ClimateChange Assessment Guide.pdf - University of Waterloo

Guide for Assessment of Hydrologic Effects of Climate Change in Ontario16events, water quality, and the ecosystem. In the future,these studies will evaluate adaptation alternatives withconsideration of potential climate change impacts.Box 2.1 Environmental monitoring programs in Ontario and issues associated with climate change• Meteorological Monitoring. Climate data are collected for the most part by the Meteorological Service of Canada(MSC), a branch of Environment Canada, throughout Ontario. The MSC climate network is supplemented by municipal,conservation authority and university-based climate stations. However, these stations are not installed, operatedor maintained to the same standards as the MSC stations. The parameters typically observed at these stations aretemperature and precipitation, and stations with a full range of meteorological observations relevant to hydrology(evaporation, wind speed, relative humidity, solar radiation, etc.) are in short supply. The lack of detailed meteorologicaldata causes most water managers to rely upon temperature-based relationships to estimate significant hydrologicprocesses such as evapotranspiration or snowmelt.• Long time series of climate information are necessary for the identification of climate and hydrologic trends.There is a deteriorating trend in the integrity of the existing observation system; it is critical that there is an adequatenetwork of long-term high quality observation stations in light of issues with respect to a changing climate. Challengesinclude maintaining the current long-term stations and filling gaps in the network.• Water Quantity Monitoring. Water quantity monitoring is undertaken by an Environment Canada, Ministry of NaturalResources and conservation authority partnership. This interagency cost-share agreement constructs, operatesand maintains stream gauges that are of federal and provincial significance. Local conservation authority gaugessupplement the federal/provincial stream gauge network; however, they are not typically operated to the samestandards.Historically, stream gauges have been installed to provide flood warning and flood forecast information; as such,stream gauges have not been installed with the goal of characterizing baseflow conditions. Since baseflow could besignificantly affected by climate change, the stream gauge network may need to be evaluated and expanded. In factmodelling studies in Ontario are often limited in their ability to achieve high quality calibrations due to a shortage ofgauged sites with high quality continuous data streams. To better evaluate changes in baseflow-driven systems, thestream gauge network should include more headwater sites and watercourses which are not typically flood prone.Groundwater levels are also monitored throughout the Province in a partnership between the MOE and conservationauthorities. The Provincial Groundwater Monitoring Network, started in 2001, now has over 400 wells which monitorambient groundwater level and water quality information from key aquifers. This monitoring network is continuing to beexpanded, and despite its short record, will be in a good position to observe possible changes in groundwater levelsas a result of climate change. The system integrity must be maintained so that long-term records, necessary for theinvestigation of climate-related trends, will be available.• Water Quality Monitoring. Water quality monitoring is the responsibility of the MOE, through the Provincial WaterQuality Monitoring Network (PWQMN). This monitoring program consists of eight grab samples conducted at varioustimes throughout the year at specific locations. Each sample is analyzed for a comprehensive list of water qualityparameters. This program is capable of providing a reasonable characterization of water quality under prevailing intereventdry weather conditions.Some impacts of climate change on water quality may be transient in nature, occurring during extreme events (i.e.,storms, drought or heat wave). Water quality during these critical time periods is not characterized with the PWQMN.This could be accomplished with strategic sampling that collects flow weighted or time intensive samples duringselected storms or droughts specifically so that these events may be characterized.In addition to the consideration of climate change whendesigning new SWM facilities, the ability of current SWMcontrols to cope with climate change impacts shouldbe investigated. Anticipated future precipitation events,with both higher volume and intensity, will (unlesseffectively mitigated) translate into higher peak flows.These higher peak flows increase the probability ofexceeding conveyance and treatment system capacitywhich could result in reduced effectiveness or completefailure.