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1.
《水文科学杂志》2013,58(4):676-689
Abstract

Global climate change is affecting Africa, as it is every other continent and region of the world. The absolute poverty of a large proportion of the continent's people renders them highly vulnerable to changes in climate. Mitigation of climate change is a global imperative. However, numerous other changes continue apace, notably population growth, natural resource degradation, and rural—urban migration. Probably 50% or more of the continent's population rely on groundwater. This paper explores the relative impacts of changes in climate, demography and land use/cover on groundwater resources and demands. It concludes that the climate change impacts are likely to be significant, though uncertain in direction and magnitude, while the direct and indirect impacts of demographic change on both water resources and water demand are not only known with far greater certainty, but are also likely to be much larger. The combined effects of urban population growth, rising food demands and energy costs, and consequent demand for fresh water represent real cause for alarm, and these dwarf the likely impacts of climate change on groundwater resources, at least over the first half of the 21st century.  相似文献   

2.
Abstract

Changes in water resources availability, as affected by global climate warming, together with changes in water withdrawal, could influence the world water resources stress situation. In this study, we investigate how the world water resources situation will likely change under the Special Report on Emissions Scenarios (SRES) by integrating water withdrawal projections. First, the potential changes in water resources availability are investigated by a multi-model analysis of the ensemble outputs of six general circulation models (GCMs) from organizations worldwide. The analysis suggests that, while climate warming might increase water resources availability to human society, there is a large discrepancy in the size of the water resource depending on the GCM used. Secondly, the changes in water-stressed basins and the number of people living in them are evaluated by two indices at the basin scale. The numbers were projected to increase in the future and possibly to be doubled in the 2050s for the three SRES scenarios A1b, A2 and B1. Finally, the relative impacts of population growth, water use change and climate warming on world water resources are investigated using the global highly water-stressed population as an overall indicator. The results suggest that population and socio-economic development are the major drivers of growing world water resources stress. Even though water availability was projected to increase under different warming scenarios, the reduction of world water stress is very limited. The principal alternative to sustainable governance of world water resources is to improve water-use efficiency globally by effectively reducing net water withdrawal.
Editor Z.W. Kundzewicz; Associate editor D. Gerten  相似文献   

3.
The paper presents the results of analysis of present-day scientific data on the dynamics of global hydroclimatic processes (with the establishment of long-term variations in the global water exchange processes) and the features of water abundance in territories under the effect of various natural and anthropogenic factors. Possible transformations of the hydrogeological situation under global climate changes are considered. The basic principles of the concept regarding the assessment of the effect of global hydroclimatic changes on the population health are presented. Medical-environmental data on the consequences of water-triggered environmental crises, taken as analogous natural models, are analyzed. The processes and regularities in the development of human pathology under the conditions of higher and lower water abundance in a territory are identified. The succession, time stages, and phases of the development of infection, parasitic, noninfectious pathologies are determined. Cause-and-effect relationships were established between the observed pathology and the effect of a complex of changing natural, anthropogenic, and social-environmental factors. Methodological approaches to the assessment of medical-environmental consequences of distinct changes in the water abundance in the territories are described. The possible use of subsurface water sources as a reserve of domestic water supply under emergencies are considered.  相似文献   

4.
ABSTRACT

With global climate change and impacts of human activity, the water cycle, which has a close relationship with local water resources, has changed rapidly. Based on different greenhouse gas emission scenarios, five relatively independent global climate models are selected from 47 CMIP5 models to simulate future climatic conditions. Data are downscaled to the local projection, with bias neutralized before applying them to the hydrological models, by which availability of future water resources are calculated for the Dongting Lake basin. The results show that the water resources of the Dongting Lake basin are likely to increase in the future, but be distributed more unevenly. All scenarios indicate that water availability will increase during the flood season and decrease during the dry season, with a prominent increase in annual discharge. The scenarios also predict that the greater the greenhouse gas emissions, the more uneven the water distribution becomes. Overall, the water resources of the Dongting Lake catchment show the same increasing and unevenly distributed trend in the future, which could be further accelerated by human activities.
Editor Z.W. Kundzewicz; Associate editor Q. Zhang  相似文献   

5.
Climate change and its impact on hydrological processes are overarching issues that have brought challenges for sustainable water resources management. In this study, surface water resources in typical regions of China are projected in the context of climate change. A water balance model based on the Fu rational function equation is established to quantify future natural runoff. The model is calibrated using data from 13 hydrological stations in 10 first-class water resources zones of China. The future precipitation and temperature series come from the ISI-MIP (Inter-Sectoral Impact Model Intercomparison Project) climate dataset. Taking natural runoff for 1961–1990 as a baseline, the impacts of climate change on natural runoff are studied under three emissions scenarios: RCP2.6, RCP4.5 and RCP8.5. Simulated results indicate that the arid and semi-arid region in the northern part of China is more sensitive to climate change compared to the humid and semi-humid region in the south. In the near future (2011–2050), surface water resources will decrease in most parts of China (except for the Liaozhong and Daojieba catchments), especially in the Haihe River Basin and the middle reaches of the Yangtze River Basin. The decrement of surface water resources in the northern part of China is more than that in the southern part. For the periods 2011–2030 and 2031–2050, surface water resources are expected to decrease by 12–13% in the northern part of China, while those in the southern part will decrease by 7–10%.
EDITOR D. Koutsoyiannis

ASSOCIATE EDITOR R. Hirsch  相似文献   

6.
《水文科学杂志》2013,58(1):100-111
Abstract

The runoff of Iceland has been evaluated for the period 1961–1990, and changes in runoff from then to the period 2071–2100 predicted according to a future projection of climate change. The hydrological model WASIM-ETH was used, with meteorological data from the PSU/NCAR MM5 numerical weather model. The evaluation of the effects of climate change on water resources was based on a future climate simulation from the HIRHAM regional climate model with boundary conditions from the HadAM3H global climate model using A2 and B2 emissions scenarios. Future runoff was shown to become much higher in 2071–2100 compared to 1961–1990, predominantly due to increased glacial melt caused by increased temperature. Furthermore, changes in runoff seasonality would be substantial. Thus, according to this projection there could be great changes in hydropower production potential associated with climate change in Iceland.  相似文献   

7.
Generating estimates of the future impacts of climate change on human and natural systems is confounded by cascading uncertainties which propagate through the impact assessment. Here, a simple stochastic rainfall–runoff model representing 238 river basins on the Australian continent was used to assess the sensitivity of the risk of runoff changes to various sources of uncertainty. Uncertainties included global mean temperature change, greenhouse gas stabilisation targets, catchment sensitivities to climatic change, and the seasonality of runoff, rainfall, and evaporation. Model simulations provided estimates of the first-order risk of climate change to Australian catchments, with several regions having high likelihoods of experiencing significant reductions in future runoff. Climate uncertainty (at global and regional scales) was identified as the dominant driving force in hydrological risk assessments. Uncertainties in catchment sensitivities to climatic changes also influenced risk, provided they were sufficiently large, whereas structural assumptions of the model were generally negligible. Collectively, these results indicate that rigorous assessment of climate risk to water resources over relatively long time-scales is largely a function of adequately exploring the uncertainty space of future climate changes.  相似文献   

8.
The formation of the fresh groundwater natural resources of the platform territories is analyzed. It is shown that within the artesian areas of platforms, the formation of the fresh groundwater natural resources is governed by the following main factors: the climatic conditions of the territory; the geological-structural features of the basin, substantially different in its peripheral and central parts; the structure of the zone of intense water exchange; the type of the water-bearing rocks and the character of the spatial variability of their hydraulic parameters; the aeration zone composition; the specific features of interaction between the groundwater and the hydrographic network and micro-relief of the territory. It is emphasized that the formation of the fresh groundwater natural resources within the hydrogeological massifs is governed not only by the physical-geographical conditions, but by the geological-structural factors as well. The formation and distribution of groundwater resources are governed by numerous natural and anthropogenic factors [11]. The combination of these factors and the significance of each factor are not constant but considerably vary in space, depending on the physical-geographical, geological, and hydrogeological conditions.Translated from Vodnye Resursy, Vol. 32, No. 2, 2005, pp. 146–153.Original Russian Text Copyright © 2005 by Vsevolozhskii, Kochetkova.  相似文献   

9.
Population explosion and its many associated effects (e.g. urbanization, water pollution, deforestation) have already caused enormous stress on the world’s fresh water resources and, in turn, environment, health, and economy. According to latest World Health Organization estimates, about 900 million people still lack access to safe drinking water, about 2.5 billion people lack access to proper sanitation, millions of people die every year from water-related disasters and diseases, and economic losses in the order of billions of dollars occur due to water-related disasters. With the global climate change anticipated to have threatening consequences on our water resources and environment both at the global level and at local/regional levels (e.g. increases in the number and magnitude of floods and droughts, increases in sea levels), a general assessment is that the future state of our water resources will be a lot worse than it is now. The facts that over 300 rivers around the world are being shared by two or more nation states and that there are already numerous conflicts in the planning, development, and management of water resources in these basins further complicate matters for future water resources planning. In view of these, any sincere effort towards proper management of our future water resources and resolving potential future water-related conflicts will need to overcome many challenges. These challenges are both biophysical science-related and human science-related. The biophysical science challenges include: identification of the actual causes of climate change, development of global climate models (GCMs) that can adequately incorporate these causes to generate dependable future climate projections at larger scales, formulation of appropriate techniques to downscale the GCM outputs to local conditions for hydrologic predictions, and reliable estimation of the associated uncertainties in all these. The human science challenges have social, political, economic, and environmental facets that often act in an interconnected manner; proper ‘communication’ of (or lack thereof) our climate-water ‘scientific’ research activities to fellow scientists and engineers, policy makers, economists, industrialists, farmers, and the public at large crucially contributes to these challenges. The present study is intended to review the current state of our water resources and the climate change problem and to detail the challenges in dealing with the potential impacts of climate change on our water resources.  相似文献   

10.
Watersheds are complex systems due to their surface and subsurface spatially connected water fluxes and biochemical processes that shape Earth's critical zone. In intensively managed landscapes, the implementation of watershed management practices (WMPs) regulate their short‐term responses, whereas climate variability controls the long‐term processes. Understanding their responses to anthropogenic and natural stressors requires a holistic approach that takes into account their multiscale spatio‐temporal linkages. The objective of this study was to simulate the impacts of spatially and temporally varying WMPs and projected climate changes on the surface and groundwater resources in the Upper Sangamon River Basin (USRB), a watershed in central Illinois greatly impacted by agricultural and industrial operations. The physically based hydrologic model MIKE‐SHE was used to simulate the hydrologic responses of the basin to different WMPs and climatic conditions. The simulation of a WMP was varied spatially across the basin to determine the spectrum of responses and critical conditions. In general, the wetlands and forested riparian buffer scenarios were found to cause a reduction in the average streamflow, whereas crop rotation had varied responses depending on the location of implementation and the climate condition assumed. Reductions of up to 30% in the average streamflow were found for the forested riparian buffer under the ESM 2M climate projections, whereas an increase of up to 13% with the crop rotation schemes under CM3 climate was predicted. The model results showed that the installation of tile drains across the USRB increased the water table depth (from ground level) by up to 56%, making crop production possible. Groundwater level in USRB appeared to be more sensitive to future climatic conditions than to WMP implementation. The impacts of WMPs are determined to depend on the climate conditions under which they are applied. Investigating individual and combined stressors' effects over the critical zone at a watershed scale can lead to a more comprehensive analysis of the risk and trade‐offs in every managerial decision that will enable an efficient use of resources.  相似文献   

11.
Heyin Chen 《水文科学杂志》2013,58(10):1739-1758
Abstract

Changes in climate and land cover are among the principal variables affecting watershed hydrology. This paper uses a cell-based model to examine the hydrologic impacts of climate and land-cover changes in the semi-arid Lower Virgin River (LVR) watershed located upstream of Lake Mead, Nevada, USA. The cell-based model is developed by considering direct runoff based on the Soil Conservation Service - Curve Number (SCS-CN) method and surplus runoff based on the Thornthwaite water balance theory. After calibration and validation, the model is used to predict LVR discharge under future climate and land-cover changes. The hydrologic simulation results reveal climate change as the dominant factor and land-cover change as a secondary factor in regulating future river discharge. The combined effects of climate and land-cover changes will slightly increase river discharge in summer but substantially decrease discharge in winter. This impact on water resources deserves attention in climate change adaptation planning.
Editor Z.W. Kundzewicz  相似文献   

12.
Abstract

Among the processes most affected by global warming are the hydrological cycle and water resources. Regions where the majority of runoff consists of snowmelt are very sensitive to climate change. It is significant to express the relationship between climate change and snow hydrology and it is imperative to perform climate change impact studies on snow hydrology at global and regional scales. Climate change impacts on the mountainous Upper Euphrates Basin were investigated in this paper. First, historical data trend analysis of significant hydro-meteorological data is presented. Available future climate data are then explained, and, finally, future climate data are used in hydrological models, which are calibrated and validated using historical hydro-meteorological data, and future streamflow is projected for the period 2070–2100. The hydrological model outcomes indicate substantial runoff decreases in summer and spring season runoff, which will have significant consequences on water sectors in the Euphrates Basin.

Citation Yilmaz, A.G. & Imteaz, M.A. (2011) Impact of climate change on runoff in the upper part of the Euphrates basin. Hydrol. Sci. J. 56(7), 1265–1279.  相似文献   

13.
Abstract

A semi-distributed hydrological model and reservoir optimization algorithm are used to evaluate the potential impacts of climate change on existing and proposed reservoirs in the Sonora River Basin, Mexico. Inter-annual climatic variability, a bimodal precipitation regime and climate change uncertainties present challenges to water resource management in the region. Hydrological assessments are conducted for three meteorological products during a historical period and a future climate change scenario. Historical (1990–2000) and future (2031–2040) projections were derived from a mesoscale model forced with boundary conditions from a general circulation model under a high emissions scenario. The results reveal significantly higher precipitation, reservoir inflows, elevations and releases in the future relative to historical simulations. Furthermore, hydrological seasonality might be altered with a shift toward earlier water supply during the North American monsoon. The proposed infrastructure would have a limited ability to ameliorate future conditions, with more benefits in a tributary with lower flood hazard. These projections of the impacts of climate change and its interaction with infrastructure should be of interest to water resources managers in arid and semi-arid regions.
Editor D. Koutsoyiannis  相似文献   

14.
Reserves of fresh groundwater on atoll islands are extremely fragile due to climatic and anthropogenic stresses. Of major concern is the quantity of water to be available in the coming decades under the influence of variable rainfall patterns, rising sea level, environmental conditions, and expected population growth that depends on groundwater resources. In this study, a 3‐dimensional numerical modelling approach using the SEAWAT modelling code is used to estimate freshwater lens volume fluctuation for 4 representative islands in the Republic of Maldives in response to long‐term changes in rainfall, sea‐level rise (SLR), and anthropogenic stresses such as groundwater pumping and short‐term impacts from tsunami‐induced marine overwash events. This work is divided into 2 papers. This first paper presents numerical model set‐up and calibration, and the effect of future rainfall patterns and SLR on fresh groundwater reserves. The second paper focuses on marine overwash events. The results of simulated future freshwater lens volume presented in the first study contribute to efficient groundwater resources planning and management for the Maldives in the upcoming decades. Freshwater lenses in small atoll islands (area < 0.6 km2) are shown to have a strong variability trends in the upcoming decades with expected reduction in lens volume between 11% and 36% due to SLR. In contrast, freshwater lenses in larger atoll islands (area > 1.0 km2) are shown to have less variability to changing patterns with expected reduction in lens volume between 8% and 26% due to SLR. Study results can provide water resource managers with valuable findings for consideration in water security measures.  相似文献   

15.
Abstract

Climate change is recognized to be one of the most serious challenges facing mankind today. Driven by anthropogenic activities, it is known to be a direct threat to our food and water supplies and an indirect threat to world security. Increase in the concentration of carbon dioxide and other greenhouse gases in the atmosphere will certainly affect hydrological regimes. The consequent global warming is expected to have major implications on water resources management. The objective of this research is to present a general approach for evaluating the impacts of potential climate change on streamflow in a river basin in the humid tropical zone of India. Large-scale global climate models (GCMs) are the best available tools to provide estimates of the effect of rising greenhouse gases on rainfall and temperature. However the spatial resolution of these models (250 km?×?250 km) is not compatible with that of watershed hydrological models. Hence the outputs from GCMs have to be downscaled using regional climate models (RCMs), so as to project the output of a GCM to a finer resolution (50 km?×?50 km). In the present work, the projections of a GCM for two scenarios, A2 and B2 are downscaled by a RCM to project future climate in a watershed. Projections for two important climate variables, viz. rainfall and temperature are made. These are then used as inputs for a physically-based hydrological model, SWAT, in order to evaluate the effect of climate change on streamflow and vegetative growth in a humid tropical watershed.

Citation Raneesh, K. Y. & Santosh, G. T. (2011) A study on the impact of climate change on streamflow at the watershed scale in the humid tropics. Hydrol. Sci. J. 56(6), 946–965.  相似文献   

16.
Abstract

The long term hydrological response of a medium-sized mountainous catchment to climate changes has been examined, The climate changes were represented by a set of hypothetical scenarios of temperature increases coupled with precipitation and potential evapotranspiration changes. Snow accumulation and ablation, plus runoff from the study catchment (the Mesochora catchment in central Greece) were simulated under present (historical) and altered climate conditions using the US National Weather Service snowmelt and soil moisture accounting models. The results of this research obtained through alternative scenarios suggest strongly that all the hypothetical climate change scenarios would cause major decreases in winter snow accumulation and hence increases in winter runoff, as well as decreases in spring and summer runoff. The simulated changes in annual runoff were minor compared with the changes in the monthly distribution of runoff. Attendant changes in the monthly distribution of soil moisture and actual evapotranspiration would also occur. Such hydrological results would have significant implications on future water resources design and management.  相似文献   

17.
Water is our most precious and arguably most undervalued natural resource. It is essential for life on our planet, for food production and economic development. Moreover, water plays a fundamental role in shaping weather and climate. However, with the growing global population, the planet’s water resources are constantly under threat from overuse and pollution. In addition, the effects of a changing climate are thought to be leading to an increased frequency of extreme weather causing floods, landslides and drought. The need to understand and monitor our environment and its resources, including advancing our knowledge of the hydrological cycle, has never been more important and apparent. The best approach to do so on a global scale is from space. This paper provides an overview of the major components of the hydrological cycle, the status of their observations from space and related data products and models for hydrological variable retrievals. It also lists the current and planned satellite missions contributing to advancing our understanding of the hydrological cycle on a global scale. Further details of the hydrological cycle are substantiated in several of the other papers in this Special Issue.  相似文献   

18.
Quantitative relationships between groundwater runoff and other water balance components are obtained. These relationships enable the prediction of changes in groundwater nourishment in different natural-geographic zones on the Earth because of global climatic changes and intense anthropogenic impact on the water regime of different areas. Groundwater runoff values (natural groundwater resources) in individual river basins are estimated. Digital maps (grid-models) of the space and time distribution of water balance elements (based on GIS-technology) are constructed for major river basins in European Russia, and river runoff is calculated in each grid node in river basins with a step of 0.1° in geographic coordinates. The values of major water balance components, thus related with one another, serve as the basis for their spatial and temporal analysis and cartographic representation. The proposed method was tested against data on Volga basin where long-term observational data on water balance elements are available in a number of hydrometric sections.  相似文献   

19.
Projections of changes in climate are important in assessing the potential impacts of climate change on natural and social systems. However, current knowledge on assembling different GCMs to estimate future climate change over the Pear River basin is still limited so far. This study examined the capability of BMA and arithmetic mean (AM) method in assembling precipitation and temperature from CMIP5 under RCP2.6, RCP4.5 and RCP8.5 scenarios over the Pearl River basin. Results show that the BMA outperforms the traditional AM method. Precipitation tends to increase over the basin under RCP2.6 and RCP4.5 scenarios, whereas decrease under RCP8.5. The most remarkable increase of precipitation is found in the northern region under RCP2.6 scenario. The linear trend of the monthly mean near-surface air temperature increases with the growing CO2 concentration. The warming trends in four seasons are distinct. The warming rate is prominent in summer and spring than that in other season, meanwhile it is larger in western region than in other parts of the basin. The findings can provide beneficial reference to water resources and agriculture management strategies, as well as the adaptation and mitigation strategies for floods and droughts under the context of global climate change.  相似文献   

20.
Southeast Australia is currently in a prolonged drought. The ongoing drought has placed immense pressure on the limited water resources and a perception that this may be the start of a persistent change from historical conditions. Several studies have suggested that part of the current drought could be associated with global warming, and many global climate model projections for southeast Australia are for a drier future on average. However, it is difficult, if not impossible, to separate a global warming signal from the high natural variability observed over the last two centuries and revealed in palaeo-climate records.  相似文献   

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