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We have found 377 datasets for the keyword " snow areal extent". You can continue exploring the search results in the list below.
Datasets: 103,401
Contributors: 42
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377 Datasets, Page 1 of 38
Areal Extent of Wetlands
The data represents the density of wetland habitat in the agricultural region of Alberta in 2002. Wetlands are depressional areas that are wet for a long enough period that the plant and animals living in them are adapted to, and often dependent on, living in wet conditions for at least part of their life cycle. In drier areas of the province, wetlands tend to be more intermittent, while in wetter areas, wetlands tend to be more persistent. Topography also affects the occurrence of wetlands. Hummocky landscapes allow for pooling of water in depressions, while landscapes with longer slopes (e.g. the foothills) generally have better defined surface drainage patterns. A wetland in influenced by the interaction between the wet area, the wetland margin and upland area.Wetlands provide important habitat for waterfowl and many other types of wildlife. Wetlands reduce the impact of flooding, provide erosion control, purify water by removing sediment and nutrients, and contribute to groundwater recharge. This resource was created using ArcGIS.
Probability of the annual minimum snow and ice (MSI) presence over Canada
Snow and ice are important hydrological resources. Their minimum spatial extent here referred to as annual minimum snow/ice (MSI) cover, plays a very important role as an indicator of long-term changes and baseline capacity for surface water storage. The MSI probability is derived from sequence of seventeen 10-day clear-sky composites corresponding to April, 1 to September, 20 warm period for each year since 2000. Data from Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra satellite for the period since 2000 have been processed with the special technology developed at the Canada Centre for Remote Sensing (CCRS) as described in Trishchenko, 2016; Trishchenko et al., 2016; 2009, 2006, Trishchenko and Ungureanu, 2021, Khlopenkov and Trishchenko, 2008, Luo et al., 2008. The presence of snow or ice is determined for each pixel of the image based on snow/ice scene identification procedure and the probability if computed for the entire warm season as a ratio of number of snow/ice flags to the total number of pixels available (less or equal to 17). The minimum snow and ice extent can be derived from the probability map by applying a certain threshold. New data version V5.0 replaces previous version V4.0 for all data available since 2000. All MSI files were reprocessed for all MODIS input data based on collection 6.1. The output format has not changed since previous version. It is described in Trishchenko (2024). The impact of input data change is small and can be detected only for time interval 2000-2015. Data starting 2016 has been already derived using MODIS collection 6.1 input.The differences between the MSI data based on MODIS Collection 5 (i.e. MSI V4) versus MODIS Collection 6.1 (i.e. MSI V5), on average, are quite small. The region-wide relative difference in the MSI extent varies from -3.97% to +1.75%. The mean value is -0.14%, the median value is 0.18% and standard deviation is 1.83%. As such, we do not expect any sizeable impact of the version change on our previous conclusions regarding trends and climate variations, except for refining the relative values of statistical parameters within the range of a few percents. References:TRISHCHENKO, A.P., 2024: Probability maps of the annual minimum snow and ice (MSI) presence over April,1 to September, 20 period since 2000 derived from MODIS 250m imagery over Canada and neighbouring regions. Data format description. CCRS, NRCan. 4pp.
Distribution of the Lacombe Aquitard (GIS data, polygon features)
This GIS dataset illustrates the areal extent (surface and subsurface) of the Lacombe aquitard. It is in ESRI shapefile format.
Distribution of the Haynes Aquifer, Alberta (GIS data, polygon features)
This is a polygon dataset illustrating the areal extent (surface and subsurface) of the Haynes aquifer. It is in ESRI shapefile format.
Distribution of the Sunchild Aquifer, Alberta (GIS data, polygon features)
This GIS dataset illustrates the areal extent (surface and subsurface) of the Sunchild aquifer. It is in ESRI shapefile format.
Annual 30 m snow dynamics (2018-2019 to 2023-2024) – Canada
This catalog contains annual 30 m spatial resolution snow dynamics metrics for each snow-year from 2018-2019 to 2023-2024 for all of Canada. We gather all Landsat and Sentinel-2 images collected over Canada and identify the status of each pixel observation on the image collection date: snow (and ice), non-snow (i.e., land, water), unclear (i.e., clouds, shadows). We built an algorithm to calculate snow cover metrics for each pixel during each winter: start date of the first (and biggest) snow period [startF, startB], end date of the last (and biggest) snow period [endL, endB], number of days with snow cover in total (or in the biggest snow period) [lengthT, lengthB], number of snow periods (i.e., separated times with multiple confirmed snow observations) [periods], and a status classification (e.g., continuous snow, snow free) [status]. We do not obtain a clear observation every day because of satellite orbit frequencies and clouds. This means that timing-based metrics are identified by the middle date between two clear observations, with uncertainty quantified as half the length of the gap (i.e., ± days) [startF_u, startB_u, endL_u, endB_u, lengthT_u, lengthB_u].
Solonetzic Soils
This map displays the distribution of Solonetzic soils in the agricultural region of Alberta. Solonetzic soils have developed on saline parent material that is high in sodium and have a characteristic hardpan layer that has formed in the subsoil. This hardpan is very hard when dry and has low permeability when wet. This results in restricted root and water penetration that may limit the productivity of these soils. Solonetzic soils occur in association with Chernozemic soils and, to a lesser extent, with Luvisolic soils.The Agricultural Region of Alberta Soil Inventory Database (AGRASID) soil landscape polygons that contained soils belonging to the Solonetzic Order were identified, and the areal extent of these soils was represented as a percentage of the total area using the following classes: greater than 30, 10 to 30 and less than 10. This resource was created in 2002 using ArcGIS.
Daily snow cover fraction maps over Canada of the period of 2006-2010 from 1km resolution NOAA AVHRR imagery
This dataset corresponds to daily snow cover percentage at 1km resolution grid over land areas of Canada from 2006-2010. The data are subsampled by 4km to reduce data volumes and considering the geolocation uncertainty of the input satellite imagery. The daily maps are generated by assimilation of daily cloud screened NOAA AVHRR satellite imagery and Canadian Meteorological Centre (CMC) snow depth analysis snow depth and density fields within an off-line version of the CMC daily snow depth model. The snow depth model is modified to include snowpack reflectance model and a surface radiative transfer scheme that relates vegetation and snowpack reflectance to top-of-canopy bi-directional reflectance. A logistic vegetation phenology model is used to parameterize temporal dynamics of canopy leaf area index. A per-pixel particle filter with a 30 day moving window is applied to assimilation observations corresponding to 1km resolution visible band directional reflectance and normalized difference vegetation index and 24km CMC daily snow depth and monthly snow density fields. The assimilation is forced using daily air temperature and precipitation fields. Validation of the datasets has been performed by comparison to MODIS snow cover maps and in-situ snow depth stations across Canada. Validation suggests similar accuracy to MODIS snow cover products over relatively flat terrain. Validation over mountainous regions is ongoing.
Manual Snow Survey Site Locations
Manual snow survey (active & inactive) locations as part of the BC Snow Survey program.
North American Radar Composite (1 km)
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.
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