Appendix A: Measuring Ecosystem Goods and Services geodatabase

The Measuring Ecosystem Goods and Services (MEGS) geodatabase includes several publicly available spatial datasets, facilitating access to integrated biophysical data, such as land cover, elevation, climate, as well as socio-economic data, such as land use and income, for the entire country (Table 1, Appendix A).

The 250 m resolution ¹  25 class land cover data produced annually since 2001 by the Canada Centre for Remote Sensing (CCRS) using Moderate Resolution Imaging Spectroradiometer (MODIS) forms the base land cover layer of the MEGS geodatabase.

The advantages of using the CCRS land cover data are:

1. it is a publicly available national dataset
2. it covers the whole Canadian landmass
3. it is produced on an annual basis using consistent parameters allowing for temporal change analysis.

The disadvantages of using CCRS land cover data are:

1. identification of land cover types other than forest cover (e.g., wetlands) is less consistent
2. the 250 m resolution does not provide detailed spatial accuracy for smaller objects or features (e.g., roads and highways).

Several other spatial data sources were integrated and reconciled with the CCRS land cover to develop a consolidated MEGS geodatabase. Added datasets available at the national scale include Natural Resources Canada’s CanVec hydrographic and wetlands geospatial datasets ²  and Statistics Canada’s Road Network (2011) ³  and Settlements spatial dataset, ⁴  which depicts where people are settled. Socio-economic information from the 2006 and 2011 Census of Population and Census of Agriculture were also included. Environment Canada’s 1961 to 1990 climate normals (e.g., temperature and precipitation) by ecodistrict and Agriculture and Agri-Food Canada’s (AAFC) soil component tables (e.g., soil composition, parent material, and slope) at the soil landscape unit were also consolidated.

These datasets were added as geocoded layers on top of the original CCRS dataset. By undertaking a series of overlay analyses using the capabilities of a geographic information system (GIS), information from these datasets was used to complement the original land cover classifications found in the MODIS product where appropriate (Map 1, Appendix A). The additions add relevant information to the CCRS dataset, enhancing its utility for land cover analysis. Other datasets that do not span the entire landmass of Canada but are of value to MEGS were also integrated. For example, it included the AAFC 30 m land cover dataset, which was used in section 3.1 to study land cover change.

Measuring Ecosystem Goods and Services spatial hierarchy

MEGS uses both the ecozone and the drainage area hierarchies as the reporting and accounting framework for the outputs from the geodatabase (see Appendix H Geographies). Ecozones and major drainage areas aggregate data provided at lower levels of geography. Figure 1 (Appendix A) illustrates the various levels of the MEGS spatial hierarchy.

Figure 1: Measuring Ecosystem Goods and Services spatial hierarchy and accounting units

The lowest level of accounting unit in the MEGS geographic hierarchy, the basic statistical unit (BSU), is the smallest spatial unit available for the entire landmass, currently provided by MODIS.

MEGS aggregates the BSU and associated data into land cover ecosystem units (LCEU), which are the statistical proxy of terrestrial ecosystems. ⁵  Although ecosystems cannot be defined purely in spatial terms, combining land cover, elevation and terrain ruggedness data with other datasets provides a reasonable surrogate measure to differentiate between ecosystems.

LCEUs represent common biophysical characteristics, and as such are valuable for studying the impact of human activities on the environment, including socio-economic and environmental analyses.

A digital elevation model was used as an input into the elevation classification and terrain ruggedness index calculation, ⁶  providing data for each individual BSU. Once the elevation and terrain ruggedness index attributes have been added to a BSU, adjacent areas with the same land cover type, elevation and ruggedness are grouped together to form distinct LCEUs. This added layer of information can help further define important land cover characteristics that are otherwise not provided by MODIS.

In Canada, there are 420 distinct types of LCEU, with the most common type being Water, followed by Wetlands and Evergreen forest (Table 2, Appendix A).

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