Before making large changes to land use, such as new transport networks, it is important to assess what the environmental impact will be. Ideally, the assessment should be conducted as early as possible and to be useful, must be fast and simple with clear recommendations. Researchers have developed a new environmental impact assessment method for changes to large geographic areas, which they believe meet these criteria.
Spanish researchers developed the initial screening process for large-scale land-use plans so that the degree of impact on wildlife habitats and the environment can be rapidly assessed at an early stage, taking into account the sensitivity of zones affected. The method uses eleven criteria to evaluate the natural quality of the environment, listed below. These are closely linked with the fifteen criteria listed in the EU Strategic Environmental Assessment Directive1.
- Air quality
- Material assets
The new environmental impact method was used to assess planned reform of the Spanish transport infrastructure. The researchers used a digital Geographic Information System to assess 12 kilometre wide corridors of land alongside planned routes of new roads, urban highways and railways. A score of between 0-3 was given to each area based on the potential impact of the development on the environmental criteria listed above.
Crucially, the screening process produced clear maps that could be easily understood by all involved in the planning process. It was able to highlight the most sensitive areas, where development should be avoided or more detailed Strategic Environmental Assessments should be undertaken. It also generated less damaging alternative routes at an early stage in the planning process.
The screening showed that 25 per cent of the land affected by the Spanish Transport Infrastructure Plan 2000-2007 was highly sensitive and would be critically affected, and that a further 14 per cent of land, while slightly less sensitive, was still at serious risk of negative impact. The findings generated positive changes: amendments to the new Spanish Transport Infrastructure Plan 2005-2020 were based on the results of this research.
The authors argue that while, in countries as large and diverse as Spain, it is difficult to conduct a thorough environmental assessment at initial stages, failure to do so can result in much greater costs at later stages as plans have to be changed. It also puts environmentally sensitive areas at risk.
This method can be applied to a large volume of information and is effective in contributing to better and more transparent decision-making for large-scale plans to change land-use, the authors write. They recommend that where more detailed Strategic Environmental Assessments are required, these should incorporate the impact on energy resources, pollution, climate and changes in demographic distribution and socio-economic factors.