Climate change is expected to modify the hydrological cycle and affect freshwater resources. Groundwater is a critical source of fresh drinking water for almost half of the worlds population and it also supplies irrigated agriculture. Groundwater is also important in sustaining streams, lakes, wetlands, and associated ecosystems. But despite this,

There is a general consensus that for the next few decades at least, the Earth will continue its warming. This will inevitably bring about serious environmental problems. For human society, the most severe will be those related to alterations of the hydrological cycle, which is already heavily influenced by human activities. Climate change will directly affect groundwater recharge, groundwater quality and the freshwater-seawater interface. The variations of groundwater storage inevitably entail a variety of geomorphological and engineering effects. In the areas where water resources are likely to diminish, groundwater will be one of the main solutions to prevent drought. In spite of its paramount importance, the issue of 'Climate Change and Groundwater' has been neglected. This volume presents some of the current understanding of the topic.

Climate change is expected to modify the hydrological cycle and affect freshwater resources. Groundwater is a critical source of fresh drinking water for almost half of the world’s population and it also supplies irrigated agriculture. Groundwater is also important in sustaining streams, lakes, wetlands, and associated ecosystems. But despite this, knowledge about the impact of climate change on groundwater quantity and quality is limited. Direct impacts of climate change on natural processes (groundwater recharge, discharge, storage, saltwater intrusion, biogeochemical reactions, chemical fate and transport) may be exacerbated by human activities (indirect impacts). Increased groundwater abstraction, for example, may be needed in areas with unsustainable or contaminated surface water resources caused by droughts and floods. Climate change effects on groundwater resources are, therefore, closely linked to other global change drivers, including population growth, urbanization and land-use change, coupled with other socio-economic and political trends. Groundwater response to global changes is a complex function that depends on climate change and variability, topography, aquifer characteristics, vegetation dynamics, and human activities. This volume contains case studies from diverse aquifer systems, scientific methods, and climatic settings that have been conducted globally under the framework of the UNESCO-IHP project Groundwater Resources Assessment under the Pressures of Humanity and Climate Change (GRAPHIC). This book presents a current and global synthesis of scientific findings and policy recommendations for scientists, water managers and policy makers towards adaptive management of groundwater sustainability under future climate change and variability.

National and global security can be assessed in many ways but one underlying factor for all humanity is access to reliable sources of water for drinking, sanitation, food production and manufacturing industry. In many parts of the world, population growth and an escalating demand for water already threaten the sustainable management of available water supplies. Global warming, climate change and rising sea level are expected to intensify the resource sustainability issue in many water-stressed regions of the world by reducing the annual supply of renewable fresh water and promoting the intrusion of saline water into aquifers along sea coasts, where 50% of the global population reside. Pro-active resource management decisions are required, but such efforts would be futile unless reliable predictions can be made about the impact of the changing global conditions on the water cycle and the quality and availability of critical water reserves. Addressing this wide spectrum of issues, a team of expert authors discusses here the impacts of climate change on the global water resources, the long-term resource management goals at global and local scales, the data requirements and the scientific and technical advances necessary to mitigate the associated impacts.

The book collects seven original contributions in the field of climate and underlying human influences on renewable groundwater resources and/or stream–aquifer interactions. The first contribution introduces the following six ones into the overall framework of the topic. The second contribution assesses the impact of climate change scenarios on land subsidence related to groundwater level depletion in detrital aquifers. The third contribution studies the patterns of river infiltration and the associated controlling factors by using a combination of field investigations and modeling techniques. The fourth contribution introduces a method to improve the modeling of streamflow in high-permeability bedrock basins receiving interbasin groundwater flow. The fifth contribution discusses the role of resilience of hydrogeological systems affected by either climate and/or anthropic actions in order to understand how anticipating negative changes and preserving its services. The sixth contribution analyzes the water balance of wetlands, which are systems highly sensitive to climate change and human action. The seventh contribution identifies groundwater bodies with low vulnerability to pumping to be used as potential buffer values for sustainable conjunctive use management during droughts.

Academic Paper from the year 2014 in the subject Geography / Earth Science - Meteorology, Aeronomy, Climatology, language: English, abstract: Climate change poses uncertainties to the supply and management of water resources. The Intergovernmental Panel on Climate Change (IPCC) estimates that the global mean surface temperature has increased 0.6 0.2 oC since 1861, and predicts an increase of 2 to 4 oC over the next 100 years. Temperature increases also affect the hydrologic cycle by directly increasing evaporation of available surface water and vegetation transpiration. Consequently, these changes can influence precipitation amounts, timings and intensity rates, and indirectly impact the flux and storage of water in surface and subsurface reservoirs (i.e., lakes, soil moisture, groundwater). In addition, there may be other associated impacts, such as sea water intrusion, water quality deterioration, potable water shortage, etc. While climate change affects surface water resources directly through changes in the major long-term climate variables such as air temperature, precipitation, and evapotranspiration, the relationship between the changing climate variables and groundwater is more complicated and poorly understood. The greater variability in rainfall could mean more frequent and prolonged periods of high or low groundwater levels, and saline intrusion in coastal aquifers due to sea level rise and resource reduction. Groundwater resources are related to climate change through the direct interaction with surface water resources, such as lakes and rivers, and indirectly through the recharge process. The direct effect of climate change on groundwater resources depends upon the change in the volume and distribution of groundwater recharge. Therefore, quantifying the impact of climate change on groundwater resources requires not only reliable forecasting of changes in the major climatic variables, but also accurate estimation of groundwater recharge. This art"

Climate change is occurring, is caused largely by human activities, and poses significant risks for-and in many cases is already affecting-a broad range of human and natural systems. The compelling case for these conclusions is provided in Advancing the Science of Climate Change, part of a congressionally requested suite of studies known as America's Climate Choices. While noting that there is always more to learn and that the scientific process is never closed, the book shows that hypotheses about climate change are supported by multiple lines of evidence and have stood firm in the face of serious debate and careful evaluation of alternative explanations. As decision makers respond to these risks, the nation's scientific enterprise can contribute through research that improves understanding of the causes and consequences of climate change and also is useful to decision makers at the local, regional, national, and international levels. The book identifies decisions being made in 12 sectors, ranging from agriculture to transportation, to identify decisions being made in response to climate change. Advancing the Science of Climate Change calls for a single federal entity or program to coordinate a national, multidisciplinary research effort aimed at improving both understanding and responses to climate change. Seven cross-cutting research themes are identified to support this scientific enterprise. In addition, leaders of federal climate research should redouble efforts to deploy a comprehensive climate observing system, improve climate models and other analytical tools, invest in human capital, and improve linkages between research and decisions by forming partnerships with action-oriented programs.

"Climatic Change and Water Resources in the Middle East and North Africa" is dedicated to high-priority topics related to the impact of climate change on water resources in a water scarce region. The subject is described and discussed in three main chapters and different case studies. The three main chapters are (1) Climatic changes - sources and effects on the water cycle, (2) Impact of climate change on water resources, (3) Water resources and water management. These chapters are split up into further 26 sections. A total of 64 individuals from many countries have made contributions to this book. All topics in this book are complimentary and contribute to a comprehensive understanding of the interactions between global climate change, world water cycle and water resources. A valuable and meaningful interdisciplinary mixture of topics is combined in this book which will be of great interest to many scientists.

Climate change is likely to continue to have severe impacts, including sea level rise. At the same time, population increase and development imperatives create additional pressure on available water resources. These changes are problematic for the Mediterranean coastal areas and especially the Nile Delta coast. Particular focus of this study is on salinization of groundwater resources in the Nile Delta Aquifer (NDA) due to saltwater intrusion. To assess current conditions and develop future adaptation strategies for the NDA, a 3D model simulating regional variable-density groundwater flow and coupled salt transport was constructed based on available data set, using the SEAWAT code. A method for identification of the most representative model has been developed, based on testing different simulation periods during which the NDA has ‘evolved’ from completely fresh groundwater conditions to conditions representative for the year 2010.This model was then applied to analyze possible future NDA conditions under several predefined scenarios of sea level rise and groundwater extraction. This analysis indicated that the impacts from further extractions of groundwater on availability of fresh groundwater in the aquifer are more significant compared to those from sea level rise. Furthermore, three different adaptation measures and their impacts in the Sharkeya Nile Delta governorate were tested. It was shown that that changing crop types and irrigation practices towards water saving options seem to be more promising than artificial recharge with injection wells or extraction and usage of brackish groundwater after desalination. The developed model is useful for further Water-Food Nexus studies.

The majority of the examples are taken from regions where the rivers run most of the year.