Overview of Groundwater in Canada: Perspective of Data & Information

Transcription

1 Overview of Groundwater in : Perspective of Data & Information Alfonso Rivera Geological Survey of Arid/Semi-Arid Groundwater Governance & Management Workshop 3-8 April, 2005, Cairo Egypt

2 OUTLINE Introduction Groundwater in How Information is delivered Institutional Capacity Quality of Data Emerging IM/IT Issues

3 Introduction and Background The groundwater resources at the scale of -- quantity, location, use, quality-- are virtually unknown Close to 10 M people rely on groundwater 85% of rural population rely on GW Domestic, 43% Industry, 14% Agriculture, 43%

4 Groundwater Resources Trends & Use

5 Groundwater Trends & Use 1998). Industry Agriculture Domestic Total Surface Water 71% 11% 17% 44.1 km 3 Groundwater 14% 43% 43% 1.0 km 3 Total 70% 12% 18% 45.1 km 3

6 Groundwater Trends & Use Too early to frame a Canadian portrait of GW resources at national scale Regional-scale trends indicate predevelopment conditions most everywhere Regional aquifers are exploited at shallow depths No evidence of GW overdraft Current knowledge gaps Geological frameworks (lack of Quaternary maps and buried valleys) SW/GW interactions GW use (supply) Sustainability and vulnerability of regional aquifers

7 Groundwater Management Resource Mgmt Provincial Federal Research Provincial & Federal

8 General Approach for Groundwater Management 1998). Divide authority between federal and provincial levels of government Jurisdiction over water may be conferred as the result of proprietary rights, as opposed to legislative authority Because of the overlap of authority, water management in depends on cooperation between the two levels of government

9 Water Laws and Regulations 1998). GW management based in water laws and regulations, when existing. Otherwise is based on prior apportionment (practice in western Provinces); or On the riparian doctrine of common law (eastern Provinces). No consistent or uniform approach for GW management, there has been no need most water supply used to come from surface water sources. This has changed in the last decade.

10 Problems associated with Groundwater Management 1998). Lack of groundwater information and data; Lack of groundwater use data; Lack of regulations; Lack of management strategies; Lack of water laws; Use of old principles of apportionment; and Lack of knowledge of the groundwater needs for ecosystems and base flow in rivers.

11 Groundwater Management 1998). The lack of due attention to groundwater in has now been recognized more widely. Reasons for this are: increase public awareness; droughts; point and non-point pollution; decrease in surface water quality; water conflicts; inter-jurisdictional water issues; climate changes; and international commitments (i.e., Great Lakes, transboundary aquifers).

12 How Information is delivered Considerable amount of GW data & information exists in municipalities, provincial and federal agencies, universities and private sector Most are not readily available or are not commonly known to exist A new national initiative (2003): - Goal is to establish new, or link existing databases and compilation of GW knowledge to ensure easy access through the web

13 How Information is delivered Main steps in the process : - Construct an archive of existing GW databases - Identify relevant information systems - Construct an archive of existing GW knowledge - Upgrade or transfer databases to new platforms as required - Facilitate the move to Internet access for databases and information - Establish links for GIS and computermodelling applications

14 National Groundwater Database External dataset Envirodat NGWD There is a relevant paper on water contamination here Provincial Database CCRS Recharge Database I know I can get water quality data for the Atlantic from this place, using this service INTERNET Catalog of Resource and services ESS GW Ess dataset INTERNET NGWD does not store copies of data, but keeps tracks of where Natural Resources Ressources naturelles they are and how to access them.

15 External dataset National Groundwater Database WMS NGWD WMS WMS Catalog of Resource and services INTERNET ESS GW Ess dataset INTERNET Web Map Service CGDI-OGC Standard protocol to extract map pictures

16 External dataset National Groundwater Database WFS NGWD WFS Catalog of Resource and services It can also provide actual data for specific applications INTERNET WFS ESS GW Ess dataset INTERNET supply deman d Web Feature Service Natural Resources Ressources naturelles CGDI-OGC Standard protocol to extract features (actual data)

17 QUALITY OF THE DATA Error characterization and propagation Effet d échelle dans les processus d interpolation Le rayon d influence est à l origine du degré d hétérogénéité mis en évidence. Obtention des données par des essais dont l impact est significatif à: - quelques mètres ou - 100m ou - quelques km (varie avec le type d essai) Valeurs de conductivité hydraulique Choix de l essai: Essai de pompage Slug test Hydrogeological models are used to evaluate aquifer Vulnerability and sustainability, commonly developed in combination with GIS GIS allows to precisely superpose all relevant data and solves problems due to the treatment of data: e.g., integration of data at different scales and from different sources However, new problems may appear when using GIS such as the smoothing of data when point data are used for interpolation Modélisable par un milieu équivalent poreux à une échelle régionale Every treatment of data is a source of error which in turn adds to the already existing errors (i.e., measurements errors) The accumulation of the ensemble of those errors produces an uncertainty in the final product (map)

18 QUALITY OF THE DATA Error characterization and propagation FOUR main sources of possible errors in the process of GIS data manipulation are identified : Conceptual Errors Errors of measurement Storage support errors Data processing errors

19 Aquifer classification types according to 6 different specialists A Geologist B Geologist C Hydrogeologist D Hydrogeologist E Geologist F Geologist

20 QUALITY OF THE DATA Uncertainty assessment in GIS-based implementation indicate that the main sources of errors occur during data acquisition, data transfer, as well as in the data handling process The knowledge of the errors allows for better gathering, treatment and control of the data Uncertainty depended on the number of parameters involved in a model Thus, the higher the number of parameters, the lower the uncertainty, but the higher the error!

21 QUALITY OF THE DATA A systematic analysis of the errors during regionalscale projects would make hydrogeological characterization more efficient Errors should be minimized mainly at the level of data acquisition (field work and testing), but also in the treatment of the data Using GIS, even if it allows better management, storing and analysis tools, it creates new sources of uncertainty There is a clear process in place for controlling and ensuring the quality of data and information provided

22 Emerging IM/IT Issues Remote Sensing (i.e., Thermal high-resolution imagery) Radar imagery ET-recharge linked to monitoring systems Interactive databases, OGCstandards, linked to numerical models Data Integration from Oil surveys

23 Summary 1998). Regional-scale trends indicate pre-development conditions most everywhere in No evidence of GW overdraft Current knowledge gaps: - Geological frameworks (lack of Quaternary maps and buried valleys) - SW/GW interactions - GW use (supply) - Sustainability and vulnerability of regional aquifers Data and information for decision-making is the backbone of any GW management approach

24 Conclusions and Recommendations Overall, -wide vision and leadership wrt GW is in the making Increase cooperation amongst all levels of governments through a National Groundwater Council Fill in knowledge gaps of the resource Towards standardized data and Information with easily accessible databases through the web