Literature Review
The theories of location
Location can outdo be described as the arrangement or siting of an activity system at a point in relation to other activity systems to which persons, corporate organic structures or an full community may patronize. A batch of theoretical accounts have been developed for the location of activities in infinite.
Walter Christaller in 1963 propounded the & A ; lsquo ; cardinal topographic point theory ‘ which explains the relationship between assortment of services and the population needed to back up it, the size of field within which such a population was contained and the size of the cardinal topographic point itself. Park and Burgess ( 1925 ) is another theoretical account of location which discusses the ecological form of location within metropoliss. Hoover ( 1937 ) in his theory explains the premise of perfect competition between manufacturers or Sellerss at anyone location and perfect mobility of factors of production and so discusses conveyance costs and production or extraction costs as the determiner of location. Colby ( 1933 ) discusses the centripetal and centrifugal forces and their consequence on concentration of certain activities.
Categorization of waste
Waste can be anything discarded by an person or administration. It can be in signifier of gas, liquid or solid. Gaseous and liquid wastes are free-flowing and can be moved by air or H2O. Solid wastes on the other manus are non. The World Health Organization ( WHO ) defines waste as anything & A ; lsquo ; the proprietor no longer wants at a given clip and infinite and which has no current or sensed market value ‘ .
Causes of addition in the coevals of solid waste
Historically, the sum of waste generated by human population was undistinguished chiefly due to the low population densenesss. With the coming of industrial revolution, waste direction became a critical issue. & A ; lsquo ; This was due to the addition in population and the monolithic migration of people to industrial towns and metropoliss from rural countries during the eighteenth century ‘ . There was a attendant addition in industrial and domestic wastes presenting menace to human wellness ( Wikipedia 2009 ) .
McLain ( 1995 ) attributes the addition in the coevals of waste to alterations in the life styles of people in the last 52 old ages. He observed that the addition in atomic households has caused more merchandises to be packaged in small-serving parts, thereby speed uping the after-consumption rate of waste. Although municipal solid waste is chiefly seen as coming from families, offices, hotels, shopping composites, schools every bit good as municipal services are seen as important. The major types of municipal solid waste are nutrient waste, paper, plastic, shreds, metal and glass ( Lant and Sherill 1995 ) .
Municipal solid waste direction
Municipal solid waste direction is one of the challenges confronting urban countries in the universe ( Ogwueleka 2009 ) . This may be attributed to the fact that collection of human colonies has the capableness to bring forth a huge volume of solid waste. In developed states, aggregation, transportation and disposal of such waste have been by and large assumed by municipal authoritiess and there are equal commissariats and direction of wastes. However, waste direction has therefore become a large issue of concern for many under-developed states, particularly as populations grow ( Omoleke 2004 ) .
The job of urban waste direction is compounded as many states continue to see rapid urbanization. Senkoro ( 2003 ) studies that the authoritiess of African states confirmed to the World Health Organisation that solid waste was identified as the 2nd most of import job ( after H2O quality ) in prioritizing environmental wellness concerns and less than 30 % of urban populations have entree to regular refuse aggregation.
The job of solid waste coevals is aggravated in Africa by the unfastened shit nature of disposing waste particularly in the slum countries of most metropoliss ( Hammer, 2003 ) . Most disposal permitted the uncontrolled dumping in abandoned prey sites with no proper and equal proviso for healthful landfill, doing immense wellness jobs ( Mato 1999, Hammer 2003 ) . A larger portion of the job is unequal informations resources for site choice and direction ( Mwanthi et al. 1997 ) .
Nature of waste direction in developing states
By and large, there is deficiency of informations in developing states in the waste sector and as a consequence it has been impossible to look into the job of deficient aggregation and improper disposal which characterise these states ( Baabereyir 2009 ) . Despite the famine of informations to carry on surveies on waste direction, surveies have revealed that all the constituents of solid waste direction are abysmal ( Baabereyir 2009 ) . In many of the big metropoliss, there is accretion of wastes on streets which is ensuing in environmental debasement and hapless environmental sanitation ( Onibokun and Kumuyi 1999, Pacione 2005 ) .
Many authors have noted that most 3rd universe states do non hold proper waste aggregation and disposal in their metropoliss. Wastes end up in drains, streets and watercourses ( Pacione 2005 ) . Pacione ( 2005 ) remarks that authoritiess in hapless metropoliss find it disputing implementing an equal proviso for aggregation and disposal of solid wastes. In his survey, it was estimated that about 50 per centum of solid wastes that are generated in 3rd universe metropoliss are non collected. Similarly, Cointreau ( 2001 ) estimates that around 60 per centum of the entire solid wastes in urban metropoliss in hapless states are non collected and therefore hold led to accumulation on streets and roads.
A survey sponsored by International Development Research Centre ( IDRC ) , Canada in 1999, in four metropoliss in Africa ( Ibadan in Nigeria, Abidjan in Ivory Coast, Dar es Salaam in Tanzania and Johannesburg in South Africa ) , reports more on the jobs of waste direction in developing states. Onibokun and Kumuyi ( 1999 ) in this survey discovered that solid wastes in the metropolis of Ibadan are found everyplace from streets to major roads and around residential countries. In the same vena, Koffi ( 1999 ) studies that merely 54 per centum of all the wastes generated in Abidjan were collected for disposal while the staying forty-six ended up choke offing up watercourses and drains. The state of affairs in Tanzania and Johannesburg is non in any manner different. Sloping and Hutt ( 1999 ) who investigated the state of affairs in South Africa concluded that accretion of waste has become a large concern for public wellness and the environment at big. In Dar Es Salaam, Kironde ( 1999 ) in his findings studies that merely a little fraction of solid wastes is collected and disposed of in the metropolis.
GIS in the direction of waste
The function of GIS in solid waste direction is really big as many facets of its planning and operations are extremely dependent on spacial informations. In general, GIS plays a cardinal function in keeping informations to ease aggregation operations. In this mode, facets such as client service, analyzing optimum locations for transportation Stationss, turn uping new landfills and supervising the landfill, are of import. GIS is a tool that non merely reduces clip and cost of site choice, but besides provides a digital information bank for future monitoring programme of the site ( Tomlinson 1990 ) .
The US Federal Integrating Committee on digital mapmaking defines GIS as & A ; lsquo ; a system of computing machine hardware, package and process, designed to back up the gaining control, direction, use, analysis and show of spatially referenced informations for work outing complex planning and direction job ‘ . There can be small uncertainty that the GIS attack has broad pertinence in all kinds of location jobs where the end is to understate handiness to a population ( Jensen and Christense 1986, Openshaw et Al. 1989 ) . A peculiarly good application of GIS is the hunt for possible sites for the disposal of wastes ( Masser and Blakemore 1991 ) .
Waste direction rating in Ibadan North
The common disposal methods for solid wastes in Ibadan North include disposal in unfastened mopess ( Figure 2a ) and disposal by the wayside ( Figure 2b ) .
Illegal shit sites
The prevalence of illegal garbage dumps particularly in the interior portion is a beginning of concern to everyone who cares about healthy life. Topographic points like Yemetu and Agbadagbudu are filled with indiscriminate dumping of garbage. For case, around Ibadan house in Ijokodo, there are four illegal garbage dumps, each of them separated by an mean distance of about 80 meters ( Figure 2a ) . Peoples interviewed informally lamented that the authorities did non supply any installation for waste aggregation therefore the major ground why the waysides are littered with garbage ( Figure 2b ) .
Improper usage of skips by occupants
In some topographic points where skips are provided, occupants frequently abuse such installations. They litter the milieus of the skips with all kinds of waste even without the skips acquiring filled up in some countries ( Figure 2b ) . They throw their waste far off from the location of the skip bins, littering the whole topographic point with waste.
Handiness
Accessibility is of great importance in turn uping installations in infinite. The unplanned nature of the country makes location of installations really hard. The solid waste aggregators complained that some topographic points can non be reached particularly the interior portion of Ibadan North.
GIS based site choice
Nathanat, et Al. ( 1998 ) points out & A ; lsquo ; that the efficaciousness of solid waste disposal depends upon choice of proper site and that there are several issues that have impact for site choice & A ; lsquo ; which includes, economic, societal and environmental. Mahoney ( 1991 ) references that it is within the kingdom of GIS to supply determination support systems, which are capable of being used by applied scientists, contrivers, and policy shapers to find the optimal effectual solution to spacial jobs.
Site choice analysis can be improved by utilizing GIS. GIS is a suited tool for site
choice since it has the capableness to pull off big sum of spacial informations that comes from assorted beginnings. Kao et Al. ( 1996 ) points out that big sum of spacial informations can be processed utilizing GIS and therefore, it potentially saves clip that would usually be spent in choosing an appropriate site, while Daneshvar et Al. ( 2005 ) claim that GIS is an ultimate method for preliminary site choice as it expeditiously shops, retrieves, analyses and shows information harmonizing to user-defined specification. However, GIS can be limited by the bing beginnings of informations needed in locating analysis.
Many attacks have been employed in looking for the perfect site for an activity. Most of these attacks to a great extent rely on mathematics and optimisation techniques. Since, site choice is a spacial job, mathematics and optimization techniques are frequently unequal to offer acceptable solution because of their failure to integrate all relevant facets of the job in the overall model. An alternate model that is capable of deciding site choice is Geographic Information Systems.
GIS has been successfully applied in the yesteryear for site choice for which certain demands have to be fulfilled ( Burrough 1983, Despotakis and Economopoulos 2007 ) . Examples include turn uping air current farms in a part ( Baban and Parry, 2001, Bennui et Al. 2007 ) . The cardinal analytical map of a GIS based spacial determination support system include query analysis, propinquity or buffer analysis, sheathing analysis, neighbourhood analysis and web analysis. Assorted combinations of these maps are normally used during the geographical informations analysis procedure ( BESR 2002 ) .
An overview of multiple standards determination devising ( MCDM )
The usage of sophisticated determination devising tools for municipal solid waste direction has increased well ( Everett and Modak 1996, Revelle et Al. 1997, Chandrakanthi et Al. 2002 ) . Multi criteria determination devising ( MCDM ) is a term including multiple attribute determination devising ( MADM ) and multiple nonsubjective determination devising ( MODM ) . MADM is applied when a pick out of a set of distinct actions is to be made. In MODM, it is assumed that the best solution can be found anyplace in the executable options infinite, and hence is perceived as a determination job which is uninterrupted in nature ( Eldrandaly et al. , 2005 ) . MADM is frequently referred as multi-criteria analysis ( MCA ) or multi-criteria rating ( MCE ) .
The chief aim of MCDM is & A ; lsquo ; to help the decision-maker in choosing the & A ; lsquo ; best ‘ option from the figure of executable choice-alternatives under the presence of multiple standards and diverse standard precedences ‘ ( Jankowski 1995 ) . Every MCDM technique has common process stairss, which are called a general theoretical account ( Jankowski 1995 ) . This process includes the undermentioned actions:
- Deducing a set of options
- Deducing a set of standards
- Estimating impact of each option on every standard to acquire standard tonss
- Explicating the determination tabular array with usage of the distinct options, standards and standard tonss
- Stipulating decision-maker ‘s penchants in the signifier of standard weights
- Aggregating the information from the determination tabular array in order to rank the options
- Performing sensitiveness analysis in order to cover with impreciseness, uncertainness, and inaccuracy of the consequences
- Making the concluding recommendation in the signifier of either one option, reduced figure of several & A ; lsquo ; good options ‘ , or a ranking of options from best to pip.
All the MCDM techniques are based on the below presented general theoretical account.
Multi-criteria determination devising and GIS.
Spatial determinations are multi-criteria in nature ( Nijkamp 1979, Nijkamp and Rietveld 1986, Chakhar and Mousseau 2008, ) . Many existent universe ‘s & A ; lsquo ; spatially related jobs give rise to geographical information system based multi-criteria determination devising. Although Geographic information systems and multi-criteria determination devising have developed mostly independently, a tendency towards the geographic expedition of their synergisms is now emerging & A ; lsquo ; ( Drobne and Lisec 2009 ) . GIS and MCDM presently stand to be the two most common determination support tools that are used in work outing spacial decision-making jobs.
Multi-criteria Evaluation ( MCE ) is a determination support technique where a determination is a pick between options. The footing for a determination is known as a standard, and this can be measured or evaluated ( Drobne and Lisec 2009 ) . In MCE, & A ; lsquo ; effort is made to unite a set of standards to accomplish a individual composite footing for a determination harmonizing to a specific aim ‘ ( Sharif 1995 ) .
The set of rating standards for a peculiar determination job may be developed through an scrutiny of relevant literature, analytical survey and sentiments ( MacCrimmon 1969, Keeney and Raiffa 1976, Pitz and McKillip 1984 ) . A study of sentiments may besides be utile in choosing standards ( Keeney and Raffia 1976 ) . Malczewski ( 1999 ) suggests that people that will be straight affected by site choice can be asked to stipulate the standards that should be included in a determination analysis.
Multi-criteria determination doing techniques, as standalone tools, have been computerised, and today there is much package to utilize ( e.g. Super Decision package ) . However, such package is capable of managing spacial job in the signifier of maps. By and large talking, multi-criteria rating with the usage of GIS can be done in two phases, ( I ) study and ( two ) preliminary site designation. In the first measure, the country is screened for executable options. Here, all the sites which meet all the exclusion standards ( restraints ) are identified. This phase is sometimes referred as suitableness analysis, traditionally performed by manual map sheathing, farther revolutionised by GIS digital maps.
The 2nd phase, called preliminary site designation, is operationalised by MCE techniques. First, secondary posing factors are elaborated and so weighted harmonizing to their importance. The 2nd phase allows managing multiple nonsubjective jobs ( Carver 1991, Jankowski 1995 ) .
Surveies on GIS and installation siting
Several techniques that use GIS for landfill site choice have been found in the literature ( Kao et al. 1996, Basagaoglu et Al. 1997, Kao et Al. 1999, Kontos et al. 2003, Sener 2004, ) . A suitableness analysis for turn uping a landfill site was carried out in Larimer county of Colorado, USA. Several locating factors were considered in geting at a suited site in the survey. Criteria like H2O organic structures, airdrome, propinquity to habitat and endangered species, suitableness of dirt, distance to population Centres, lift and cost were put into consideration. The methodological analysis employed includes GIS and MCDA. GIS was used to place campaigner sites while MCDA method assisted in taking the best option from a figure of options ( Herzog 1999 ) .
GIS was used by Gaim ( 2004 ) as determination support tool in doing determination about landfill locating in Malaysia. Factors for locating include roads, unfastened H2O, residential countries, dirt types, landuse and distance from transit paths. It was impossible to include incline in these factors as there was no digital information for analysis. A two phase multi-criteria rating was used in Western Macedonia to besides choose a landfill site for waste disposal. ArcView 3.2 tools were used in uniting different land-use maps. Several other restraints maps were besides considered. In geting at the most suited option, the research workers used quality of life indexs ( economic efficiency, proficient and environmental standards ) . Multi-criteria ranking technique was besides used to choose possible sites ( Vitalis and Manoliadis 2002 ) .
Analytic Hierarchical Process ( AHP )
& A ; lsquo ; Selection of the best alternate frequently requires the usage of MCDM techniques ‘ ( Jankowski 1995 ) . AHP is one of the most effectual MSDM methodological analysiss ( Lirn 2003 ) . The AHP was developed by Thomas Saaty ( 1990 ) and has been applied to state of affairss that involve decision-making in both the private and public sector. It is really straightforward and comprehensive, doing the determination rating easy to pass on to relevant stakeholders. The AHP theoretical accounts a determination devising job and allows the inclusion of touchable and intangible objects ( Mu 2005 ) . The top component of the hierarchy is the end for the determination theoretical account.
The AHP methodological analysis is a flexible tool that can be applied to any hierarchy of public presentation steps. Zimmermann ( 1991 ) is of the position that most MCDM attacks consist of two stairss: ( 1 ) collection of the opinions with regard to all ends and decision-making options ; and ( 2 ) ranking of the determination options based on the judgement mark.
Application of AHP in choosing best alternate
The AHP has been diversely applied in the literature. While its advantages have been extensively discussed in Saaty ( 2001 ) , Chang and Yeh ( 2001 ) , Vreeker et Al. ( 2002 ) and Yedla and Shrestha ( 2003 ) applied it to work out transit jobs. Yelda and Shrestha in their effort examined the impact of including assorted qualitative standards for the choice of alternate transit option in the capital metropolis of India where urban transit is a job due to rapid urbanization and pullulating population. Using three alternate conveyance options ( 4-stroke 2-wheelers, CNG autos and CNF coachs ) based on six different standards ( energy, environment, cost, engineering, adaptability and barrier ) , CNG auto showed more possible in lending to environmentally sustainable conveyance system.
Ulutas ( 2005 ) uses the Super Decision package in measuring the public presentation of airdromes in Turkey. Pairwise comparings for all the standards used were carried out and comparings were made based on Saaty ‘s cardinal graduated table ( Saaty, 1980 ) . The writer was able to choose the most of import factors that contribute to airport public presentation in Turkey. In the same state, Banar et Al. 2007 in taking a municipal landfill site for the metropolis of Eskisehir used the Super Decision package to analyze the benefit, chance, cost and hazard of each alternate site chosen for their survey. Within the context of their work, four sites were assessed based on proficient, economical and societal factors utilizing the Analytical Network Process. At the terminal of the analysis, based on the consequences from both AHP and ANP, the site which was presently in usage was found to be the best option. The survey concluded that utilizing & A ; lsquo ; Super Decision ‘ package could lend vastly to determination devising procedures.
