Urban population growth causes the development of the city based on a distant spread of urbanization [1]. Increase in population appears as one of the major modernization processes, and persevering development of specific activity sectors around and in the city [2]. At its best, it promotes new infrastructures on the periphery and abandonment of land in areas located at the city center [3]. However, it is also the production of bulky waste on good land, exacerbating environmental degradation and increasing the vulnerability of habitats to natural hazards [4] [5]. Some studies even specify that the ephemeral nature of the empty spaces creates a massive diffusion and exhibition and the usefulness of biodiversity in cities [6] [7] [8].

In Niger, the critical situation regarding life quality in urban areas highlights the acute problem of managing waste produced in cities [9]. This problem can be observed in almost all the streets of the big cities, which are often infested with too much waste of all kinds [10] [11]. In the same vein, a whole range of landscape trivialization has emerged, creating an alarming situation regarding the balance of the urban ecosystem [12]. However, in Niger, there are quite a number of legislative and regulatory texts and Niger seems to be ahead of many West African countries [13]. An example is the Framework law 98-56 of 29 December 1998 on environmental management [14]. This law recalls, for example, in its article (Art. 27) that “It is forbidden to deposit household waste, stones, gravel, wood, industrial waste in the bed or on the banks of rivers, lakes, ponds or lagoons and canals of the public domain. It is also forbidden to let water whether infected or harmful, to run out”. In addition, Section 5 (Art. 64) states that “decentralized local authorities shall ensure the disposal of household waste, excreta, wastewater and other related waste throughout their territory in collaboration with public or private sanitation services”. What matters from this point of view is the practical implementation of strategies, i.e., the effective urban planning scheme that arises with enormous difficulties [15].

The case of the city of Maradi is quite typical. Being the economic capital of Niger [16], Maradi is indisputably a city that attracts a lot of people. This attractiveness is mainly linked to the countless markets and commercial hubs that operate seven days a week. People migrate to Maradi due to job opportunities that, large construction sites offer [17]. Maradi is also and above all the town of “Elhazai,”“the rich people” who represent the city business owners as well as landlords. For these individuals, land is an object of commercial speculation, in addition to it being an inheritance for their offspring. Thus, the “Elhazai” and their heirs exert an influence on the city center by promoting the emergence of large unbuilt estates in anticipation of more interesting auction [18]. This means that the waste from all these activities generates considerable heap of waste, which increases as we approach the shopping malls markets and empty spaces [19].

Previous works [20] [21] [22] [23] [24] have shown that laws and regulations are taken mainly to address prevailing corruption. Indeed, some believe that the state services are themselves troublemakers because they are more concerned with immediate interests to meet their own needs in maintaining their way of life in a healthy state. So, a kind of expectation and resignation prevails among the population. Ultimately, estimating the intensity of contact between biological diversity and agents present in different environments is a difficult task. It would be desirable, according to the above-mentioned authors, that local authorities should be able to improve their methods in order to avoid all possible consequences, including soil contamination. Finally, we should mention local knowledge which, according to some authors, is another important bias to be discussed in the process of identifying urban problems. However, very little attention has been paid so far to the environmental and landscape issues posed by empty plots.

The present study aims at contributing to a better understanding of the environmental issues related to the presence of empty spaces, sometimes transformed into uncontrolled waste depots, in the urban fabric of the city of Maradi (Niger). The research seeks to tackle the following s points: 1) identifying forms of occupancy of space on vacant land, 2) specifying the positive and negative environmental impacts on the living environment, and finally 3) proposing technical and regulatory developments to reinforce the positive consequences and limit the problems linked to these empty plots.

While the tolerant trivialization of the empty plots is good for some people and bad for others, and optimal for some activities but not for the physical environment. The ultimate water source and sink problems are uncontrolled crowding of the younger generation of traders and the crowded streets. These results are comparable to those of other works carried out by [30] in the agglomeration of Souk-Ahras in Algeria, and by [31] in the city of San-Pedro in Côte d’Ivoire.

The reality on the ground shows that the non-built plots, by their owners constitute wild deposits of various wastes. While wild dumps continued to accumulate around empty plots, agricultural practices in these city plots, as well as the flora and fauna favored there, contribute to the visual degradation of the environment, pollution and nuisances. This is the case for inhabitants, who dwell close to wild deposits, who undergo the ordeal of cockroaches during the night [12], and that of mice and rats which turn into real invaders out of the rubbish heaps [32].

Beyond these reasons, respondents have contributed to two major ideas. Firstly, the attractiveness of garbage on certain fauna and flora species is the source of many diseases such as malaria, as well as the proliferation of stray dogs, rodents, insects and birds [33]. Secondly, the waste diffusion and appearance of plant species also exacerbate scarcity or even extinction elements of the flora useful for the human population and animals (medicinal plants, plants used as pasture, trees used as nesting boxes for birds, etc.). As [34] points out, some plants can assimilate toxic substances from this waste and transmit them to animals that are consumed by humans. Consequently, the waste disposal environments can become favorable grounds for the proliferation of the cryptogamous flora and the population that comes to collect these plants can be infected by the waste.

Burning waste produces larger amounts of particle matter and fly ash. The most threatening product of waste-burning activities are particles of toxic metals (e.g., Hg, Pb, Fe, Cu, Cr, Ni, Cd, …; [21] ) which could contaminate the grounds and the people of the neighboring school (Figure 8, Figure 9 and Figure 14). This practice, like the croaking of toads in ponds in the truck parking lot (Figure 11), does not comply with Article 74 [14] which prohibits the emission of noise and odors that may harm human health, to constitute an excessive embarrassment for the neighborhood or to damage the environment. The people behind these emissions, as well as the owners of empty plots, must take all necessary steps to remove them.

Furthermore, the leachate mediates between waste water, rainwater and runoff crossed the landfill (Figure 8, Figure 9 and Figure 14). The relevance of this can be seen as a key to an overall understanding of the interaction between human activities, soil and groundwater. Furthermore, growing evidence indicates that in the city of Maradi, informal economic activities are more frequent during the rainy season (53% of respondents; [19] ). Thus, the evolution of seasonal rhythms suggests that the climate is the main determinant of the diet of the population and, consequently, influences the production of waste in the environment. Roughly, a source of more extending waste problems would begin with water throughput and the reduction of infiltration. To corroborate this idea, [1] consistently found that all waterproofed surfaces (roads and car parks) are relevant to carbon destocking in the soils, and that they are probably other ways of conceptualizing the majority use of the car and more energy mobilization.

This evidence has profound implications for understanding and addressing the current piles of uncollected garbage and decomposing wild deposits (Figure 9 and Figure 14). In many cases, those are also responsible for poor drainage in the region by preventing the correct evacuation of rainwater [35]. With the same basic assumptions, the results obtained by the present study are consistent with those of [32] in the city of Porto-Novo (Benin) and [36] in the city of M’Bahiakro in Côte d’Ivoire.

Overall, the flooding around houses near empty plots (Figure 10 and Figure 15) increases the disfigurement of the neighborhood (Figure 13). The drainage problems undoubtedly reinforce the phenomenon of erosion in the study environment. In support of this result, [37] also found that the nature of the soil, like precipitation and slope systems, is a determining factor in rainfall erosion in the city of Adjarra in Benin. Additionally, erosion phenomena leave remarkable sections of the land (e.g., herbaceous carpet; Figure 13) to escape rain erosion. Those non-significant stripping levels are areas that benefit from a special arrangement or a measure of protection by invasive species. In spite of these visual degradation of the environment and different multiplication conditions of certain diseases, the flora contributes to soil protection and grazing. In other words, the criteria for dealing with such problems are in the values that guide its management, in terms of consensus on the protection parameters.

At least the advantage of abandoned land is that “empty” spaces emerge as the last vestiges of urban biodiversity (Figure 16). Under these ecological conditions, the development and distribution of the flora are linked to pollination by the wind which carries the pollens, as well as to the conservation of seeds in the edaphic substrate of these soils. Additionally, field observations advocated that such undeveloped land is a favorable environment for wildlife by creating an important source of food webs entering nearby houses (Figure 7). This is in accordance with the findings of [1] study that reported that “Talking about biodiversity in the city may seem paradoxical. However, if urbanization is a source of biodiversity loss due to the areas occupied by housing, roads (...), it can also maintain it, either by preserving specific habitats (brownfields, wetlands (…), Parks and gardens, …), either by the large landscape mosaic of the urban and periurban areas, or by the introduction, voluntary or not, of exogenous species (…)”.

Still, it is clear that the regeneration of flora in empty plots stems mainly from the tolerance of the inhabitants towards pioneer wild species that evolves over time. Food security is crucial if we expect people, who are denied access to basic resources, to continue to struggle against in order to alleviate poverty. Counterintuitive, as rural population migration grows, the empty plots have a better factual demand from low-income families (Figure 5). Many of these migrants find shelter in the empty plots. Consequently, these people contribute to the improvement of the quality of life of the residents through their participation in financial activities (e.g., field work, market gardening, baby seating and domestic work; Figure 11 and Figure 12) which develop there. In fact, undeveloped land can have a positive impact on food security, in addition to the fact that they can contribute to the fight against poverty. In addition to the usefulness of plant regeneration in empty plots, the sandy nature and the maintenance of some of them (Figure 16(b)) contrast with the capacity of these areas to be privileged areas for a “clean” recharge of urban aquifers.

The identification and citation of the mitigation measures presented in Table 7 make it possible to draw unequivocal conclusions about their impacts on the determinants of urban insalubrity. It is the bins and public dumps that are the most involved. In other words, the installation of these containers and their surveillance by the authorities (19% of respondents) should promote the cleanliness of the premises and the sector under study; but, this is not the case (Figure 8). Particularly, low sensitivity (5% of respondents) to any form of practices degrading environment may refer to the whole extreme vulnerability of population to natural risk problems in the study area. To this end, [22] revealed that the population is partly responsible for the unhealthiness in the city of Maradi. For these authors, the adoption of malpractice management and the routinely discharged in the street gutters if they exist or even in the courtyard of the concession, in which they live, characterize the behavior of residents regardless of their level of education. Thus, changing the way we look at empty spaces and any sanitation or road works remains one of the rooms for maneuver to mitigate or compensate the effects and the impacts of our practices on the environment. In fact, countermeasures will be all more useful if we take into account traditional structures (equipment and tools for maintaining sanitation) and series of indirect approaches in the field. These include awareness-raising and the strong state support for all forms of local organizations.

As [7] reports, in order to enhance the naturalness of the neglected and improve their representation, “it is not about accepting nature, it is about making it acceptable”. Several conditions are therefore necessary: 1) adapting to risks, environments (slope, soil, plant cover) and types of nuisances and urban pollution, 2) enhancing the complementarities of agriculture, habitat, and livestock services by promoting early crops in the plots. Finally, these authors recommend the cultivation and the maintenance of fruit trees and legumes directly influence the risks associated with runoff and urban biodiversity. According to [38], it is also possible to intervene at several levels. The two most classic methods are urban renewal and brownfield redevelopment. But, as the saying goes, “prevention is better than cure”! That is to say, it is better to fight against the consequences upstream, by initiating and managing good practices. In relation to the perceptions expressed by the respondents and the reality on the ground, neighborhood-oriented social networking remains one of the least expensive strategies. Thus, the specific points contributing to the integrated management of a site are part of an intrinsic change of approach with regard to the “wild” nature of the abandoned urban areas [39].

Monitoring and any development of co-produced territories should contribute to the fight against unhealthy urban environments [38]. In the same way, [39] goes into more details and noted that these territories, provided they are made sustainable, could ultimately constitute real vectors for the involvement of residents in the management of local spaces. Overall, the generalization of eco-gestures (e.g., make compost from feathers) and measures promoting respect for the environment and the protection of urban biodiversity make shared spaces viable tools for mediating and disseminating “good practices” in terms of sustainability and environmental efficiency [40].

The present work is motivated by the observation of the extent of the consequences generated by the uncontrolled landfills in the city of Maradi (Niger), in particular in the empty plots of communes 2 and 3. Waste proliferation along with unformal economic activities in these places, poses more and more the problem of urban waste management, pollution and nuisances as well as the degradation of the environment. The streets providing access to certain essential services, soils and homes are invaded and sometimes devastated by runoffs. Under the current environmental conditions, the whole population, with the exception of some of the privileged, is under very high annoyance stress.

The results of the present study showed that the severity of the effects is related to several factors. These include, among others, the development of wild flora and fauna, as well as the prevalence of seasonal diseases. In addition this is the inadequacy of garbage disposal methods, the most common of which are incineration and in situ decomposition. In fact, these various waste treatment processes are the basis of the residues responsible for the emission of polluting fumes into the air and the pollution of groundwater by various contaminants.

These results also showed that wastelands and other empty plots constitute the last vestiges and privileged places for a certain urban biodiversity. Grass mats, adjacent to the walls of empty plots, increase the importance of protective measures against soil erosion. Interestingly, besides the nuisances, we must also notice the contribution of empty plots to income increase, the fight against poverty and also carbon dioxide (CO₂) emissions. It is undeniable that the empty plots constitute a city within a city without which many residents would find themselves in slums. This should particularly attract the attention of decision makers, who must take measures and carry out actions aimed at limiting the constraints to protect the environment in a sustainable manner.

The authors are grateful to Mrs. Ikilima Elh. Yaou Mamane and Mrs. Jamila Laouali Ousmane for assisting with the selection of fieldwork areas. We express our gratitude du Dr Yacoubou Alou for his untimely proofreading and correcting the manuscript.

Data will be made available upon request.

The authors declare no conflicts of interest regarding the publication of this paper.

Hantchi, K.D., Zango, O., Oumarou, A., Morou, B. and Konaté, M. (2022) Wasteland and Empty Plots Trivialization in the Maradi City (Niger): Between Environmental Degradation and Consequent Nuisance, Quality of life and Sustainability of Biodiversity. Occupational Diseases and Environmental Medicine, 10, 13-34. https://doi.org/10.4236/odem.2022.101002