Landfill sitting: WHY GIS and WHY NOT / Los SIG como herramienta efectiva de gestión de vertederos

2012-01-24T16:46:00.001-08:00

WHY GIS?...A number of authors have agreed about the importance of using GIS in geographic analysis in general and particularly in the landfill site selection criteria. The importance and advantages of using GIS technologies for waste management, landfill sitting and hazardous waste disposal management have been recently discussed.

GIS are able to manage different data sources on geology, land use or census track maps in order to establish a criterion for the location of a landfill. There have been several approaches to develop a GIS to make easy the complicated labour of landfill sitting. In this sense the EA (Environment Agency) have recently carried out evaluation of landfill sittings in which GIS played a major role (Zamorano et al. 2007:473).

GIS can unify and combine different geographic sources improving the analysis by combining different data. Apart from its analysis capacity, GIS can respond to the needs of geographers, environmental and civil engineers in the decision-making on landfill site selection by processing high loads of data as well as other disciplines related to waste management such as natural resources management (water and groundwater) or natural protected habitats (Chang, 2010:4).

WHY NOT?...

In the decision-making to locate a landfill, GIS have not yet been able to resolve problems usually arising during the analysis and discussion of the best location. Chang et al. (2007:150) have reported that “Selection of the best candidate site is dependent on the judgments of the domain experts and can be sensitive to changes in the decision weights associated with criteria. In certain situations, two experts may have contradicting judgments about suitability of a candidate site”.

Some other sorts of problems linked to GIS technologies are all those related to the elevated costs associated to software and hardware required for GIS analysis and the lack of training of some personnel no familiar with map making (Merritt, 2005) .

Overlay of different constrained maps. Source: Chang, 2007

Land suitability assessment for a windfarm location / Estudio de viabilidad parque eólico

2012-01-23T19:02:00.000-08:00

After acquiring data, the second step in a GIS analysis is its representation. This is a very important step that researchers have to do carefully in order to avoid future problems and mistakes in the final analysis. O’Leary et al. (1986) report that “Methodologies used are normally based on a composite suitability analysis using thematic map overlays”.

Also know as layer-based GIS, this is the most frequent form of geographic-data space representation. Particularly, LSA (Land Suitability Assessments) is a very complex analysis in which the overlapping of thematic maps result helpful. The analysis is based on the combination of different thematic layers such as topographic, geologic or drainage as well as in their interpretation independently from one to another.

Land suitability analysis. wind farm UK

Criteria to locate a wind farm in Europe differ a little bit from one country to another. The British Wind Energy Association (BWEA) estimates that the extension average of a wind farm with 20 turbines is 1 square kilometer (BWEA).

The location and how turbines are distributed goes from 300-600 meters distance between turbines to a kilometer in Spain or Scotland (National Wind Watch).

In this case study, the location selected has an extension of more than 7.5 square kilometres meeting the requirements of energy production (90 MW) exposed in the beginning of the work.

Local analysis. Scotland

GIS prospects

Landfill sitting: WHY GIS and WHY NOT / Los SIG como herramienta efectiva de gestión de vertederos

Land suitability assessment for a windfarm location / Estudio de viabilidad parque eólico