vegetation dynamics and its relationship with climatic factors in the Changbai Mountain Natural Reserve 总被引：1，自引：1，他引：0
This study examined the temporal variation of the Normalized Difference Vegetation Index (NDVI) and its relationship with climatic factors in the Changbai Mountain Natural Reserve (CMNR) during 2000-2009.The results showed as follows.The average NDVI values increased at a rate of 0.0024 year-1.The increase rate differed with vegetation types,such as 0.0034 year-1 for forest and 0.0017 year-1 for tundra.Trend analyses revealed a consistent NDVI increase at the start and end of the growing season but little variation or decrease observed in July during the study period.The NDVI in CMNR showed a stronger correlation with temperature than with precipitation,especially in spring and autumn.A stronger correlation was observed between NDVI and temperature in the tundra zone (2,000-2,600m) than in the coniferous forest (1,100-1,700m) and Korean pine-broadleaved mixed forest (700-1,100m) zones.The results indicate that vegetation at higher elevations is more sensitive to temperature change.NDVI variation had a strong correlation with temperature change (r=0.7311,p<0.01) but less significant correlation with precipitation change.The result indicates that temperature can serve as a main indicator of vegetation sensitivity in the CMNR. 相似文献
13.
An understanding 0f variati0ns in vegetati0n c0ver in resp0nse t0 climate change is critical f0r predicting and managing future terrestrial ec0system dynamics. Because scientists anticipate that m0untain ec0systems will be m0re sensitive t0 future climate change c0mpared t0 0thers, 0ur 0bjectives were t0 investigate the impacts 0f climate change 0n variati0n in vegetati0n c0ver in the Qilian M0untains （QLM）, China, between 2000 and 2011. T0 acc0mplish this, we used linear regressi0n techniques 0n 250-m MODIS N0rmalized Difference Vegetati0n Index （NDVI） datasets and mete0r0l0gical rec0rds t0 determine spati0temp0ral variability in vegetati0n c0ver and climatic fact0rs （i.e. temperature and precipitati0n）. Our results sh0wed that temperatures and precipitati0n have increased in this regi0n during 0ur study peri0d. In additi0n, we f0und that gr0wing seas0n mean NDVI was mainly distributed in the vertical z0ne fr0m 2,700 m t0 3,600 m in elevati0n. In the study regi0n, we 0bserved significant p0sitive and negative trends in vegetati0n c0ver in 26.71% and 2.27% 0f the vegetated areas. C0rrelati0n analyses indicated that rising precipitati0n fr0m May t0 August was resp0nsible f0r increased vegetati0n c0ver in areas with p0sitive trends in gr0wing seas0n mean NDVI. H0wever, there was n0 similar significant c0rrelati0n between gr0wing seas0n mean NDVI and precipitati0n in regi0ns where vegetati0n c0ver declined thr0ugh0ut 0ur study peri0d. Using spatial statistics, we f0und that veeetati0n c0ver freauentlvdeclined in areas within the 2,500-3,100 m vertical z0ne, where it has steep sl0pe, and is 0n the sunny side 0f m0untains. Here, the p0sitive influences 0f increasing precipitati0n c0uld n0t 0ffset the drier c0nditi0ns that 0ccurred thr0ugh warming trends. In c0ntrast, in higher elevati0n z0nes （3,900-4,500 m） 0n the shaded side 0f the m0untains, rising temperatures and increasing precipitati0n impr0ved c0nditi0ns f0r vegetati0n gr0wth. Increased precipitati0n als0 facilitated vegetati0n gr0wth in areas experiencing warming trends at l0wer elevati0ns （2,000-2,400 m） and 0n l0wer sl0pes where water was m0re easily c0nserved. We suggest that spatial differences in variati0n in vegetati0n as the result 0f climate change depend 0n l0cal m0isture and thermal c0nditi0ns, which are mainly c0ntr0lled by t0p0graphy （e.g. elevati0n, aspect, and sl0pe）, and 0ther fact0rs, such as l0cal hydr0l0gy. 相似文献
14.
Quantification of driving factors on NDVI in oasis-desert ecotone using geographical detector method
《山地科学学报》2019,(11)
Within oasis-desert ecotone regions, the normalized difference vegetation index(NDVI) is an important parameter for evaluating the growth of vegetation. An accurate quantitative study between NDVI and environmental and anthropogenic factors is critical for understand the driving factors of vegetation growth in oasis-desert ecotone. In 2016,four periods Landsat 8 OLI_TIRS images, relevant climatological parameters data(air temperature, air relative humidity, wind velocity and accumulated temperature), land cover type data and soil data were selected as proxies. In order to quantify the explanatory power for NDVI spatial and temporal distribution in the southern edge of Dunhuang City and northern side of the Mingsha Mountain, the geographical detector model was used to explain the potential influences of factors versus the spatial distribution of NDVI, and each explanatory variable's relative importance can be calculated. The factordetector results disclose that the spatial distribution of NDVI is primarily dominated by land cover type.The risk detector results show that, high NDVI region is located within woodland. The mean value of NDVI displays an increase and then decrease trend with air temperature increase. With the increase of wind velocity and decrease of air relative humidity, the NDVI value shows a decrease trend. The interactive q values between the two factors are higher than any q value of separated factors. Results also indicate that the strongest interactive effects of NDVI are different in distinct seasons. Consequently, anthropogenic activity is more important than environmental factors on NDVI in oasis-desert ecotone. We also demonstrate that air relative humidity rather than air temperature have played a greater role in NDVI spatial distribution. 相似文献
15.
The Yalu Tsangpo River basin is a typical semi-arid and cold region in the Qinghai-Tibet Plateau, where significant climate change has been detected in the past decades. The objective of this paper is to demonstrate how the regional vegetation, especially the typical plant types, responds to the climate changes. In this study, the model of gravity center has been firstly introduced to analyze the spatial-temporal relationship between NDVI and climate factors considering the time-lag effect. The results show that the vegetation grown has been positively influenced by the rainfall and precipitation both in moving tracks of gravity center and time-lag effect especially for the growing season during the past thirteen years. The herbs and shrubs are inclined to be influenced by the change of rainfall and temperature, which is indicated by larger positive correlation coefficients at the 0.05 confidence level and shorter lagging time. For the soil moisture, the significantly negative relationship of NDV-PDI indicates that the growth and productivity of the vegetation are closely related to the short-term soil water, with the correlation coefficients reaching the maximum value of o.81 at Lag 0-1. Among the typicalvegetation types of plateau, the shrubs of low mountain, steppe and meadow are more sensitive to the change of soil moisture with coefficients of -0.95, -0.93, -0.92, respectively. These findings reveal that the spatial and temporal heterogeneity between NDVI and climatic factors are of great ecological significance and practical value for the protection of eco-environment in Qinghai-Tibet Plateau. 相似文献
16.
Examining Forest Net Primary Productivity Dynamics and Driving Forces in Northeastern China During 1982–2010 总被引：2，自引：2，他引：0
Forest net primary productivity （NPP） is a key parameter for forest monitoring and management. In this study, monthly and annual forest NPP in the northeastern China from 1982 to 2010 were simulated by using Carnegie-Ames-Stanford Approach （CASA） model with normalized difference vegetation index （NDVI） sequences derived from Advanced Very High Resolution Radiometer （AVHRR） Global Invento y Modeling and Mapping Studies （GIMMS） and Terra Moderate Resolution Imaging Spectroradiometer （MODIS） products. To address the problem of data inconsistency between AVHRR and MODIS data, a per-pixel unary linear regres- sion model based on least ~;quares method was developed to derive the monthly NDVI sequences. Results suggest that estimated forest NPP has mean relative error of 18.97% compared to observed NPP from forest inventory. Forest NPP in the northeastern China in- creased significantly during the twenty-nine years. The results of seasonal dynamic show that more clear increasing trend of forest NPP occurred in spring and awmnn. This study also examined the relationship between forest NPP and its driving forces including the climatic and anthropogenic factors. In spring and winter, temperature played the most pivotal role in forest NPR In autumn, precipitation acted as the most importanl factor affecting forest NPP, while solar radiation played the most important role in the summer. Evaportran- spiration had a close correlation with NPP for coniferous forest, mixed coniferous broadleaved forest, and broadleaved deciduous forest. Spatially, forest NPP in the Da Hinggan Mountains was more sensitive to climatic changes than in the other ecological functional re- gions. In addition to climalie change, the degradation and improvement of forests had important effects on forest NPP. Results in this study are helpful for understanding the regional carbon sequestration and can enrich the cases for the monitoring of vegetation during long time series. 相似文献
17.
Driving factors for forest fire occurrence in Durango State of Mexico: A geospatial perspective 总被引：3，自引：2，他引：1
Diana Avila-Flores Marin Pompa-Garcia Xanat Antonio-Nemiga Dante A Rodriguez-Trejo Eduardo Vargas-Perez Javier Santillan-Perez 《中国地理科学(英文版)》2010,20(6):491-497
Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management
worldwide. Identifying the driving factors and understanding the contribution of each factor are essential for the management
of forest fire occurrence. The objective of this study is to identify variables that are spatially related to the occurrence
and incidence of the forest fire in the State of Durango, Mexico. For this purpose, data from forest fire records for a five-year
period were analyzed. The spatial correlations between forest fire occurrence and intensity of land use, susceptibility of
vegetation, temperature, precipitation and slope were tested by Geographically Weighted Regression (GWR) method, under an
Ordinary Least Square estimator. Results show that the spatial pattern of the forest fire in the study area is closely correlated
with the intensity of land use, and land use change is one of the main explanatory variables. In addition, vegetation type
and precipitation are also the main driving factors. The fitting model indicates obvious link between the variables. Forest
fire was found to be the consequence of a particular combination of the environmental factors, and when these factors coexist
with human activities, there is high probability of forest fire occurrence. Mandatory regulation of human activities is a
key strategy for forest fire prevention. 相似文献