L'Outil de surveillance des sécheresses au Canada (OSSC) est un produit composite élaboré à partir d'une vaste gamme de renseignements, comme l'indice de végétation par différence normalisée (IVDN), les valeurs de débit d'eau, l'indice Palmer de gravité de la sécheresse et les indices de sécheresse utilisés par les secteurs de l'agriculture, des forêts et de la gestion de l'eau. Les régions susceptibles d'être touchées par la sécheresse sont analysées en fonction des cartes sur les précipitations, la température, l'indice de modélisation des sécheresses ainsi que les données climatiques, et les résultats sont interprétés par des scientifiques fédéraux, provinciaux et universitaires. Une fois par mois, habituellement avant le 10 du mois courant, le Service national d'information sur l'agroclimat (SNIA) d'AAC met à jour la série de données avec celles correspondant à la fin du mois précédent; il verse ensuite ces données dans la grande base de surveillance des sécheresses de l'Amérique du Nord (NA-DM, North American Drought Monitor). Les zones de sécheresse sont classées comme suit : D0 (sécheresse anormale) - représente une situation qui survient une fois tous les trois à cinq ans. D1 (sécheresse modérée) - représente une situation qui survient tous les cinq à dix ans D2 (sécheresse grave) - représente une situation qui survient tous les 10 à 20 ans D3 (sécheresse extrême) - représente une situation qui survient tous les 20 à 25 ans D4 (sécheresse exceptionnelle) - représente une situation qui survient tous les 50 ans. Pour plus d'information, consulter : http://ouvert.canada.ca/data/fr/dataset/292646cd-619f-4200-afb1-8b2c52f984a2

Drought is a deficiency in precipitation over an extended period, usually a season or more, resulting in a water shortage that has adverse impacts on vegetation, animals and/or people. The Climate Moisture Index (CMI) was calculated as the difference between annual precipitation and potential evapotranspiration (PET) – the potential loss of water vapour from a landscape covered by vegetation. Positive CMI values indicate wet or moist conditions and show that precipitation is sufficient to sustain a closed-canopy forest. Negative CMI values indicate dry conditions that, at best, can support discontinuous parkland-type forests. The CMI is well suited to evaluating moisture conditions in dry regions such as the Prairie Provinces and has been used for other ecological studies. Mean annual potential evapotranspiration (PET) was estimated for 30-year periods using the modified Penman-Monteith formulation of Hogg (1997), based on monthly 10-km gridded temperature data. Data shown on maps are 30-year averages. Historical values of CMI (1981-2010) were created by averaging annual CMI calculated from interpolated monthly temperature and precipitation data produced from climate station records. Future values of CMI were projected from downscaled monthly values of temperature and precipitation simulated using the Canadian Earth System Model version 2 (CanESM2) for two different Representative Concentration Pathways (RCP). RCPs are different greenhouse gas concentration trajectories adopted by the Intergovernmental Panel on Climate Change (IPCC) for its fifth Assessment Report. RCP 2.6 (referred to as rapid emissions reductions) assumes that greenhouse gas concentrations peak between 2010-2020, with emissions declining thereafter. In the RCP 8.5 scenario (referred to as continued emissions increases) greenhouse gas concentrations continue to rise throughout the 21st century. Provided layer: projected mean annual Climate Moisture Index across Canada for the long-term (2071-2100) under the RCP 2.6 (rapid emissions reductions). Reference: Hogg, E.H. 1997. Temporal scaling of moisture and the forest-grassland boundary in western Canada. Agricultural and Forest Meteorology 84,115–122.

Drought is a deficiency in precipitation over an extended period, usually a season or more, resulting in a water shortage that has adverse impacts on vegetation, animals and/or people. The Climate Moisture Index (CMI) was calculated as the difference between annual precipitation and potential evapotranspiration (PET) – the potential loss of water vapour from a landscape covered by vegetation. Positive CMI values indicate wet or moist conditions and show that precipitation is sufficient to sustain a closed-canopy forest. Negative CMI values indicate dry conditions that, at best, can support discontinuous parkland-type forests. The CMI is well suited to evaluating moisture conditions in dry regions such as the Prairie Provinces and has been used for other ecological studies. Mean annual potential evapotranspiration (PET) was estimated for 30-year periods using the modified Penman-Monteith formulation of Hogg (1997), based on monthly 10-km gridded temperature data. Data shown on maps are 30-year averages. Historical values of CMI (1981-2010) were created by averaging annual CMI calculated from interpolated monthly temperature and precipitation data produced from climate station records. Future values of CMI were projected from downscaled monthly values of temperature and precipitation simulated using the Canadian Earth System Model version 2 (CanESM2) for multiple RCP radiative forcing scenarios. Provided layer: Climate moisture index (CMI) - Future projections using RCP 8.5 for 2011-2040. Reference: Hogg, E.H. 1997. Temporal scaling of moisture and the forest-grassland boundary in western Canada. Agricultural and Forest Meteorology 84,115–122.

This data contains information on active precipitation gauges in Ontario. These precipitation gauges: * measure how much rainfall/precipitation falls on the ground (mm) * are peripherals to hydrometric monitoring stations within the Ontario Hydrometric Network Rainfall and snowmelt are primary causes of flooding in Ontario. The lack of precipitation often causes low water and drought conditions. Data from the gauges is collected and maintained by the Surface Water Monitoring Centre (SWMC). The data supports SWMC and partner organization such as conservation authorities, on the local and provincial scale, with: * flood forecasting and warning * drought monitoring The SWMC transfers precipitation data to Environment and Climate Change Canada (ECCC). This happens through an automated process integrated into the SWMC corporate water and climate database. ECCC publishes and maintains a variety of datasets on their Meteorological Services of Canada Datamart, a publicly accessible source for meteorological and hydrological data. This data source has 24/7 operational service and provides support on a best effort basis during normal business hours.

Point locations of water and weather monitoring stations used by the [Surface Water Monitoring Centre](http://www.ontario.ca/page/surface-water-monitoring-centre) to assess flood and drought conditions across Ontario. Monitoring station types include: * streamflow gauge stations * Environment and Climate Change Canada climate stations * Ministry of Transportation road weather stations * Ministry of Natural Resources and Forestry (MNRF) fire weather stations * MNRF snow network stations (wildlife) * MNRF snow survey stations (weather) * Ontario Power Generation snow survey stations (weather)