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1.
Regional climate models project significant changes in temperature and rainfall over the Greater Mekong Subregion over the twenty-first century. The potential impacts of climate change on areas affected by waterlogging and shallow saline groundwater in Northeast Thailand was investigated using the variable density groundwater model SEAWAT supported with recharge estimates derived from the hydrologic model HELP3. The focal area is the 154 km2 Huai Kamrian subwatershed. Changes in groundwater salinity and waterlogging areas at the middle and end of this century were predicted using the calibrated model. These predictions used the dynamically downscaled PRECIS regional climate change scenarios generated by ECHAM4 GCM A2 and B2 scenarios. Recharge rates are predicted to increase as a result of the higher intensity of rainfall. Shallow watertable areas are projected to increase by approximately 23 % from existing conditions during the middle of the century and up to 25 % by the end of this century. Although the precise rate and timing of climate change impacts are uncertain, all of the scenarios clearly point towards an extension in the area of waterlogging and area affected by shallow saline groundwater areas. Given that areas affected by shallow saline watertables are predicted to expand for both climate change scenarios as well as for the base case, it is concluded that climate change will have a significant impact on the area affected by salinity and waterlogging areas for both climate change scenarios. Evaluation of management options that explore the adaptation to saline environments and to means to reduce salt affected areas are required.  相似文献   

2.
Anthropogenic climate change is the Earth's most serious large-scale environmental concern. While the projected changes of global temperatures, rainfall and surface water have been modelled in a sophisticated manner, the impact on groundwater resources is much less well constrained. In southeast Australia, the decrease in rainfall amount and an increase in temperature that are predicted by climate models are generally assumed to reduce the amount of recharge to the groundwater systems. However, the increase in recharge that has resulted from clearing of the native vegetation will almost certainly produce a greater impact on the groundwater system, increasing quantity and potentially improving quality. Additionally, the impact on recharge of changes to rainfall frequency rather than just total amount is not well documented. Overall our understanding of the impacts of climate change on groundwater systems is insufficiently advanced to make firm predictions. Indirect impacts of climate change, particularly the projected increased demand for groundwater or surface water to supplement surface water supplies also will have a major impact that may be greater than the direct effect of climate change.  相似文献   

3.
Effective information regarding environmental responses to future land-use and climate change scenarios provides useful support for decision making in land use planning, management and policies. This study developed an approach for modeling and examining the impacts of future land-use and climate change scenarios on streamflow, surface runoff and groundwater discharge using an empirical land-use change model, a watershed hydrological model based on various land use policies and climate change scenarios in an urbanizing watershed in Taiwan. The results of the study indicated that various demand and conversion policies had different levels of impact on hydrological components in all land-use scenarios in the study watershed. Climate changes were projected to have a greater impact in increasing surface runoff and reducing groundwater discharge than are land use changes. Additionally, the spatial distributions of land-use changes also influenced hydrological processes in both downstream and upstream areas, particularly in the downstream watershed. The impacts on hydrological components when considering both land use and climate changes exceeded those when only considering land use changes or climate changes, particularly on surface runoff and groundwater discharge. However, the proposed approach provided a useful source of information for assessing the responses of land use and hydrological processes to future land use and climate changes.  相似文献   

4.
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   

5.
A methodology is presented for assessing the average changes in groundwater recharge under a future climate. The method is applied to the 1,060,000 km2 Murray-Darling Basin (MDB) in Australia. Climate sequences were developed based upon three scenarios for a 2030 climate relative to a 1990 climate from the outputs of 15 global climate models. Dryland diffuse groundwater recharge was modelled in WAVES using these 45 climate scenarios and fitted to a Pearson Type III probability distribution to condense the 45 scenarios down to three: a wet future, a median future and a dry future. The use of a probability distribution allowed the significance of any change in recharge to be assessed. This study found that for the median future, climate recharge is projected to increase on average by 5% across the MDB but this is not spatially uniform. In the wet and dry future scenarios the recharge is projected to increase by 32% and decrease by 12% on average across the MDB, respectively. The differences between the climate sequences generated by the 15 different global climate models makes it difficult to project the direction of the change in recharge for a 2030 climate, let alone the magnitude.  相似文献   

6.
Episodic recharge and climate change in the Murray-Darling Basin, Australia   总被引：1，自引：0，他引：1  
In semi-arid areas, episodic recharge can form a significant part of overall recharge, dependant upon infrequent rainfall events. With climate change projections suggesting changes in future rainfall magnitude and intensity, groundwater recharge in semi-arid areas is likely to be affected disproportionately by climate change. This study sought to investigate projected changes in episodic recharge in arid areas of the Murray-Darling Basin, Australia, using three global warming scenarios from 15 different global climate models (GCMs) for a 2030 climate. Two metrics were used to investigate episodic recharge: at the annual scale the coefficient of variation was used, and at the daily scale the proportion of recharge in the highest 1% of daily recharge. The metrics were proportional to each other but were inconclusive as to whether episodic recharge was to increase or decrease in this environment; this is not a surprising result considering the spread in recharge projections from the 45 scenarios. The results showed that the change in the low probability of exceedance rainfall events was a better predictor of the change in total recharge than the change in total rainfall, which has implications for the selection of GCMs used in impact studies and the way GCM results are downscaled.  相似文献   

7.

Three-dimensional transient groundwater flow and saltwater transport models were constructed to assess the impacts of groundwater abstraction and climate change on the coastal aquifer of Tra Vinh province (Vietnam). The groundwater flow model was calibrated with groundwater levels (2007–2016) measured in 13 observation wells. The saltwater transport model was compared with the spatial distribution of total dissolved solids. Model performance was evaluated by comparing observed and simulated groundwater levels. The projected rainfalls from two climate models (MIROC5 and CRISO Mk3.6) were subsequently used to simulate possible effects of climate changes. The simulation revealed that groundwater is currently depleted due to overabstraction. Towards the future, groundwater storage will continue to be depleted with the current abstraction regime, further worsening in the north due to saltwater intrusion from inland trapped saltwater and on the coast due to seawater intrusion. Notwithstanding, the impact from climate change may be limited, with the computed groundwater recharge from the two climate models revealing no significant change from 2017 to 2066. Three feasible mitigation scenarios were analyzed: (1) reduced groundwater abstraction by 25, 35 and 50%, (2) increased groundwater recharge by 1.5 and 2 times in the sand dunes through managed aquifer recharge (reduced abstraction will stop groundwater-level decline, while increased recharge will restore depleted storage), and (3) combining 50% abstraction reduction and 1.5 times recharge increase in sand dune areas. The results show that combined interventions of reducing abstraction and increasing recharge are necessary for sustainable groundwater resources development in Tra Vinh province.

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8.
The sea levels along the semi-arid South Texas coast are noted to have risen by 3–5 mm/year over the last five decades. Data from General Circulation Models (GCMs) indicate that this trend will continue in the 21st century with projected sea level rise in the order of 1.8–5.9 mm/year due to the melting of glaciers and thermal ocean expansion. Furthermore, the temperature in South Texas is projected to increase by as much as 4 °C by the end of the 21st century creating a greater stress on scarce water resources of the region. Increased groundwater use hinterland due to urbanization as well as rising sea levels due to climate change impact the freshwater-saltwater interface in coastal aquifers and threaten the sustainability of coastal communities that primarily rely on groundwater resources. The primary goal of this study was to develop an integrated decision support framework to assist land and water planners in coastal communities to assess the impacts of climate change and urbanization. More specifically, the developed system was used to address whether coastal side (primarily controlled by climate change) or landward side processes (controlled by both climate change and urbanization) had a greater control on the saltwater intrusion phenomenon. The decision support system integrates a sharp-interface model with information from GCMs and observed data and couples them to statistical and information-theoretic uncertainty analysis techniques. The developed decision support system is applied to study saltwater intrusion characteristics at a small coastal community near Corpus Christi, TX. The intrusion characteristics under various plausible climate and urbanization scenarios were evaluated with consideration given to uncertainty and variability of hydrogeologic parameters. The results of the study indicate that low levels of climate change have a greater impact on the freshwater-saltwater interface when the level of urbanization is low. However, the rate of inward intrusion of the saltwater wedge is controlled more so by urbanization effects than climate change. On a local (near coast) scale, the freshwater-saltwater interface was affected by groundwater production locations more so than the volume produced by the community. On a regional-scale, the sea level rise at the coast was noted to have limited impact on saltwater intrusion which was primarily controlled by freshwater influx from the hinterlands towards the coast. These results indicate that coastal communities must work proactively with planners from the up-dip areas to ensure adequate freshwater flows to the coast. Field monitoring of this parameter is clearly warranted. The concordance analysis indicated that input parameter sensitivity did not change across modeled scenarios indicating that future data collection and groundwater monitoring efforts should not be hampered by noted divergences in projected climate and urbanization patterns.  相似文献   

9.
Water resources play an important role in supporting the economic and social development of China. The impact of climate change on water resources has become a bottleneck in this process, especially for major projects, with surface water and groundwater systems experiencing considerable impacts. The annual natural recharge of fresh groundwater is 8 840×10~8 m~3, which accounts for approximately 31% of the water resources. Groundwater is the most significant water source for many cities and energy bases, and it is also the main source acting as a buffer against extreme climate events caused by climate change. However, most of the groundwater in China buried deeply and unevenly, which increases the difficulty of investigating and exploiting this resource.This paper illustrates the general conditions of China water resources and hydrogeological hazards, such as karst sinkholes, surface subsidence, and soil salinization, caused by climate change, El Nino, La Nina, other climate events and human activities and presents the regulatory measures enacted to mitigate these issues in China.The China Geological Survey(CGS) has organized professional teams to investigate and evaluate groundwater resources and the environment since 1999. Based on these investigations, the total quantity, expected exploitable quantity and current exploited quantity of groundwater in whole China have been evaluated. In addition, an evaluation of the groundwater pollution caused by climate change throughout China and key areas has been conducted. At present, the CGS is conducting national groundwater monitoring projects and establishing regional engineering and technical measures for water resource exploitation and utilization.  相似文献   

10.
Climate change has become a major global concern and threatens the security of natural environmental resources, including groundwater, especially for Cambodia. In this study, literature reviews related to climate change and groundwater resources in Cambodia were evaluated to address the impact of climate change on the groundwater environment. In Cambodia, global climate change will likely affect available water resources by driving changes in the groundwater recharge and usage pattern. Despite a general increase in the mean annual rainfall, a reduction in rainfall is anticipated during the dry season, which could lead to shortages of fresh water during the dry season. The impact of climate change on water resource environments can significantly affect national economic development. Thus, strategic management plansfor groundwater in response to climate change should be established to ensure the security of water resources in Cambodia.  相似文献   

11.
Mitja Janža 《Natural Hazards》2013,67(3):1025-1043
According to climate change projections, the Alps will be one of the most affected regions in Europe. A basis for adaptation measures to climate changes is the quantification of the impact. This study investigates the impact of projected climate change on the hydrological cycle in the Upper So?a River basin. It is based on the use of climate model data as input for hydrological modelling. The climatic input data used were generated by a global climate model (IPCC A1B emission scenario) and downscaled for local use. Hydrological modelling was performed using the distributed hydrological model MIKE SHE. The simulated impact was quantified by comparing results of the hydrological modelling for the control period (1971–2000) and different scenario periods (2011–2040, 2041–2070, 2071–2100). The climate projections show an increase in the average temperature (+0.9, +2.3, +3.8°C) and negligible changes in average precipitation amounts in the scenario periods. More distinctive are changes in the temporal pattern of mean monthly values (up to +5.2°C and ±45% for precipitation), which result in warmer and wetter winters and hotter and drier summers in the scenario periods. The projected rise in temperature is reflected in the increased actual evapotranspiration, the reduction of snow amount and summer groundwater recharge. Changes of monthly and period average discharges follow the trends of the meteorological variables. Changes in precipitation patterns have a major influence on the projected hydrological cycle and are the most important source of uncertainty. Estimated extreme flows indicated increased hazards related to floods, especially in the near-future scenario period, while in the far future scenario period, distinctive drought conditions are projected.  相似文献   

12.
The national economy of Lao PDR is highly dependent on water resources. Consequently, the sustainable management of groundwater and successful adaptations to future climate change are major concerns. Climate projections for Lao PDR predict increased rainfall and hot weather, with more intense rainfall events and more frequent and severe droughts and floods. Under climate change, reductions in the amount and quality of groundwater are two critical problems. Reductions of the groundwater level will restrict the access of local people to groundwater resources, thereby posing a threat to food security and livelihoods. Lao PDR suffers from a limited number of human resources with the requisite skills to perform groundwater investigations and provide sustainable management. For the successful implementation of groundwater management plans, limitations associated with funding and technology should be resolved via support from the government and international cooperation. Advanced action plans for capacity building and training courses should be established to strengthen administrative and individual capacities. Technical measures, such as groundwater monitoring, aquifer characterizations, and water treatment systems, should be implemented to manage future climate change and water resource security.  相似文献   

13.
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.
I. P. HolmanEmail: Phone: +44-(0)1525-863000Fax: +44-(0)1525-863344
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14.
Temporal and spatial changes of the hydrological cycle are the consequences of climate variations. In addition to changes in surface runoff with possible floods and droughts, climate variations may affect groundwater through alteration of groundwater recharge with consequences for future water management. This study investigates the impact of climate change, according to the Special Report on Emission Scenarios (SRES) A1B, A2 and B1, on groundwater recharge in the catchment area of a fissured aquifer in the Black Forest, Germany, which has sparse groundwater data. The study uses a water-balance model considering a conceptual approach for groundwater-surface water exchange. River discharge data are used for model calibration and validation. The results show temporal and spatial changes in groundwater recharge. Groundwater recharge is progressively reduced for summer during the twenty-first century. The annual sum of groundwater recharge is affected negatively for scenarios A1B and A2. On average, groundwater recharge during the twenty-first century is reduced mainly for the lower parts of the valley and increased for the upper parts of the valley and the crests. The reduced storage of water as snow during winter due to projected higher air temperatures causes an important relative increase in rainfall and, therefore, higher groundwater recharge and river discharge.  相似文献   

15.
Groundwater resources have considerable influences on the human population and socioeconomic development of Vietnam and the Mekong River Delta (MRD). This paper presents an overview of the relationship between climate change and groundwater in the MRD, including the challenges, strategies and technical measures. Our results showed that groundwater levels are related to other climate and hydrological variables (i.e., rainfall, river levels, etc.); therefore, the impacts of climate change on the groundwater resources of the Mekong delta are significant, especially on groundwater recharge. Based on the results of this study, it is recommended that groundwater development in the future should focus on reducing groundwater harvesting, enhancing groundwater quantity by establishing artificial works and exploiting surface water. This study suggests that the Artificial Neural Network (ANN) model is an effective tool for forecasting groundwater levels in periods of 1 month and 3 months for aquifers in the natural and tidal regime areas of the delta.  相似文献   

16.
Groundwater recharge is a complex process reflecting many interactions between climate, vegetation and soils. Climate change will impact upon groundwater recharge but it is not clear which climate variables have the greatest influence over recharge. This study used a sensitivity analysis of climate variables using a modified version of WAVES, a soil-vegetation-atmosphere-transfer model (unsaturated zone), to determine the importance of each climate variable in the change in groundwater recharge for three points in Australia. This study found that change in recharge is most sensitive to change in rainfall. Increases in temperature and changes in rainfall intensity also led to significant changes in recharge. Although not as significant as other climate variables, some changes in recharge were observed due to changes in solar radiation and carbon dioxide concentration. When these variables were altered simultaneously, changes in recharge appeared to be closely related to changes in rainfall; however, in nearly all cases, recharge was greater than would have been predicted if only rainfall had been considered. These findings have implications for how recharge is projected to change due to climate change.  相似文献   

17.
全球气候变化及其影响   总被引：20，自引：2，他引：20       下载免费PDF全文
全球气候变化及其对社会与自然系统产生的影响已日益受到全世界各国政府与广大民众的关注。与天气和气候有关的灾害给人类生命财产造成的损失日益增大,社会与生态系统似乎变得日趋脆弱。人们关心刚刚过去的20世纪的天气与气候发生了什么变化,更希望了解未来的21世纪,人类居住的地球会出现什么样的气候情景。根据一些国家和地区的观测记录、研究成果以及科学家们对气候变化的评估与预测展望,对全球气候变化问题进行概括。首先阐明20世纪地区性气候变化的事实;并根据政府间气候变化委员会(IPCC)科学技术报告中关于20世纪全球气候变化进行的总结性评估以及对21世纪全球气候变化的预测,作为阐述过去与未来全球气候变化的主要依据。同时,还介绍了一些科学家对IPCC关于全球气候变化的结论所持的不同观点或质疑。还就气候变化对社会与自然系统可能产生的影响略作论述。  相似文献   

18.
Rising sea levels due to climate change are expected to negatively impact the fresh-water resources of small islands. The effects of climate change on Shelter Island, New York State (USA), a small sandy island, were investigated using a variable-density transient groundwater flow model. Predictions for changes in precipitation and sea-level rise over the next century from the Intergovernmental Panel on Climate Change 2007 report were used to create two future climate scenarios. In the scenario most favorable to fresh groundwater retention, consisting of a 15% precipitation increase and 0.18-m sea-level rise, the result was a 23-m seaward movement of the fresh-water/salt-water interface, a 0.27-m water-table rise, and a 3% increase in the fresh-water lens volume. In the scenario supposedly least favorable to groundwater retention, consisting of a 2% precipitation decrease and 0.61-m sea-level rise, the result was a 16-m landward movement of the fresh-water/salt-water interface, a 0.59-m water-table rise, and a 1% increase in lens volume. The unexpected groundwater-volume increase under unfavorable climate change conditions was best explained by a clay layer under the island that restricts the maximum depth of the aquifer and allows for an increase in fresh-water lens volume when the water table rises.  相似文献   

19.
Flooding is a major environmental hazard in Poland with risks that are likely to increase in the future. Land use and land cover (LULC) have a strong influencing on flood risk. In the Polish Carpathians, the two main projected land use change processes are forest expansion and urbanization. These processes have a contradictory impact on flood risk, which makes the future impact of LULC changes on flooding in the Carpathians hard to estimate. In this paper, we investigate the impact of the projected LULC changes on future flood risk in the Polish Carpathians for the test area of Ropa river basin. We used three models of spatially explicit future LULC scenarios for the year 2060. We conduct hydrological simulations for the current state and for the three projected land use scenarios (trend extrapolation, ‘liberalization’ and ‘self-sufficiency’). In addition, we calculated the amount of flood-related monetary losses, based on the current flood plain area and both actual and projected land use maps under each of the three scenarios. The results show that in the Ropa river, depending on scenario, either peak discharge decreases due to the forest expansion or the peak discharge remains constant—the impact of LULC changes on the hydrology of such mountainous basins is relatively low. However, the peak discharges are very diverse across sub-catchments within the modeling area. Despite the overall decrease of peak discharge, there are areas of flow increase and there is a substantial projected increase in flood-related monetary losses within the already flood-prone areas, related to the projected degree of urbanization.  相似文献   

20.
With the ever-accelerating economic and social growth in Asia, the sustainable development of environment, economy and society of Asia and beyond, is severely constrained by a series of grave issues, such as global climate change, population explosion, resource shortage, and rampant disasters. The need for study on groundwater resources and environment in Asia as part of the efforts to tackle global climate change looms even larger. In analyzing how global changes of modern times and human activities are related to primary geo-environment, the groundwater environment serial maps of Asia introduces a new concept for mapping geo-environment of Asia that connects the geological background to groundwater environment. The serial maps reveal the geographic environment that is closely related to groundwater, the special-temporal features of the geo-environment and how it is distributed. The study is vital not only to the harmonious development among environment, economy and society as well as ecological progress in Asia, but also to the strategic requirements posed by the “One Belt One Road”.  相似文献   

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