What is the role of GIS and Remote Sensing in
1. Environmental Impact Assessment
2. Substance Flow Analysis
3. Carbon Foot printing
4. Health Impact Assessment
5. Social Impact Assessment
Geospatial techniques such as Geographic Information Systems (GIS) and remote sensing play a pivotal role in Environmental Impact Assessments (EIAs) and their various components such as ecological, social and hydrological impact assessment. These tools have proved so useful that they have also been incorporated into carbon foot printing and substance flow analysis. This paper will discuss how GIS and remote sensing have been incorporated into each of the assessment techniques highlighted above.
GIS and EIA
The most common application of GIS is concerned with environmental issues with half of all GIS work undertaken since the 1980s worldwide having been related to environmental or rural issues including GIS (Antunes, et al., 2001). This prominent role has been attributed to the fact that GIS can answer questions that are central to the EIA process which according to ESRI (1995) are
“1. What is where?
2. What spatial patterns exist?
3. What has changed since?
4. What if?”
The knowledge of “what is where” is pivotal to in conducting the screening, scoping and baselines studies while on the other hand data on the existing spatial patterns can help in developing an understanding of the baseline conditions as well as in impact prediction and mitigation. For instance the location of a wetland near to the proposed project site can identify impacts to do with effluent discharge while the impact of the effluent can be determined by the wetland’s ability to self purify which depends on the soil type as well as flora and micro fauna. An understanding of “what has changed” can then be relevant to impact prediction, prediction of changes in the absence of the project (i.e. business as usual alternative) and impact monitoring. GIS assists in answering the “what if” question by assisting in the exploration of alternatives as well as in the formulation of mitigation measures. At the most basic level the GIS system can be used to produce map and visual aids that will be used by project managers, consultants and the EIA team. At a more sophisticated level, however, GIS functions such as overlays, spread and materials flow analysis can be used for the assessment of the significance of impacts. The maps produced in the earlier stages of the EIA study for baseline and impact assessment could then be used to investigate the potential for minimising impacts on nature conservation sites or habitat patches by project design modifications such as minor road alignments as well, as the potential for species translocation 9to suitable sites) or habitat creation including the creation of stepping stone or corridor habitats between fragmented habitat patches (Wood, 1999). Wood (2000) points out that GIS could also be used to create optimum location...