Making sense of files in ArcMap

Overview

The purpose of this project is to determine whether or not linear density (LD) and surface disturbance (SD) are the best metrics for assessing ecological integrity, more specificaly landscape fragmentation, for the North Yukon Land Use Scenarios Report. Footprint data has been collected to measure the degree of fragmentation using three different scenarios: oil and gas, tourism, and mining. Our project doesn't specifically deal with these scenarios, and I will therefore abstain from going into specific detail. Rather, this project will introduce a third measure, the Effective Mesh Size (or Density), that will offer a more elaborate assessment of the degree of landscape fragmentation.

Using ArcMap

The data provided to us by the North Yukon Planning Commission was analysed using ESRI's ArcGIS software. Quite a bit of time was spent making sense of the multiple layers and upon review the following layers are deemed essential for the project:

yt_planning_regions_250k
This layer outlines the administrative divisions of the entire Yukon Territory, as shown in the image below.



nypr_lmu_mar08
This layer outlines the landscape management units (LMU) specific to the North Yukon administrative region. ''LMUs are distinct areas of land that have similar ecological properties (landform and vegetation) or were previously delineated (e.g. Old Crow Flats SMA). The borders of the units are usually drawn around rivers, roads, existing SMAs or identifiable features. LMUs are intended to form the spatial framework for cumulative effects monitoring'' (Metadata NYLMU, 2008). There are 13 different LMUs in the given region, as shown in the image below.



nypr_linear_features_50k

This layer shows linear features present in the North Yukon region. Linear features include: access roads (AR), main roads (MR), national roads (roads), seismic lines (SL), traplines (TR) and winter roads (WR). The distinction between access roads, main roads and national roads still needs to be adressed. Layers have been created for each of these features in order to manipulate them individually. The image below shows these linear features along with the previous layers.



ny_footprint
This layer is very similar to the previous layer, only that features appear to be polygons rather than polylines. Even when changing the colour of these features, they still appear as grey. It is still unclear whether or not this layer will be useful in measuring the effective mesh size (or density), but I believe it is still worthy of our attention.

NY_LT_2005 & NY_LTRC_2005
This layers is a raster biophysical map for the NY. ''Landscape types were classified and mapped through the NY Biophysical Mapping Project using a predictive modeling approach. The NY biophysical map currently contains 18 district landscape types and 10 seral types for a total of 28 biophysical units" (NYLTRC metadata, 2005). For the purpose of setting criteria for the fragmentation geometries (FG), I wanted to create a layer for all water bodies. Unfortunately, I wasn't able to do so, which is something I'll have to look into.

The next step will be to:

• Describe in detail what are the advantages of using meff when measuring landscape fragmentation in the context of cumulative impact assessment;
• Measure meff for each landscape management unit (LMU) and sub-unit (SU), giving special interest to the Eagle Plain region;
• Come up with 2-3 fragmentation geographies. Based on their scenario building models, I suggest the following FG's:
• Seismic lines: linear feature that has the potential to be re-vegetated through natural processes over time;
• Winter access roads: although not as significant as seismic lines, this FG could measure the difference between summer and winter seasons;
• Although negligible, natural features (lakes, rivers, etc.) could act as barriers. Mountains will not be included in this FG since the maximum elevation in the NY region is 1800 metres.