The Report of the Expert Panel on the Sustainable Management of Groundwater in Canada: The Council of Canadian Academies
The Expert Panel on Groundwater was established in response to a request from the Minister of Natural Resources Canada, asking the Council of Canadian Academies to assess what is needed to achieve sustainable management of Canada's groundwater resources, from a science perspective. To this end, the Council of Canadian Academies assembled an interdisciplinary panel of experts who interpreted science, in the context of this assessment, to include natural and social sciences as well as local, provincial, and federal governance. The panel's report, released on May 11th 2009, noted that nearly 10 million Canadians rely on groundwater for household purposes, in addition to uses for agriculture and industry. Both media and public have expressed many recent concerns about water supplies and their quality. The concept of groundwater sustainability developed by the panel encompasses five interrelated goals: three that involve primarily the physical sciences and engineering, and two that are essentially socio-economic in nature. These goals are as follows: i. Protection of groundwater supplies from depletion ii. Protection of groundwater quality from contamination iii. Protection of ecosystem viability iv. Achievement of economic and social well-being v. Application of good governance The achievement of groundwater sustainability requires a careful analysis and balancing of the five goals; a comprehensive sustainability framework for groundwater has not yet been implemented in Canada. Adoption by federal, provincial and local jurisdictions of such a framework, based on the goals outlined above, would be invaluable in guiding efforts to improve the understanding and management of groundwater. To contextualize the components of the sustainability framework, the panel examined a series of case studies that typify examples along a spectrum, from near-sustainable, to situations that are fail to meet the outlined criteria. The panel identified the fragmentation of water management at all levels, between groundwater and surface water and between quantity and quality, as a major hindrance to the sustainable management of groundwater in Canada. Several problem areas were highlighted in the report, including the need for a cooperative data management system; inadequate numbers of well-trained hydrogeologists and other water specialists; and a frequent failure to consider groundwater as part of the hydrological cycle in watersheds or ground-watersheds. A series of recommendations to address these, and other problems, were developed by the Panel and will be outlined in the presentation.
General Trends of Groundwater Renewal in North America and Scandinavia
Depletion of groundwater resources is a pressing problem for large parts of the world's population and has significant ecological impact. Increased water demand due to energy production, population growth, and changes in the water supply due to climate change is increasing the importance of methods for understanding groundwater circulation and renewal. Even if it is well known that topography and geology are key factors controlling groundwater circulation, we have a surprisingly limited quantitative understanding of this control. In humid regions with low permeable rock, where the groundwater surface is a replica of the topography, differences in hydraulic potential created by topography are the main driving force for groundwater flow. In these regions the topography can be used to predict the renewal rate and circulation of groundwater. This is especially useful in data sparse areas or if the aerial extension of the study is large. Here we make use of spectral analysis to relate saturated groundwater flow to landscape topography over all scales of the continental shield. Based on extensive data from Scandinavia and North America, reflecting the topography of landscapes, the bedrock, and the presence of Quaternary deposits, we have found that general trends in the topography creates universal patterns in the groundwater flow. Our results imply that the amount of accessible groundwater decreases fast with depth and at 99.9% of all groundwater circulation occurs at depths less than 700 m. Furthermore, about 90% of the groundwater circulation occurs in Quaternary deposits, even in comparatively thin soil layers like in Scandinavia and parts of North America. The theoretical explanation and the new understanding of the rapidly decaying renewal rate of groundwater with depth are of great importance for water resource management. Our results give an indication of sustainable extraction rates at various depths in the subsurface. The method presented here also enhances our ability to relate changes in surface water levels with increased groundwater withdrawal at a wide range of temporal and spatial scales.
Evaporation From Lake Superior
Evaporation is a critical component of the water balance of each of the Laurentian Great Lakes, and understanding the magnitude and physical controls of evaporative water losses are important for several reasons. Recently, low water levels in Lakes Superior and Michigan/Huron have had socioeconomic, ecological, and even meteorological impacts (e.g. water quality and quantity, transportation, invasive species, recreation, etc.). The recent low water levels may be due to increased evaporation, but this is not known as operational evaporation estimates are currently calculated as the residual of water or heat budgets. Perhaps surprisingly, almost nothing is known about evaporation dynamics from Lake Superior and few direct measurements of evaporation have been made from any of the Laurentian Great Lakes. This research is the first to attempt to directly measure evaporation from Lake Superior by deploying eddy covariance instrumentation. Results of evaporation rates, their patterns and controlling mechanisms will be presented. The direct measurements of evaporation are used with concurrent satellite and climate model data to extrapolate evaporation measurements across the entire lake. This knowledge could improve predictions of how climate change may impact the lake's water budget and subsequently how the water in the lake is managed.
Response of River Discharge to Changing Climate Over the Past Millennium in the Upper Mackenzie Basin: Implications for Water Resource Management
Runoff generated from high elevations is the primary source of freshwater for western North America, yet this critical resource is managed on the basis of short instrumental records that encompass an insufficient range of climatic conditions. Like other streams that drain this part of the continent and flow across the northern Great Plains, where seasonal and extended intervals of water deficit are a natural element of the landscape, the Peace and Athabasca rivers provide water that is crucial for societal needs. Climate variability and rapidly increasing industrial development are, however, raising concerns over the future availability of water resources for continued economic growth in these watersheds and to maintain the integrity of aquatic ecosystems, including the Peace-Athabasca Delta (PAD). This is particularly acute for the Athabasca River because the Alberta oil sands industry remains dependent on its water for bitumen extraction. Here we report the effects of climate change over the past 1000 years on river discharge in the upper Mackenzie River system based on paleoenvironmental information from the PAD and Lake Athabasca. The delta landscape responds to hydroclimatic changes with marked variability, capturing systematic changes in ice-jam flood frequency and perched basin water balance. Lake Athabasca level appears to directly monitor overall water availability with the highest levels occurring in concert with maximum glacier extent during the Little Ice Age, and the lowest during the 11th century prior to medieval glacier expansion. Recent climate-driven hydrological change appears to be on a trajectory to even lower levels as high-elevation snow and glacier meltwater contributions both continue to decline. The temporal perspective offered by these paleohydrological reconstructions indicates that climatic changes over the past millennium have led to characteristic responses in the quantity and seasonality of streamflow generated from the hydrographic apex of North America. For water resource managers, a key feature that emerges from these results is that the hydrograph of the 21st century may be evolving towards conditions unprecedented over the past 1000 years, extending beyond the 11th century when reduced glacier meltwater contributions were partly compensated by abundant snowmelt runoff. Continuing reduction in both peak and total discharge clearly underscores the need for stringent allocation of freshwater resources in these watersheds.
Advancing Water Science through Data Sharing
Collection of field data on water and water quality is expensive. Vast quantities of data are collected by
research, monitoring, and operational projects in North America, yet only monitoring data are routinely
available. The Hydrologic Information System (HIS) project of the Consortium of Universities for the
Advancement of Hydrologic Science, Inc (CUAHSI) has developed Water Data Services (WDS) using a
services-oriented architecture to aid in the publication, discovery and access to time-series data collected at a
fixed point. The underlying technological developments include WaterML, an XML-based language for
transmission of time-series data, and WaterOneFlow, a set of web services that can provide access to data
and metadata using standard web protocols. These technologies form the basis for an easy-to-use data
publication system. WDS also includes a registration service for published web services and maintains a
metadata catalogue of all services. An ontology of hydrologic concepts is included as part of this central service
to enable variables to be mapped to a common set of concepts. A map-based discovery tool, Hydroseek
(http://www.hydroseek.net/), has been developed using the ontology and metadata catalogue. CUAHSI has
been working with US government agencies, such as the US Geological Survey, on providing access to their
data holdings using web services and transmitting data using WaterML. Metadata from these agencies has
been included in the central metadata catalogue, thereby enabling seamless access to both government and
academic environmental data. This system could be expanded through the participation of other national
governments, provinces, states and cities, as well as entities engaged in operational monitoring. All software
is freely available.
Estimation of Hydrologic Components of a Watershed With a coupled Hydro-Climatic Model : the CRCM and its Application Over Some Catchment Basins in Québec
Knowledge of the hydrologic behaviour of a watershed, particularly its anticipated reactions to unknown but not unlikely meteorological events, is necessarily derived by the development and application of a hydrologic model. Whatever its type, such a model needs basic calibration and validation data, which is not always available in sufficient quantity and quality. An interesting alternative is the use of coupled hydro-climatic models. Numerous developments have been made in this direction over the last few years at Ouranos with the Canadian Regional Climate Model (CRCM). The main advantage of climate models is that they are based on closed water and energy budgets and include feedbacks between the surface and the atmosphere. The CRCM is a gridded model, now used operationally at a nominal 45 km resolution. Covering a limited area, this embedded model must be driven at its lateral boundaries by atmospheric data either from observational reanalyses or from a Global Climate Model (GCM). The hydro-energetic budget, computed over each grid point, provides directly the main components of the hydrologic budget: runoff and evaporation. Results from simulations performed over the recent past are then compared to observations, allowing the validation of the approach. Future climate projections can then be produced by changing the evolution of greenhouse gas concentrations, following various scenarios proposed by the IPCC (e.g., A2). These then allow for an estimation of the future hydrological behaviours with a changing climate. Studies have been performed over 21 basins covering the province of Québec, with drainage areas varying from 13 000 to 177 000 km2. Results obtained are promising and should allow interesting applications in the field of hydro-energetic production, and for water management. Examples presented from analyses performed over a large northern basin (La Grande) and a smaller southern one (Châteauguay) will illustrate this potential.
Hydrologic modelling for climate change impacts analysis of shifts in future hydrologic regimes: implications for stream temperature and salmon habitat
The challenges faced by climate change impact analysts must be solved through interdisciplinary collaboration between research scientists, institutions and stakeholders. In particular, hydrologic modelers, climate scientists, biologists, ecologists, engineers and water resource managers must interact to pool expertise and provide tools to address the complex issues associated with future climate change. The current study examines the results of an application of the VIC macro-scale hydrologic model to predict future changes to soil moisture, snowpack, evapo-transpiration, and streamflow in the Fraser Basin of British Columbia - and then apply these results to stream temperature and fish habitat models to predict future impacts on freshwater ecosystems. The results of this work will be presented to fisheries managers to provide them with the information needed to develop adaptation strategies that will help mitigate the adverse effects of climate change. This presentation will focus on the hydrologic modelling results of a number of downscaled scenarios to examine the projected differences for the 2050s (2041 - 2070) as compared to the historical baseline (1961- 1990). By the 2050s, although the magnitude of change varies by GCM and emissions scenarios, overall precipitation and temperature is projected to increase, particularly in the winter, which leads to increased winter time runoff for many basins. However, this is combined with declines in snow water equivalent (SWE) for many sites, which coupled with lower early season soil moisture, leads to declines in summer runoff and baseflow. SWE increases in some basins under the cgcm3 A1B and echam5 A1B scenarios at high elevations. A similar result was found in this region with the Canadian Regional Climate Model (CRCM) 4, driven with run 4 of the CGCM3 under the A2 emissions scenario. Lack of water availability during the summer time periods appears to limit evaporation, causing declines in summer ET across most sites. Higher peak flows, a shift in the spring melt (earlier) and increased winter runoff are characteristics observed at many of the streamflow sites analysed. These results suggest that while an increase in winter rain events will cause higher peak flows, winter warming generally leads to lower snowpacks and soil moisture stores, leading to a decline in summer water availability in this region. Lessons learned from the applications of modelling data and results across different model frameworks and for different scales will be discussed.