Benefits Of Using Gis In Waste Management Environmental Sciences Essay

Solid waste management involves a number of stages starting from the choice of sites for landfill, collection, transportation and disposal of the solid waste. Both economic and environmental planners are concerned with the setting up of cost effective and environmentally friendly systems for solid waste management. Geographical Information System (GIS) is a tool that can provide spatial and non spatial information for urban planning and management. This paper focuses on the application of GIS as a planning and data collection tool in Solid Waste Management and analyses to what extent GIS is being used in solid waste management by the local authorities in Mauritius and also identifies the barriers to the proper use of GIS in this sector. A GIS model for the Grand Port-Savanne District Council (GPSVDC) a local authority in Mauritius is produced using ArcGIS software and this can be used as a decision support tool in planning waste collection and disposal.

The Republic of Mauritius is a small island developing state (SIDS), situated at 800 km off the East coast of Madagascar at longitude 58° East and latitude 20° South in the Indian Ocean with a total surface area of 1870 km². In addition to the island of Mauritius, the Republic includes the islands of Cargados Carajos, Rodrigues and the Agalega Islands. The main island of Mauritius has a population of around 1.28 million inhabitants. The rapid industrialization and urbanization during the past decade have led to changing production and consumption patterns that continue to present new demands for natural resources and create new waste streams. It is expected that solid waste produced in Mauritius is about 380,000 tons a year (or 1,200 tons per day) and is expected to reach 418,000 tonnes in 2014. The present strategy of disposing wastes at the landfill and/or dumping sites will in the long-run be no longer sustainable or appropriate with the rapid increase in waste generation, scarcity of appropriate landfill sites and the density of human settlement. The development of an integrated solid waste management strategy is among the priorities identified in the National Environmental Strategies to reduce future costs from environment degradation. Government’s policy is to promote waste reduction, minimize its generation, encourage the adoption of environmentally sound methods of resource recovery and modernize the institutional and legal framework for the entire logistical chain – collection, storage, transfer and disposal – and introduce a cost recovery mechanism.

“There has been awareness regarding waste management amongst many countries. There has been development of new technologies for improving the waste management systems. GIS is one of the new technologies which have contributed a lot in very less time span to the waste management society.” (Moiz Ahmed Shaikh, 2006)

This paper analyses the benefits of using GIS as a tool in solid waste management and makes an assessment of how far GIS is being used by the local authorities in Mauritius and identifies the barriers to the use of GIS in solid waste management in Mauritius. A GIS model for the Grand Port-Savanne District Council (GPSVDC) a local authority in Mauritius is produced using ArcGIS software and this can be used as a decision support tool in planning waste collection and disposal.

SOLID WASTE MANAGEMENT IN MAURITIUS

Solid Waste Management in Mauritius falls under the responsibility of the Ministry of Local Government and Outer Islands. The main island of Mauritius has five Municipal Councils namely (i) Port Louis, (ii) Beau Bassin/Rose Hill, (iii) Quatre Bornes , (iv) Vacoas/Phoenix and (v) Curepipe. There are also four District Councils namely (i) Pamplemousses/Rivière du Rempart, (ii) Moka-Flacq, (iii) Grand Port-Savanne and (iv) Black River. Solid waste collection and disposal is undertaken by these local authorities in areas under their jurisdiction and is disposed of at the Mare Chicose landfill via a network of transfer stations situated in St Martin, Roche Bois, Poudre D’Or and La Brasserie. Waste collection and disposal is also carried out by private companies on contract basis. The only landfill on the island is at Mare Chicose which is managed by a private contractor. With the increase in waste production the life span of the landfill is going on decreasing and soon there will be a need to increase the capacity of the landfill or to find another locality to set up a second landfill.

The daily management of waste collection and disposal activities is carried out by officers of the Health Department of the Municipal Councils and the District Councils.

1.3 What is GIS?

GIS is a computer system for capturing, storing, checking, integrating, manipulating, analyzing and displaying data related to positions on the Earth’s surface. Typically, a Geographical Information System is used for handling maps of one kind or another. These might be represented as several different layers where each layer holds data about a particular kind of feature. Each feature is linked to a position on the graphical image on a map and a record in an attribute table. GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. A GIS helps you answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared. GIS technology can be integrated into any enterprise information system framework.

1.4 Uses of GIS in Solid Waste Management

Solid waste management comprises several phases, starting from the stage where the waste is generated till it reaches its final destination or at a stage where it is no more a threat to the environment. “It is observed that solid waste management can be bifurcated into mainly two phases. One is the waste management in the area where it is generated and second is the management of waste at dumping grounds.” (Moiz Ahmed Shaikh, 2006). The development of Geographic Information System (GIS) and its use throughout the world has contributed a lot in improving waste management systems. GIS helps to manipulate data in the computer to simulate alternatives and to take the most effective decisions. GIS can add value to waste management applications by providing outputs for decision support and analysis in a wide spectrum of projects such as route planning for waste collection, site selection exercises for transfer stations, landfills or waste collection points. GIS provides a flexible platform which integrates and analyses maps and waste management databases.

GIS allows us to create and store as many layers of data or maps as we want and provides various possibilities to integrate tremendous amounts of data and map overlays into a single output to aid in decision making (Chang et al. 1997).

The changing production and consumption patterns have caused a rise in the volume of solid waste putting considerable pressure on Governments in dealing with the increased waste generation. It implies that local authorities will require huge capital investments and operational strategies for collection, transportation and disposal of solid waste. Delimiting factors such as limited financial resources have made it imperative to replace existing ad hoc methods employed in solid waste management and planning (Vijay et al. 2008).

Sarptas et al. (2005) studied the use GIS in solid waste management in coastal areas as a decision support system with a case study on landfill site selection. The results of the study are that GIS is becoming a powerful tool in SWM. However there are still some drawbacks and deficiencies in applying the method extensively. For example, it is not applied in solid waste generation studies because large fluctuations in solid waste generation by time and space and the dynamic nature of urban areas generate several difficulties in determining the current solid waste generation patterns. In the early period of GIS technology, from the 1980’s to the early 1990’s, GIS software was capable of executing only basic geographical operations. These capabilities of GIS software limited the user to only basic tasks such as exclusion and allowed them to determine only alternative landfill sites in landfill siting applications. Advances in information technology and increasing access to computer systems by decision makers have improved the usefulness of computer models and computer aided technologies in DSS in the last decade. One of the typical examples is the SWM systems. The GIS models do not only support the decision procedure but also facilitate the communication and mutual understanding between decision maker and the people, because the implications of a SWM closely affects the society. However, the basic limitations in the use of GIS in SWM is the data availability. Because, especially in developing countries the available data are very scarce and access to the data is very poor and tiring. In addition, the existing data are not reliable, not collected, stored and disseminated systematically. More comprehensive researches and more efforts on data gathering to fulfill the needs of GIS models are recommended.

Since routing models make extensive use of spatial data, GIS can provide effective handling, displaying and manipulation of such geographical and spatial information. For example, Ghose et al. (2006) proposed a model for the system of Municipal Solid Waste (MSW) collection that provides planning for distribution of collection bins, load balancing of vehicles and generation of optimal routing based on GIS.

According to Reddy et al. (2007), traditional and static approaches are no longer adequate for analyzing network flows and conducting minimum cost routing. Reddy et al. attempted to develop a decision support system for generating an optimum route for solid waste disposal in Hyderabad City and hence to reduce the distance ran by the collection vehicle using GIS. GIS tool provides an effective decision support through its database management capabilities, graphical user interfaces and cartographic visualization. The system developed by Reddy et al. used the Network Analyst module available in Arcview, which is a path-finding program used to model the movement of resources between two points or more.

Chatila (2008) developed a GIS system for natural resources management and recycling of solid waste in the village of Marjeyoun in Southern Lebanon. A GIS map was prepared to serve as a zone management plan along with an environmental assessment that identifies cumulative pressures and impacts of some human activities on the village and the environment. A recycling program was developed based on solid waste sampling and analysis of collection systems.

In a study carried out by Bergeron et al. (2010), 3D visualization and GIS were used to produce a digital city model for the Star City, West Virginia to allow government officials and managers to manage assets and perform day-to-day operations, develop sustainable planning initiatives, and management of solid waste assets and facilities, planning for solid waste and recycling facilities and drop-offs, mapping and planning efficient waste hauler routes and identifying issues such a underserved populations and illegal dumping. However, building and using a GIS requires expert knowledge, and can often prevent such systems from being used to their full capability by local officials. In addition, local government is often comprised of mature citizens who are committed to serving their community but may be wary of new technologies that are unfamiliar to them.

1.5 AIMS AND OBJECTIVES

The aim of this paper is to analyse the extent to which GIS is being used in waste management by the local authorities in Mauritius, to identify barriers to proper use of GIS in solid waste management and to assess to what extent GIS affects sustainable waste management as a decision support tool in planning waste collection, recycling, waste segregation and disposal in order to create cost-effective systems. Finally a model will be proposed for the Grand Port-Savanne District Council (GPSVDC) a local authority in Mauritius using ArcGIS software that could be used as a decision support tool in planning waste collection and disposal. The model produced will be used to store information regarding the existing collection routes, land use data, population data etc and data regarding the volume of waste produced. Based on these information decisions appropriate decisions can be taken to improve the existing solid waste management system and also predictions can be made for future plans.

Hence, in short the aims of this project are mainly as follows:

To identify to what extent GIS is being used in waste management in Mauritius.

To identify barriers to proper use of GIS in waste management.

To assess to what extent GIS affects sustainable waste management as a decision support tool in planning waste collection, recycling, waste segregation and disposal

To carry out a case study for the Grand Port-Savanne District Council (GPSVDC) a local authority in Mauritius in order to produce a database for decision making.

The paper will also carry out a literature study of some examples of GIS work for waste management. The study will include a discussion and a critical analysis of the models. The analysis of these studies will allow us to learn about the usefulness of GIS as a tool is solid waste waste management and these may be developed for Mauritius in the context of creating an Integrated Solid Waste Management Plan.

Further to literature review, a number of hypotheses have been designed and have been described briefly

GIS and Social Development

H1: There is a significant link between GIS and Social Development.

H0: There is no significant link between GIS and Social Development.

GIS and Economic Development

H1: There is a significant link between GIS and Economic Development.

H0: There is no significant link between GIS and Economic Development.

GIS and Environmental Development

H1: There is a significant link between GIS and Environmental Development.

H0: There is no significant link between GIS and Environmental Development.

To achieve these aims, a logical step has been carried out to complete this project. The structure of the research gives an idea of the issues covered in this project.

1.6 Methodology

In order to analyse the general waste management situation in the local authorities (Municipalities and District Councils) in Mauritius, a scientific approach was implemented to gather primary information which comprises of different steps. These steps are as follows:

Step 1: The target group was identified. 30 officers working in the Local Authorities were interviewed. Alongside, a questionnaire – vide Appendix 1, was designed to retrieve information from the respondents.

Step 2: The 30 officers were interviewed and the questionnaire was used as a guide to ensure proper flow of questions. However, much emphasis was put in open ended questions so as to get maximum information concerning their point of view relating to the present waste management system.

Step 3: The data collected was analyzed using SPSS and Excel whereby results were shown on a first instance in terms of descriptive statistics being line charts, bar charts and in terms inferential statistics being correlation, cross tabulation.

Step 4: A list of recommendations and suggestions are given regarding the use of GIS in solid waste management in Mauritius and how they it can help in sustainable waste management. As well as, what can be done to mitigate the barriers that prevent the proper use of GIS.

Chapter 2

GIS Model Analysis

2.1 Model 1

This is an overview and a discussion of the paper, “A case study of fuel savings through optimisation of MSW transportation routes” written by Gilberto Tavares, Zdena Zsigraiova, Viriato Semiao, Maria da Graça Carvalho published in 2008 in the Journal Management of Environmental Quality, Volume: 19 Issue: 4.

At the end of the discussion there are critical views on this paper work.

2.1.1 Waste management background in Cape Verde

This study has been carried out for Cape Verde where the demographic growth, tourism and other economic activities are putting enormous pressure on government. “There is still evident lack of development plans, the existing waste management being rather poor and characterized by inefficient collection systems.” (Gilbero Tavares, 2008)

“Besides, the negative impact of untreated waste on public health and on public concern, which focused the attention of engineers and scientists on the quest for waste management solutions viewing the prevention of undesired environmental effects, economy plays also an important role on this activity. In fact, collection and transportation of waste can absorb as much as 75 per cent of the municipalities’ MSWM budget that are usually the institutions responsible for such activities.” (Gilbero Tavares, 2008)

One of the heavy costs present in MSWM systems is the fuel price and its consumption is inevitably associated with undesired pollutants emissions. Therefore, the minimisation of fuel consumption to perform waste collection and transportation to its treatment or final disposal brings enormous savings and environmental benefits.

2.1.2 GIS approach

The methodology used comprised of three phases.

Phase 1 – The model of the terrain and the road network

A 3D model of the entire island of Santo Antao, Cape Verde was produced based on a digitised map provided in CAD files. The 3D model is generated as polylines based on contour lines that reflect the actual relief of the terrain. Using ArcGIS 3D Analyst, the 3D road network is then generated from both the 2D road network and the terrain model complying with the road gradients. This methodology makes possible the generation of road networks in the appropriate form allowing for the calculation of all inclinations of each road segment, which permits to determine the fuel consumption for both road directions (uphill and downhill). The 3D digital model and the road network obtained allows the large variability of the relief to be observed.

Phase 2 – Calculation of actual fuel consumption

“Fuel consumption during waste collection and transportation is influenced by the travelled distance and by the actual operation conditions of a given vehicle. These effects are incorporated in the model through the methodology established by Ntziachristos and Samaras (2000) in COPERT, which is a computer programme to calculate emissions from transport vehicles on road. ” (Gilbero Tavares, 2008)

Besides considering specific vehicle parameters, the methodology also takes into account different driving conditions, namely the type of the driving situation, the vehicle load and the road gradient. The gradient of a road increases, when positive, or decreases, when negative, the resistance of a vehicle to traction. Therefore, and because of their large masses, the power employed during the driving is the decisive parameter for the fuel consumption. Once calculated, the fuel consumption value for each route arc is stored in the spatial data base to be used later during the route solver procedure that searches for the route with minimum fuel consumption.

Phase 3 – Optimisation of vehicle routing

The efficiency of a management system that is able to solve problems related to vehicles circulation in road networks can be measured through its capacity to obtain optimised routes. For a system of MSW transportation, this consists of generating an optimal route for a given vehicle so that the value of the selected cost criterion is minimised.

For the calculation of the optimal routing, the model used herein makes recourse to ESRI’s programs ArcGIS, ArcInfo and Network Analyst extension, and it finds the minimum defined impedance path through a network. In order to compare solutions and clarify the potential of the present methodology, the routes are optimised regarding either the lowest fuel consumption or the shortest distance.

Findings

The findings of the study showed that the optimisation for the lowest fuel consumption yields 52 per cent savings in fuel, when compared to that for the shortest distance, even travelling a 34 percent longer distance, which shows the importance of considering simultaneously the relief of the territory and the lowest fuel consumption criterion when optimising vehicle routes.

2.1.3 Critical views

With such a supporting decision tool savings in fuel are huge, the efficiency of management systems is improved and the environmental impact during daily operation is reduced. The GIS 3D route modelling takes into account the effects of both the road inclination and the vehicle load. The originality of the work lies in the chosen approach. To optimize vehicle routes the criterion of minimum fuel consumption rather than the commonly used shortest distance is used, since fuel consumption is the factor reflecting actual costs relative to MSW management.

2.2 Model 2

This is an overview and a discussion of the paper, “A GIS Approach to Waste Management and Recycling in New York State.” Written by Ghaly, Ashraf and published in 2009 in the journal Proceedings of the International Conference on Waste Technology & Management, p1140-1150.

At the end of the discussion there are critical views on this paper work.

2.2.1 Purpose of the study

“Solid waste and recycling programs requires management of large databases including collection data, transfer, processing, disposal, export, import, and future planning. The body of information involved in the decision making process is too challenging to effectively mange due to the many components it contains. A GIS approach takes advantage of the spatial nature of data presentation to illustrate the areas of strength in the system and to identify the areas in need for improvement. Such a system is not only useful to managers and state officials but it also is easier for the public to comprehend and appreciate. GIS also makes it easier to measure success and detect trends, which ultimately help improve the system to better manage collection, sorting, and recycling facilities.” (Ghaly A., 2009)

The existing recycling programs are put in place to reduce the use of virgin materials from forests, energy consumption, greenhouse gas (GHG) emissions, and water pollution. These programs ultimate goal is to promote conservation and to encourage the members of the public to be active participants in this effort. This paper uses GIS to demonstrate, using maps, the current state of waste management and recycling efforts, future plans, and methods of measuring success

across geographic boundaries. The paper concludes that a spatially-based management system

offers advantages, which makes it superior to non-spatial systems.

Data Collection

This paper uses data published by the New York State Department of Environmental Conservation (DEC) for all the counties in the state to study the efficiency of the existing recycling programs and to find ways to optimize the use of landfills. This analysis is done for Municipal Solid Waste (MSW), industrial waste, demolition and construction debris, and for waste exported out of the state to neighboring North East states.

For better management of solid waste in the state of New York, the Department of Environmental Conservation (DEC) maintains a comprehensive database on waste composition, pattern of waste generation, and methods of disposal. The success of this operation depends on the quality and accuracy of data collected. This data helps in the decision making process regarding the transfer and processing of solid waste, disposal, import/export, recycling, and in making plans for the future.

To contribute to these efforts, the Northeast Recycling Council (NERC) developed an “Environmental Benefits Calculator” which generates estimates of the environmental benefits based on the tonnages of recycled materials. Environmental benefits metrics involves quantifying

the reduction in use of virgin materials from forests, oil supplies, and mines; reduction in energy

consumption; reduction of Green House Gas (GHG) emissions; and the reduction of water pollution, and conservation of natural resources. These are all goals that DEC is interested in increasing awareness for.

Waste management and recycling are impacted by economic and political factors. These factors add a layer of complexity to the data collection process. Some of the concerns related to these issues are solid waste migration of recyclables across geographic boundaries, which involve dealing with regulations of various agencies and governments. In addition, the diversity and variety of recyclable materials add to the difficulty of compliance with required transportation methods across boundary lines.

Four Phase Plan

The DEC developed ambitious plans for data collection and analysis. This plan is made of four

phases:

Phase 1: Fill in data gaps by enforcing reporting requirements; researching recyclables data available from transfer or disposal facilities; and seeking voluntary data from non-regulated recyclers.

Phase 2: Validate/improve data by using metrics to compare data from Planning Units and facilities; auditing a sampling of annual reports; include data source checks at facility inspections; and investing in electronic reporting mechanisms.

Phase 3: Develop State policies to improve recycling by updating regulations to foster increased recycling; using permit conditions to promote best practices; involving State agencies/facilities; and incorporating these ideas into the State SWM Plan.

Phase 4: Work with Planning Units to grow recycling by establishing more recycling metrics; reestablishing State promotion of 3Rs (reduce, reuse, and recycle); targeting higher recovery for paper and organics; and targeting outreach toward specific sectors such as government agencies, schools, and food service.

Role of GIS in NYS Plan

Data is the heart and soul of waste management analysis and future planning. In complying with their reporting requirements, the enormous number of facilities involved in waste management and recycling in NYS delivers tremendous amount of data. With its spatial nature as shown in the above maps, GIS can add a visual dimension to data that is otherwise too complex to comprehend. With more emphasis placed on enhancing reporting to comply with regulations, the bulk of the collected data is expected to increase and become more elaborate. It is believed that GIS with its excellent spatial techniques can help in the analysis phase and in the decision making process as well.

Critical views

A spatially-based geographic information system (GIS) for data management and analysis seems to be more capable of handling enormous amount of data similar to the volume collected by New York State’s Department of Environmental Conservation on solid waste and recycling activities in the state. With the Department of Environmental Conservation (DEC) aiming at improving reporting and analysis for better management, GIS can offer the tool necessary to accomplish these tasks with efficiency and ease.

Based on this model, GIS can be used to collect data in respect of the type and volume of recyclable materials around the island of Mauritius. We can thus better plan the collection of recyclable wastes.

2.3 Model 3

This is an overview and a discussion of the paper, “GIS Application in Coordinating Solid Waste Collection: The Case of Sinza Neighbourhood in Kinondoni Municipality, Dar es Salaam City, Tanzania.” Written by Alphonce Kyessi and Victoria Mwakalinga and published in 2009 in the journal FIG Working Week 2009.

At the end of the discussion there are critical views on this paper work.

In this paper Alphonce Kyessi used GIS in “ROUTING EFFICIENCY ANALYSIS FOR SOLID WASTE COLLECTION IN SINZA “A” NEIGHBOURHOOD IN DAR ES SALAAM”.

6.1 Location

Sinza “A” is one of five residential neighbourhoods of Sinza ward in Kinondoni Municipality in Dar es Salaam. Accommodation about 5,000 people, the neighbourhood is located about 12 kilometres from the Dar es Salaam city centre. The Kinondoni Municipal Council had contracted private companies and civil societies’ organisations in the collection of solid waste in residential neighbourhoods. Kimangele Company Limited is one of those private contractors.

The routing system for Kimangele Company was studied in detail to assess the solid waste collection efficiency as shown in Figure 5 and 6.

Figure 5: Location of Sinza “A” area for Kimangele Contractor

Source: Mwakalinga, 2005

Kimangele plies from house to house to establish a solid waste collection system known as bring system in Sinza “A”. The bring system is done in big catchment areas i.e. above 50 metres in radius.

Waste generation and collection

Sinza “A” consisted of 876 households (Mwakalinga, 2005). Generally the area generates about 14.5 tonnes of waste per day. The waste composes of plastics, tins, organic food waste, packaging materials, clothes, metals and bottles.

Out of the waste generated, the contractor collects 8.4 tonnes from households. The rest About 5.1 tonnes (47.7%) of waste are collected by informal collectors (using wooden carts) to designated collection centres. The rest (about 1 tonne) is haphazardly dumped in rivers, on roads sides, burnt or buried.

About 160 households are not members of house to house collection service; they prefer using the informal collectors instead of the contractor’s trucks. When interviewed, these households complained of ineffective collection system by the Contractor. One of the given reasons was that the truck was not following the rout as agreed. Others households said the collection charge of TShs. 2000/= per household was too high. They were ready to pay only TShs. 500/= per house regardless the number households in the house.

Figure 6: Collection Systems as applied by Kimangele Company in Sinza “A”

Source: Mwakalinga, 2005

When the Contractor was interviewed in 2005, he replied that, out of 716 households he was serving only 70% paid the refuse collection charges (Mwakalinga, 2005).

According to Figure 8 below, there are some areas where the truck drives twice creating overlaps. Normally, a truck stands at a pick-up point, about 50 meters from the other. In other circumstances, the distance is more than 50 metres, and as a result more waiting time by the truck is needed indicating that the whole system of waste collection was foiled.

Work Organisation

The collection frequency by Kimangele was done twice a week i.e. Wednesdays and Saturdays. The service starts at 6.30 am to 5.30pm. The truck was making two trips on each day due to the amount of waste generated and the ability of the truck to carry the waste. The route for the first trip starts at Superstar area and ends at Kivulini through Sam Nujoma road to Mtoni kwa Kabuma dump site, about 30 kilometres away (see Figure 7). The route for the second trip passes through Morogoro road via Shekilango road; the first point in this trip is Super Star Street ending at café Latino Street. Thereafter the route enters Sam Nujoma road to the main dump site, Mtoni kwa Kabuma.

Figure 7: Existing Route for Kimangele Company in Sinza “A” Neighbourhood

6.4 Distance Covered and Cost of Solid Waste Collection

The distance covered for the two trips is 10,920 metres. The first trip covers 7,270 metres while the second one covers 3,650 metres. The time spent per day is 11hours, from which 6 and 5 hours are consumed by the first and second trips respectively. The analysis shows that much time is spent on waiting for waste brought from a distance of above 50 metres in the area where the bring system is applied.

Apart from that the contractor employs 4 labourers (only during the collection days). Each of them is paid TShs. 5000/= per day; their job being to bring waste from long distant areas to the pick up points where the truck stands. Additionally, the contractor uses 20 litres of diesel costing 18,000/= in each collection day.

In the analysis, there are some costs which the Contractor could avoid if the routing system is rearranged and reassigned. For instance, the action of the labours to bring waste to the pick-up point could be eliminated while the fuel spent by the truck could be reduced if the catchments and overlapping are controlled.

One of the basic criteria for a least cost route is to start from furthest point when the vehicle is empty. As the load increases, the vehicle should be moving to the point near the main route on the way to the dump site. This criterion was not considered by the Contractor. The existing road network was used arbitrary with no prior studies.

6.5 GIS in network design

A least cost route is obtained through considering various criteria as per the Network Theory (.Mwakalinga, 2005). These criteria include topography, distance, landuse type, road condition, cost involved, time spent and population. In the case of Sinza, only one contractor’s route was assessed; the area is small relatively flat, thus there were no constrains of topography, landuse or population. In that regard, only two criteria were applied i.e. cost and distance. In consideration of the two criteria the GIS as a tool was applied to establish the least cost route (Figure 8).

Figure 8: A least cost route for Sinza “A” Neighbourhood.

Source: Mwakalinga, 2005

6.6 Comparison between existing route and the established least cost route

The new route prepared covers the distance of 9,140 metres, about 5,430m less that the old route. Additionally, the new route has got less overlaps; only two while the old had four. The catchment area in the new route is within accepted limits i.e. the contractor will not employ many labourers for the bring system, but only one labourer will be required.

Table 2: Efficient analysis between the existing and proposed route

Source: Mwakalinga, 2005

As the cost reduced the contractor can afford to deliver the service by charging fees per house instead of household. If this is applicable people will be willing to pay for the service and the service delivery will be improved. According to information on Table 2 above, new route is cheaper by almost 50% of the old route.

7. EMERGING ISSUES

There are several issues that have emerged in the application of GIS as tool for coordinating solid waste collection in residential neighbourhoods, they include:

Factors related to establishing a GIS database

There was no database for solid waste management system established for Kinondoni municipality. This computer based collection system was established in a study of establishing the least cost route. Information on waste generators (households) and performance of the contractors was not readily available.

(a) Waste composition in most (75%) of the collection points was not known. There were recycled materials like plastic, metal, tins, etc. which could be traded while creating employment. However, there was no an established figure that could attract buyers although sorting at source (see Plates 1 and 2) of the waste could have assisted in reduction of cost of solid waste management at the municipal level.

(b) Catchments areas of most of the collection points along the designated routes are often too large i.e. majority were of a distance of between 500 to 1000 metres instead of 50 to 150 metres. This led to under estimate of the required trucks and collection points for the waste collection. As a result, some households resorted to private hand push carts (see Plates 3 and 4), thus undermining the private contractor. Often, the hand cart pullers do not normally take waste to the collection points due to long distances.

Instead, they dumped it on the streets or roads, in valleys or open spaces and in ditches.

(c) Waste generation rates were not yet established in most of the settlements including Sinza “A”. This situation contributed to under estimation of the collection points, trailers needed and number of trips to be made per week, resulting to high piles of waste at collection points necessitating crude dumping (see Plate 5).

(d) Burning is one of the crude methods performed at some collection points, leading to air pollution posing health risks to people (see Plate 6).

Factors related to locational suitability analysis of collection points

The collection points were found to be arbitrarily located while the traditional method of selection them was not a scientific one. There was no background information collected to support the sitting of the collection points. In general, the collection points were on an inefficient route.

Factors related to routing efficiency

The existing routes were long and expensive due to lack of awareness and skills on how to apply the geo-information technology (GIT) in route planning. The Contractors would like to maximise profits by minimising operational costs, however, they lack the technical know-how to do so. As a result the service delivery becomes inefficient and thus making the households not to have trust on the Contractors.

8. CONCLUSION

The application of GIS in route planning and designation of collection points in Sinza “A” has brought up a number of lessons. First, GIS is capable and can help improve waste collection in residential neighbourhoods in urban areas. Secondly, in order to have an efficient solid waste management system, GIS may be adopted because it is capable of handling both spatial and non-spatial data necessary for effective solid waste collection system. Thirdly, solid waste collection Contractors prefer routes which are short and cheap, with high rate of return within a short period; however, traditional methods of handling data are incapable of identifying the least cost routes for solid waste collection. Fourthly, GIS has been proved to be a tool that provides the alternative method of minimising operational costs for Contractors, although neither the urban councils nor the designated solid waste collection Contractors are utilizing it.

Other issues like organisation setup, legal framework and ways used to select the SWCS add to complicated waste management issues in the city.

9. RECOMMENDATIONS

Based on the foregoing findings and discussion, there are three recommendations to make:

•€ Aspect regarding information

GIS for solid waste collection needs to be institutionalised. It needs to be introduced to the Contractors, municipal and city councils officials in order to ease information management for both spatial and non-spatial data. GIS can be used as a planning tool for sold waste management. On the other hand, the spatial and non-spatial data should be updated from time to time in order to support decision making. In addition

•€ Aspect related to capacity building

Private contractors and civil societies organisation involved in solid waste management, as well as practitioners, need to be trained in the use of GIS as a toll for planning in solid waste collection. Short courses, seminars and workshops need to be conducted to build their capacity in waste collection. The focus should be based on empowering the stakeholders about importance of information, information needs, collection, storage, analysis and use.

•€ Aspect related bring system in built-up areas

The bring system is suitable for large and high density areas since it is proved to be more efficient and least cost than the house to house system. The optimal distance should be 150 metres from the furthest dwelling/housing unit. GIS should therefore be utilised to plan for the bring system.

Chapter 3

Mare Chicose Landfill

Existing SWM situation in Mauritius

Chapter 4

Case Study Area – Rose Belle

Data Collection in case study area

The methodology will consist of an analysis of the present route planning and transportation situation in Rose Belle Village neighbourhood in the Grand Port-Savanne District Council (GPSVDC) and to identify the problems faced by the present system.

In order to assess the present waste management system in the case study area, a face to face interview has been carried out with the Chief Health Inspector of the GPSV District Council who is responsible for the daily waste management and the following questions were asked to him:

Q1. How is the working system of waste management in the GPSV District Council?

There are 36 villages in the GPSV District Council area. These 36 villages are divided into three sections each comprising of 12 villages. Waste collection is done one time per week in each village. There is no planning of the collection routes, waste collection is done so that the service is provided to each village.

Q2. What are the methods for waste collection?

The waste is collected directly from households by waste pickers.

Q3. What types of vehicles are used in the whole system?

There are normal lorries of 5 tons capacity and compactor lorries of 5 tons capacity

Q4. How many vehicles are there in all in the GPSV District Council waste management system?

There are 16 lorries (5 tons capacity) and 4 compactor lorries (5 tons capacity)

Q5. Which categories of waste do we have in the area?

Mostly kitchen waste.

Q6. What is the waste disposal techniques used?

All collected waste is disposed of at the Mare Chicose landfill.

Q7. How many times a vehicle travels from the collection area to the landfill per day?

Q8. Is there any waste segregation for recycling?

There is no waste segregation or collection points for recyclable materials in the area.

Q9. Is there any other technique used for waste disposal?

No.

Q10. How many employees are there in your team?

Each lorry has a team attached to it. Normal lorries have 8 workers whereas compactor lorries have 4 persons.

Q11. Are the number of employees and vehicles sufficient to maintain waste in the areas allotted to you?

There is a need to increase the number of vehicles.

Q12. Is there any complaint registration system and of what type?

Rarely. Except in cases of vehicle break down or absenteeism.

Based on recent aerial photography and digital maps available at the Ministry of Housing and Lands a GIS model will be produced to give a visual display of the waste collection and transportation routes that are presently being used until final disposal at the Mare Chicose landfill. A proposal will then be made for improving the route planning for collection and transportation of waste to the landfill site.

Then based on analysis and related literature reviews a model will be proposed to using of ArcGIS software to analyse the most appropriate routes for waste collection and transportation in the case study area.