SITE SUITABILITY ANALYSIS FOR SOLID WASTE DISPOSAL IN PORT HARCOURT

CHAPTER ONE

INTRODUCTION

Background of the Study

Waste is a material discharged and discarded from each stage of daily human life activities, which leads to adverse impacts on human health and the environment (Bringi, 2007); whereas, solid waste refers to the leaves/ twinges, food remnants, paper/cartons, textile materials, bones, ash/dust/stones, dead animals, human and animal excreta, construction and demolishing debris, biomedical debris, household hardware (electrical appliances, furniture, etc) (Sha’Ato et al., 2007; Babatunde et al., 2013). Solid waste is a global environmental problem in today’s world both in less developing and developed countries. Increasing population, rapid economic growth and the rise in community living standards accelerate solid waste generation in the world (Elmira et al., 2010). Solid waste disposing is an important part of waste management system, which requires much attention to

avoid environmental pollution and health problems. However, most solid waste disposal sites are found on the outskirts of the urban areas where there are water bodies, crop filed, settlement, around road, etc. These are suitable sites for the incubation and proliferation of flies, mosquitoes and rodents. They transfer diseases that affect human health (Abul, 2010). Inappropriate disposal of solid waste can be manifested by conta-mination of surface and ground water through leachate, soil contamination through direct waste contact, air pollution by burning of wastes, spreading of diseases by different vectors like birds, insects and rodents, or uncontrolled release of methane by anaerobic decomposition of waste (Visvanathan and Glawe, 2006). Solid wastes indiscriminately thrown resulted also in aesthetic problems, nuisance, and pollution of land and water bodies of an area (Hammer, 2003). Therefore, locating proper sites for solid waste disposal and selecting appropriate landfill site far from residential areas, environmental resources and settlement is the main issue for the management of solid waste. One way to dispose solid waste is to place it in properly designed, constructed, and managed landfills, where it is safely contained. African nations (with the exception of South Africa) had the fewest engineered landfills, with most nations practicing open dumping for waste disposal. So as to identify appropriate site, several studies have indicated that slope less than 12% would be suitable for the prevention of contaminant runoff. This will reduce the amount of earth moving required during landfill construction, thereby reducing the overall costs. Similarly, most studies suggested that the solid waste dumping site should be located within a 1 km buffer from the roads and other transportation facilities (Chang et al., 2008). Also, solid waste disposal sites should not be placed too far from the roads to decrease the cost of transportations. Solid waste disposal site should not be placed too close to settlement areas and recreation centers. The finding in Turkey by Sener et al. (2011) had shown that the distance between disposal sites and settlement areas must be more than 1000 m and the haul distance between the solid disposal site and the main city centre should not exceed 30 km. Land use types such as grassland, forests, agricultural land, wet land, bush lands would be considered and assigned an appropriate index of land use suitability. The importance of minimizing the association of conflicting land-use (LU) in solid waste disposal siting can be realized by reviewing locally unwanted land-use areas. Public acceptance of unwanted facility sitings vary with land-use (Baban and Flannagan, 1998). However, selecting appropriate site and managing the solid waste dumping in countries like Ethiopia with limited financial and rapid population growth rate is more severe. Degnet (2008) stated that, like in many other developing Ebistu et al. 977 countries, the majority of inhabitants in most towns of Ethiopia often use unsafe solid waste disposal practices, such as open dumping, burning and burying. As a result, many households practice uncontrolled open dumping and others employ various household solid waste disposal practices, such as burning, burying and composting. However, all self-managed waste disposal practices do not guarantee cleanliness and safety. For example, burning one’s trash can give rise to significant albeit localized, negative externalities, like air pollution depending on how it is burned, local hydrology, etc. Similarly in Bair Dar town, the study area, there are problems of solid waste disposal sites. Even if most of the solid wastes are collected from the source using push carts to the temporary transfer stations, there are no scientifically approved sites. There are no standard transfer stations in the city. All health institutions and industries follow their way of removal of waste, while some others dispose it to the nearby water body, Abay/Blue Nile and Lake Tana. The dumping sites are not well planned, and they are open field disposal (no sanitary landfill), are close to rural settlements and not at appropriate distance from the center of the city. In order to alleviate these problems, integrating GIS and remote sensing techniques to select the best possible solid wastes dumping is a recent essential technology. The selection of solid waste disposal sites using GIS and remote sensing requires many factors that should be integrated into one system for proper analysis. The selection criteria should consider and combine surface water, soil type, slopes, settlements, groundwater, protected areas, land use and road networks. However, because of absence of data geology, groundwater data were not included in the study. Remote sensing can provide information about the various spatial criteria such as land use/land cover, drainage density, slope, etc (Emun, 2010), where as GIS aided utilizing and creating the digital geodatabase as a spatial clustering process and easily understood way for solid waste dumping site selection process. In multicriteria evaluation many data layers are to be handled by GIS and remote sensing in order to arrive at the suitable site, this can be achieved conventionally using GIS. Therefore, the study was aimed at providing suitable solid waste disposal sites by using GIS and remote sensing techniques in order to minimize risk of ecological and human health problem from Bahir Dar. It is also helpful to set appropriate selection criteria for the identification of new solid waste dumping sites through scientific methods.

Statement of the Problem

Rapid population growth and urbanization has increased the volume and range of residential and commercial solid waste generated in Port Harcourt Municipal area. The handling and disposal of this large waste with conventional methods have become increasingly difficult.

The recurrent problem of solid waste management in our urban areas has lead to the issue of environmental sanitation gaining popular concern in Nigeria and the outside world so as to bring about a distinction between the volume of solid waste actually generated and the rate at which it  is evacuated or disposed or left to accumulate.

In Port Harcourt Municipal, there are few, less significant and inadequately positioned Solid wastes are disposed indiscriminately often in open spaces such as playgrounds, market places, roadside, river banks, gutters (during heavy rainfalls), most of which pile up and later block or choke the city drainage lines. Thus, there is need to create and an ideal environment where solid waste disposal and transportation could work to contribute to a clean environment.

The selection of suitable sites for solid waste disposal is the focus of this project. The choice of this project is Port Harcourt municipal due to the need to plan for an effective waste disposal in the area to avoid environmental hazards and improper disposal of waste. Moreover, since the present administrations major programme is ensuring a clean and healthy environment, GIS technology can thus aid in locating the suitable sites for solid waste disposal. This work is therefore designed to apply GIS in site selection of dumping sites for effective solid waste management in Port Harcourt municipal.

Significance of the study

The main benefit of this study is to provide an assessment of sites for solid waste disposal within the Port Harcourt, in terms of present and future capacity that will create an ideal environment for the Port Harcourt community. Locating a suitable site or land fill within the Port Harcourt will also reduce the cost of transporting solid wastes disposal. This will reduce the damage caused by pollution and provide a facility which would not endanger any environmentally sensitive areas  or have a negative impact on existing or future land use within the Port Harcourt.

Aim and Objectives of the Study

The aim of this project is to develop a GIS based site suitability analysis for solid waste disposal in Port Harcourt using Remote sensing and Geographical Information system (GIS).

In order to achieve this aim, the following objectives are followed

1. To generate a Digital Elevation Model of the study area.
2. To create Land cover classification map of Port Harcourt. (iii)To develop a GIS model for the suitable site(s)

Scope of the Study

The potential of selecting solid waste disposal site was limited to Port Harcourt made up of  Port Harcourt north, Port Harcourt south and Port Harcourt east Local Government Area. The present method elevates the entire study area using custom scale of 1 to 3(1-3) where 1 denotes a site fully unsuitable for solid waste disposal site while 3 shows optimum for dumping site. The utilization of zonal land suitability method is an innovation in a landfill sitting process. The criteria for determining the potential solid waste disposal site includes these factors i.e. roads, rivers, slope, land use (built- up). The scope however comprises data conversion from analogue to digital format of acquired data which were in hard copies, through digitizing, and the geographical analysis using ArcGIS 9.3.

Study Area

The study area is Port Harcourt; Port Harcourt  urban is the  capital city  of Port Harcourt  state  Nigeria . It  falls within the geographic coordinate of the Lat. 6°19’54’’N and 6°32’24’’N and Long. 7°22’57’’E and 7°35’36’’E .It is located in the  south  eastern geopolitical zone  of  Nigeria  and it is largely populated by  members of the  Igbo ethnic group , one of the  largest ethnic  groups  in Nigeria.  It has a very large population, about 722,664 (2006  census) .Port Harcourt   urban consist  of three local government area,  which is Port Harcourt  north,  Port Harcourt  east , Port Harcourt  south.