DISCUSSION
GIS, especially when combined with Raster data and remote sensing techniques, are amazing tools for identifying areas and locations most suitable for a given landuse or a particular activity.
As shown in the above maps, spatial analysis of complex problems such as finding the best place for several activities has never been so facilitated by technology.
A GIS can perfom several kind of analysis in a separate and/or combined manner. It is possible, for example, to quantify and apply particular buffering zones to the most important environmental resources such as forests, biospheres in danger, or simply protect wetlands from pollution. The wide range of personalized tools it is possible to apply, in fact, are able to satisfy almost an infinite number of spatial requirements such as the preferred buffer zones from a particular animal habitat or river. Thanks to the different formats of datasets: Vector, Raster and database, it is possible to visualize, measure, store and work on any typology of information needed by the analysis process.
In the case above, several variables have been considered in order to find the suitable locations for the construction of a new landfill in the territory of a county:
As shown in the above maps, spatial analysis of complex problems such as finding the best place for several activities has never been so facilitated by technology.
A GIS can perfom several kind of analysis in a separate and/or combined manner. It is possible, for example, to quantify and apply particular buffering zones to the most important environmental resources such as forests, biospheres in danger, or simply protect wetlands from pollution. The wide range of personalized tools it is possible to apply, in fact, are able to satisfy almost an infinite number of spatial requirements such as the preferred buffer zones from a particular animal habitat or river. Thanks to the different formats of datasets: Vector, Raster and database, it is possible to visualize, measure, store and work on any typology of information needed by the analysis process.
In the case above, several variables have been considered in order to find the suitable locations for the construction of a new landfill in the territory of a county:
Calculed Elevations of Slopes, Terrain surface coverage, distance from existing landfills and wetlands, as well as terrain's permeability have been all studied and considered properly, then finally weighted according their real importance as a factor affecting the project.
This makes GIS an irreplaceable tool for Urban and Regional Planning, and should be always considered when performing complex spatial analysis, also because it may reveal patterns or relationships hidden at the bare human eye.
As an example of its powerful analysis capability, it has been recently put focus on the case of the expansion of a landfill in California's Central Valley: some people died and others had serious health trouble and birth defects for the contamination of the Drinking water system of Kettleman, a city in the Central valley which has high levels of agricultural and farming activities. the Element responsible for the deaths apparently is the Arsenic, highly used in pesticides, herbicides and metal alloys. A Landfill is currently located 3.2 miles south of the city, and until present times it has been used as waste disposal area for Mothball and other dangerous elements. It is likely that the Waste Management company built that facility in times when only surface features such as elevation were taken into account when deciding the suitable location.
There are many factors involved into the spread of polluting substances into environment and their interrelation with human activities. The reasons of this fatality may have been related with a wrong spatial analysis, which took into account exclusively the presence of people in the immediate nearby of the waste facility. In reality, the factors and the risks are several and different, and also have different weight in terms of importance. The presence of wetlands of subterranean rivers and the porosity of the soil are factors that can extend enormously the area of risk, and in a way which is not uniform but has influences from the slopes and the elevation of the area, or even the amount of rain within the site.
Only a well planned GIS analysis can take into account all these factors and establish a proper mathematical formula and model that takes into account all the known variables.
- Soil permeability/drainage
- Distance from Wetlands and their eventually connected river system network;
- Land typology Coverage with qualitative differences between the surfaces involved;
- Elevation;
- Slopes of elevation;
- Distance from human settlements and activities including land used for farming, agriculture, ect.
would be possible to establish a standard GIS model and procedure that can be applied to all the locations nationwide or Statewide when deciding the suitable location for a waste treatment zone or landfill area.
The second most important advantage is that with GIS, using the Raster Calculator and the Reclassification tools, it is possible to change the importance of each singular factor to a scale that fits well the reality and the game of factors involved.
Examples of bad environmental management such as Kettleman City could be in this way avoided in future and the whole general procedures generally enhanced for a better and qualitative service to citizens.
Giuseppe Riccardo Belvisi
This makes GIS an irreplaceable tool for Urban and Regional Planning, and should be always considered when performing complex spatial analysis, also because it may reveal patterns or relationships hidden at the bare human eye.
As an example of its powerful analysis capability, it has been recently put focus on the case of the expansion of a landfill in California's Central Valley: some people died and others had serious health trouble and birth defects for the contamination of the Drinking water system of Kettleman, a city in the Central valley which has high levels of agricultural and farming activities. the Element responsible for the deaths apparently is the Arsenic, highly used in pesticides, herbicides and metal alloys. A Landfill is currently located 3.2 miles south of the city, and until present times it has been used as waste disposal area for Mothball and other dangerous elements. It is likely that the Waste Management company built that facility in times when only surface features such as elevation were taken into account when deciding the suitable location.
There are many factors involved into the spread of polluting substances into environment and their interrelation with human activities. The reasons of this fatality may have been related with a wrong spatial analysis, which took into account exclusively the presence of people in the immediate nearby of the waste facility. In reality, the factors and the risks are several and different, and also have different weight in terms of importance. The presence of wetlands of subterranean rivers and the porosity of the soil are factors that can extend enormously the area of risk, and in a way which is not uniform but has influences from the slopes and the elevation of the area, or even the amount of rain within the site.
Only a well planned GIS analysis can take into account all these factors and establish a proper mathematical formula and model that takes into account all the known variables.
In the particular case of Kettleman City, a previous GIS analysis should have been conducted in order to establish if the location was suitable, considering the river systems, the permeability of the soils, and the typology of material disposed in that facility.
The Department of Toxic Substances, having the power to establish State or Nation level Guidelines and provide experts for GIS analysis, should establish a process of deep investigation to be addressed before every new waste management plant or landfill is created.
Using all the possible and known factors, including but not limited to:
- Climate and Rainfall factors;The Department of Toxic Substances, having the power to establish State or Nation level Guidelines and provide experts for GIS analysis, should establish a process of deep investigation to be addressed before every new waste management plant or landfill is created.
Using all the possible and known factors, including but not limited to:
- Soil permeability/drainage
- Distance from Wetlands and their eventually connected river system network;
- Land typology Coverage with qualitative differences between the surfaces involved;
- Elevation;
- Slopes of elevation;
- Distance from human settlements and activities including land used for farming, agriculture, ect.
would be possible to establish a standard GIS model and procedure that can be applied to all the locations nationwide or Statewide when deciding the suitable location for a waste treatment zone or landfill area.
The second most important advantage is that with GIS, using the Raster Calculator and the Reclassification tools, it is possible to change the importance of each singular factor to a scale that fits well the reality and the game of factors involved.
Examples of bad environmental management such as Kettleman City could be in this way avoided in future and the whole general procedures generally enhanced for a better and qualitative service to citizens.
Giuseppe Riccardo Belvisi
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