Karst Risk Map of Nova Scotia

DP ME 494, Version 1, 2019, Digital Version of Karst Risk Map of Nova Scotia, by J. Drage and J.S. McKinnon.


Location Map


Format and Projection


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Related Products

Information about Sinkholes

View Basic Interactive Karst Risk Map
(Link to User Guide)

View Advanced Interactive Karst Risk Map (AGOL)

Open File Report ME 2019-001


This dataset was developed to show areas of Nova Scotia where there is a relative high-medium-low risk of encountering karst and naturally occurring sinkholes caused by soluble bedrock. Karst refers to the distinctive terrain that develops over soluble bedrock and includes features such as sinkholes, caves, and springs. Sinkhole development in karst terrain can cause extensive damage to buildings, roads, and other infrastructure. The primary geohazard in karst areas is the sudden catastrophic subsidence of the ground. This may occur due to the collapse of cavities in bedrock that have been created by the dissolution of soluble evaporite rocks (e.g. gypsum, anhydrite, salt) or carbonate rocks (e.g. limestone, dolostone). It may also occur when soil is washed into openings in underlying soluble bedrock, which creates a void in the soil that migrates upwards by progressive collapse. Sinkholes can be a serious geohazard in some areas of the province and, therefore, caution should be exercised in potential karst areas when constructing buildings, roads, or other infrastructure.

This dataset was prepared using provincial geology maps, sinkhole occurrence data, lidar data and hydrogeological databases. The sinkhole occurrence data was obtained from geology maps, lidar, municipalities and consultants. The resulting database contains 1057 records of known locations with sinkholes, karst topography, and karst springs. The risk zones are based on several factors, including geology, sinkhole locations and professional judgment. The high-risk zone contains 96% of the sinkholes in the Nova Scotia Sinkhole Database and has densities of greater than 1 sinkhole per 100 km2. This zone includes the Windsor Group, a 500 m buffer zone around the Windsor Group which contains abundant sinkholes, and the George River Metamorphic Suite. The medium-risk zone contains 3.9% of the sinkholes in the Nova Scotia Sinkhole Database and has densities between 0.1 and 1 sinkholes per 100 km2. This zone includes the Horton and Mabou Groups. The low-risk zone contains less than 0.1% of the sinkholes in the Nova Scotia Sinkhole Database. This zone typically does not contain sinkholes or karst topography. However, sinkholes may still occur in this area due to unmapped soluble rocks (i.e. evaporites or carbonates) or where soluble rocks are close to the ground surface but overlain by other rock types or unconsolidated material.



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The entire risk as to the quality and accuracy of the DATA is with the USER and the USER shall use his/her own judgment in making use of the DATA or drawing conclusions based upon it.

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Format and Projection

Format ESRI shape files (SHP) and ArcGIS File Geodatabase (GDB) files compressed in a ZIP file (more information on data formats)

SHP and GDB - 114 MB (compressed), 287 MB (uncompressed)

Projection The data is in six-degree Universal Transverse Mercator (UTM) projection, Zone 20, Central Meridian 63° 00' West using the North American Datum of 1983 (NAD83).

Downloading Instructions

The data files have been compressed using IZArc into a single ZIP file.

  1. Read the Licence before accepting the data.
  2. Download the ZIP file to the desired location on your computer hard drive.
  3. Unzip and extract the data onto your computer. We STRONGLY recommend you unzip our data to a consistent area on your hard drive (e.g. C:\nsDNR\).

All data sets are in six-degree Universal Transverse Mercator (UTM) Zone 20 projection using the NAD83 datum.

A readme file and a copy of the licence agreement are also included with each data set.

Download Digital Data Set DP ME 494