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The Qinghai–Tibet Plateau is the largest permafrost region at low latitude in the world. Climate warming may lead to permafrost
temperature rise, ground ice thawing and permafrost degradation, thus inducing thermal hazards. In this paper, the ARCGIS
method is used to calculate the changes of ground ice content and active layer thickness under different climate scenarios
on the Qinghai–Tibet Plateau, in the coming decades, thus providing the basis for hazards zonation. The method proposed by
Nelson in 2002 was used for hazards zonation after revision, which was based on the changes of active layer thickness and
ground ice content. The study shows that permafrost exhibits different degrees of degradation in the different climate scenarios.
The thawing of ground ice and the change from low-temperature to high-temperature permafrost were the main permafrost degradation
modes. This process, accompanied with thinning permafrost, increases the active layer thickness and the northward movement
of the permafrost southern boundary. By 2099, the permafrost area decreases by 46.2, 16.01 and 8.5% under scenarios A2, A1B
and B1, respectively. The greatest danger zones are located mainly to the south of the West Kunlun Mountains, the middle of
the Qingnan Valley, the southern piedmont of the Gangdise and Nyainqentanglha Mountains and some regions in the southern piedmont
of the Himalayas. The Qinghai–Tibet Plateau permafrost region is in the low-risk category. Climate warming exacerbates the
development of thermal hazards. In 2099, the permafrost region is mainly in the middle-risk category, and only a small portion
is in the low-risk category. 相似文献
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Changes in the climatic system introduce uncertainties in the supply and management of water resources. The Intergovernmental Panel on Climate Change(IPCC) predicts an increase of 2 to 4 °C over the next 100 years. Temperature increases will impact the hydrologic cycle by directly increasing the evaporation of surface water sources. Consequently, changes in precipitation will indirectly impact the flux and storage of water in surface and subsurface reservoirs(i.e., lakes, soil moisture, groundwater, etc.). In addition, increases in temperature contribute to increases in the sea level, which may lead to sea water intrusions, water quality deterioration, potable water shortages, etc. Climate change has direct impacts on the surface water and the control of storage in rivers, lakes and reservoirs, which indirectly controls the groundwater recharge process. The main and direct impact of climate change on groundwater is changes in the volume and distribution of groundwater recharge. The impact of climate change on groundwater resources requires reliable forecasting of changes in the major climatic variables and accurate estimations of groundwater recharge. A number of Global Climate Models(GCMs) are available for understanding climate and projecting climate change.These GCMs can be downscaled to a basin scale, and when they are coupled with relevant hydrological models, the output of these coupled models can be used to quantify the groundwater recharge, which will facilitate the adoption of appropriate adaptation strategies under the impact of climate change. 相似文献
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《Geomechanics and Geoengineering》2013,8(3):227-234
An extensive experimental investigation of microstructural changes in granites under freeze–thaw cycles using permeability and P-wave velocity measurements is described. Two types of natural granite rocks are considered and tested under dry and saturated conditions. The specimens were subjected to 200 heating–cooling cycles (??20°C/?+?20°C); each cycle had a duration of 24 h. The results indicate that the ageing process decreases the permeability and the P-wave velocity. The reduction in P-wave velocity is likely to be due to microcrack development (material damage). In dry samples, the microcracks result from the repeated differential contraction–dilatation of the mineral components. In water-saturated samples, there is an additional effect of freezing and thawing of water in the porous network. The decrease in permeability in the dry samples is due to partial closure of existing microcracks. In water-saturated samples, there was no increase in the permeability. A physically acceptable explanation is that new microcracks are not necessarily connected with those that already exist. Therefore the physicochemical process resulting from water–rock interactions also affects the permeability. This phenomenon reduces fluid flow in the material. 相似文献
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GeoJournal - Climate change is recognised among the drivers of conflicts in developing regions but the growing studies on climate change–violent conflict nexus in Africa have paid little... 相似文献
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Qiao Hu Zhenghong Tang Martha Shulski Natalie Umphlett Tarik Abdel-Monem Frank E. Uhlarik 《Natural Hazards》2018,90(2):777-801
Disasters continue to have a dramatic impact on lives, livelihoods and environments communities depend on. In response to these losses, the global community has developed various theories, assessment methodologies and policies aimed at reducing global losses. A contemporary outcome of these interventions is to build the disaster resilience. However, despite the disaster resilience-building endeavours espoused by policies, theories and methodologies, very little progress is being made in reducing disaster losses. This paper argues that a possible reason behind the limitations of current resilience-building policies and methodologies could be that most of these policies are based a mechanistic scientific paradigm that places an emphasis on system components that are perceived to build resilience and not the function of systems as a whole. This often leads to resilience-building initiatives that are based on a ‘one-size-fits-all’ approach. This paper argues for the use of a complex adaptive systems approach to building resilience. This approach argues that contextual factors within different social systems will have a nonlinear affect on disaster resilience-building efforts. Therefore, it is crucial to move away from ‘one-size-fits-all’ approaches to more flexible approaches to building resilience. These hypotheses are tested by means of a correlation statistical analysis of agricultural communities in Southern Africa. Results of this analysis indicate that unique resilience profiles are evident in almost all of the communities studied. This indicates that resilience is not the same for everybody, and that resilience-building endeavours should be flexible enough to be adapted for different contexts. 相似文献
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This paper analyses General Household Survey data for London and Great Britain from 1979 to 1993 to examine the changes in
household income distribution over this period. In particular it looks at the implications of this data for theoretical claims
made by Pahl and Sassen regarding social polarisation. It is argued that London has not experienced greater social polarisation,
in the sense that the size of both the top and bottom income groups have not grown at the expense of the middle. Instead,
what has happened is that the higher income group has grown considerably at the expense of the middle. This has, however,
been accompanied by the growth of income inequality in London. Incomes at the top end have increased much faster than at the
bottom. Two earner professional/managerial households have been the biggest gainers in financial terms although the proportion
of households with no earner has grown most rapidly.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Natural Hazards - Under the background of climate warming, drought events occur frequently. Generally, meteorological drought leads to agricultural drought. Understanding the spatiotemporal... 相似文献
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Kirsty A. Golding Ian A. Simpson J. Edward Schofield Kevin J. Edwards 《Geoarchaeology》2011,26(3):315-345
Ruins representing both medieval Norse and Inuit (Thule culture) settlements can be found together on the coast at Sandhavn (59°59′ N, 44°46′ W), Greenland. The site presents a rare opportunity to investigate the character of past contact and interaction between these two peoples. Soils‐based, radiocarbon, and palynological analyses demonstrate the creation of hortic anthrosols within Norse home‐fields used between the mid‐11th and late 14th centuries A.D. Irrigation channels have been identified within the home‐fields, while rising grass pollen influx reveals intensification in hay production over the period ca. A.D. 1260–1350 despite climatic deterioration setting in around this time. Floor deposits and wall packing from an Inuit winter house returned dates of cal. A.D. 1220–1290 (2σ), yet no direct landscape‐based evidence for Inuit activity could be determined. Although the exact nature of the relationship between Norse and Thule at Sandhavn remains unclear, the role of this site as a harbor and possible trading area may have attracted Inuit settlers keen to participate in European trade networks. © 2011 Wiley Periodicals, Inc. 相似文献
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Birte Frommer 《Natural Hazards》2013,67(1):99-115
For the last five years, climate change has been increasingly perceived as a challenge for regional development. Compared to other nations, Germany is relatively ‘safe’, but the German regions are prone to different impacts of climate change; some of them might be positive but most will be negative in the long run. Strategic concepts are therefore needed to reduce the negative impacts and use the potential positive effects. Due to enforced research funding, several German regions are currently developing adaptation strategies within transdisciplinary research projects. Based on a comparative case study analysis of three of these projects, this paper looks for the benefits of resilience thinking in the context of climate change adaptation. The analysis shows that the case study regions try to increase their resilience to climate change by strengthening the properties of (1) resistance, (2) recovery and (3) creativity. But the discussion also reveals that only parts, certain sectors or subjects, of the region can increase their distinct resilience. Regional stakeholder networks as established within the case study regions can make a significant contribution to linking different sectors and levels of action. Therefore, this approach seems to be applicable for integrating the need for adaptation within the whole region. It is believed that the regionalized communication of potential climate change impacts raises awareness for climate change adaptation, helps to develop appropriate adaptation measures and encourages action. Hence, different approaches can indeed lead to more resilient structures. But the resilient society at regional level remains utopia. 相似文献
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Birte Frommer 《Natural Hazards》2011,58(1):85-101
For the last five years, climate change has been increasingly perceived as a challenge for regional development. Compared
to other nations, Germany is relatively ‘safe’, but the German regions are prone to different impacts of climate change; some
of them might be positive but most will be negative in the long run. Strategic concepts are therefore needed to reduce the
negative impacts and use the potential positive effects. Due to enforced research funding, several German regions are currently
developing adaptation strategies within transdisciplinary research projects. Based on a comparative case study analysis of
three of these projects, this paper looks for the benefits of resilience thinking in the context of climate change adaptation.
The analysis shows that the case study regions try to increase their resilience to climate change by strengthening the properties
of (1) resistance, (2) recovery and (3) creativity. But the discussion also reveals that only parts, certain sectors or subjects,
of the region can increase their distinct resilience. Regional stakeholder networks as established within the case study regions
can make a significant contribution to linking different sectors and levels of action. Therefore, this approach seems to be
applicable for integrating the need for adaptation within the whole region. It is believed that the regionalized communication
of potential climate change impacts raises awareness for climate change adaptation, helps to develop appropriate adaptation
measures and encourages action. Hence, different approaches can indeed lead to more resilient structures. But the resilient
society at regional level remains utopia. 相似文献
14.
Climate change impacts on groundwater recharge- uncertainty, shortcomings, and the way forward? 总被引：1，自引：0，他引：1
I. P. Holman 《Hydrogeology Journal》2006,14(5):637-647
An integrated approach to assessing the regional impacts of climate and socio-economic change on groundwater recharge is described from East Anglia, UK. Many factors affect future groundwater recharge including changed precipitation and temperature regimes, coastal flooding, urbanization, woodland establishment, and changes in cropping and rotations.Important sources of uncertainty and shortcomings in recharge estimation are discussed in the light of the results. The uncertainty in, and importance of, socio-economic scenarios in exploring the consequences of unknown future changes are highlighted. Changes to soil properties are occurring over a range of time scales, such that the soils of the future may not have the same infiltration properties as existing soils. The potential implications involved in assuming unchanging soil properties are described.To focus on the direct impacts of climate change is to neglect the potentially important role of policy, societal values and economic processes in shaping the landscape above aquifers. If the likely consequences of future changes of groundwater recharge, resulting from both climate and socio-economic change, are to be assessed, hydrogeologists must increasingly work with researchers from other disciplines, such as socio-economists, agricultural modellers and soil scientists.
相似文献
| I. P. HolmanEmail: Phone: +44-(0)1525-863000Fax: +44-(0)1525-863344 |
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The study addresses population dynamics in Ghana on the urban and regional levels between 1984 and 2000. At the urban level,
the development trends are analyzed for urban localities (population above 5,000) on the basis of geo-coded census data. Potential
driving forces for rapid population growth related to size, location, accessibility and facility counts are examined using
bivariate and multivariate analysis. An index of weighted accessibility relative to other urban localities provides significant
explanation at the national level, as does initial locality size. At the regional level, population development is analyzed
to provide insight into the rural–urban relations. The level of urbanization is steadily increasing but varies considerably
between regions. Areas of high population growth are found in some rural areas that have a remote location relative to the
large urban centers. This seems to indicate the existence of ‘frontier’ regions, i.e. areas that experience a high degree
of in-migration by people aiming to undertake specific farming activities. A high proportion of the population growth in these
areas appears to take place in relatively small towns. The paper concludes with a more in-depth discussion of the development
characteristics of Ghana’s Western Region. This region has experienced one of the highest regional population growth rates,
mainly due to its status as a ‘frontier’ for cocoa production.
相似文献
| Lasse Moller-JensenEmail: |
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《Proceedings of the Geologists' Association. Geologists' Association》2023,134(4):416-431
The Kula–Salihli UNESCO Geopark, western Turkey, is a tectonically and volcanically active region in which the most recent eruptions of basaltic lava, associated with scoria cone formation, were during the latest Pleistocene and the Holocene. Much older volcanism within the same volcanic province is also in evidence, with some of the older lavas capping mesa-style uplands, such that they have preserved underlying poorly consolidated sediments that would otherwise have been lost to erosion. Beneath these hill-capping lavas, above the Neogene sediments representing endorheic basin-fill, are the early gravels of the River Gediz system, forming narrowly separated terraces (separation by a few metres) thought to have been formed in response to the ~ 41 kyrs obliquity-driven climate cycles of the Early Pleistocene. The rarity of terrace preservation from this early part of the Quaternary makes this a very valuable part of the geopark, in which there is also evidence for the progressive incision into the landscape, and for periodic damming of the river system by lava eruptions, bringing about lacustrine phases that can be recognized from lake sediments and deltas that were built into the former lakes. The combination of volcanic and drainage evolutionary evidence has few if any parallels elsewhere. The geopark, which also contains sites of archaeological and historical importance, is managed sustainably in order to maximize its educational, economic, touristic and heritage value. 相似文献
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Pastoralists’ perception of and adaptation strategies for climate change: associations with observed climate variability 总被引：1，自引：0，他引：1
Zhang Qin Cui Fengqi Dai Luwei Feng Bing Lu Yunjing Tang Haiping 《Natural Hazards》2019,96(3):1387-1412
Natural Hazards - Although climate change is a universal phenomenon, its indicators and manifestations are entirely local, as are adaptation choices, strategies, and practices. Based on... 相似文献
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Assessing the impact of climate change on Mogan and Eymir Lakes’ levels in Central Turkey 总被引：1，自引：1，他引：0
Global warming is likely to have significant effect on the hydrological cycle. Some parts of the world may see significant
reductions in precipitation or major alterations in the timing of wet and dry seasons. Climate change is one of the serious
pressures facing water resources and their management over the next few years and decades. As part of the southern belt of
Mediterranean Europe, Turkey is highly vulnerable to anticipated climate change impacts. The changes in global climate will
seriously affect inland freshwater ecosystems and coastal lakes. Mogan and Eymir Lakes located in Central Turkey are shallow
lakes that may be impacted significantly by climate change. The interaction between the lakes and groundwater system has been
modelled in order to analyse the response of lake levels to climate change over a planning period of 96 years, beginning from
October 2004 and ending in September 2100. The impacts of the emission scenarios of A2 and B1 of the Intergovernmental Panel
on Climate Change (IPCC) on lake levels have been analyzed with the help of the lake-aquifer simulation model. The fluctuations
in lake levels due to climate change scenarios are compared with the results of a scenario generated by the assumption of
the continuation of the average recharge and discharge conditions observed for 1999 and 2004. The results show that very small,
but long-term changes to precipitation and temperature have the potential to cause significant declines in lake levels and
temporary drying of the lakes in the long-term. The impact of climate change on lake levels will depend on how these water
resources are managed in the future. 相似文献
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Wang Zengru Yang Guojing Yi Shuhua Wu Zhen Guan Jianyue He Xiaobo Ye Baisheng 《Environmental Earth Sciences》2012,66(3):985-991
The effects of the depth of the active layer of permafrost on aboveground vegetation in semi-arid and semi-humid regions of the Qinghai–Tibetan Plateau were studied. The depth of active permafrost was measured and aboveground vegetation recorded. Differences in correspondence between permafrost depth and aboveground vegetation in semi-arid and semi-humid regions were analyzed. Vegetation cover and biomass were well correlated with permafrost depth in both semi-arid and semi-humid regions, but the correlation coefficient in the semi-arid region was larger than in the semi-humid region. With the increase in permafrost depth, vegetation cover and biomass decreased in both regions. Species richness and diversity decreased with increasing depth of permafrost in the semi-arid region. In the semi-humid region, these at first increased and then decreased as permafrost depth increased. It seems likely that vegetation on the Qinghai–Tibetan Plateau will degenerate to different degrees due to permafrost depth increasing as a result of climatic warming. The influence would be especially remarkable in the semi-arid region. 相似文献