Use of GIS for Digital Mapping and Spatial Analysis of Landfills: Case of the Settat Province in Morocco

In Morocco, the population growth and changes in consumption and production patterns are increasing the amount of generated waste, particularly household solid waste. It is estimated at 6.9 million tons per year, of which 5.5 million tons in urban areas, with a ratio of 0.76 kg/inhabitant/day (Ministry of the Interior, national portal for local authorities, National Household Waste Program). In the absence of controlled landfills, this waste negatively affects living spaces and generates health and environmental problems. The province of Settat, which is affected by this scourge, inefficiently manages this household waste as in other regions, thus requiring improvement with the involvement of the actors concerned. This work involves the creation of a cartographic database of household waste in the province of Settat using a Geographic Information System (GIS). The analysis of the maps made, the observation of photos of existing landfills, and a diagnosis of the landfills in the Settat province have shown a direct negative impact on the different vital axes.

for solid waste management provisions have not been applied in some provinces. The province of Settat, located in the central northern part of the Kingdom, is part of the Casablanca-Settat region with an area of approximately 7220 km 2 and 634,184 inhabitants according to the 2014 General Census of Population and Housing (RGPH). It is composed of 46 local authorities. Except for the Commune of Settat, which has delegated the waste management service to a private company, all the other communes in the province manage their waste directly.
This work aimed to develop a diagnosis of the current state of affairs to highlight the problems arising from the current management of household waste in the province of Settat based on the design and analysis of a cartographic database.

Geographic setting of the province
The province of Settat includes 5 urban communes and 41 rural communes grouped in 3 circles. It is bounded administratively by the provinces of Berrechid and Benslimane to the north, the province of Kalla-Sraghna to the south, the provinces of Fquih Ben Saleh and Khouribga to the east, and the provinces of Sidi Bennour and BenGrir to the west ( Figure 1).

climate
The province of Settat is characterized by a semi-arid continental type climate. Its summers are hot with temperatures from 35°C to 45°C and its winters are cold from 5°C to 15°C. Fluctuating from year to year, rainfall is low, amounting to about 372 mm in an average year (Ben Ouakkass et al., 2018).

relief
The territory of the Settat province is characterized by a certain physical homogeneity. Indeed, two zones can be distinguished: Lower Chaouia, where the soils are Tirs, and Upper Chaouia, where there is a progressive decrease infertile land. It is made up of limestone plateaus of an accident landscape, reinforced by the spreading of phosphate layers (Icole, 1964).  The approach taken for this study is presented as follows: • Data Collection: Population of the province (High Commission for Planning HCP), the surface area of the commune, number of households, and Quantities of waste (Settat prefecture). • Retrieving the map of the communes of the province of Settat in shapefile form (SHP) from the Settat prefecture. • After data collection, the information was mapped using ArcGIS 10.7.1 (GIS) software as follows: − A georeferencing of the maps according to a North Morocco degree coordinate system. − Creation of layers to define the geographical delimitation of each circle within the province. − Combining the attributes (number of populations, number of households, the quantity of waste produced and collected, X and Y coordinates of existing landfills) with the geographical references for each commune. − Elaborating the maps of population, location of existing landfills, and the map of waste quantities produced. − Providing a layout necessary for each map containing a legend, orientation, a coordinate system, and an adequate scale.
• The observation of the photos of existing landfills, the analysis of the maps produced, and a diagnostic of the current state of the existing landfills enable to highlight the current environmental situation in the province.

results and dIscussIon
Population Table 1 shows the distribution of the total population over all the communes making up the province of Settat, the number of households, the surface area of each commune, and the population density per commune. The integration of this information into the database made it possible to produce the population map ( Figure 2).
The population is concentrated in the urban communes of each circle with 141,637 inhabitants in Settat (chief town of the former Wilaya Chaouia Ouardigha), 32,528 in Ben Ahmed, and 19,229 inhabitants in El Borouj.

household waste
Uncontrolled landfills in the province are a source of pollution. They are located near cities and sometimes not far from water environments (wadis or groundwater). They produce the leachates that reach surface water and generate direct     Figure 3 shows the location of the existing landfills in the province of Settat with three landfills in the Settat circle, four landfills in the Ben Ahmed circle, and only one landfill in the Elbrouj circle. Table 2 summarizes the quantities of household waste produced, collected, and the collection rate by urban and rural areas in the province of Settat. A large amount of waste is found in the urban area because of the high density of the population in these municipalities. Figure 4 shows the amount of waste generated in the province. The city of Settat ranks first in the production of household waste with a quantity of about 133 T/day, which represents 34% of the waste produced at the provincial level. The collection rate at the provincial level is about 58%, with a rate of 86% in urban areas and 2% in rural areas. It should be noted that in the rural areas, the douars do not benefit from any services to manage the waste produced: organic waste is reused to feed livestock and the animal excrement is used as fertilizer. The broken metals, wood, plastic, and cardboard are used in the consolidation of dwellings and traditional ovens and hammams. Table 3 shows how household waste is disposed of. The most important mode is the communal bin. The Figure 5 shows that the landfills in the province exist on the edges of agricultural fields and near houses, wells, chaâbas, thus causing visual nuisances, fire hazards, an increase in black spots, the affectation of soil fertility, loss of livestock, and degradation of the ecological value of certain natural sites. This situation thus causes several nuisances on the landscape aspect, as well as risks of contamination of surface and groundwater. Table 4 provides a description and diagnosis of the current state of landfills in the province of Settat.

recovery activities
Informal waste recovery is an aspect of household waste management that is present in the Settat province, as well as in other areas (Makamté Kakeu-Tardy, 2018). Recovered waste is generally reused in two ways: • For subsistence and livestock feed.
• For resale, which allows objects to be reintroduced into the economic circuit (for example, paper, cardboard, iron, cans, glass, plastic, aluminum, and rubber).
Sorting/recovery of waste is a sector that concerns the entire chain from the garbage cans and containers to the landfill. Thus, this activity, despite its defects, makes it possible to: • Valorize a non-negligible quantity of waste.
• Reduce the volumes of waste sent to landfills.
• Guarantee a source of income for many underprivileged families. • Presence of houses near the dump.
• Existence of reclaimers exposed to health risks in the landfill.
• Existence of livestock and dogs inside the landfill.
• Landfill near the center of the town.
• Existence of a wetland that stores the leachate below the site.
Oulad Said 0.2 1.0 • Discharge 200 m from the center.
• Existence of population and agricultural land • nearby.

Ben Ahmed
Ben Ahmed 6 0.5 -2.0 • Landfill is located 5 km from the center.
• Existence of two châabas near the dump.
• Existence of a well downstream of the dump was condemned by the inhabitants because suspected of being contaminated.
• Existence of three wells abandoned by the inhabitants near the dump.
Ouled M'Rah 2 1.0 • Landfill is located 1.5 km from the center.
• Existence of houses next to the dump.
• Existence of a wadi that drains the city's wastewater and flows below the landfill site and also receives the leachate in case of rain.
Loulad 0.5 1.0 • Discharge is located 1km from the center.
• The landfill receives a wastewater discharge that is • mixed with household waste-producing • more leachate.
• Existence of a wadi at the bottom of the landfill filled with directly dumped waste.
However, if this recovery is carried out by sorting and collecting waste at the source, the results in terms of recovery and especially in terms of preserving the health of the population would be greater.

conclusIons
This study has established the current mode of household waste management, which influences the environmental quality of the Settat province as well as directly impacts the population and the natural environment of the province. The results have shown the urgency to take the decision to move to the effective implementation of planning tools under the national household waste program PNDM and thus to consider the creation of waste transfer centers in the territory of the Settat province and an inter-municipal landfill that will only receive non-recoverable waste. A questionnaire, intended for the various administrations and the population concerning the modalities of sorting, collection, and recovery of waste from households to the landfill, is being prepared.