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1.
Land cover change affects surface radiation budget and energy balance by chang- ing surface albedo and further impacts the regional and global climate. In this article, high spatial and temporal resolution satellite products were used to analyze the driving mechanism for surface albedo change caused by land cover change during 1990-2010. In addition, the annual-scale radiative forcing caused by surface albedo changes in China＇s 50 ecological regions were calculated to reveal the biophysical mechanisms of land cover change affecting climate change at regional scale. Our results showed that the national land cover changes were mainly caused by land reclamation, grassland desertification and urbanization in past 20 years, which were almost induced by anthropogenic activities. Grassland and forest area decreased by 0.60% and 0.11%, respectively. The area of urban and farmland increased by 0.60% and 0.19%, respectively. The mean radiative forcing caused by land cover changes during 1990-2010 was 0.062 W/m2 in China, indicating a warming climate effect. However, spatial heterogeneity of radiative forcing was huge among different ecological regions. Farmland conversing to urban construction land, the main type of land cover change for the urban and suburban agricultural ecological region in Beijing-Tianjin-Tangshan region, caused an albedo reduction by 0.00456 and a maximum positive radiative forcing of 0.863 WIm2, which was presented as warming climate effects. Grassland and forest conversing to farmland, the main type of land cover change for the temperate humid agricultural and wetland ecological region in Sanjiang Plain, caused an albedo increase by 0.00152 and a maximum negative radiative forcing of 0.184 W/m2, implying cooling climate effects. 相似文献
2.
Modeling the impacts of climate change on China''s agriculture 总被引：1，自引：0，他引：1
1 Introduction Since recognition of the potential climate change [IPPC, 1990], efforts have been made to estimate the economic impacts of projected changes in climate on important sectors, such as agriculture, forestry and ecosystem, coastal zones and fisheries, water resource, and energy development. Although several sectors have been studied, none have received more attention than agriculture. Countrywide economic analysis has been completed for the United States[1-4], India[5] and Brazil… 相似文献
3.
Climate change adaptation (CCA) ‘barriers’ are frequently seen as responses to biophysical climate impacts, and thus defined as ‘obstacles’ to be ‘overcome’, rendered into categories of the techno-managerial. However, barriers are often undertheorized and are blind to explanations of their origins or the causal mechanisms by which they operate. This is especially complex for barrier critiques in the Global South in particular. Using a ‘hybrid’ assemblage and postcolonial approach, this paper disentangles existing barrier critiques in Thailand to lay bare underlying power imbalances and tensions. It finds that ‘simplistic’ vulnerability framings have deep roots in postcolonial histories; ‘complacent’ mainstreaming/budgeting trajectories have been nurtured by various IOs, and not necessarily much-maligned Thai bureaucrats; and limited technical expertise/willingness to engage are not so illogical, but rather results of diverse external forces. Given this, this paper urges institutional actors and researchers to reflect on epistemology, ontology, and their own positionality when assessing barriers in future. 相似文献
4.
N. Dendoncker C. Schmit M. Rounsevell 《International journal of geographical information science》2013,27(9):1013-1030
This paper evaluates errors and uncertainties in representing landscapes that arise from different data rasterization methods, spatial resolutions, and downscaled land‐use change (LUC) scenarios. A vector LU dataset for Luxembourg (minimum mapping unit: 0.15 ha; year 2000) was used as the baseline reference map. This map was rasterized at three spatial resolutions using three cell class assignment methods. The landscape composition and configuration of these maps were compared. Four alternative scenarios of future LUC were also generated for the three resolutions using existing LUC scenarios and a statistical downscaling method creating 37 maps of LUC for the year 2050. These maps were compared in terms of composition and spatial configuration using simple metrics of landscape fragmentation and an analysis of variance (ANOVA). Differences in landscape composition and configuration between the three cell class assignment methods and the three spatial resolutions were found to be at least as large as the differences between the LUC scenarios. This occurred in spite of the large LUC projected by the scenarios. This demonstrates the importance of the rasterization method and the level of aggregation as a contribution to uncertainty when developing future LUC scenarios and in analysing landscape structure in ecological studies. 相似文献
5.
Land use change in Bohai Rim: a spatial-temporal analysis 总被引：5，自引：0，他引：5
Land use change is one of the important aspects of global change[1-3]. The Bohai Rim is a hot spot of economic development in China, where land use changes remarkably. Analyzing land use change in this area is significant to the research of global change and regional sustainable land use. Although there has been much work undertaken on regional land use change in China, it was mainly on urban land use change[4-11], and few researches integrated remote sensing and GIS method. Based on data f… 相似文献
6.
1IntroductionIn recent 20 years, Chinese scientists have conducted a lot of studies on characteristics and regularity of climate variation over China on various spatial and temporal scales. Most of the studies using temperature records have shown that the… 相似文献
7.
1 IntroductionCoastal areas, with dense population and high urbanization, are highly sensitive to global environmental change. The impacts of coastal environmental changes, such as sea level rise and related disasters exacerbation on socio-economic development of coastal areas, have become a matter of public concern. To study the vulnerable scope and degree of impacts of sea level rise and related exacerbating coastal hazards can provide a scientific basis for lessening the potential losses th… 相似文献
8.
《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2012,112(2):135-143
Abductive causal eventism (ACE) is an analytical methodology based on a pragmatic view of research methods and explanation that places at the center of research inquiry the answering of ‘why’ questions about events, including human actions or environmental changes of interest. When used in human–environment research, the methodology entails constructing causal histories of interrelated social and/or biophysical events backward in time through a process of eliminative inference and reasoning from effects to causes, called abduction. ACE encourages an eclectic use of methods, models, and theoretical ideas. It fosters integrative, interdisciplinary analysis without being committed either to systems as ontological entities or to holistic analytical frameworks. By not privileging particular theories or explanatory factors in advance, ACE enables researchers to interrogate the plausibility of different causal influences, including local environmental changes that may be related to much wider changes in climate. Likewise, behaviors or practices that may be of value in light of anticipated environmental changes can be studied without their presuming to be caused by these changes or by changes in climate per se. Research on coastal mangrove planting for storm protection in the Philippines and upland tree planting in St. Lucia are used to illustrate these arguments. 相似文献
9.
YANGOing CUICaixia 《地理学报(英文版)》2005,15(1):20-28
To reveal the changing trend and annual distribution of the surface water hydrology and the local climate in the Bayanbuluk alpine-cold wetlands in the past 50 years, we used temperature, precipitation, different rank precipitation days, evaporation, water vapor pressure, relative humidity, dust storm days and snow depth to analyze their temporal variations. We conclude that there were no distinct changes in annual mean temperature, and no obvious changes in the maximum or minimum temperatures. Precipitation in warm season was the main water source in the wetlands of the study area and accounted for 92.0% of the annual total. Precipitation dropped to the lowest in the mid-1980s in the past 50 years and then increased gradually. The runoff of the Kaidu River has increased since 1987 which has a good linear response to the annual precipitation and mean temperature in Bayanbuluk alpine-cold wetland. Climate change also affected ecosystems in this area due to its direct relations to the surface water environment. 相似文献
10.
Iraq has experienced significant agricultural land use changes throughout its history, including recent changes initiated by the 2003 US-led military invasion, the end of United Nations' economic sanctions and the onset of overt domestic conflict. Conflict and sociopolitical forces are important drivers of land use/land cover change and often have disproportionate impacts on agricultural systems. However, there has been little research to investigate recent changes in agricultural land use/land cover in Iraq over the recent tumultuous period that has included war and the transition of its political system from a dictatorship to an emerging but beleaguered democracy. Our objectives were to (1) determine if cropland area in Iraq changed significantly between 2001 and 2012, (2) identify regional patterns of cropland area change, and (3) identify sociopolitical forces driving those changes. We used MODIS Land Cover Product yearly data to quantify the amount of land cover dedicated to croplands. We regressed cropland area (ha) on time (2001, 2002, 2003,…) and years with drought influence (yes, no). The results revealed significant changes in cropland area for Iraq as a whole, with cropland area decreasing over 30,000 ha per year. Regionally, there were significant decreases in the Kurdish Autonomous Region and central Iraq, and initial increases in the southern marshlands followed by decreases related to drought. 相似文献
11.
Stephen Trudgill 《Area》2008,40(1):99-107
12.
Richard Moye 《Urban geography》2013,34(2):236-263
A limited number of studies have addressed residential self-selection when considering the relationship between the built environment (BE) and physical activity. Ignoring self-selection may bias the estimate of the strength of the relationship and misinform public policy. Using 2011 data from the Twin Cities, this study employs cross-sectional and quasi-longitudinal analyses to disentangle the impacts between self-selection (through residential preferences and travel attitudes) and neighborhood characteristics on active travel (AT). The two approaches produce somewhat different outcomes: attitudinal factors are extensively present in the cross-sectional analysis and the associations between neighborhood characteristics and AT are greatly attenuated after controlling for attitudinal factors. In contrast, neighborhood characteristics play a dominant role in the quasi-longitudinal analysis, while attitudinal and demographic characteristics carry additional impacts on AT. Overall, both preferences and attitudes help explain the difference in AT. I find that while physical activity infrastructure impacts biking, physical activity infrastructure together with transit and accessibility affects walking, even after controlling for demographic and attitudinal characteristics. The results highlight the importance of shaping the BE in order to provide an infrastructure of alternative modes of transport and access to different land uses in policy efforts to increase AT. 相似文献
13.
Progress in China’s climate change study in the 20th century 总被引：2，自引：0，他引：2
Studies on the 20th century climate change in China have revealed that under the background of global warming over the past
century, climate in China has also experienced significant change with mean annual temperature increased by about 0.5 °C.
More reliable results for the latter part of the 20th century indicate that the largest warming occurred in Northwest China,
North China and Northeast China, and the warming in winter is most significant. Although no obvious increase or decrease trends
were detected for mean precipitation over China in the past half century, regional differences are very distinct. In the middle
and lower reaches of the Yangtze River, precipitation increased, while that in the Yellow River Basin markedly decreased.
Studies suggest that climate change in China seems to be related not only with the internal factors such as ENSO, PDO, and
the others, but also with the anthropogenic effects such as greenhouse gas emissions, and land use. The future climate change
studies in China seem to be important in narrowing understanding the nature of China’s climate change and its main causes,
since it is significant for projection and for impact assessment of climate change in the future. 相似文献
14.
Jia Ning Jiyuan Liu Wenhui Kuang Xinliang Xu Shuwen Zhang Changzhen Yan Rendong Li Shixin Wu Yunfeng Hu Guoming Du Wenfeng Chi Tao Pan Jing Ning 《地理学报(英文版)》2018,28(5):547-562
Land use/cover change is an important theme on the impacts of human activities on the earth systems and global environmental change. National land-use changes of China during 2010–2015 were acquired by the digital interpretation method using the high-resolution remotely sensed images, e.g. the Landsat 8 OLI, GF-2 remote sensing images. The spatiotemporal characteristics of land-use changes across China during 2010–2015 were revealed by the indexes of dynamic degree model, annual land-use changes ratio etc. The results indicated that the built-up land increased by 24.6×103 km2 while the cropland decreased by 4.9×103 km2, and the total area of woodland and grassland decreased by 16.4×103 km2. The spatial pattern of land-use changes in China during 2010–2015 was concordant with that of the period 2000–2010. Specially, new characteristics of land-use changes emerged in different regions of China in 2010–2015. The built-up land in eastern China expanded continually, and the total area of cropland decreased, both at decreasing rates. The rates of built-up land expansion and cropland shrinkage were accelerated in central China. The rates of built-up land expansion and cropland growth increased in western China, while the decreasing rate of woodland and grassland accelerated. In northeastern China, built-up land expansion slowed continually, and cropland area increased slightly accompanied by the conversions between paddy land and dry land. Besides, woodland and grassland area decreased in northeastern China. The characteristics of land-use changes in eastern China were essentially consistent with the spatial govern and control requirements of the optimal development zones and key development zones according to the Major Function-oriented Zones Planning implemented during the 12th Five-Year Plan (2011–2015). It was a serious challenge for the central government of China to effectively protect the reasonable layout of land use types dominated with the key ecological function zones and agricultural production zones in central and western China. Furthermore, the local governments should take effective measures to strengthen the management of territorial development in future. 相似文献
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16.
Over the past two decades, neoliberal reforms, soaring commodity prices and heightened global resource demands have led to significant growth in extractive industry investment across sub-Saharan Africa. A surge of investment has triggered a variety of responses in mineral-rich communities – from outright rejection, to protest over labour conditions, to acceptance in anticipation of gainful employment. Drawing on recent research carried out in Kono District in Sierra Leone, this article critically explores these contrasting responses to mining activities, by focussing on how youth perceive and respond to extractive industry expansion. In doing so, the paper broadens understanding of why youth perceptions of mining investment differ, and illuminates the various factors underlying a diverse range of responses to the expansion of extractive industries. The focus on youth and its heterogeneity as a social category has important policy implications and the paper makes a contribution to understanding the dynamics and diversity of youth livelihood strategies in resource rich developing countries. In making a distinction between autonomous spaces of community-led development 'from below' and corporate controlled spaces of development 'from above', the article reflects on how youth perceptions of extractive industry expansion may also be influencing the ways in which mining companies understand and fashion their business and social responsibility strategies. 相似文献
17.
This research explores the factors that shape the evolving geographic distribution of business headquarters (HQ) activity. We address an understudied influence on HQ geographies: metropolitan HQ changes driven by the process of small, rapidly expanding businesses growing into mature companies. This investigation focuses on the developmental paths followed by fast-growing firms (FGFs) and the geographic distinctions that can be observed in a FGF tracking study of Canada’s metropolitan regions from 1987 to 2005. Our research findings indicate that geography plays an important role in this development, as FGF tracking records throughout Canada’s metropolitan areas diverge sharply. We find that most FGFs that emerged in Vancouver and Toronto continued as ongoing businesses following their rapid growth phase, while a high proportion of FGFs based in Montréal and Calgary did not. These results contribute to a greater understanding of metropolitan economies, business development, and HQ location in Canada 相似文献
18.
Local governments are responding to top-down policy initiatives from both federal and State governments to reduce emissions, and adapt to any potential impacts of climate change. Although climate change is clearly a global problem, many of the solutions will be implemented at the local level. To explore this issue, the aim of this research was to examine regional variation in climate change response across New South Wales (NSW). To this end, between September 2010 and September 2011, we reviewed publicly available council and regional documentations for all NSW councils. The indicators of response examined were based on the NSW Greenhouse Plan (2005). These were awareness-raising, emissions reduction and adaptation planning. It was found that councils were undertaking many practical projects to fulfil the goals of this plan. As a result, they are abating significant quantities of emissions. Adaptation is progressing through the development of risk-based climate change adaptation plans. Councils are addressing particular areas of management, such as water management, assisted by guidelines which incorporate consideration for climate change as part of best practice. While overall responses to this threat are progressing, a distinct urban bias in action has been observed, due to biases in policy and funding arrangements. 相似文献
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20.
Progress in China’s climate change study in the 20th century 总被引：4，自引：0，他引：4
IPCC (2001) pointed out that the earth's climate was undergoing a remarkable change with characteristics of global warming over the past 100 years. The latest research showed that the global mean surface temperature has increased by about 0.6 oC since 1861. It is very likely that the last 20 years in the 20th century was the warmest decades. The Northern Hemisphere temperatures in the 20th century appeared to have been unprecedented during the past millennium. The research also indicates th… 相似文献