Introduction to Unit 4: DEMs for Environmental Management
This unit looks at how Digital Elevation Models (DEMs) can be used in practice to manage environmental resources. A DEM is a digital representation of the Earth’s surface in terms of elevation values. DEMs are used in many environmental applications of GIS, including wildlife management, river catchment management, forestry, and the renewable energy sector. In this unit, we focus especially on the latter two application areas: forestry and the renewable energy sector.
The unit contains the following sections:
- Estimating radiation budgets using elevation
- Siting wind turbines
- Forest management using DEMs
- Coursework assignment – visual impact assessment
Terrain affects the micro-climate of different sites. In the northern hemisphere, north-facing slopes are typically cooler than sunnier south-facing slopes. The first section (‘estimating radiation budgets using elevation’) looks at how DEMs can be used to assess such differences in micro-climate. The second section (‘siting wind turbines’) looks at how DEMs can be used in planning in the renewable energy sector. In particular, this section looks at the visual impact of a new development on the landscape. The third section (‘forest management using DEMs’) looks at how DEMs can be used to help plan forestry operations. Terrain is an important consideration when selecting sites both for commercial forestry plantations and for native woodland restoration. Differences in terrain also need to be taken into account when planning tree-felling operations. This section therefore looks at how DEMs can be used to plan both planting and forest harvesting operations. The wind turbine and forest management objects include extensive practical exercise using ArcGIS.
The final section reviews the environmental management concepts covered both in this unit and in Unit 3, which looked at techniques for working with DEMs. The section includes details of the assessed work for this unit and involves analysis of the visual impact of a proposed mobile phone mast using three dimensional GIS processing.