1982-2006年加纳植被覆盖时空变化及其气候影响

doi:10.3724/SP.J.1047.2015.00078

摘要/Abstract

摘要：

非洲陆地生态系统是气候变化的高敏感区,研究该区域植被覆盖变化及其控制因素,对深刻认识气候变化的影响具有重要意义。本文利用1982-2006年植被指数（NDVI）数据,研究位于非洲西部热带地区的加纳共和国植被覆盖的时空变化特征,结合同期的气温和降水量数据,分析其植被活动对气候变化的响应特征。研究结果表明,加纳86.4%的植被覆盖区NDVI在25 a间都呈现不同程度的增加趋势。20世纪80年代初和21世纪初这2个时期,NDVI值大于0.4的面积百分比呈增加趋势;NDVI值大于0.5的面积百分比从26%增加到38.2%;NDVI值在0.4-0.5之间的面积百分比从47.5%增加到51.9%。NDVI受降水量控制的区域占总区域面积的57.2%,而受气温控制的面积占总区域面积的42.8%。总的来看,加纳植被覆盖对降水量变化的敏感程度强于气温变化。

关键词: 非洲, NDVI, 植被活动, 控制因素

Abstract:

As African terrestrial ecosystem is highly sensitive to climate change, considerable researches during the past several decades have focused on monitoring vegetation activity and its responses to climate change, thus we can thoroughly understand the progress of climate change. It's significant to study the vegetation variation and its control factors in this area.We combined datasets of the satellite-derived Normalized Difference Vegetation Index (NDVI),whose spatial resolution is 8 km, and climate factors (temperature and precipitation) to detect vegetation activity change. Additionally, we analyzed the spatial correlations among NDVI, temperature, precipitation on the spatio-temporal patterns from 1982 to 2006 in Ghana. In order to conduct certain spatial correlation analysis, we interpolated the temperature and precipitation data from Climatic Research Unit (CRU3.0) datasets with respect to the spatial resolution of NDVI. At the regional scale, the results from this study showed the different increase trends occurred in the vegetation area of Ghana in the recently 25 years, which suggested that the vegetation activity has been strengthened. Compare the spatial distribution of NDVI in the early 1980 s (1982-1986) with the early 21st century (2002-2006), we found that the areas whose NDVI value is greater than 0.5 and whose value is between 0.4 and 0.5 all show a trend of increase; area percentage with NDVI value greater than 0.5 had increased from 26% to 38.2%, and the area percentage with NDVI value between 0.4 and 0.5 had increased from 47.5% to 51.9%.Spatial correlation analysis showed that the area with precipitation governed NDVI accounted for 57.2% of the total area, and the area with NDVI controlled by the temperature accounted for 42.8% of the total area. In summary, the vegetation of Ghana is more sensitive to the rainfall changes than the temperature changes.

Key words: Africa, NDVI, vegetation activity, influencing factor

王昭生, 黄玫, 闫慧敏, 王军邦, 岳溪柳. 1982-2006年加纳植被覆盖时空变化及其气候影响[J]. 地球信息科学学报, 2015, 17(1): 78-85.DOI:10.3724/SP.J.1047.2015.00078

WANG Zhaosheng,HUANG Mei,YAN Huimin,WANG Junbang,YUE Xiliu. Spatiotemporal Variation of Vegetation and Climate Impacts on It in Ghana from 1982 to 2006[J]. Journal of Geo-information Science, 2015, 17(1): 78-85.DOI:10.3724/SP.J.1047.2015.00078

图/表 7

图1

图2

图3

图4

图5

图6

图7

参考文献 43

[1]	Cramer W P, Leemans R.Assessing impacts of climate change on vegetation using climate classfication systems[M]. London: Chapman and Hall, 1993:190-217.
[2]	朴世龙,方精云.1982-1999年我国陆地植被活动对气候变化响应的季节差异[J].地理学报,2003,58(1):119-125.
[3]	Fu C B, Wen G.Variation of ecosystems over East Asia in association with seasonal, interannual and decadal monsoon climate variability[J]. Climatic Change, 1999,43:477-494.
[4]	Tucker C J, Fung I Y, Keeling C D, et al.Relationship between atmospheric CO2 variations and a satellite-derived vegetation index[J]. Nature, 1986,319:195-199.
[5]	Sellers P J, Meeson B W, Hall F G, et al.Remote sensing of the land surface for studies of global change: Models-Algorithms-Experiments[J]. Remote Sensing of Environment, 1995,51:3-26.
[6]	Potter C S, Randerson J T, Field C B, et al.Terrestrial ecosystem production: a process model based on global satellite and surface data[J]. Global Biogeochemical Cycles, 1993,7:811-841.
[7]	Field C B, Randerson J T, Malmstrom C M.Global net primary production: combining ecology and remote sensing[J]. Remote Sensing of Environment, 1995,51:74-88.
[8]	Fang J Y, Piao S L, Tang Z Y, et al.Interannual variability in net primary productivity and precipitation[J]. Science,2001,293:1723a-1723.
[9]	Zhou L M, Tucker C J, Kaufmann R K, et al.Variations in northern vegetation activity inferred from satellite data of vegetation index during 1981 to 1999[J]. Journal of Geophysical Research,2001,106(D17):20069-20083.
[10]	Weiss J L, Gutzler D S, Allred Coonrod J E, et al. Seasonal and interannual relationships between vegetation and climate in central New Mexico USA[J]. Journal of Arid Environments, 2004,57:507-534.
[11]	IPCC. Climate Change 2001: The Scientific Basis Houghton J T, Ding Y H, Griggs D J. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change[M]. Cambridge: Cambridge University Press, 2001.
[12]	王建英,韩相斌,王超,等.豫东北主要农作物对气候变暖的响应[J].气象与环境科学,2009,32(1):43-46.
[13]	徐铭志,任国玉.近40年中国气候生长期的变化[J].应用气象学报,2004,15(3):306-312.
[14]	Schmidt H,GitelsonA.Temporaland spatial vegetation cover changes in Israeli transition zone: AVHRR-based assessment of rainfall impact[J].International Journal of Remote Sensing,2000,21:997-1010.
[15]	方精云,朴世龙,贺金生,等.近20年来中国植被活动在增强[J].中国科学(C辑),2003,33(6):554-567.
[16]	IPCC. Climate Change 2001: The Scientific Basis Houghton J T, Ding Y H, Griggs D J. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change[M]. Cambridge: Cambridge University Press, 2001.
[17]	IPCC. Climate Change 2001: Impacts, Adaptation and Vulnerability Houghton J T, Ding Y H, Griggs D J. Contribution of Working Group II to the Third Assessment Report of the Intergovernmental Panel on Climate Change[M]. Cambridge: Cambridge University Press, 2001.
[18]	Williams J W, Jackson S, Kutzbach J.Projected distributions of novel and disappearing climates by 2100 AD[J]. Proceedings of the National Academy of Science,2007,104:5738-5742.
[19]	Herrmann S M, Anyamba A, Tucker C J.Recent trends in vegetation dynamics in the African Sahel and their relationship to climate[J].Global Environmental Change, 2005,15:394-404.
[20]	Malo A R, Nicholson S E.A study of rainfall and vegetation dynamics in the African Sahel using NDVI[J]. Journal of Arid Environments, 1990,19:1-24.
[21]	Tucker C J, VanPraet C L, Sharman M J, et al. Satellite remote sensing of total herbaceous biomass production in the Senegalese Sahel: 1980-1984[J]. Remote Sensing of the Environment, 1985,17:233-249.
[22]	Davenport M L, Nicholson S E.On the relation between rainfall and the normalized difference vegetation index for diverse vegetation types in East Africa[J]. InternationalJournal of Remote Sensing,1993,14:2369-2389.
[23]	Justice C O, Holben B N, Gwynne M D.Monitoring east African vegetation using AVHRR data[J]. International Journal of Remote Sensing, 1986,7:1453-1474.
[24]	Farrar T J, Nicholson S E, Lare A R.The influence of soil type on the relationships between NDVI, rainfall, and soil moisture in semiarid Botswana. II. NDVI response to soil moisture[J]. Remote Sensing of Environment, 1994,50:121-133.
[25]	Nicholson S E, Farrar T J.The influence of soil type on the relationships between NDVI, rainfall, and soil moisture in semiarid Botswana. I. NDVI response to rainfall[J]. Remote Sensing of Environment,1994,50:107-120.
[26]	Scanlon T M, Albertson J D, Caylor K K, et al.Determining land surface fractional cover from NDVI and rainfall time series for a savanna ecosystem[J]. Remote Sensing of Environment,2002,82(2-3):376-388.
[27]	Gondwe M P, Jury M R.Sensitivity of vegetation (NDVI) to climate over Southern Africa: Relationships with summer rainfall and OLR[J]. South African Geographical Journal, 1997,79(1):52-60.
[28]	Richard Y, Poccard I.A statistical study of NDVI sensitivity to seasonal and interannual rainfall variations in Southern Africa[J]. International Journal of Remote Sensing, 1998,19:2907-2920.
[29]	Hellden U, Eklundh L.National drought monitoring: A NOAA NDVI and precipitation data study of Ethiopia[J]. Lund Studies in Geography. Ser. C, General and Mathematical Geography, 1988,15:55-55.
[30]	Hielkema J U, Prince S D, Astle W L.Rainfall and vegetation monitoring in the savanna zone of the Democratic Republic of Sudan using NOAA advanced very high resolution radiometer[J]. International Journal of Remote Sensing, 1986,7:1499-1514.
[31]	Diouf A, Lambin E F.Monitoring land-cover changes in semi-arid regions: remote sensing data and field observations in the Ferlo, Senegal[J]. Journal of Arid Environments, 2001,48:129-148.
[32]	Li J, Lewis J, Rowland J, et al.Evaluation of land performance in Senegal using multi-temporal NDVI and rainfall series[J]. Journal of Arid Environments, 2004,59:463-480.
[33]	Archer E R M. Beyond the “climate versus grazing” impasse: Using remote sensing to investigate the effects of grazing system choice on vegetation cover in the eastern Karoo[J]. Journal of Arid Environments, 2004, 57:381-408.
[34]	Richard Y, Poccard I.A statistical study of NDVI sensitivity to seasonal and interannual rainfall variations in Southern Africa[J]. International Journal of Remote Sensing, 1998,19:2907-2920.
[35]	Lambin E F, Ehrlich D.Land-cover changes in sub-Saharan Africa (1982-1991): Application of a change index based on remotely sensed surface temperature and vegetation indices at a continental scale[J]. Remote Sensing of Environment, 1997,61:181-200.
[36]	Camberlin P, Martiny N, Philippon N, et al.Determinants of the interannual relationships between remote sensed photosynthetic activity and rainfall in tropical Africa[J]. Remote Sensing of Environment, 2007,106:199-216.
[37]	Clark N L.Forestry in Ghana-A Country Study: Ghana[M]. Library of Congress Federal Research Division,1994.
[38]	Wikipedia.Forestry in Ghana[EB/OL]..
[39]	Immigration and Refugee Board of Canada.Ghana: Conflict between the Konkomba and Nanumba tribes and the government response to the conflict (1994-September 2000), 26 September 2000, GHA35249E[EB/OL]. .
[40]	IUCN (International Union for Conservation of Nature). Parks and Reserves of Ghana: Management Effectiveness Assessment of Protected Areas[J]. UICN/PACO,Ouagadougou, BF, 2010.
[41]	BGCI. Botanic Gardens Conservation Internation[EB/OL]..
[42]	Aneani F, Ofori-Frimpong K.An Analysis of Yield Gap and Some Factors of Cocoa (Theobroma cacao) Yields in Ghana[J]. Sustainable Agriculture Research, 2013,4(2):117-127.
[43]	Fuwape J A, Jonathan C.Onyekwelu. Urban Forest Development in West Africa: Benefits and Challenges[J]. Journal of Biodiversity and Ecological Sciences, 2011,1(1):77-94.