889 resultados para Land use, rural.
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Most of the cities in India are undergoing rapid development in recent decades, and many rural localities are undergoing transformation to urban hotspots. These developments have associated land use/land cover (LULC) change that effects runoff response from catchments, which is often evident in the form of increase in runoff peaks, volume and velocity in drain network. Often most of the existing storm water drains are in dilapidated stage owing to improper maintenance or inadequate design. The drains are conventionally designed using procedures that are based on some anticipated future conditions. Further, values of parameters/variables associated with design of the network are traditionally considered to be deterministic. However, in reality, the parameters/variables have uncertainty due to natural and/or inherent randomness. There is a need to consider the uncertainties for designing a storm water drain network that can effectively convey the discharge. The present study evaluates performance of an existing storm water drain network in Bangalore, India, through reliability analysis by Advance First Order Second Moment (AFOSM) method. In the reliability analysis, parameters that are considered to be random variables are roughness coefficient, slope and conduit dimensions. Performance of the existing network is evaluated considering three failure modes. The first failure mode occurs when runoff exceeds capacity of the storm water drain network, while the second failure mode occurs when the actual flow velocity in the storm water drain network exceeds the maximum allowable velocity for erosion control, whereas the third failure mode occurs when the minimum flow velocity is less than the minimum allowable velocity for deposition control. In the analysis, runoff generated from subcatchments of the study area and flow velocity in storm water drains are estimated using Storm Water Management Model (SWMM). Results from the study are presented and discussed. The reliability values are low under the three failure modes, indicating a need to redesign several of the conduits to improve their reliability. This study finds use in devising plans for expansion of the Bangalore storm water drain system. (C) 2015 The Authors. Published by Elsevier B.V.
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Bioenergy deployment offers significant potential for climate change mitigation, but also carries considerable risks. In this review, we bring together perspectives of various communities involved in the research and regulation of bioenergy deployment in the context of climate change mitigation: Land-use and energy experts, land-use and integrated assessment modelers, human geographers, ecosystem researchers, climate scientists and two different strands of life-cycle assessment experts. We summarize technological options, outline the state-of-the-art knowledge on various climate effects, provide an update on estimates of technical resource potential and comprehensively identify sustainability effects. Cellulosic feedstocks, increased end-use efficiency, improved land carbon-stock management and residue use, and, when fully developed, BECCS appear as the most promising options, depending on development costs, implementation, learning, and risk management. Combined heat and power, efficient biomass cookstoves and small-scale power generation for rural areas can help to promote energy access and sustainable development, along with reduced emissions. We estimate the sustainable technical potential as up to 100EJ: high agreement; 100-300EJ: medium agreement; above 300EJ: low agreement. Stabilization scenarios indicate that bioenergy may supply from 10 to 245EJyr(-1) to global primary energy supply by 2050. Models indicate that, if technological and governance preconditions are met, large-scale deployment (>200EJ), together with BECCS, could help to keep global warming below 2 degrees degrees of preindustrial levels; but such high deployment of land-intensive bioenergy feedstocks could also lead to detrimental climate effects, negatively impact ecosystems, biodiversity and livelihoods. The integration of bioenergy systems into agriculture and forest landscapes can improve land and water use efficiency and help address concerns about environmental impacts. We conclude that the high variability in pathways, uncertainties in technological development and ambiguity in political decision render forecasts on deployment levels and climate effects very difficult. However, uncertainty about projections should not preclude pursuing beneficial bioenergy options.
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Despite an increasing literary focus on climate change adaptation, the facilitation of this adaptation is occurring on a limited basis (Adger et al. 2007) .This limited basis is not necessarily due to inability; rather, a lack of comprehensive cost estimates of all options specifically hinders adaptation in vulnerable communities (Adger et al. 2007). Specifically the estimated cost of the climate change impact of sea-level rise is continually increasing due to both increasing rates and the resulting multiplicative impact of coastal erosion (Karl et al., 2009, Zhang et al., 2004) Based on the 2007 Intergovernmental Panel on Climate Change report, minority groups and small island nations have been identified within these vulnerable communities. Therefore the development of adaptation policies requires the engagement of these communities. State examples of sea-level rise adaptation through land use planning mechanisms such as land acquisition programs (New Jersey) and the establishment of rolling easements (Texas) are evidence that although obscured, adaptation opportunities are being acted upon (Easterling et al., 2004, Adger et al.2007). (PDF contains 4 pages)
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Lough Erne in Northern Ireland has been the subject of much research over the last 30 years by, amongst others, the Department of Agriculture and Rural Development (DARD). In this article, the authors provide a summary of a workshop held on the 16–17th October 2003 in Enniskillen, on the shores of Lough Erne, which gave an opportunity to step back and take a holistic look at the Erne lakes. Ecological change has been driven by many factors, including land use changes and species invasions. The workshop consisted of five sessions which are summarised in this article: Session 1 – Invasive species, nutrients, phytoplankton and macrophytes; Session 2 – Zooplankton, benthic macroinvertebrates and fish; Session 3 – An ecosystem approach – relating the previous sessions; Session 4 – How does Lough Erne fit into lake classifications? Implications of the Water Framework Directive; Session 5 – Using new techniques to examine food webs and species invasions. Identifying a future research programme for Lough Erne.
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O município de Petrópolis, palco de recorrente de problemas ambientais envolvendo movimentos de massa concentrados historicamente na sua área mais urbanizada, os distritos Sede e Cascatinha, vive nas últimas décadas um crescimento populacional que se orienta basicamente para antigas áreas rurais de Itaipava, Pedro do Rio e Posse. O objetivo geral da pesquisa é investigar como este crescimento vem ocorrendo, analisando as características geológico-geomorfológicas dos novos espaços ocupados, os fatores predisponentes às novas condições de risco envolvendo os movimentos de massa e as inundações. Assim, foi elaborado um panorama sócio-evolutivo do processo de ocupação do solo em Petrópolis, considerando especialmente a dinâmica demográfica registrada nos distritos através dos censos demográficos a partir da década de 1940. Utilizando o geoprocessamento como ferramenta e a classificação visual de segmentação de OrtofotosCarta IBGE na escala 1: 25.000, foram produzidos mapas de uso do solo para o município e distritos detalhando a área ocupada. Com o fim de atender ao diagnóstico das situações de risco foi realizado o levantamento da situação atual da ocorrência dos movimentos de massa e inundações no município, comparando levantamentos anteriores e verificando a distribuição das ocorrências e a população atingida. Por fim, a avaliação da execução da política de desenvolvimento e expansão urbana definida no Plano Diretor de Petrópolis e na Lei de Uso, Parcelamento e Ocupação do Solo, analisando o zoneamento e seus usos (rural, rururbano, urbano e zona de proteção especial) resultando no entendimento de como os aspectos normativos vem sendo tratados, naquilo que são respeitados e naquilo que não são cumpridos na dinâmica da ocupação do espaço, levantando as ações de prevenção, ou não, dos problemas ambientais. Contudo, a definição dos objetivos do trabalho teve dois momentos. O primeiro com a análise da expansão urbana construindo novas condições de risco e o segundo momento, lamentavelmente, aquele no qual as evidências ganharam contorno de realidade com o ocorrido em dezembro de 2010 e em janeiro de 2011, principalmente quando inundações bruscas associadas aos deslizamentos de terra nas encostas atingiram áreas de Petrópolis e de outros municípios da região Serrana do Estado do Rio de Janeiro, certamente, a maior tragédia ambiental ocorrida no Centro-Sul do país até então. Com mais de 900 mortos, centenas de desaparecidos e milhares de desabrigados e desalojados, os eventos suplantaram os objetivos do trabalho, colocando novas questões, ao mesmo tempo em que a realidade demonstrou a coerência e pertinência daqueles objetivos com os problemas apresentados. Assim, dentre os objetivos passou a constar também a verificação in loco das conseqüências de movimentos de massa e inundações nas áreas apontadas anteriormente, como foi o caso do vale do Rio Santo Antônio em Itaipava. O trabalho, assim, se pautou por indicar a necessidade ter-se maior atenção às novas áreas de ocupação no município, considerando a natureza do território, contribuindo como um subsídio na prevenção ao risco.
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A degradação ambiental do Noroeste do Estado do Rio de Janeiro tem se intensificado nas últimas décadas devido às práticas agrícolas não preservacionistas. Esta situação, que decorre do uso inadequado do solo, tem implicado em mudanças na oferta hídrica em grau variável nos municípios da região com prejuízos econômicos nas atividades dos pequenos e médios proprietários rurais e na qualidade de vida. A abordagem para enfrentar problemas deste tipo depende da participação efetiva das instâncias de governo e dos órgãos responsáveis pela gestão dos recursos hídricos. No âmbito da hidrologia os modelos hidrológicos com base no uso e ocupação do solo são ferramentas que podem auxiliar com ótimo custo e benefício a geração de informações em bacias hidrográficas, instrumentadas ou não. Os modelos são úteis ao planejamento e à tomada de decisão por possibilitarem a previsão de vazões e simulação de cenários sobre o uso do solo e qualidade da água. Neste sentido, o presente estudo pretende dar sua contribuição ao avaliar a adequabilidade do modelo SWAT simular o processo chuva-vazão na microbacia experimental de Santa Maria e Cambiocó, com 13,5 km2, localizada na região hidrográfica do rio Muriaé, afluente do rio Paraíba do Sul. O SWAT tem sido empregado em bacias agrícolas nos EUA, na Europa e, atualmente, na China, sudeste asiático e Irã, entre outros países, e na última década maior inserção no meio acadêmico brasileiro. A versão 2005 do modelo foi utilizada por meio da sua interface SIG para simular as vazões médias diárias com base na precipitação medida no intervalo de 15 minutos no período de 2005/2006. As vazões simuladas foram comparadas com as vazões observadas no exutório da microbacia. Foram testadas as ferramentas de análise de sensibilidade e autocalibração. O método de calibração manual foi usado para o ajuste por tentativa e erro. Os parâmetros ajustados corresponderam ao CN2 e ESCO. Os valores obtidos na calibração para os coeficientes estatísticos R2, NSE, PBIAS e RSR foram 0,80, 0,80, 7,02 e 0,45, respectivamente, indicando escore muito bom, o que foi confirmado pela inspeção dos hidrogramas. As saídas validadas para período diferente da calibração forneceram para os mesmos coeficientes os valores 0,84, 0,80, 25,92 e 0,44. Os dois primeiros, com escore muito bom. O valor de PBIAS, no limite do satisfatório, e RSR, muito bom. O desempenho permitiu concluir que a simulação com o SWAT foi adequada. Em relação às pesquisas que têm sido realizadas no Brasil os valores obtidos para os indicadores foram semelhantes, indicando a capacidade do modelo para novos estudos nesta microbacia que considerem os usos consuntivos e cenários de uso do solo.
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This is the Acid waters in North West England: The effect of liming agricultural land on the chemistry and biology of the River Esk, North West England report produced by National Rivers Authority in 1992. This report focuses on the study of Acid Waters in the North West Region of England, UK, which began in 1982 and sampling was completed in October 1990. This work was initiated because of the observation of the simultaneous mortality of adult and juvenile salmon and sea-trout in both the River Esk and adjacent River Duddon in June 1980. Investigations at that time indicated that an "acid episode" was the most likely cause of this mortality. A land use study indicated that a reduction in agricultural liming may have been a major factor in the development of acid episodes and consequent fish kills in the River Esk and River Duddon. However there was no evidence that the mortalities of salmonids in the early 1980's were due to a reduction in agricultural liming. They were due to some other phenomenon such as a period of intense acid deposition.
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The St. Croix East End Marine Park (STXEEMP) was established in 2003 as the first multi-use marine park managed by the U.S. Virgin Islands Department of Planning and Natural Resources. It encompasses an area of approximately 155 km2 and is entirely within Territorial waters which extend up to 3 nautical miles from shore. As stated in the 2002 management plan, the original goals were to: protect and maintain the biological diversity and other natural values of the area; promote sound management practices for sustainable production purposes; protect the natural resource base from being alienated for other land use purposes that would be detrimental to the area’s biological diversity; and to contribute to regional and national development (The Nature Conservancy, 2002). At the time of its establishment, there were substantial data gaps in knowledge about living marine resources in the St. Croix, and existing data were inadequate for establishing baselines from which to measure the future performance of the various management zones within the park. In response to these data gaps, National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Monitoring and Assessment, Biogeography Branch (CCMA-BB) worked with territorial partners to characterize and assess the status of the marine environment in and around the STXEEMP and land-based stressors that affect them. This project collected and analyzed data on the distribution, diversity and landscape condition of marine communities across the STXEEMP. Specifically, this project characterized (1) landscape and adjacent seascape condition relevant to threats to coral reef ecosystem health, and (2) the marine communities within STXEEMP zones to increase local knowledge of resources exposed to different regulations and stressors.
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北京市郊区可持续景观生态规划及优化生态生产范式研究是指要遵循区域自然地理要素的分异规律,以土地利用现状格局为基础,以景观生态学原理和可持续发展准则为理论指导,以景观空间分析为具体研究内容来揭示区域土地利用类型结构、功能的异质性和有序性,以期提出优化的土地利用格局。本论文主要通过大量数据、图件的收集、野外考察与调查,文献查阅与数据处理、分析,得出以下主要结论: 一、理论方面 基于景观生态学理论——景观要素,空间结构与生态学过程,景观动态,异质性,等级结构,连接度以及景观的时空性等,以北京地区为例阐述了景观生态学理论如何合理地整合于生态建设与保育之中,并重点阐释了北京生态建设与保育“小三圈”格局的结构与功能,该系统包括山区外圈层、郊区平原中圈层和城区内圈层,其目标要实现:(1)山区发挥以水源涵养、水土保持防护为主的生态功能;(2)郊区创建农田、林地、草地异质性的人工稀树草原景观,形成带、网、片、点相结合的绿网系统;(3)城区以自身绿化和美化为主。同时,本研究针对我国的区域可持续发展进一步提出更加有效的建设性意见:(1)开展区域生态适宜性评价;(2)区域水平的土地利用格局、动态以及预测性研究;(3)进行区域可持续景观生态规划,建立区域优化生态生产范式,最终实现可持续发展目标。 二、研究方法方面 利用空间自相关指数,并结合“城-郊-乡”梯度分析法研究景观格局对尺度(包括粒度、幅度、方向)变化的响应。得出以下主要结论: 1、景观格局对于尺度变化有着不同的响应,随着空间粒度的增加,空间自相关均呈下降趋势;随着幅度的增加,空间自相关基本不变;人类干扰较多的景观几乎不受“划区效应”的影响;不同的数据类型,同一数据类型的不同景观对于尺度的变化均有着不同的响应。 2、沿“城-郊-乡”样带,空间自相关呈阶梯状增加趋势。景观空间自相关大小顺序:林牧景观>林果景观>农田景观>都市景观>都市化景观,人为干扰较多的景观具有较低的空间自相关,但对尺度的变化表现出较强的敏感性。 三、实例研究 北京市郊区可持续景观生态规划及优化生态生产范式研究是以昌平区为例,从昌平区经济与产业结构现状分析出发、以昌平区土壤理化性状分析为背景,以景观格局现状、动态,以及土地利用内部转移格局与过程、驱动因素分析为主要内容,并且重点探讨了昌平区城镇化的过程特征及空间特征,得出以下主要结论: 1、昌平区GDP配比方式,以及昌平区农村GDP结构模式均为“三二一”。昌平区在北京市农业中的地位,以及农业在昌平区GDP中所处地位均弱化。截止2001年,昌平区农业产值中,牧业>种植业>渔业>林业,牧业居于首位,占到46.70%,而传统种植业也正以小汤山为龙头向现代化、高科技、高效化的“六种农业”转化。总体讲,农业的粮食生产功能在昌平区已不再是一个重要功能,传统种植业正逐步地让位于畜牧业(人工牧草)、林业(疏林、苗圃),突出体现了具有良好生态学效益的牧草、林果在未来大农业发展中的战略地位。 2、昌平土壤肥力状况良好,景观分区与土壤理化性质是吻合的。基于土壤理化基质,昌平区应形成林、灌、草为主的山区景观,园林式城镇、林、果、灌相结合的山前倾斜平原景观,以及农、林、草配置的生态农业景观和花卉、种苗、绿化带相辉映的绿色生态住宅景观。 3、从1989~2001年期间,研究区内土地利用景观经历了很大的变化。土地利用景观的量变主要体现在城镇用地的迅速扩张和耕地的锐减,而土地利用类型的变化则体现在水田、传统菜地的逐渐消失,以及2001年后人工牧草的大面积推广种植。景观格局在不同景观分区的差异也得以论证,中北部山麓平原卫星城镇、旅游林果区(III)具有最高的多样性和最低的优势度、聚集度,中南部平原高科技、都市生态农业区(II)的多样性最低,而优势度、聚集度最高,对于南部平原都市边缘、城镇住宅区(I)各指标则介于III和II区之间。 4、从1989~2001年期间,土地利用的内部转移主要体现在耕地向城镇用地的大面积转移,其次,传统菜地转向城镇用地和其他种植耕地,而人工牧草是由部分耕地转移而来的。城镇化、水资源短缺和农业政策是主要驱动因素。土地利用的内部转移具有明显的区域差异,中北部山麓平原卫星城、旅游林果区体现出卫星城镇的发展,南部平原都市边缘住宅区则反映出北京都市边缘的向外扩张,而中南部平原高科技都市农业区则正向现代化的、高科技都市农业示范区发展。 5、昌平区三种主要的城镇化模式,即都市边缘带状城镇扩展模式、交通主轴线状城镇扩展模式和卫星城面状城镇扩展模式。研究表明,昌平区的城镇化主要集中在1989~1996年期间。 基于昌平区的产业与经济结构现状,土壤养分状况,景观结构现状、动态,土地利用转移方向,并且结合昌平区自然地理分异规律,社会经济因素对昌平区进行了可持续景观规划,昌平区应遵循的四个景观分区为:北部中低山生态保护、生态旅游区;中北部山麓平原卫星城镇、旅游林果区;中南部平原高科技、都市生态农业区;南部平原都市边缘、城镇住宅区。 最后作为总结、归纳,我们提出昌平区优化生态生产范式,昌平区的发展应定位于(1)生态环境保护与水源涵养的生态功能;(2)教育、示范、创新功能;(3)生活功能,并且遵循自然地域分异规律原则、因地制宜原则、生态主导性原则、统筹兼顾原则,大力发展昌平区经济的优势产业,即畜牧业、林果业和旅游业,突出肉羊、苹果、牧草和林木种苗等四个具有昌平特色的主导产业。 景观生态学;景观空间格局;可持续景观生态规划;土地利用变化;优化生态生产范式;北京昌平区
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黄土高原沟壑区王东沟流域从1986年至2006年的土地利用/覆被发生了较大变化,土地利用动态指数分别为:耕地3.21%,园地-36.11%,林地-4.05%,牧草地4.24%,居民点及独立工矿用地-0.62%,交通运输用地-12.27%,未利用地1.85%;变化趋势是:耕地逐年向园地流转,园地变化烈度较大,其他各类用地变化不太显著。引起这一变化的主要因素是自然、社会、经济、技术以及政策因素。结合这一变化,针对黄土高原沟壑区的实际情况,在黄土高原沟壑区土地利用经营与管理方面,应重视土地产出效益与粮食安全的关系,在保障区域粮食安全的基础上实现效益最大化。
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China has witnessed fast urban growth in the recent decade. This study analyzes spatio-temporal characteristics of urban expansion in China using satellite images and regionalization methods. Landsat TM images at three time periods, 1990/1991, 1995/1996, and 1999/2000, are interpreted to get 1:100000 vector land use datasets. The study calculates the urban land percentage and urban land expansion index of every 1 km(2) cell throughout China. The study divides China into 27 urban regions to conceive dynamic patterns of urban land changes. Urban development was achieving momentum in the western region, expanding more noticeably than in the previous five years, and seeing an increased growth percentage. Land use dynamic changes reflect the strong impacts of economic growth environments and macro-urban development policies. The paper helps to distinguish the influences of newly market-oriented forces from traditional administrative controls on China's urban expansion. (c) 2005 Elsevier Ltd. All rights reserved.
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Using meteorological data and RS dynamic land-use observation data set, the potential land productivity that is limited by solar radiation and temperature is estimated and the impacts of recent LUCC processes on it are analyzed in this paper. The results show that the influence of LUCC processes on potential land productivity change has extensive and unbalanced characteristics. It generally reduces the productivity in South China and increases it in North China, and the overall effect is increasing the total productivity by 26.22 million tons. The farmland reclamation and original farmlands losses are the primary causes that led potential land productivity to change. The reclamation mostly distributed in arable-pasture and arable-forest transitional zones and oasises in northwestern China has made total productivity increase by 83.35 million tons, accounting for 3.50% of the overall output. The losses of original farmlands driven by built-up areas invading and occupying arable land are mostly distributed in the regions which have rapid economic development, e.g. Huang-Huai-Hai plain, Yangtze River delta, Zhujiang delta, central part of Gansu, southeast coastal region, southeast of Sichuan Basin and Urumqi-Shihezi. It has led the total productivity to decrease 57.13 million tons, which is 2.40% of the overall output.
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Due to its inert reaction in soil system and distinctive vertical distribution in soil profile, caesium-137 (Cs-137) has been used as a tracer to assess wind erosion. In this study, 62 soil samples were collected from 4 sampling sites in Taipusi County, Inner Mongolia; Caesium-137 activities for those soil samples were measured using a gamma-ray spectrometry in Sichuan University, Chengdu. Distribution pattern of Cs-137 in vertical soil profile was different for different land use and land cover types. Caesium-137 was distributed homogeneously in plow layer of cropland, and negatively exponential in low to medium cover grassland. Distribution pattern in high covered grassland was represented by a peak at 2-4 cm soil depth followed by a negative exponential curve. Based on those findings, simplified mass balance model was chosen to estimate the rate of wind erosion for cropland, while profile distribution model was used for grassland. Estimated wind erosion rates were 7990, 4270 and 1808 Mg(.)km(-2.)a(-1) for cropland, low cover grassland and medium cover grassland, respectively. Wind erosion intensity correlated negatively with plant cover.
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Along with its economic reform, China has experienced a rapid urbanization. This study mapped urban land expansion in China using high-resolution Landsat Thematic Mapper and Enhanced Thematic Mapper data of 1989/1990, 1995/1996 and 1999/2000 and analyzed its expansion modes and the driving forces underlying this process during 1990-2000. Our results show that China's urban land increased by 817 thousand hectares, of which 80.8% occurred during 1990-1995 and 19.2% during 1995-2000. It was also found that China's urban expansion had high spatial and temporal differences, such as four expansion modes, concentric, leapfrog, linear and multi-nuclei, and their combinations coexisted and expanded urban land area in the second 5 y was much less than that of the first 5 y. Case studies of the 13 mega cities showed that urban expansion had been largely driven by demographic change, economic growth, and changes in land use policies and regulations.
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Over last two decades, numerous studies have used remotely sensed data from the Advanced Very High Resolution Radiometer (AVHRR) sensors to map land use and land cover at large spatial scales, but achieved only limited success. In this paper, we employed an approach that combines both AVHRR images and geophysical datasets (e.g. climate, elevation). Three geophysical datasets are used in this study: annual mean temperature, annual precipitation, and elevation. We first divide China into nine bio-climatic regions, using the long-term mean climate data. For each of nine regions, the three geophysical data layers are stacked together with AVHRR data and AVHRR-derived vegetation index (Normalized Difference Vegetation Index) data, and the resultant multi-source datasets were then analysed to generate land-cover maps for individual regions, using supervised classification algorithms. The nine land-cover maps for individual regions were assembled together for China. The existing land-cover dataset derived from Landsat Thematic Mapper (TM) images was used to assess the accuracy of the classification that is based on AVHRR and geophysical data. Accuracy of individual regions varies from 73% to 89%, with an overall accuracy of 81% for China. The results showed that the methodology used in this study is, in general, feasible for large-scale land-cover mapping in China.