The Adjusted Precipitation data consist of monthly, seasonal and annual totals of daily adjusted rain, snow and total precipitation (millimetres) for 464 locations in Canada. Adjusted precipitation data incorporate adjustments (derived from comparison of instruments) to the original station data to account for discontinuities from non-climatic factors, such as instrument changes or station relocation. The time periods of the data vary by location, with the oldest data available from the early 1880s at some stations to the most recent update in 2017. Observations at co-located sites were sometimes joined in order to create longer time series. Data availability over most of the Canadian Arctic is restricted to the mid-1940s to present.

This polygon layer depicts sub-basin average observed precipitation from the High Resolution Deterministic Precipitation Analysis (HRDPA). Offers insight into how much rain/snow actually fell across each watershed in the past observation period. Observation periods we are interested are for past 1 day, 3 days and 7 days.HRDPA is ECCC’s high-resolution precipitation analysis, merging gauge, radar, and HRDPS model data. This layer aggregates the final (or preliminary) HRDPA accumulations to sub-basin polygons. Each record indicates the average precipitation that truly occurred over each watershed, vital for verifying model forecasts, calibrating hydrological models, and conducting post-event analyses of flood or drought severity.

This mosaic is calculated over the North American domain with a horizontal spatial resolution of 1 km. This mosaic therefore includes all the Canadian and American radars available in the network and which can reach a maximum of 180 contributing radars. To better represent precipitation over the different seasons, this mosaic renders in mm/h to represent rain and in cm/h to represent snow. For the two precipitation types (rain and snow), we use two different mathematical relationships to convert the reflectivity by rainfall rates (mm/h rain cm/h for snow). This is a hybrid mosaic from DPQPE (Dual-Pol Quantitative Precipitation Estimation) for S-Band radars. For the US Nexrad radars, ECCC uses the most similar product from the US Meteorological Service (NOAA). This product displays radar reflectivity converted into precipitation rates, using the same formulas as the Canadian radars.

The Acidic Precipitation in Ontario Study (A.P.I.O.S.) was established in 1979 by the Ontario Ministry of the Environment to protect the environment from the detrimental effects of acidic deposition and determine the effects of acidic deposition on terrestrial ecosystems. The effect of acid inputs on the environment depends on the quantity and acidity of atmospheric inputs, and the buffering capacity of the terrestrial and aquatic ecosystems. The effect of acidic precipitation on soil is potentially significant because the soil is the reservoir of plant nutrients and the source of much of the water for aquatic systems. Changes in the soil's chemistry may therefore be reflected in both the terrestrial and aquatic environments. Information on the effects of acidic precipitation on soils is available from effects near point sources of pollution, from experimentation with simulated rain solutions, from natural changes observed in soil over time, and from models and soil forming theories. Anticipated effects of soil acidification include: reduced pH, leaching of basic cations (such as magnesium and calcium) and other exchangeable plant nutrients, reduction in base saturation and cation-exchange capacity, mobilization of soil-bound metals such as aluminum, and changes in biological activity such as decreased nitrification and soil respiration. The principal objective of the baseline program is to establish a uniform data base for soils across the province. This data base * provides current data to identify future trends, * enables the development of laboratory experiments which define soil sensitivity criteria to acidic precipitation, and * provides information required for sensitivity mapping of soils throughout Ontario.

This polygon layer shows sub-basin averages of HRDPS (High Resolution Deterministic Prediction System) precipitation. Ideal for capturing short-range (0–48h) high-resolution precipitation forecasts aggregated at the watershed scale.The HRDPS is a 2.5 km resolution model used for short-range, convection-permitting forecasts in Canada. This layer takes HRDPS precipitation totals and aggregates them by each sub-basin polygon, revealing how localized rain or snow could impact individual watersheds. Useful for near-term flood or flash-flood risk, as well as local water management during intense weather.

The Turkey Lakes Watershed Study (TLWS) was established in 1979 and is one of the longest running ecosystem studies in Canada. It is 10.5 km2 and is located approximately 60 km north of Sault Ste. Marie, Ontario at the northern margin of the Great Lakes – St. Lawrence forest region. Researchers from Natural Resources Canada, Environment Canada and Fisheries and Oceans Canada established the research watershed to evaluate the impacts of acid rain on terrestrial and aquatic ecosystems. Since its inception, the study has taken a multi-disciplinary approach to investigating the processes that govern ecosystem responses to natural and anthropogenic perturbations.The goal of the TLWS is to obtain a whole-ecosystem analysis of the biogeochemical processes operating at the site. This permits system models to be developed and validated. The holistic approach that has been adopted from the outset allows research to evolve and expand from its original acidification focus to include evaluations of other environmental issues.Partnerships and collaboration are part of the founding principles behind the TLWS to improve our ability to measure, model and predict effects of human activity on ecosystem function. Over time, research and monitoring have expanded to explore the effects of forest harvesting, climate change, aquatic habitat manipulations and toxic contaminants. Advancements of our scientific knowledge of forest ecosystems and a baseline of long-term environmental data enables study results to inform Canadian governments on environmental policy and forest management legislation.Hydrological, meteorological, and vegetation data collected by scientists at the Great Lakes Forestry Centre is included in this directory. Experimental sites and scientific investigations in the TLW are summarized in the compendium document. Visit our website at:

Data on flood zones include mapping carried out as part of the mapping program of the Canada-Quebec Convention from 1976 to 2001, the Program for the determination of flood ratings from 2001 to 2004 (PDCC), as well as the mapping carried out after that date by the Centre d'expertise du Québec (CEH) and its various partners.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

Acid-Sensitive LakesNine hundred and thirty-three lakes located in Saskatchewan, Alberta and the Northwest Territories were sampled to establish current acidification status. Of the 933 lakes, 244 (or 26%) are considered acid sensitive, almost always because of naturally low calcium and magnesium (or "base cation") concentrations. The most acid-sensitive lakes (i.e., those with extremely low base cation concentrations) are located on the Canadian Shield in both Alberta and Saskatchewan and east of the oils sands development area.Fifty-one of the 244 acid-sensitive lakes were sampled twice annually (spring and fall) to identify chemical changes through trend analyses. Results revealed that 55% of these lakes had concentrations of some metals in excess of Canadian Council of Ministers of the Environment guidelines. Of the 291 samples taken in the 51 lakes, iron concentrations were greater than guidelines in 36% (105 samples), aluminum in 33% (97 samples), lead in 0.3% (1 sample) and copper in 0.3% (1 sample). The metals in these lakes occur naturally and are expected to be found in a wide range of concentrations given the geology and physiography of the Canadian Shield. It remains to establish the relationship between acid sensitivity, geology and high metal concentrations.

This product shows the rain accumulation, in mm, over the last 24 hour period based on DPQPE. This product is available every 6 minutes.

In 2018, Fisheries and Oceans Canada initiated the Multidisciplinary Arctic Program (MAP) – Last Ice, the first ecosystem study of the poorly characterized region of Tuvaijuittuq, where multiyear ice still resides in the Arctic Ocean. The program MAP-Last Ice takes a coordinated approach to integrate the physical, biochemical, and ecological components of the sea ice-ocean connected ecosystem and its response to climate and ocean forcings. This program provides baseline ecological knowledge for Tuvaijuittuq and, in particular, for its unique multiyear ice ecosystem. The database provides baseline data on fatty acid composition and stable isotopes signatures of sea ice communities in multi- and first-year ice in Tuvaijuittuq. The data were collected during the 2018 spring field campaign of the MAP-Last Ice Program, offshore of Canadian Forces Station (CFS) Alert, in the Lincoln Sea.