deutsch
english
français

C08.34 Water Sustainability

Session: Water resources and climate change

Chair(s): Claudio Cassardo & J.A.A. Jones

Abstract:
The recently observed warming has been linked to changes in the large-scale hydrological-cycle components: increasing atmospheric water vapour content and evapotranspiration; changing precipitation patterns, intensity and extremes; reduced snow cover and widespread melting of ice; and changes in soil moisture and runoff. Climate model simulations for the 21st century show precipitation increases in high latitudes (very likely) and parts of the tropics, and decreases in some subtropical and lower mid-latitude regions (likely). As a consequence, by the middle of the 21st century, annual average river runoff and water availability are projected to increase at high latitudes and in some wet tropical areas, and decrease over some dry regions at mid-latitudes and in the dry tropics. Precipitation variability and intensity are expected to increase, reflecting in an increment of the risks of flooding and drought in many areas. Water supplies stored in glaciers and snow cover are also projected to decline in the course of the century. These effects are projected to affect water quality and food availability, stability, access and utilisation; exacerbate many forms of water pollution; affect the function and operation of existing water infrastructures, as hydropower, structural flood defences, drainage and irrigation systems, as well as water management practices. Globally, the negative impacts of future climate change on freshwater systems are expected to outweigh the benefits.
Adaptation options are required to ensure an adequate water supply during average and drought conditions require. At the same time, mitigation measures can reduce the magnitude of impacts of global warming on water resources, in turn reducing adaptation needs.

Timespots: 1

Session: Water and mining (Water pollution)

Chair(s): Frank Winde & NN

Abstract: Water is essential to life on our planet. A sustainable development should ensure uncontaminated streams, rivers, lakes and oceans. There is growing public concern in certain regions of the world about the conditions of fresh water. Mining is necessary for nations to have adequate and dependable supplies of minerals and materials to meet their economic and defense needs at acceptable environmental, energy, and economic costs.
Some of the nonfuel minerals mined, such as nonmetallic or industrial minerals, can be used directly from the earth. Metallic minerals, which are also nonfuel minerals, conversely, are usually combined in nature with other materials as ores. These ores must be treated, generally with chemicals or heat to produce the metal of interest. Most bauxite ore, for example, is converted to aluminum oxide, which is used to make aluminum metal via heat and additives. Fuel minerals, such as coal and uranium, must also be processed using chemicals and other treatments to produce the quality of fuel desired.
Mining affects fresh water through heavy use of water in processing ore, and through water pollution from discharged mine effluent and seepage from tailings and waste rock impoundments. Increasingly, human activities such as mining threaten the water sources on which we all depend. Mining by its nature consumes, diverts and can seriously pollute water resources.
While there have been improvements to mining practices in recent years, significant environmental risks remain. Negative impacts can vary from the sedimentation caused by poorly built roads during exploration through to the sediment, and disturbance of water during mine construction. Water pollution from mine waste rock and tailings may need to be managed for decades, if not centuries, after closure. These impacts depend on a variety of factors, such as the sensitivity of local terrain, the composition of minerals being mined, the
type of technology employed, the skill, knowledge and environmental commitment of the company, and finally, the human ability to monitor and enforce compliance with environmental regulations. Furthermore, as mine technologies are developed to make it more profitable to mine low grade ore, even more waste will be generated in the future.

Timeslots: 1

Sesion: GIS in water research (Hydro GIS)

Chair(s): NN & Frank Winde

Abstract:
Geographic information systems (GISs) became an important tool in hydrology in the scientific study and management of water resources. Climate change and greater demands on water resources require a more knowledgeable disposition of this vital resource. Because water varies spatially and temporally throughout the hydrologic cycle, its study using GIS is especially practical.
In the hydrologic budget, the inputs are precipitation, surface/groundwater inflows, while outputs are evapotranspiration, infiltration, surface runoff, and surface/groundwater outflows. All of these quantities, including storage, can be measured or estimated, and their characteristics can be graphically displayed in GIS and studied. In particular, the characteristics of groundwater (which constitute about the 98% of the world’s available freshwater) can readily be input into GIS for further study and management of water resources.
Within a GIS, it is possible to direct link via the Internet to real time data (providing a spatial representation of the data), delineate a watershed (using for instance digital elevation model data), map precipitation and other hydrologic data as evapotranspiration, infiltration, and groundwater.
In the future, due to population increment and global warming, an increasing demand of water resources is expected, hence it is likely that the demand for groundwater resources will increase too. In some places, this resource has already been severely tapped, and even mismanaged. Although not as apparent as surface water flow, groundwater can also be characterized spatially in a GIS and analyzed by scientists and natural resource managers. Groundwater flows much more slowly than surface water, is 3-dimensional and depends on terrain and rock characteristics, quantities which may be presented spatially in GIS and used for analysis, management of water availability and water quality, and land use practices. A very large amount of data from wells is available and can be managed in a GIS and manipulated to display spatial characteristics for analysis and water resource planning.

Timeslots: 1

Session: Water in urban environments

Chair(s): Kazuki Mori & Frank Winde

Abstract:
The world has seen a fifteen-fold increase in urban populations since the beginning of the twentieth century. Both total and urban population, independently on the development rate, are increasing, though at a decreasing rate. Nowadays more than half of the world’s population lives in urban areas. Wealthier and more developed nations are characterised by greater levels of urbanisation. However, the majority of urban growth is occurring in lesser developed countries, where the rate of urbanisation is as much as seven times that in the most developed nations. This trend in urban expansion is expected to continue, as transportation and communication networks, two of a city’s most extensive infrastructure systems, expand outside traditional inner-city boundaries. As the size and make-up of those cities changes, new urban economic and social inequalities come to the fore, and new pressures on the local environment are created. Concerning the water resources, the following aspects must be considered for an accurate planning of the water resources: the threat of sea-level rise for coastal cities, the storm water drainage and sewage systems, the damages connected to severe wet weather events and eventual flooding, the damages connected to severe dry weather events and eventual droughts, the general increment of water demand, the need of a major number of water supply and treatment systems, the increment of toxicity of waste water and the eventual contamination of water resources, etc. All these themes are connected to their associated impacts on housing structures, transportation networks, water supply and water quality.

Timeslots: 1
 

Session: Water resources and management, hydrological budget and hydraulic emergencies

Chiar(s): Changseng He & Olga Eugenia Scarpati

Abstract:
Water is an essential resource for all life on our planet. Of all water resources on the Earth, only about 0.08% of all the world’s fresh water is exploited by mankind in ever increasing demand for sanitation, drinking, manufacturing, leisure and agriculture. Much effort in water management is directed at optimising the use of water and in minimising the environmental impact of water use on the natural environment.
A successful resource management requires accurate knowledge of the resource available, the uses to which it may be put, the competing demands for the resource, measures to and processes to evaluate the significance and worth of competing demands and mechanisms to translate policy decisions into actions on the ground.
For water as a resource, this is particularly difficult since sources of water can cross many national boundaries and the uses of water include many that are difficult to assign financial value to and may also be difficult to manage in conventional terms.
To accurately reproduce the hydrological cycle components, hydrological models able to represent a part of the hydrologic cycle with an increasing level of complexity have been developed in the last half of century. They are primarily used for hydrological prediction and for understanding hydrological processes. Recent research in hydrological modeling tries to have a more global approach to the understanding of the behaviour of hydrologic systems to make better predictions and to face the major challenges in water resources management.
Measurement is fundamental for assessing water resources and understanding the processes involved in the hydrologic cycle, as well as to check the results of hydrological models.
River floods are of the natural disasters that affects consistently human lives and properties, which could be severely threatened. In modern times, floods have cause more casualties and damage than any other destructive natural event. Furthermore, over the globe a noticeable increase in the magnitude of destruction, associated with increased average and extreme flood events to some extent influenced by anthropogenic activities, has been observed. These events, in turn, have attracted a high media profile, thereby increasing public the awareness and concern. As a direct result, there is an ever-increasing demand for efficient flood management and mitigation systems. To fill this niche, an optimised combination of prevention, early warning, crisis and post-crisis activities, and standard terminology, based on one commonly available platform is required.

Timeslots: 1

Session: Hydrological Process and Watershed Management in Arid Regions

chair(s): Chansheng He & N.N.
Abstract:
Dry lands, including arid, semi-arid, and areas that are characterized by scarce and unpredictable precipitation, account for approximately 41 percent of the global land surface and are home to over 38 percent of the world population of 7 billion. Proper management of the limited water resources is essential to ensure the welfare of human beings and the sustainability of dry land ecosystems. During the past few decades, however, improper water resource management has resulted in numerous problems worldwide, including poor food security, increased human diseases, conflicts between different users, limitations on economic development and human welfare, desertification, salinization, sand storms, water pollution, and so forth.
Net water supply in arid watershed is often a combination of precipitation and snow and glacial melt in the upper reach mountain area. Surface runoff from the upper reach is the main source of water supply for the downstream oasis system where agricultural irrigation is the main water user. If the flow from the upper reach is unable to meet the evapotranspiration need of the oasis system, then the vegetated areas downstream would shrink, lakes would go dry, and desertification would expand. Thus, understanding of the magnitude, processes, and transfer mechanisms among the precipitation, snow and glacial melt, surface water, evapotranspiration, and groundwater of the dry land watershed system is fundamental to appropriate allocation of the limited water resources among the competing demands for water to ensure the sustainable regional development.

Timeslots: 1