Landfill sites selection using MCDM and comparing method of change detection for Babylon Governorate, Iraq

Literature analysis of the location selection studies related to the waste facilities within MCDM approaches

The increase in waste and related environmental problems is one of the major problems compromising health and environmental quality in urban and rural areas. There are a number of policies that can be implemented to reduce waste, but since it cannot be completely eliminated, recycling and disposal facilities for waste will always be required. Researchers and professionals are currently grappling with the issue of where to locate waste facilities. In the light of all this information, a literature review is presented so that researchers can easily access and systematically review previous studies on the waste facility location selection problem. At this point, in order to reduce the reviewed studies to a reasonable level and to conduct a more organized research, this literature research has conducted within the framework of multi-criteria decision-making (MCDM) approaches, which is one of the most applied methods in location selection problems. The subsequent strengths, weaknesses, opportunities, and threats (SWOT) analysis delves into the strengths, weaknesses, opportunities, and threats in the field, offering a concise guide for future research in waste facility location selection problem. The SWOT analysis highlights the strengths of global environmental awareness and versatile MCDM approaches, while addressing weaknesses in emerging technology integration and potential biases. Opportunities for interdisciplinary collaboration and integration of sustainability metrics provide strategic pathways, but threats such as regulatory changes and limited funding underscore challenges. This analysis serves as a concise guide for future research in waste facility location selection.

Assessment of inorganic solid waste management techniques using full consistency and extended MABAC method

Population and industrial growth have spiked product consumption, which in turn have caused an abrupt rise in municipal solid waste (MSW) production. Due to the lack of resources allocated to waste management, municipal inorganic solid waste (ISW) has increased exponentially, posing a significant strain on the environment and health. To mitigate these issues, sustainable waste management strategies need to be implemented to reduce environmental impacts and improve waste collection and disposal efficiency. The objective of our work was to analyse and identify the most effective techniques for disposing of ISW in India by employing multi-criteria decision-making (MCDM). This technique entails selecting the most suitable alternative based on a variety of competing and interactive criteria. A fusion decision model named the FULL COnsistency Method (FUCOM) and Multi-Attributive Border Approximation area Comparison (MABAC) based on the interval-valued q-rung orthopair fuzzy (IV q-ROF) was developed. Finally, a comparative analysis was performed to demonstrate the system's robustness.

Landfill site selection using MCDM methods and GIS in the central part of the Nile Delta, Egypt

One of the most prevalent and serious issues afflicting developing countries is the lack of adequate space for waste disposal. Al-Gharbia Governorate, located in the middle of the Nile Delta in Egypt, suffers from random selection of sites for solid waste disposal, resulting in significant environmental challenges. The aim of this study is to determine optimal landfill locations within Al-Gharbia Governorate and validate the existing landfill sites. Four techniques of multi-criteria decision-making (MCDM) were applied to generate suitability maps for the Governorate: the analytical hierarchy procedure (AHP), ratio scale weighting (RSW), straight rank sum (SRS), and Boolean method. Eleven effective criteria were considered: groundwater, surface water, elevation, slope, soils, land use, roads, railways, urban areas, villages, and power lines. The suitability maps were categorized into four different classes: suitable, moderately suitable, low suitable, and unsuitable. The latest suitability map was determined by combining the results from the different methods, providing decision-makers with the means to select the optimal landfill site. The suitable zone encompasses a small area (3%), predominantly located in the northeast region (Al-Mahalla), central region (Tanta), and northern region (Kotour). Conversely, the unsuitable area covers a substantial portion (72.7%) due to the agricultural nature of the governorate, high population density, and elevated groundwater levels. Furthermore, all existing landfill sites fall within unsuitable or low suitable areas, inflicting severe impacts on the nearby environment, public health, and groundwater integrity.

Site suitability analysis for sanitary landfills using geospatial methods in a part of southern Peninsular Malaysia

Globally, around 1.3 billion tonnes of waste are generated annually, and solid waste management has thus become a major concern worldwide. There are projections of a 70% increase in waste generation from 2016 to 2050 owing to urbanization and the rapid growth of the global population. Estimates indicate that around 38,200 tonnes of waste are generated per day in Malaysia, and this volume of waste is significantly shortening the planned life spans of operating sanitary landfills in the country. Batu Pahat is a district in the state of Johor, Malaysia, with a relatively large population of 495,000 and with no record of an operational sanitary landfill. This study was conducted to identify and classify the most suitable sites for sanitary landfill developments in southern Peninsular Malaysia by means of the Analytical Hierarchy Process (AHP), which is recognized as a competent technique for multicriteria decision-making. The resulting landfill site suitability index map established 33.88 km2 of area coverage as very highly suitable for landfill development, while 353.86 km2 of area coverage was classified as unsuitable. Sites 1-6 were identified as the most suitable for landfill activities. Sites 1-5 are situated in agricultural land areas, while site 6 is in a forested land area; this implies public participation and the adoption of compensatory measures in the event of landfill development in these areas, given their socioeconomic importance. The six suitable sites are all at least 2000 m from rivers: 2000-3000 m for sites 1, 3, and 5 and > 3000 m for sites 2, 4, and 6. The six sites are all > 3000 m from fault zones and > 1000 m from flood-prone areas, meaning that occurrences such as fault movements and flooding will have minimal impact on the operational activities of landfills at these sites. The selection of sites 1-6 as very suitable for landfill development was associated with an overall accuracy rating of 93.33% and kappa coefficient score of 0.92 based on accuracy assessment analysis of all sites. This study will guide the actions of policymakers, city planners, and local authorities toward sustainable and environment-friendly landfill development and operation in Batu Pahat and other districts in the state of Johor.

Identification of Suitable Land for Livestock Production Using GIS-Based Multicriteria Decision Analysis and Remote Sensing in the Bale Lowlands, Ethiopia

Rangeland resources of the Bale lowlands have been degraded due to climate change, human factors, lack of sufficient environmental and rangeland policies, disaster mitigation strategies, and good management. The study identified suitable rangeland for cattle, sheep, goat, and camel production in the Bale lowlands using GIS-Based Multicriteria Decision Analysis and remote sensing techniques. Land-use and land-cover, rainfall, water accessibility, slope, and soil types were used for the suitability analysis. The study showed that an area of 4112, 16311, 6643, and 9820 km2 was highly suitable for cattle, sheep, goats, and camels, respectively. The results of the study also indicated that an area of 40099, 30925, 41981, and 36802 km2 was moderately suitable for cattle, sheep, goats, and camels, respectively. In addition, an area of 7644, 4671, 3630, and 5632 km2 was marginally suitable for cattle, sheep, goats, and camels, respectively. On the other hand, an area of 399 and 346 km2 was not suitable for cattle and sheep, respectively. The study is important for improving livestock production and mitigating the impacts of traditional livestock mobility on local communities. The study can also provide insights for government authorities to formulate environmental and rangeland policies to identify rangeland types and separate the rangeland for each livestock category.

Site selection of municipal solid waste incineration plant using GIS and multicriteria decision analysis

Fast population growth and urbanization has increased the generation of municipal solid waste in Oman. Currently, Oman relies on landfills to handle growing amounts of waste, which has burdened the existing solid waste management infrastructure. This situation calls for establishing incineration plants that can considerably reduce the volume of waste, and can simultaneously produce electricity. However, one of the crucial steps in the planning of an incineration plant is the selection of an appropriate site that can overcome environmental and economic implications and eliminate community dissatisfaction. Therefore, to select an optimal site for incineration plant in Muscat and South Batinah governorates, where landfills receive the highest waste amounts per day, this research identified 11 criteria that cover the environmental, economic, and social concerns. These criteria were processed by combining the multicriteria decision making (MCDM) method and geographical information system (GIS) software where the suitability of individual criteria were evaluated and then integrated using the weighted overlay analysis to generate a final suitability map for incineration site selection. The final suitability map indicated that only 2% of the land is suitable for setting up an incineration plant in the study area, and the most suitable location with adequate area was found in Barka wilaya of South Batinah governorate.Implications: Due to the escalation in MSW generation, Oman is looking for alternative strategies to reduce the volume of MSW. This has led to country's interest in establishing a waste-to-energy plant (particularly incineration) in the future. However, locating a suitable site for the installation of an MSW incineration plant in Oman has never been studied before. Therefore, to bridge the gap in knowledge, this research focuses on selecting a suitable site for a municipal solid waste incineration plant using GIS and multicriteria decision analysis. This study highlights the suitability of Muscat and North Batinah governorates of Oman where landfills receive huge amounts of MSW on a daily basis and are close to becoming saturated. Moreover, the suitability of land in both governorates is assessed to overcome environmental and economic implications and eliminate community dissatisfaction. This research not only provides the level of suitability of land in both governorates, but also selects a suitable site, which will be beneficial for the government of Oman in future when making a decision regarding the location of the plant.

Geospatial Analysis of Land Use/Cover Change and Land Surface Temperature for Landscape Risk Pattern Change Evaluation of Baghdad City, Iraq, Using CA–Markov and ANN Models

Understanding future landscape risk pattern change (FLRPC) scenarios will help people manage and utilize natural resources. In this study, we have selected a variety of landscape and anthropogenic factors as risk parameters for FLRPC assessment. Land use/cover change (LUCC) and land surface temperature (LST) are regarded as significant factors that have resulted in large-scale environmental changes. Result analysis of the previous LUCC from 1985 to 2020 showed that construction land and water body (WB) increased by 669.09 and 183.16 km2, respectively. The study continues to predict future LUCC from 2030 to 2050, in which the result has shown that a large land use conversion occurred during the future prediction period. In addition, the LST forecasting analysis illustrated that the previous LST maximum and minimum are 38 °C and 15 °C, which will be increased to 40.83 °C and 26.25 °C in the future, respectively. Finally, the study used the weighted overlay method for the FLRPC analysis, which applies analytic hierarchy process techniques for risk evaluation. The FLRPC result demonstrated that Baghdad City is in the low-risk and medium-risk to high-risk categories from 2020 to 2050, while AL and BL are in the very-high-risk categories. Meanwhile, WB and NG have always been safe, falling into the very-low-risk and low-risk categories from 2020 to 2050. Therefore, this study has successfully assessed the Baghdad metropolitan area and made recommendations for future urban development for a more safe, resilient, and sustainable development.

MCA and geospatial analysis-based suitable dumping site selection for urban environmental protection: A case study of Shambu, Oromia Regional State, Ethiopia

A lack of suitable dumping sites in a town or city can have an impact on the health of the residents as well as the quality of the urban environment. There are no identified dumping sites in this study area that meet scientific or urban standards. Residents are dumping solid waste into ditches, roads, public water sources, and small streams. The solid and liquid wastes generated by residential areas, state prisons, religious areas, public markets, and business centers have a negative impact on the town. The purpose of this study is to demonstrate the novelty of using Multi-Criteria Analysis (MCA)-based geospatial analysis to select suitable dumping sites in Shambu town. Key factors for dumping site selection, such as LULC, road networks, private well locations, slope, geomorphology, geology, soil texture, drainage density, and lineament density, were confirmed as geospatial analysis criteria. In the Analytical Hierarchy Process (AHP), the importance of the key factors was weighted and prioritized, and thematic maps were created using weighted overlay analysis. The suitable dumping sites were identified using qualitative classifications such as ^“highly suitable^” (13.84%), ^“moderately suitable^” (7.35%), ^“less suitable^” (30.41%), and ^“not suitable^” (48.40%). The consistency of AHP was determined to be CI = 0.012, indicating that the weights assigned to each factor were correct. As a result, the use of geospatial and MCA analysis for dumping site suitability analysis was successful, and the findings of this study will be useful in taking action to reduce the impacts of solid waste by developing dumping plants on the identified sites.

A spatial decision support system for municipal solid waste landfill sites (case study: The Mazandaran Province, Iran)

Landfilling is an inevitable step for the municipal solid waste (MSW) management system in developing countries. This article presents a Spatial Decision Support System (SDSS) that was developed for the monitoring of municipal landfills and siting the new places for waste disposal at Mazandaran province, south of Caspian Sea, Iran. The effective criteria and evaluation constraints were chosen according to the Iran waste management law. The ArcGIS 10.4.1 software was used for creating a geospatial database and the analytic hierarchy process (AHP) was used for ranking the criteria. By integrating the criteria, a suitability map was generated into four categories: high suitability, moderate suitability, low suitability and illegal areas. Using ArcGIS online, the maps were shared on a website that was specifically designed for this purpose. The decision-makers can check online the laws, the effective criteria and the results of spatial analysis for optimal siting. Also, the results of environmental evaluations for active landfills have been provided. Given the characteristics of active landfills and the optimal sites for the possible development, the SDSS can provide a mutually beneficial relationship between the experts, decision-makers and stakeholders to decide about the priority of actions required for the relocation of landfills, site closure or emergency care.

A Cluster-based Stratified Hybrid Decision Support Model under Uncertainty: Sustainable Healthcare Landfill Location Selection

Nowadays, healthcare waste management has become one of the significant environmental, health, and social problems. Due to population and urbanization growth and an increase in healthcare waste disposals according to the growing number of diseases and pandemics like COVID-19, disposal of healthcare waste has become a critical issue. Authorities in big cities require reliable decision support systems to empower them to make strategic decisions to provide safe disposal methods with a prospective vision. Since inappropriate healthcare waste management systems would definitely bring up dangerous environmental, social, health, and economic issues for every city. Therefore, this paper attempts to address the landfill location selection problem for healthcare waste using a novel decision support system. Novel decision support model integrates K-means algorithms with Stratified Best-Worst Method (SBWM) and a novel hybrid MARCOS-CoCoSo under grey interval numbers. The proposed decision support system considers waste generate rate in medical centers, future unforeseen but potential events, and uncertainty in experts’ opinion to optimally locate required landfills for safe and economical disposal of dangerous healthcare waste. To investigate the feasibility and applicability of the proposed methodology, a real case study is performed for Mazandaran province in Iran. Our proposed methodology could efficiently deal with 79 medical centers within 4 clusters addressing 9 criteria to prioritize candidate locations. Moreover, the sensitivity analysis of weight coefficients is carried out to evaluate the results. Finally, the efficiency of the methodology is compared with several well-known methods and its high efficiency is demonstrated. Results recommend adherence to local rules and regulations, and future expansion potential as the top two criteria with importance values of 0.173 and 0.164, respectively. Later, best location alternatives are determined for each cluster of medical centers.

Remote Sensing-Based Urban Sprawl Modeling Using Multilayer Perceptron Neural Network Markov Chain in Baghdad, Iraq

The global and regional land use/cover changes (LUCCs) are experiencing widespread changes, particularly in Baghdad City, the oldest city of Iraq, where it lacks ecological restoration and environmental management actions at present. To date, multiple land uses are experiencing urban construction-related land expansion, population increase, and socioeconomic development. Comprehensive evaluation and understanding of the effect of urban sprawl and its rapid LUCC are of great importance to managing land surface resources for sustainable development. The present research applied remote sensing data, such as Landsat-5 Thematic Mapper and Landsat-8 Operation Land Imager, on selected images between July and August from 1985 to 2020 with the use of multiple types of software to explore, classify, and analyze the historical and future LUCCs in Baghdad City. Three historical LUCC maps from 1985, 2000, and 2020 were created and analyzed. The result shows that urban construction land expands quickly, and agricultural land and natural vegetation have had a large loss of coverage during the last 35 years. The change analysis derived from previous land use was used as a change direction for future simulation, where natural and anthropogenic factors were selected as the drivers’ variables in the process of multilayer perceptron neural network Markov chain model. The future land use/cover change (FLUCC) modeling results from 2030 to 2050 show that agriculture is the only land use type with a massive decreasing trend from 1985 to 2050 compared with other categories. The entire change in urban sprawl derived from historical and FLUCC in each period shows that urban construction land increases the fastest between 2020 and 2030. The rapid urbanization along with unplanned urban growth and rising population migration from rural to urban is the main driver of all transformation in land use. These findings facilitate sustainable ecological development in Baghdad City and theoretically support environmental decision making.

Sanitary landfill site selection by integrating AHP and FTOPSIS with GIS: a case study of Memari Municipality, India

Sanitary landfill is still considered as one of the most significant and least expensive methods of waste disposal. It is essential to consider environmental impacts while selecting a suitable landfill site. Thus, the site selection for sanitary landfill is a complex and time-consuming task needing an assessment of multiple criteria. In the present study, a decision support system (DSS) was prepared for selecting a landfill site in a growing urban region. This study involved two steps of analysis. The first step of analysis involved the application of spatial data to prepare the thematic maps and derive their weight. The second step employed a fuzzy multicriteria decision-making (FMCDM) technique for prioritizing the identified landfill sites. Thus, initially, the analytic hierarchy process (AHP) was used for weighting the selected criteria, while the fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS) was applied for addressing the uncertainty associated with decision-making and prioritizing the most suitable site. A case study was conducted in the city of Memari Municipality. The main goal of this study was the initial evaluation and acquisition of landfill candidate sites by utilizing GIS and the following decision criteria: (1) environmental criteria consisting of surface water, groundwater, land elevation, land use land cover, distance from urban residence and buildup, and distance from sensitive places; and (2) socioeconomic criteria including distance from the road, population density, and land value. For preparing the final suitability map, the integration of GIS layers and AHP was used. On output, 7 suitable landfill sites were identified which were further ranked using FTOPSIS based on expert's views. Finally, candidate site-7 and site-2 were selected as the most suitable for proposing new landfill sites in Memari Municipality. The results from this study showed that the integration of GIS with the MCDM technique can be highly applied for site suitability. The present study will be helpful to local planners and municipal authorities for proposing a planning protocol and suitable sites for sanitary landfill in the near future.

Evaluation of landfill sites using GIS-based MCDA with hesitant fuzzy linguistic term sets

There are many criteria to be considered in environmental, social, and economic issues for the landfill site selection (LSS). Multi-criteria decision analysis (MCDA) methods are often used to solve complex decision-making problems such as LSS. However, decision-makers (DMs) may hesitate during the evaluation of the landfill sites with possible incorrect evaluation concerns. Therefore, the inclusion of the hesitant fuzzy linguistic term sets (HFLTS), which considers the hesitations in the preferences of DMs, is suitable for the solution of the problem. On the other hand, geographic information systems (GIS) is an important decision support tool that can analyze different types of spatial data. The aim of this study is to evaluate landfill sites. To do so, the applied approach includes the processes of identifying appropriate alternative sites for landfills by combining HFLTS-based MCDA method and GIS and evaluation of alternative sites with Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The applicability of the proposed approach is tested on Samsun city, Turkey. As a result, scenario analysis, which is dominated by environmental criteria, provides better results dominated by social-economic criteria. Consequently, 12 alternative locations are selected and evaluated for the LSS. Atakum and Canik districts of Samsun city are determined as very suitable locations for landfill sites.

Multi-period evaluation and selection of rural wastewater treatment technologies: a case study

Rapid population growth and agricultural development are generating a considerable amount of effluents, which poses threats to the quality of rural water resources as well as sanitary conditions. However, with a range of rural wastewater treatment (WT) technologies available, one major problem facing the practitioners is which to choose as the most favorable option suited to specific areas. In this study, a novel decision-making framework is proposed to evaluate and select the optimal alternative in rural areas of Xi'an within multiple consecutive time periods. Firstly, an evaluation index system is constructed and picture fuzzy numbers (PFNs) are used to represent both evaluation levels and experts' refusal due to limitation of knowledge. Secondly, fuzzy analytical hierarchy process (FAHP) is applied to derive weights of criteria, which enables experts to assign fuzzy numbers to express their preferences for comparison judgments. Thirdly, evidence theory is utilized to obtain the aggregated values from multiple time periods. Finally, based on the belief intervals obtained, sequencing batch reactor (A₄) is determined as the optimal rural WT technology in Xi'an from 2006 to 2020, whereas the membrane bio-reactor (A₂) is the last option. The effectiveness of the proposed framework is further validated by comparative analysis. This research can hopefully serve as useful guidance for the assessment of rural WT technologies in various regions.

A novel spherical fuzzy AHP-integrated spherical WASPAS methodology for petrol station location selection problem: a real case study for İstanbul

The petrol station location selection problem is taken into consideration in this study. In order to identify the main and sub-criteria for evaluation, the literature is reviewed and five experts from different companies are interviewed. After that, thirteen different alternative locations are for specified to evaluation. Then, the novel spherical fuzzy AHP-integrated spherical WASPAS methodology is structured in a fuzzy environment, and the petrol station location selection problem is evaluated with this methodology. In this study, a real application is presented for Istanbul to show the applicability of the proposed methodology. Subsequently, a sensitivity analysis is performed to explain and analyze the proposed methodology results. Finally, the results are presented and discussed with future directions.

Optimal Site Selection for a Solar Power Plant in the Mekong Delta Region of Vietnam

Following the recent development trend in the struggle for cleaning the earth’s environment, solar is the one of most promising area that can partially be used as a replaceable energy from non-renewable fuel sources. As such, it plays a significant role in protecting the environment from global warming. As solar power does not emit harmful gases into the atmosphere, its production, distribution, setup, and operation are vital should the production remain constant. Even solar energy waste emissions are small; when compared to current energy sources, the amount of harmful gases is negligible. This paper presented an integrated approach for site of solar plants by using data envelopment analysis (DEA) and Fuzzy Analytical Network Process (FANP). Furthermore, these integrated methodologies, incorporated with the most relevant parameters of requirements for solar plants, are introduced. First, the paper considers an integrated hierarchical DEA and FANP model for the optimal geographical location of solar plants in Mekong Delta Region, Vietnam. Using the proposed model for implementation would allow the renewable energy policy makers to select and control the optimal location for allocating and constructing a solar energy power plant in Vietnam. This is the preferred strategy for location optimization problems associated with solar plant units in Vietnam and around the world.

Introducing the coupled stepwise areal constraining and Mahalanobis distance: a promising MCDM-based probabilistic model for landfill site selection

This study sets out to propose a new ensemble of probabilistic spatial modeling and multi-criteria decision-making comprised of stepwise areal constraining and Mahalanobis distance algorithms in order to assess areal suitability for landfilling. The Ardak watershed was selected as the study area due to encountering several cases of open garbage dumps and uncontrolled landfills which are one of the main sources of river water pollution in the upstream of the Ardak dam. The results revealed that the proposed algorithm successfully assists in inventory-irrespective probabilistic modeling of landfill siting which is mainly indebted to the role of areal constraining in providing training and validation samples for the Mahalanobis distance model. The latter also showed a robust pattern recognition results from which a discernible differentiation of the area was attained while the spatial dependencies between the environmental factors were taken into account. Mahalanobis distance also gave an outstanding performance in terms of goodness of fit (area under the success rate 89.367) and prediction power (area under the success rate 89.252). Based on a five-point scale classification scheme, about 2.7% and 2.6% of the study area, respectively, have high and very high suitability for landfilling, while the remaining area is shared between very low-to-moderate suitability classes. According to the current trail of literature regarding landfill site selection which mostly relies on mere areal filtering, a probabilistic model would give invaluable inferences regarding the pattern of suitability/susceptibility of the area of interest and causative role of the influential factors. Graphical Abstract.

Combining AHP and ROC with GIS for Airport Site Selection: A Case Study in Libya

Choosing airport locations requires thorough and comprehensive decisions to be made. To do so in a professional and logical manner is crucial for the social, economic, and logistic settings intended for any region. The present research takes place in Libya, where airports are just as vital for the economy in terms of tourism and investment by allowing for improved transportation throughout the developing market and supplier locations as well as trading between the industrial and financial sectors. For this reason, using the geographic information system (GIS) to determine the appropriate airport site, twenty-three criteria were considered. In addition, two different methods—analytic hierarchy process (AHP) and rank order centroid (ROC)—were utilized to derive the related weights. The comparison of the output maps from these two distinctive approaches shows that both approaches provide identical results. Finally, a sensitivity analysis was carried out to evaluate the reliability of the method used and select the best site among the proposed ones based on the result of the highest suitability index for each candidate site. This research provides a siting approach and substantial support for decision-makers in the issue of airport locations selection in Libya and other developing countries.

GIS-based MCDM modeling for landfill site suitability analysis: A comprehensive review of the literature

One of the cheapest and proper methods for the ultimate disposal of Municipal Solid Waste (MSW) is landfilling. However, determining the location of landfill sites is a difficult and complex task due to depending on social, environmental, technical, economic, and legal factors. To solve the aforementioned challenges related to the landfill site suitability analysis, the combinations of Geographic Information System (GIS) and Multi-Criteria Decision-Making (MCDM) have been studied by academia and applied by experts over the years. This notice is apparent by the large number of academic papers which have been announced in the near future. To provide a framework of the existing literature, and to guide colleagues, a state-of-the-art of recent papers is crucial. The goal of this study is to review all scientific papers in GIS-based MCDM modeling for landfill site suitability analysis in academic journals. A total of 106 studies published between 2005 and 2019 are recorded and surveyed. The studies are then investigated and classified by a generated taxonomy including following categories: GIS software, application area, uncertainty, MCDM techniques, cell sizes in GIS, and criteria. Based on the review conducted, it is observed that while Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC) are the most widely used MCDM methods for weighting the criteria and ranking the alternatives, respectively. On the other hand, while environmental dimension is the most commonly preferred main criteria, surface water comes first in the sub-criteria pool. Criteria analysis shows that surface and ground water, geology, land use, distance to fault zone, distance to urban areas, and distance to road and slope are the most commonly used criteria groups among others. These classifications and observations are helpful for identifying research gaps in the current literature and provide insights for future modeling and research efforts in the field.

Impact of organic contaminants from dumpsite leachates on natural water sources in the Enugu Metropolis, southeastern Nigeria

This study evaluates the impact of leachates from a municipal dumpsite on the quality of domestic water sources in the area for potable use. Concentrations of leachate-associated organic contaminants (such as diethyl-phthalate, total organic halogen (TOH); 2,4-dichlorophenol; nonylphenol-ethoxylate; methyl-ethyl-phthalate; borneol; total organic carbon (TOC); total Kjeldahl-nitrogen (TKN); ammonium-nitrogen (NH₃-N); nitrate (NO₃); nitrate-nitrogen (NO₃-N); and total phosphorus (TP)) in rivers and groundwater in the Enugu Metropolis in southeastern Nigeria were assessed in this study. Results of laboratory analyses indicate that the average values of diethyl-phthalate, borneol, TOH, nonylphenol-ethoxylate and TOC are 0.08 mg/l, 0.04 mg/l, 1.05 mg/l, 0.2 mg/l and 1.64 mg/l, respectively for groundwater and 0.1 mg/l, 0.03 mg/l, 0.74 mg/l, 0.19 mg/l and 1.74 mg/l, respectively, for rivers. Three (diethyl-phthalate, borneol and TOH) out of these major five contaminants, in both rivers and groundwater, exceeded the maximum permissible limits, suggesting that the domestic water sources are marginally contaminated by the leachates. ANOVA test result suggests that the data sources were significantly variable, while principal component and correlation analyses identified TOH, 2,4-dichlorophenol, TKN, NO₃, NO₃-N, TP and borneol, which originated most probably from degradation of plastic materials and organic wastes in the dumpsite, as the priority contaminants. Consumption of domestic water sources within the dumpsite area, in untreated state, could lead to health risks as these priority organic contaminants are mostly carcinogenic, toxic and injurious to human systems.