Winter, 2017

Aspect


Download full size (A1 (23.4 x 33.1"), 17.6 MB, PDF)

This map was created to visualize surface aspect data using a TIN (triangular area network) model. 

Each polygon in the map to the left represents a facet of the land’s surface morphology and has been colour-coded to indicate cardinal and ordinal directions, allowing us to visually interpret slope direction in the terrain of our study area.

To create these features, relevant Nova Scotia Topographic Database vector layers were clipped and merged. Queries, manual edits, and feature data type conversions were performed on feature attributes and geometry to amend inconsistencies or missing information. A triangular area network (TIN) could then be computed using the Z-values inherent in these datasets. Finally, the TIN was converted to polygons and symbolized in accordance with cartographic standards.




Slope


Download full size (A1 (23.4 x 33.1"), 18.2 MB, PDF)



Slope is visualized in this map using discrete polygon features to symbolize areas of a given slope range.

To create these features, we first merged and clipped the relevant Nova Scotia Topographic Database datasets, then performed queries and manual edits on feature attributes and geometry to account for any inconsistencies or missing information. Some conversion between feature class geometry types was also required in order to preserve data integrity. After this preparation, we generated a TIN (triangular area network) using the elevation values present within our point, line, and digital elevation model data. Further geoprocessing operations were then performed on the TIN to generate triangle faces in polygon form.

A custom graduated colour ramp was created to symbolize the finished product.




Erodibility


Download full size (A1 (23.4 x 33.1"), 15.1 MB, PDF)

This map uses soils survey data combined with a TIN (triangular irregular network) created of the study area to produce a map expressing susceptibility to erosion. Python string manipulation was used to extract descriptive soil classification names from the attribute data. This was used for labeling. Some additional string manipulation was also used to amend typographical inconsistencies within attribute values. Join, dissolve, and union geoprocessing operations were executed to simplify and refine the data.



Two new defining attributes were created using a series of Select by Attributes queries: slope percent and soil texture, which were expressed as weighted integer values. These values were used to calculate a new erodibility category. An attribute domain was assigned to this field to maintain data integrity by applying a constraint of three possible attribute values: low, medium, and high and a legend in the form of a colour-coded matrix was created to express these.




Cadastral


Download full size (A1 (23.4 x 33.1"), 3.08 MB, PDF)

This map layer is the result of analysis performed on cadastral data supplied by the Nova Scotia Geomatics Centre containing property boundary shapefiles and associated tabular data.

Joins were used to relate data with one-to-one cardinalities where necessary. To access a given property's value for multiple years (a one-to-many relationship) a relate was used. Ultimately, a final output table of appropriately merged information containing only the records relevant to our analysis was created. To achieve this, selection, querying, merging, summarizing, and exporting of the table data was necessary.

Percent difference value between the two years of interest was computed using a formula in the ArcGIS Field Calculator. These values symbolized using graduated colours, and given meaningful labels, allowing readers to interpret changing property values in the area.




Back