the XXV IUGG General Assembly
Earth on the Edge: Science for a Sustainable Planet
28 June - 7 July 2011
Melbourne Convention & Exhibition Centre
Assessment of water quality under changing climate conditions
Organisers: ICWQ, ICCE, ICWRS
Lead Convenor: Jake Peters (United States of America)
Co-Convenors: Valentina Krysanova (Germany), Ahti Lepistö (Finland), Martin Thoms (Australia), Rob Wilby (United Kingdom), Rajendra Prasad (India)
Scope: Climate change coupled with geographically heterogeneous population growth, land use change, increasing urbanization, and changing water use are expected to have major effects on water supply and water quality. Increasing precipitation variability is expected to cause changes in runoff generation, and increases in frequency of floods and droughts. The consequences of increasing temperature will likely cause shifts in biological systems and changes in reaction rates for many biotic and abiotic processes. Climate change effects on streamflow, timing of snowmelt, timing and magnitude of groundwater recharge, ecosystem responses, and impacts of changing land cover and land use are likely to affect water quality. But what changes are expected to occur and where? The frequency of outbreak of blue-green algae in lakes, reservoirs and lowland rivers is likely to increase with climate change. The management of water supply and sanitation is controlled by water availability. For example, the quantity and quality of effluent discharge is determined by the quantity and quality of receiving waters. A reduction in streamflow would mandate a reduction of effluent discharge to maintain current water quality. Increasing air temperatures would result in higher stream temperatures causing a reduction in dissolved oxygen due to increased biological activity.
Several aspects of climate change influence both stream water quantity and quality. Water quality in many streams and waterbodies of the world is already inadequate, and this tendency could continue under the changing climate. This workshop aims to evaluate different types of effects of climate variability and change on water quality in natural systems, and compare them with the effects of human activities. Papers on the following issues are invited:
• observed trends in water quality in rivers and waterbodies and their relation to land use and other human activities and climate;
• interdependence of water quantity and water quality aspects in climate impact assessment;
• modelling climate change effects on water quality: tools, climate scenarios, regional applications;
• climate change and land use change interactions with freshwater ecosystems
• potential impacts of adaption strategies of water quality to changing water resource availability;
• evaluation of air, land, and water management strategies, e.g., flow control, emission control, waste management
Tracer applications in sediment research
Organiser: ICCE, ICT, ICWQ, PUB
Lead Convenor: Valentin Golosov (Russia)
Co-Convenors: Des Walling (United Kingdom), Jon Olley (Australia)
Scope: Recent decades have seen a major expansion of the application of tracer techniques in sediment research. New methods and approaches have been developed and existing tracer techniques have been refined and improved. The resulting advances have permitted the development of a more detailed understanding of the spatial-temporal dynamics of sediment in the fluvial system. Important advances have been made in a number of areas. These include, firstly, the development of an improved understanding of sediment redistribution in small catchments, which provide the main source of sediment to rivers in areas under intensive agriculture. Secondly, major progress has been made in refining sediment source fingerprinting techniques, which have been widely applied in many different environments around the globe. Thirdly, detailed investigations of rates and patterns of floodplain deposition, involving a number of different tracers, have permitted a greatly improved understanding of the role of river floodplains as sediment sinks and facilitated the validation of sediment transport models for floodplain systems. Fourthly, combination of tracer techniques with other methods and approaches has greatly facilitated the historical reconstruction of the evolution of fluvial systems. Finally, tracers have been used very successfully to investigate the source, transfer pathways and fate of sediment-bound nutrients and contaminants within the environment. Many advances in the application of tracers in sediment research demonstrate that their use is frequently most successful when combined with other techniques and approaches.
Against this background, there is a need to review the advantages and limitations of a wide range of tracer techniques used for studying sediment mobilization, transport, deposition and storage within different components of the fluvial system in different global climatic and landscape zones. This workshop will facilitate such a review, by including presentations on the application of a wide range of tracer techniques in sediment studies and a round table discussion of different facets of tracer applications including sampling strategies, sampling procedures, sample preparation and analysis and data analysis and interpretation. The topics to be addressed will include:
• Assessment of the temporal dynamics of sediment mobilisation, transport and deposition using tracers
• The use of tracer techniques for establishing sediment budgets
• Use of tracers in spatial-temporal analysis of sediment redistribution in small catchments
• Assessment of sediment sources in catchments and river basins
• Use of tracer techniques for reconstructing transformations of the fluvial system in response to land use and climate change
• Use of tracer technique for investigating floodplain evolution and the role of floodplains as sediment sinks
• Application of tracer techniques for investigating the mobilisation, transfer and fate of sediment-associated nutrients and contaminants in the fluvial system
• Use of tracer techniques for assessing the effectiveness of soil and water conservation measures
Organisers: ICSW, ICCE
Lead Convenor: Christophe Cudennec (France)
Co-convenors: Houda Boudhraâ (Tunisia), Stephan Gruber (Switzerland), Scott Peckham (United States of America), Riccardo Rigon (Italy), Colin Stark (United States of America)
Geomorphology and hydrology are intimately intricate, through a large range of space and time scales, and for various organization levels (soil/substrate unit, hillslope, channel, watershed, lowland, wetland, geological structure, mountain ridge…). Geomorphology is a major structural determinant of many surface hydrological processes, as well as of many coupled quantitative processes and interfaces with the groundwater, the cryosphere and the atmosphere dynamics. It is also, consequently, strongly determining water-related suspended and dissolved dynamics, as well as ecological systems and relationships. Conversely, hydrology is a major driving force of geomorphological dynamics, under climatic forcing and in relation to both tectonics and geography. This refers to various issues, from palaeo-hydrology to landslide hazard assessment, and even to hydrological interpretations of planetary morphologies.
Through history, mankind has dealt with hydro-geomorphology through a wide range of empirical–conceptual approaches, in order to better control the ongoing dynamics, to secure water- and relief-dependent activities and to mitigate related hazards. This has been developed in more or less explicit ways, in very diverse environments (rural, forest, urban…), through infrastructures setting up and land cover management, i.e. through the adding of anthropogenic morphological features to the natural ones.
Hydro-geomorphology is renewed and enhanced by original approaches of data acquisition, management and modelling; especially through new field and remote sensors, hydroinformatics, geomorphometric and scaling analyses, analogous and mathematical models, and field experiments. Major new approaches of observation, analysis, conceptualisation and modelling should be brought together in a comprehensive framework. Contributions are expected in this sense to better understand the hydro-geomorphological dynamics and structures, and to link them to actual issues such as of integrated water and risk management, upstream-downstream impact assessment, sustainability of water resources and uses, eco-hydrology, traditional/modern techniques assessment, scaling and complexity understanding, regionalization and PUB methodologies.
Water quality and sediment prediction in ungauged basins
Organisers: ICWQ, ICCE
Lead Convenor: Berit Arheimer (Sweden)
Co-Convenors: Michael Rode (Germany), Scott Wilkinson (Australia)
Scope: The IAHS “Predictions in Ungauged Basins” initiative (PUB) has had focus on river discharge and water budgets in catchments. However, one of the major driving forces for PUB in many countries is mapping environmental status and estimating effects of control measures. For instance, the European Water Framework Directive (WFD) requires detailed reporting with high resolution, including ecological status and hydromorphological information of each defined waterbody. Since it is not possible to monitor everywhere, some kind of expert judgements is necessary for the reporting procedure. Methods for predictions of water quality and sediments in ungauged basins are thus highly requested and desired by practitioners. The hydrological research community can contribute with experiences from PUB in this context. However, model applications always include assumptions about unknown input data and unknown model coefficients and parameters. The increase in problems when modelling water quality and sediments are twofold: 1) The lack of information is increasing with the number of variables to be predicted, and thereby, the uncertainty is higher when modelling transport of substances compared to ordinary water predictions. 2) The monitoring programmes normally include only grab samples once a week or once a month, which does not reflect the temporal concentration variation in surface water. Hence, it is also difficult to calibrate and validate a model. This workshop asks for integrated methods, using PUB approaches for water quality and/or sediment modelling of waterbodies, river reaches and the catchment scale. It also welcomes clever assumptions for unknown input variables, monitoring strategies for various variables and purposes, and definition of evaluation criteria for data sparse variables and for spatial variation. Demonstration projects are especially appreciated to flavour the discussion with practical examples.
International Symposium of IAHS-ICCE in 2012
CHENGDU, CHINA OCT. 11-15
“Erosion and sediment yields in the changing environment”