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3 GIS and impact assessment 3.1 INTRODUCTION This chapter reviews GIS applications concerning only the “natural” envir-onment and Impact Assessment in particular, as they have been reported in the published literature.6 One of the striking features of the literature is the relatively small proportion of accounts of GIS use that reaches the public domain in books or research journals, with the vast majority appearing as papers given at conferences – often sponsored at least partially by GIS ven-dors – with no follow-up publications afterwards, or as short articles in mag-azines heavily dependent on GIS advertising (GisWorld, GeoWorld, GisEurope, Mapping Awareness, GeoEurope are typical examples). In such accounts, often the interest does not lie in theoretical or technical issues raised by the particular application, but in the very fact that it happened, in the fact that GIS technology was used. This is typical of the current stage in GIS development, where much of the interest is in the diffusion of this tech-nology – who is adopting it and how fast – just as with other technologies before. The proliferation of such outlets for the monitoring of GIS diffusion also provides very useful market research for the industry itself. The chapter starts by putting Impact Assessment (IA) in the wider context of impact management – to be discussed in Chapter 4 – and the use of GIS for IA is discussed in its different levels of complexity: GIS just for mapping, GIS linked to external models, GIS using its own functionality, and combinations of the three. 3.2 IMPACT ASSESSMENT AND ENVIRONMENTAL MANAGEMENT The introduction to GIS in Chapter 1 indicated how much of the functionality of these systems is more directed to the solution of cartographic problems 6 Rodriguez-Bachiller (2000) includes an earlier version of this bibliographical review. © 2004 Agustin Rodriguez-Bachiller with John Glasson GIS and impact assessment 53 than to solving substantive analytical problems, even if the situation is changing as this technology evolves. It is not surprising therefore that the relatively complex technical operations involved in the core of Impact Assessment have made in the past only limited use of GIS. In the UK, GIS has been absent from virtually all Environmental Statements up until the end of the 1990s7 and, even afterwards, GIS use has been limited to dis-playing a few maps without any analytical manipulation of them. In terms of published references worldwide, Joao (1998) already pointed out in her brief review the paradox that, while environmental applications of GIS are very numerous, IA applications of this technology represent only a fraction, quoting as an indication the fact that in the Database GEOBASE (covering usage between 1990 and 1996) she found only 1.2 per cent of all GIS-related references being concerned with IA, and only about 6 per cent of the references related to IA involving GIS. The bibliography in Rodriguez-Bachiller (1998) also showed this apparent contradiction: more than half (53 per cent) of all GIS applications recorded were concerned with the environment, but only 8.4 per cent were concerned with IA as normally defined. Over time, the relative importance of different areas of GIS application has changed considerably. Updating the information in Rodriguez-Bachiller (2000),8 Figure 3.1 shows the relative “share” of various areas of GIS application, not in absolute numbers of publications – this would only be accurate if the bibliographical reviews had covered the same or equivalent sources every year, which they do not – but in percentages of all the pub-lications recorded each year. We can see that the share of environmental applications – the sum of “rural”, “environmental” and EIA – seems to be declining over time, as GIS use in transport and various services (public, private, “utilities”) increases, although this is probably not an indication of a decline in environmental GIS use, but a reflection of a fast increase in the diffusion of GIS in these other growing sectors. The low share of IA applications does not seem to vary much over time. Undoubtedly, this apparent anomaly is partially due to the mentioned mismatch between the relatively simple analytical functionality of GIS and the technical complexity of impact prediction and assessment. However, it is suggested here that it is also due to the relatively narrow definition of IA that is normally used, which tends to include only the technical core of IA consisting of impact scoping, prediction and mitigation. On the other hand, 7 Judging from the collection held at the Impacts Assessment Unit at Oxford Brookes University – a sample of about 25 per cent of all EIS produced in the UK covering the complete period since EIA was formally introduced – only since 1998 have some statements contained GIS (Arc View) maps (Wood, 1999c, personal communication). 8 That publication updates an earlier bibliography in Rodriguez-Bachiller (1998), which looked at GIS magazines (of the type already mentioned), books, articles and conference proceedings from the late 1980s. © 2004 Agustin Rodriguez-Bachiller with John Glasson 54 GIS and expert systems for IA 100% 80% private services 60% public services infrastructure transport urb/reg Planning EIA 40% environment rural 20% 0% 88 89 90 91 92 93 94 95 96 97 98 99 00 01 Figure 3.1 Areas of GIS applications during the 1990s. if we broaden our view, even from the abbreviated description of IA in Section 1.6 we can appreciate the wide range of environment-related opera-tions that really constitute IA: 1 Appraising the environment and assessing its quality and sensitivity, needed for the determination of the key impacts (scoping) which need investigation. 2 Identification of all potential impacts from a project to determine if it requires an impact study (screening) and which future impacts ought to be studied (scoping). 3 Consulting the public and specific interest groups about the significance of impacts, about alternative locations for the project and about possible mitigation measures. 4 Modelling and forecasting the evolution of the environment without the project, to establish the various baselines for comparison with the impact predictions. © 2004 Agustin Rodriguez-Bachiller with John Glasson GIS and impact assessment 55 5 Forecasting the impacts on that environment of the particular project, the impact prediction as such which is included in all IA reports. 6 Forecasting impacts from other projects likely to add their influence to that of the project, to determine possible cumulative impacts. 7 Assessing the significance of the likely impacts on the environment by comparison with the relevant standards. 8 Establishing possible mitigation measures to counteract any significant effects on the environment identified in the previous stages. 9 Monitoring the actual impacts once the project is under way for correc-tion and mitigation or for reassessment. What is normally considered IA constitutes the central part of this list, but the wider definition of IA also must include other tasks (in particular 1, 4 and 9) which serve the purpose of general environmental management but are also essential to good IA. One of the reasons why the relatively narrow definition of IA is normally used as opposed to the wider definition is probably that the two involve not only different sets of operations, but they are usually performed by different actors: 1 Identifying, forecasting and assessing project impacts with varying degrees of public consultation (tasks 2, 3, 5, 7 and 8, sometimes also 6) – what we can call IA as such – are project-specific and usually the responsibility, in the US and Europe, of those agencies or actors behind the project being assessed, the “developers”. 2 On the other hand, monitoring, assessing and auditing the environment (tasks 1, 4 and 9 above) – what we can call environmental management – are also essential to IA but are not necessarily associated with any project in particular, and are usually carried out by large organisations (sometimes in the public sector) or environmental agencies. In relation to this distinction between Impact Assessment and environmental management, one particular environmental management task, environmental modelling and forecasting (unrelated to any particular future project) is crucial to the baseline part of IA, but tends to “fall between two stools” and not be systematically performed by anyone. Developers do not have the data and resources to undertake it for an area where they are involved in just one project, and larger organisations and environmental agencies very rarely consider it part of their terms of reference to keep the kind of ongoing simulation of the environment in all areas of the country that this would entail. It is therefore not surprising that this part of IA is very rarely done, or done well, and baseline studies usually confine themselves to the presentation of the environmental situation at the time of the study, but with little or no forecasting. If one considers IA as the project-based process mainly carried out by developers, it is not surprising to find that GIS is scarcely used, given the © 2004 Agustin Rodriguez-Bachiller with John Glasson 56 GIS and expert systems for IA considerable costs not only of the expertise and the hardware/software (important bottlenecks years ago but gradually becoming less of an obstacle) but of the data, as Joao and Fonseca (1996) found in their small survey of environmental consultants. Even if that survey had a low number of respondents, it is interesting that the time and cost of setting up a GIS data-base to be used only for one project was quoted as the most important drawback of GIS, while the more traditional problem of start-up costs of hardware and software was the second most important, followed by lack of digital data and training requirements for the staff – not all IA consultants can afford to have up-to-date GIS experts. Nutter etal. (1996) also pointed out the difficulties in IA with GIS data managers, as well as the conflicts between the rapidly changing GIS technology and the staff involved. Although average training and hardware/software costs diminish within an organisation as GIS is applied to more projects, data problems are usually specific to only one project, unless an organisation specialises in IA in the same geographical area – of which there is no evidence, at least in the UK – and it is these very high one-off costs which are likely to be the strongest deterrent against GIS. In less developed countries, resource-related problems are likely to be even greater (Masser, 1990), and Warner etal. (1997) repeat the “health warning” about GIS data accuracy in developing countries, where data are collected only sporadically (and often from remote sensing without “ground-truthing”), not reflecting fast-changing seasonal situations which can make all the difference for IA. This chapter concentrates on reviewing GIS applications which are related more to those tasks listed above linked to the technical core of Impact Assessment as such. Those concerned with environmental manage-ment will be reviewed in the next chapter. 3.3 THE ROLE OF GIS Whether GIS is used for environmental management or IA, an aspect which is crucial to our understanding of the contribution of GIS is the role that these systems play and the sophistication of their contribution. We can express this by the degree to which GIS is used just as “provider” of information (maps or data for a technical task), or as a true analytical instrument: 1 At the lowest level of sophistication, GIS may be used just for mapping, for the production of maps of the environment, of the project, or of particular impacts from it, to provide visual aids to researchers or managers who will use this information in a non-technical way and externally to the system. 2 At the next level, GIS can itself be involved in technical analytical tasks, which can be internalised to different degrees into the GIS: © 2004 Agustin Rodriguez-Bachiller with John Glasson ... - tailieumienphi.vn
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