WOW !! MUCH LOVE ! SO WORLD PEACE !
Fond bitcoin pour l'amélioration du site: 1memzGeKS7CB3ECNkzSn2qHwxU6NZoJ8o
  Dogecoin (tips/pourboires): DCLoo9Dd4qECqpMLurdgGnaoqbftj16Nvp


Home | Publier un mémoire | Une page au hasard

 > 

Landfill sites selection for municipal solid waste using multi criteria evaluation techniques. Case of Rusizi town, Rwanda

( Télécharger le fichier original )
par Fidele RUGIRAMANZI
National university of Rwanda - Post Graduate Diploma in Applied Geo-Information Science 2013
  

précédent sommaire suivant

Bitcoin is a swarm of cyber hornets serving the goddess of wisdom, feeding on the fire of truth, exponentially growing ever smarter, faster, and stronger behind a wall of encrypted energy

3.3. Methods and techniques

The methods and techniques are research tools for data collection, adapted at the same time for investigation, adapted for analysis and above all from the point of view, guide the research. The methodology in this chapter provides evidence for analysis that is utilized to determine the optimal landfill sites. The technical approach was also employed to produce suitability maps emphasizing «suitable» geographic areas resulting from weighted and combined map layers based on established variables.

Methodologies used are normally based on a composite suitability analysis using map overlays and their extension to include statistical analysis. In this study, the approach was to utilize models that combine and integrate maps to determine an optimal landfill siting. There are a number of integration models in GIS.

Probably the simplest and best-known type of GIS model is based on Boolean operation. It involves the logical combination of binary maps resulting from applicable conditional operators. If the criteria and guidelines are to be established as a set of deterministic rules (Constraints), this method is a practical and easily applied approach (Dikshit, Padmavathi, & Das, 2000). The model consists of applying Boolean operators to a set of input maps. Each of the maps used as a condition can be thought of as a layer of evidence. The various layers of evidence are combined to support a hypothesis, or proposition. The output is a binary map, because each location is either satisfactory or is not (Bonham-Carter, 1994). The following figures show model builder that were used in this study.

Fig 3-2: Model builder for Factor Map

Source: Author

16

This model builder was used to produce Slope analysis Map (Fig 4-2).

Fig 3-3: Model builder for Constraints Map

Source: Author

17

This model builder was used to produce Constraints and Permissible Area Map (Fig 4-3).

18

Fig 3-4: Model builder for Final map

Source: Author

This model builder was used to produce Distribution of Suitable and Potential sites Maps (Fig 4-4 and Fig 4-5).

3.4. Data Analysis and Interpretation

AGIS-based analysis was conducted using ArcGIS software, Spatial Analyst. Spatial Analyst is a raster or grid based software package that provides a platform for working with gridded data sets. It was used to produce suitability maps highlighting «suitable» geographic areas derived from weighted and combined map layers based on established criteria.

Analyzing spatial layers essentially involves setting the study area boundary, making slope map, buffer zone maps, find distance from water body and roads, reclassified maps and suitability maps that are presented in Chapter 4 of this study.

Raster maps as constraints maps indicating areas, which are suitable and not suitable for the sitting of a landfill, will be provided. The non-suitable areas are known as buffers (Kontos, Komilis, & Halavdakis, 2003). These constraints maps include the surface water, towns, rivers, roads, and land-use. They will also be used as factor maps representing areas that range from low suitability to high suitability.

CHAPTER 4: WASTE GENERATION AND MANAGEMENT IN RUSIZI: BOTLENECKS' ANALYSIS AND SUITABLE LANDFILL SITES LOCATION

This chapter presents 4 different parts: Waste generation and management in Rusizi town, Gaps and challenges in waste management in Rusizi town, Site selection for landfill in Rusizi town, possibilities for landfill sites project implementation.

précédent sommaire suivant






Bitcoin is a swarm of cyber hornets serving the goddess of wisdom, feeding on the fire of truth, exponentially growing ever smarter, faster, and stronger behind a wall of encrypted energy








"Il y a des temps ou l'on doit dispenser son mépris qu'avec économie à cause du grand nombre de nécessiteux"   Chateaubriand