JURY MEMBERS :

Dr. Maïmouna Bologo/Traoré, Dr. Malicki Zorom, Dr. Yohan Richardson and Mr. Sina Thiam

list of recommendation after the defense:

-Include the principles of Integrated Water Resources Management (IWRM) in the analysis to better align proposed actions with international best practices.

-Remove outliers from the database and redo the Principal Component Analysis (PCA) to improve the quality of the results and achieve a more representative classification (NIGERIA,NIGER).

-Redo the GIS maps, updating the data and adapting them to the new PCA results to better visualize regional dynamics and critical areas.

Summarize :

The RTI project on IWRM (Integrated Water Resources Management) aims to improve water governance by promoting fair, sustainable, and coordinated management of water resources. In the face of growing challenges related to water scarcity, pollution, and conflicting uses, the project seeks to propose appropriate solutions through a participatory and integrated approach. Its specific objectives are to identify the various uses of water in the intervention area, assess the condition of available resources, analyze potential conflicts, raise awareness among affected populations, and strengthen the capacities of stakeholders. The methodology relies on field surveys and consultations with users. A mapping of resources and an analysis of existing policies. Expected results include a shared diagnosis, concrete recommendations, a roadmap for implementing IWRM at the local level, and a framework for sustainable dialogue between stakeholders. This project involves partners from research, administration, local authorities, and civil society. Ultimately, it aims to reduce water-related tensions, promote more effective integrated management, and contribute to resilient development in the face of environmental and climate challenges.

2 ZONE D’ETUDE

The study area of this project covers West Africa, a region marked by great climatic and hydrological diversity. It includes both Sahelian countries such as Mali, Mauritania and Burkina Faso, where the climate is arid to semi-arid, and wetter countries on the Atlantic coast, such as Guinea, Liberia, Côte d’Ivoire and Ghana. This climatic diversity leads to an unequal distribution of water resources: Sahelian countries receive little rainfall and face high water stress, while coastal countries benefit from abundant rainfall, but face water management and pollution problems. The region is also crossed by several major transboundary basins, such as the Niger River, the Senegal River and the Volta River, which requires coordination between States for equitable and sustainable management of resources. In addition, West Africa is facing strong demographic pressure, the growth of agricultural and industrial needs, as well as the effects of climate change, which accentuate existing imbalances. This context makes the region a strategic space for the implementation of Integrated Water Resources Management (IWRM), which aims to reconcile uses, preserve ecosystems and guarantee equitable access to water for all.

# 3 PROBLEMATIQUE :

“How can Integrated Water Resources Management (IWRM) reduce water stress in West African countries, particularly in a context of climate variability and increasing population pressure?”

4 Objectif général :

The objective of this analysis is to examine water resources management in West Africa by identifying the main dynamics that influence water access, use and availability. Using Information Research and Processing tools, this study aims to: -How are West African countries classified according to their water characteristics (availability, usage, and water stress)? -What are the main regional disparities and specific challenges related to water in each area?

-What key elements can be identified to improve water resource management, taking into account agricultural, industrial, and municipal needs?

5 Revues documentaires

West Africa is one of the regions in the world where the climate is highly variable and which has suffered greatly from climate change in the 1970s and 1980s. It is also the region least equipped with hydraulic infrastructure such as dams, wells, boreholes, water supply systems, sanitation, and irrigation. Governments in the region are attempting to bridge this gap by adopting the principles of Integrated Water Resources Management (IWRM), aimed at allocating water to the most relevant uses while balancing conflicting objectives. Tools and indicators are used to link economic efficiency, equity, and environmental impacts, taking into account demographic, economic, and climatic trends based on reasonable scenarios. Risk management, conflicts, rainfall variability, and vulnerability are central to decision-making. [1]

5.1 Theoretical and Methodological Framework

a-Definition of IWRM

Integrated Water Resources Management (IWRM) is a process aimed at promoting the coordinated development and management of water, land, and related resources. Its goal is to optimize economic and social well-being equitably while preserving the sustainability of essential ecosystems. According to the Global Water Partnership and its Technical Advisory Committee, IWRM is based on a holistic approach to water, considering its uses and impacts at the watershed scale, which is regarded as the minimal management unit. It relies on a cross-cutting approach, integrating multiple sectors and interventions, from the local (river, resource) to the global (watershed, region). [2] b-History of IWRM In 1972, an international conference on the environment was held in Stockholm, Sweden, under the auspices of the UN. During this event, a declaration was adopted, affirming the need to establish common principles to guide the efforts of the world’s peoples to preserve and improve the environment. In 1977, the Mar Del Plata Conference in Argentina highlighted water-related challenges and proposed the organization of the International Drinking Water Supply and Sanitation Decade (IDWSSD) for the period 1980-1990. This conference also emphasized the importance of coordination in the water sector and recommended a systematic assessment of water resources. In 1983, the UN General Assembly welcomed the idea of creating a special commission to draft a report on the environment and its global challenges in the 21st century. In 1987, this commission published the “Brundtland Report,” named after its chair, Norwegian Prime Minister Gro Harlem Brundtland. This report, also titled “Our Common Future,” introduced the concept of sustainable development (SD) and defined it as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” The concept of sustainable development, as defined in the Brundtland Report, underscores the need to manage water resources collectively. This management must integrate the principle of international solidarity, ensuring the preservation and equitable access to water for future generations. In 1989, the UN General Assembly debated the Brundtland Report and decided to organize a conference on environment and development. This commitment led, in early 1992, to the International Water Conference in Dublin, Ireland. During this event, a group of experts established the fundamental principles for water management, known as the “Dublin Principles” or “Guiding Principles.” These principles played a key role in the emergence and structuring of Integrated Water Resources Management (IWRM). The Dublin Principles on water management were adopted by nations as guiding principles for IWRM at the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro in June 1992. IWRM was primarily developed to promote sustainable water resources management. [2] c-Principles of IWRM Principle 1: Freshwater is a finite and vulnerable resource, essential for sustaining life, development, and the environment. Principle 2: Participation
The development and management of water should be based on a participatory approach, involving users, planners, and policymakers at all levels. Principle 3: Equity or Gender Women play a central role in the provision, management, and safeguarding of water. Women play a crucial role, without forgetting vulnerable groups such as the elderly, disabled, and children. Principle 4: Economic and Social
This principle consists of two parts:
- The first part: an observation: “Water has an economic value in all its competing uses.”
- The second part: a recommendation: “Water should be recognized as an economic and social good.” [2]

5.2 Impact of Climate Change on Water Resources

The study assesses the impact of climate change on the flows of four watersheds in West Africa: the Senegal, Gambia, Sassandra, and Chari. Using projections from the HadCM3-A2 climate model, the results show that flow variations follow those of precipitation. For the Senegal and Gambia basins, a decrease in precipitation leads to reduced flows. In contrast, the Sassandra and Chari basins see increased precipitation, resulting in higher flows. Projections indicate an increase in potential evapotranspiration (PET) due to rising temperatures, reaching up to 30% by 2080. This increase in PET is more pronounced from November to February. Precipitation shows opposite trends depending on the zone: a decrease in the northwest and an increase in the southeast. By 2080, the Senegal and Gambia basins could see significantly reduced flows, while the Sassandra and Chari basins could experience increases. [3]

5.2.1 RAINFALL VARIABILITY

The variability of rainfall patterns between Côte d’Ivoire and Benin shows that coastal areas receive the highest rainfall. However, between these two countries, isohyets (lines of equal precipitation) are irregular, with lower rainfall due to oceanic upwelling phenomena, which stabilize air masses. The irregularity of isohyets is also linked to the presence of the Togo Mountains and the Atakora Range, as well as the orientation of the coast, which is less conducive to rainfall in some areas. A north-south rainfall gradient is observed, with rainfall being more homogeneous near the ocean. Over the past four decades, a general decrease in rainfall has been noted, with peak rainfall occurring in the 1960s. In the 1980s, rainfall in the northern zone dropped below 800 mm, which was not the case in the 1950s. This trend of decreasing rainfall began in the 1970s and intensified in the 1980s. [4]

5.3.1 Conflicts and Water Culture

In West Africa, although rainfall is abundant, it primarily benefits rain-fed agriculture, while over 90% of runoff is lost to the sea. The region has significant hydraulic potential, with several major rivers such as the Niger, Senegal, and Volta, as well as Lake Chad, which play a key role in water supply. However, these resources are unevenly distributed among countries, urban and rural areas, and different sectors of activity (industry, agriculture, domestic use). Moreover, climate change exacerbates water management challenges, making rivers irregular and threatening their future availability. West Africa has 25 transboundary river basins, creating strong interdependence in water supply. Some countries, such as Niger and Mauritania, depend on over 90% of water resources originating outside their borders. The reduction in rainfall between 1970 and 1990 impacted water availability, particularly affecting irrigation, livestock, and hydroelectricity. This situation was aggravated by the expansion of agricultural land, leading to sedimentation and siltation of hydraulic infrastructure. Tensions between upstream and downstream countries are exacerbated by climate variability, with populations often blaming their neighbors rather than environmental changes. At the same time, the construction of over 110 dams has sparked controversies, particularly due to population displacement and inequitable redistribution of water resources. Water-related challenges are amplified by local social conflicts, where access to water points is governed by social structures and traditions. The transhumance of Fulani herders, intensified by droughts, has exacerbated tensions with local farmers. Additionally, populations affected by dams have often been disappointed by insufficient compensation and limited access to the benefits generated. Faced with these challenges, it is necessary to rethink water resources management in West Africa. Rather than investing heavily in costly and controversial new infrastructure, alternatives such as improving existing agricultural systems and optimizing water productivity should be prioritized. Policies like the “African Water Vision 2025” aim to integrate these considerations into a sustainable approach to water resources management. [5]

5.4 Water Management Methods

Hydro-agricultural development primarily aims to reduce agriculture’s dependence on rainfall by ensuring better control of water resources. This factor is decisive for agricultural production in lowlands and on riverbanks. Thus, whether using modern or traditional techniques, irrigation allows partial or total control of water resources to compensate for the inadequacies and variability of rainfall. [7] As shown in the table below, irrigation water is divided into three main categories: surface water, groundwater, and floodwater. Surface water, drawn from rivers such as the Niger River, its right-bank tributaries, the Dallols, and ponds, accounts for 28.9% of withdrawals. It is mainly used in public and individual developments. [8] Furthermore, 87% of the surveyed farmers use groundwater from the water table, which varies in depth between 6 and 10 meters. About 21% of producers utilize floodwater (called “black water”) for rice cultivation. [9]

5.5 Optimized Water Management in Public Perimeters

Most public perimeters use a gravity irrigation system, with the exception of Yélou, where a drip irrigation technique is being tested. Gravity irrigation, which involves letting water flow over the soil surface, is one of the oldest and most widespread systems globally. This system relies on a network of canals and structures to deliver water to agricultural plots. [9] Water supply is ensured by electric or fuel-powered pumps. However, only a few perimeters, such as Malanville in Benin, have modern electric pumps. The lifespan of this equipment ranges between 15 and 25 years, but intensive use during the dry season accelerates their deterioration. [9] Although irrigation is supposed to guarantee total water control, several constraints limit its efficiency. Aging infrastructure leads to significant water losses between pumping and effective crop irrigation. Additionally, sudden floods weaken dikes and disrupt water supply. These malfunctions increase production costs, especially during the dry season, due to prolonged pumping. [9], [10] To address these issues, water management committees have been established to optimize water use. A manager is appointed to regulate irrigation by opening and closing valves according to a set schedule. This schedule varies by season: during droughts, irrigation is strictly controlled to avoid waste, while in the wet season, it is used to supplement rainfall. These measures aim to ensure more efficient and equitable distribution of water resources. [9]

5.6 Modernization of Water Governance

Water governance refers to the set of rules and institutions governing the management and use of water resources. The reform of this governance aims to transform the current system, based on a sectoral approach, into an integrated management model that considers all relevant elements. This new approach involves the active participation of all stakeholders, promoting equitable sharing and balanced, ecologically viable, and sustainable use of water resources. [11] The implementation of this reform is based on several strategic axes: - Establish an effective legal and institutional framework,
- Develop appropriate economic governance mechanisms,
- Encourage private sector participation,
- Improve access to water-related information and knowledge,
- Promote research and strengthen stakeholder capacities,
- Fully integrate environmental issues into water resources management. [11]

5.7 Monitoring and Evaluation Mechanism

ECOWAS, in consultation with UEMOA and CILSS, establishes monitoring and evaluation tools for the implementation of the regional water policy, relying on the organs of the permanent coordination and monitoring framework. [11] The supervision of this mechanism is ensured by the Ministerial Monitoring Committee of the CPCS, which meets periodically to assess progress and make necessary adjustments. [11] The Commission encourages collaboration between ECOWAS, UEMOA, and CILSS to define a shortlist of relevant indicators for effectively monitoring the implementation of the regional water policy. [11] Furthermore, ECOWAS, in partnership with UEMOA and CILSS, ensures the technical and financial monitoring of community programs and projects related to water, in cooperation with states, basin agencies, and intergovernmental organizations. Finally, impact studies will be conducted in specific areas to assess the concrete effects of implemented measures on populations and regional integration. [11]

5.8 Action Plan

In collaboration with UEMOA and CILSS, ECOWAS is developing an action plan for the implementation of this policy, including updating the Regional Action Plan for Integrated Water Resources Management (PARGIRE). [11]

5.9 Water Resources Prediction

The VAHYNE program of Hydro Sciences aims to estimate the evolution of water resources during the 21st century based on climate scenarios from general circulation models (GCMs). [12]

5.9.1 Modeling of 350 Watersheds

The modeling of water resources for West and Central Africa involved a study of 350 watersheds. A uniform methodology was defined to ensure data comparability, taking into account the choice of hydrological model, data sources, calibration and validation periods, and climate scenarios. The GR2M model was used to simulate the evolution of water resources, based on climate projections from the HadCM3 model under the A2 scenario. [12], [13] The results showed variability in flows across the region, with decreases observed as early as 2020 in some areas, such as northwest Africa and the Congo basin, while the Chari basin would see an increase. By 2080, a generalized decrease in flows is expected, with impacts on flood seasonality. An increase in PET, linked to rising temperatures, could offset a slight increase in rainfall in some Sahelian zones. These results highlight the impact of climate change on water resources and the need to adopt adaptation strategies to manage these changes. [12]

5.10 Adaptation Strategies for Water Resources in the Agricultural Sector

Farmers in the Ouémé watershed in Bétérou (Benin) have implemented various strategies to adapt to hydroclimatic hazards. These include crop associations, lowland development, crop rotation, and the use of agricultural inputs. Adjusting the farming calendar and introducing new varieties are also common practices. The study reveals that 98% of farmers use staggered sowing to mitigate the impact of climate change. Intercropping not only preserves vulnerable soils but also optimizes yields. Moreover, nearly 39% of farmers exploit wetlands to ensure production during the dry season, although this has environmental consequences. [13], [14] Finally, ridging, a technique to channel and infiltrate water, is widely adopted to prevent floods and improve soil water retention. [15]

5.11 Adaptation Strategies for Water Resources in the Livestock Sector

Herders in the Ouémé watershed in Bétérou have implemented several strategies to adapt to hydroclimatic risks. The use of legume haulms as fodder is a solution adopted by 50% of herders to compensate for grass shortages in the dry season. To protect livestock from excessive heat, 42% of herders bathe their animals in watercourses. Additionally, 70% of agro-pastoralists share their drinking water with their cattle during shortages. Regarding water management, certain practices are implemented to overcome dry-season crises. Among them, deepening ponds and wells (29%) extends water access, while protecting water points (63%) promotes their recharge. [15] Integrated Water Resources Management (IWRM) is a strategic lever to address the impacts of climate change in West Africa. In this region, where water is already a fragile resource, climate variations exacerbate droughts, floods, and the degradation of aquatic ecosystems. An integrated approach, based on sustainable planning, stakeholder participation, and the adoption of adapted technologies, is essential to strengthen the resilience of populations and ecosystems. Thus, the effective implementation of IWRM is an indispensable solution to ensure water security, support socio-economic development, and preserve water resources

5.12Principles of IWRM

Principle 1: Freshwater is a finite and vulnerable resource, essential to sustaining life, development, and the environment.

Principle 2: Participation The development and management of water should be based on a participatory approach, involving users, planners, and policymakers at all levels.

Principle 3: Equity and Gender Women play a central role in water supply, management, and conservation. Their involvement is crucial, along with attention to vulnerable groups such as the elderly, people with disabilities, and children. Principle 4: Economic and Social Value This principle has two parts: • The first is a statement : “Water has an economic value in all its competing uses.” • The second is a recommendation: “Water should be recognized as an economic and social good.” [2]

a) IWRM Principles in Burkina Faso since 1992 :

Integrated Water Resources Management (IWRM) in Burkina Faso is based on several fundamental principles that align with international recommendations, particularly those from the Rio Summit (1992) and the Global Water Partnership. Here are the main IWRM principles applied in Burkina Faso :

1. Recognition of water as an economic, social, and environmental good

Water is recognized as having economic value while also being a fundamental human right. It must be used efficiently and equitably, considering its social and ecological roles.

2. Stakeholder participation

All relevant actors (government, local authorities, users, NGOs, private sector, etc.) must be involved in planning, decision-making, and water management, especially through Local Water Committees (CLEs).

3. River basin approach

Water planning and management must occur at the scale of river basins – the natural unit of management – rather than administrative boundaries.

4. Consideration of equity and solidarity

Special attention is given to equitable access to water, especially for vulnerable groups (women, rural populations, etc.), following a logic of national and local solidarity.

5. Decentralized and subsidiary management

Water management is entrusted as much as possible to local authorities or grassroots organizations, in a decentralized manner, close to the users.

6. Environmental protection

Water use must respect the need to preserve aquatic ecosystems and maintain sustainable ecological balance.

7. Polluter-pays and user-pays principles

Users are expected to contribute financially to water management, depending on their usage, and polluters must bear the cost of the pollution they cause.

b) Current IWRM Principles in West Africa:

In West Africa, the principles of Integrated Water Resources Management (IWRM) are broadly aligned with international principles, while also taking into account the region’s socio-economic, cultural, and environmental realities. These principles are supported by regional institutions such as ECOWAS, UEMOA, and the West Africa Water Partnership (GWP-WA). The main IWRM principles in West Africa are:

1. Water is an economic, social, and environmental good

It should be recognized for its economic value, but also for its key role in social development and environmental preservation.

2. Inclusive participation of stakeholders

All relevant actors – governments, local authorities, users, civil society, private sector, etc. – must actively participate in water management, based on the principle of participatory governance.

3. River basin approach

Water resources are managed at the level of watersheds, including transboundary basins (such as the Niger or Volta Rivers), taking into account interdependence between countries.

4. Decentralized Management

Water management should take place as close as possible to the users, through local structures (such as basin committees, local water committees, etc.), in support of national and regional policies.

5. Environmental Sustainability

Aquatic ecosystems must be protected and used in ways that preserve their capacity to regenerate, in line with the principles of sustainable development.

6. Equity in Access to Water

IWRM aims to ensure equitable access to water, particularly for vulnerable populations, including women, children, and disadvantaged rural communities.

7. User-Pays and Polluter-Pays Principles

Water users must contribute to management costs, and those who pollute must bear the costs of their pollution. This approach serves as an incentive for responsible resource management.

8. Cross-Sectoral Integration

Water policies must be consistent with those of agriculture, environment, health, energy, etc., to avoid conflicts over usage. (Taken from the ECOWAS Regional Water Charter, IWRM Regional Action Plan)

c) State of the Art

Integrated Water Resources Management (IWRM) in West Africa takes place within a context of multiple pressures: population growth, rapid urbanization, climate change, competing water uses, and often fragmented governance. Several studies and regional initiatives have highlighted both the challenges and opportunities for more sustainable, equitable, and participatory water management.

1. Climate Change and Hydrological Variability

West Africa is particularly vulnerable to the effects of climate change on water resources. According to Barbier (2011), irregular rainfall and prolonged droughts deeply affect the availability and reliability of water resources [1]. These findings are supported by the work of Ardoin-Bardin [3], who identified a downward trend in average river flows in several West African basins, notably those of the Senegal and Niger rivers. Jean Emmanuel Paturel also highlights significant interannual and seasonal variability, which exacerbates uncertainties in hydrological planning [4]. In this context, Mahé (2006) emphasizes the importance of understanding rainfall-runoff dynamics and their interactions with land-use changes [12].

2. Governance and Institutional Framework

IWRM relies on multisectoral and multilevel coordination. Niasse et al. (2002) underline the legal and institutional challenges related to water governance in a region marked by often siloed and weakly coordinated management systems [6]. This fragmentation is particularly problematic in transboundary basins. Touré (2011) uses the Niger River as an example to illustrate the tensions and negotiations surrounding water sharing between Benin, Niger, and Nigeria [9]. The “West Africa Water Resources Policy” adopted in 2008 marks significant progress in recognizing IWRM as a regional reference framework [11]. It promotes an inclusive approach that integrates environmental, economic, and social dimensions.

3. Local Approaches, Gender, and Traditional Knowledge

Local responses to the water crisis are diverse and often underestimated in public policy. Sambo (2013) highlights community perceptions of climate change and the adaptation strategies developed by rural populations [7]. Similarly, the work of Eric Roose (1989) values traditional methods of water and soil management, which are still widely practiced in rural areas [8]. The integration of gender into water management is emerging as a key lever for improved governance. As water is primarily managed daily by women in many communities, their active involvement in planning and decision-making is crucial for more sustainable and equitable management [2].

4. Competing Uses and Cooperation

Water, as a vital and strategic resource, is also a source of conflict. Kohnert (2005) refers to the dual nature of water in West Africa : both a blessing and a curse. He emphasizes the need for mediation tools adapted to local and regional realities [5]. The development of regional cooperation mechanisms, supported by international partners such as GIZ, is essential for the hydropolitical stability of the region [10].

5. Limits of Current Policies and Perspectives

According to Benblidia (2010), supply-driven policies, which still dominate in several West African countries, are reaching their limits in the face of growing demand and increasing scarcity of resources [13]. Alternative approaches focused on demand management, water reuse, and participatory governance are needed. The assessment of climate impacts on specific basins, such as the Lower Loukkos Basin in Morocco—although outside of West Africa—offers relevant lessons for the region in terms of hydrological modeling and integrated agricultural management [14]. Finally, the work of Ogouwalé et al. (2024) illustrates the ingenuity of local farming strategies in the face of hydroclimatic risks in the Ouémé River basin in Benin, confirming the importance of a multi-scale and integrated approach [15].

6 General Context

6.1 General Data on Integrated Water Resources Management (IWRM)

6.2 Definitions

Integrated Water Resources Management (IWRM) is an approach aimed at coordinating the development and management of water, land, and related resources to optimize social and economic well-being while ensuring ecosystem sustainability. It relies on the participation of all stakeholders and considers the interactions between surface water, groundwater, and aquatic ecosystems. The fundamental principles of IWRM include:

  • Watershed-based management: Water is managed at the hydrological basin level to better account for interconnections.

  • Participatory approach: The involvement of stakeholders enables a more balanced and effective management.

  • Rational water use: Reducing losses and improving infrastructure ensure better resource availability.

  • Ecosystem conservation: Preserving aquatic environments is essential to ensure the sustainability of water resources. The main goal of IWRM is to ensure equitable access to water, prevent conflicts over its use, and enhance resilience to climate change.

6.2.1 Environmental Effects of IWRM in the Face of Climate Change

IWRM helps mitigate the negative impacts of climate change on water resources by optimizing their management and use. It notably allows:

6.3 Vulnerability and Adaptation of Water Management to Climate Change

6.3.1 Impacts of Climate Change on Water Resources

Climate change alters precipitation patterns, affects temperatures, and increases the frequency of extreme weather events, directly impacting water availability and quality. The main observed effects include:

6.3.2 Adaptation Strategies for Sustainable Management

To address these challenges, several adaptation strategies can be implemented within the framework of IWRM:

7 Study Methodology

7.1. Study Parameters: The Countries of West Africa

7.1.1 Geographical Location

We selected the West African countries due to their high exposure to water stress and their increased vulnerability to the effects of climate change on water resources. Indeed, climate change represents a major challenge that considerably undermines the mechanisms of Integrated Water Resources Management (IWRM) in states already facing water tensions. The study thus focuses on the following countries: Benin, Burkina Faso, Côte d’Ivoire, The Gambia, Guinea, Guinea-Bissau, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo. Cape Verde was excluded from the analysis due to its insular geographic location, which distinguishes it from the African continent.

7.1.2. Sampling

For our study on integrated water resources management in the face of climate change in West Africa, we chose to use stratified sampling, a method that is particularly relevant for our study. This method allowed us to divide the population into homogeneous subgroups or “strata” based on certain characteristics, such as geographic region, climate type, water supply sources (groundwater, surface water), and the level of vulnerability to climate change.

Steps of Stratified Sampling:

7.2. Data Collection Tools

Data collection allowed us to obtain the information necessary for the smooth progress of our study. The information was collected from various online sources such as: https://ourworldindata.org, ……, …….., …….

To also carry out field data collection, we used two main tools:

7.3 Household Questionnaire

Survey on Access to Water, the Effects of Climate Change, and Adaptation Strategies: Public Perceptions and Practices.

7.4. Interview Guide for Institutions and Water Management Experts

Interview Guide on Water Resource Management, Climate Change Impacts, and Adaptation Solutions: Perspectives and Recommendations from Experts.

Questionnaire link : https://kf.kobotoolbox.org/#/forms/aDordBdH3kcgnLKjSv8AMf Interview Guide link: https://kf.kobotoolbox.org/#/forms/aPvcc5t64aPj83PitA8NJ5

7.5 Description of the Methodology and Methodological Tools

7.5.1. Methodology

For our study, we used scientific tools to qualitatively assess the relationship between the indicators of integrated water resources management and the impacts of climate change.

7.5.2. Materials and Data Collection Tools

Excel and Word Software:

These software programs were necessary for data entry, organization, and graphical representation of our research results, observations, analyses, and conclusions. Their versatility allowed us to interpret and understand the results obtained more easily.

KoboToolbox:

This is an open-source suite of tools designed for field data collection, management, and analysis. It allows for:

KoboCollect:

This tool was invaluable for collecting the data necessary for our analysis. This intuitive and flexible application facilitated the creation and administration of questionnaires and interview guides, providing an efficient method for field data collection.

R Studio:

This data analysis software was essential for performing our statistical analyses. Thanks to its advanced features, we were able to carry out factorial analyses, clustering methods, cross-tabulations, etc. Its accessibility and versatility make it an indispensable tool for researchers working with complex data.

QGIS:

This software proved to be a powerful tool for the visualization and spatial analysis of our data. As a Geographic Information System (GIS), it allowed us to create custom maps and explore the geographic relationships between the different elements of our study. Its advanced features helped us better understand the issues addressed in our project by highlighting the spatial and geographic aspects of the data.

Zotero:

Zotero is a comprehensive, free, and open-source bibliographic management software, valued for its ease of use. It allows, among other things:

8 PRESENTATION OF THE VARIABLES:

8.1 Definition and importance of variables:

Integrated Water Resources Management (IWRM) is based on a comprehensive approach aimed at balancing resource availability, user needs and environmental sustainability. The choice of variables in this study was guided by the need to cover the main issues of water management in West Africa. Thus, the selected variables make it possible to analyse the availability of water resources, the pressures exerted on these resources, the sectoral uses and the means put in place to ensure sustainable management.

8.1.1 Disponibilité des ressources en eau :

The assessment of available resources is an essential step in IWRM analysis, as it determines the capacity of countries to meet water needs. For this, the following variables were retained :

8.1.2 Pressure on the resource:

The effectiveness of water management depends largely on the level of pressure exerted on the available resources. Three major variables were chosen :

8.1.3 Sectoral distribution and uses of water:

The different economic sectors have specific water needs. The analysis of their consumption makes it possible to assess priorities and conflicts of use :

8.1.4 Access to water and financial management:

Sustainable water management must also ensure equitable access to populations and effective mobilization of financing. Two variables are essential for this dimension:

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##               qtt_an_eau stress_H Acc_amé flux_fin_x10.6 N_d.infr X.agri X.ind
## benin             153.44     0.98    25.1          42.90     2277   25.2 12.82
## burkina faso      818.00     7.82    22.0          83.15     3865   51.4  2.65
## cote d'ivoire    1160.00     5.09    19.1          15.18     2932   51.6 20.83
## gambie            101.60     2.21     9.1           1.81     1654   38.6 20.87
## ghana            1450.00     6.31     7.2          71.92     3270   73.1  6.49
## guinee            175.00     1.37    18.1          10.83     1866   67.4  6.74
## guinée bissau     175.00     1.50    24.4           2.25     1580   75.8  6.26
## liberia           145.90     0.26    16.2          27.36     1925    8.4 36.60
## mali             5190.00     8.00    14.6         118.82     4498   97.9  0.08
## mauritanie       1350.00    13.25    15.3          60.84     3058   90.6  2.36
## senegal          3060.00    16.28    13.0         128.21     2411   91.3  0.05
## serra lionne      212.20     0.50    29.5          33.87     2176   21.5 26.15
## togo              223.00     3.39    25.1           9.82     1505   34.1  2.83
##               X.municip précipit    t.
## benin              62.0      969 29.62
## burkina faso       45.9      700 32.82
## cote d'ivoire      27.5     1150 27.74
## gambie             40.6      944 28.00
## ghana              20.5     1019 28.93
## guinee             25.8     1790 28.35
## guinée bissau      17.9     1779 28.09
## liberia            55.0     2128 25.76
## mali                2.1      277 34.02
## mauritanie          7.1       63 33.00
## senegal             8.6      688 32.78
## serra lionne       52.3     2643 26.40
## togo               63.1     1133 28.29
RTI_scaled <- scale(RTI)
res.pca <- PCA(RTI_scaled, graph = FALSE)

9 CARTOGRAPHIC REPRESENTATION AND INTERPRETATION:

The maps were generated on the QGIS software using Shapefiles (SHP) spatial data that were uploaded to BNDT/IGB. Each map represents the spatial distribution of a specific variable over the study area (West African countries). The colors on the maps were put in order to differentiate the countries from each other. Some colours have been gradually changed so that countries with a high value (dark colour) can be distinguished from countries with a low value (light colour).

9.1 Amount of water withdrawn annually

On this map we can see that Nigeria, Mali, Senegal and Niger have a very high annual amount of water compared to the other country.

# 9.2 Water stress Water stress is the ratio between the amount of water used and the amount of water available. This rate is used to assess the risk of water scarcity in each country; the higher the rate, the more water shortages are faced.

We notice on the map that Mauritania and Senegal have a considerable stress rate, as well as Mali, Burkina Faso, Niger and Nigeria, which implies that these countries are facing water shortage problems.

9.3 Population with access to an improved water source:

This map shows us the rate of population having access to an improved water source (tap, standpipe, etc.). It is noticeable that almost all West African countries have a low rate.

9.4 Precipitation :

In this part, we evaluate the amount of rainwater that has fallen. The map shows us high rainfall in coastal countries and low rainfall in Sahelian countries. # 9.5 Number of hydraulic infrastructure:

According to the map, Nigeria is the only country that has a very high number of water infrastructures. Then we have Mauritania, Mali, Burkina Faso and Ghana which have a lot of infrastructure. Other countries do not have enough water infrastructure.

9.6 Official financial flows for water supply and sanitation:

We can see on the map that Nigeria has a very high financial flow. Nigeria, Senegal, Mali, Burkina Faso and Ghana have a remarkable financial flow. The other countries have a low financial flow

9.7 Annual amount of water withdrawn for operations:

The annual rate of water withdrawn for 03 sectors of activity (agriculture, industry and municipal needs) was evaluated. The annual water rate of one sector is found according to the other sectors.

9.7.1 Agriculture :

9.7.2 Industry

9.7.3 Municipal Needs:

According to the 03 maps; It is noticeable that countries use more water in agriculture than in the other 02 sectors (industry and municipal needs)

9.7.4 Temperature:

The map shows low temperature in coastal countries and high temperature in Sahelian countries

10 Principal component analysis:

library(corrplot)
library(prettyR)
describe(RTI)
## Description of RTI
## 
##  Numeric 
##                   mean  median        var      sd valid.n
## qtt_an_eau     1093.40  223.00 2242409.16 1497.47      13
## stress_H          5.15    3.39      25.70    5.07      13
## Acc_amé          18.36   18.10      44.37    6.66      13
## flux_fin_x10.6   46.69   33.87    1849.51   43.01      13
## N_d.infr       2539.77 2277.00  864408.69  929.74      13
## X.agri           55.92   51.60     853.39   29.21      13
## X.ind            11.13    6.49     132.77   11.52      13
## X.municip        32.95   27.50     459.58   21.44      13
## précipit       1175.62 1019.00  536211.09  732.26      13
## t.               29.52   28.35       7.38    2.72      13
describe(RTI,num.desc=c("mean","median","var","sd","valid.n","min","max"))
## Description of RTI
## 
##  Numeric 
##                   mean  median        var      sd valid.n     min     max
## qtt_an_eau     1093.40  223.00 2242409.16 1497.47      13  101.60 5190.00
## stress_H          5.15    3.39      25.70    5.07      13    0.26   16.28
## Acc_amé          18.36   18.10      44.37    6.66      13    7.20   29.50
## flux_fin_x10.6   46.69   33.87    1849.51   43.01      13    1.81  128.21
## N_d.infr       2539.77 2277.00  864408.69  929.74      13 1505.00 4498.00
## X.agri           55.92   51.60     853.39   29.21      13    8.40   97.90
## X.ind            11.13    6.49     132.77   11.52      13    0.05   36.60
## X.municip        32.95   27.50     459.58   21.44      13    2.10   63.10
## précipit       1175.62 1019.00  536211.09  732.26      13   63.00 2643.00
## t.               29.52   28.35       7.38    2.72      13   25.76   34.02
#La matrice de correlation
mat_cor<-cor(RTI[,1:10],y = NULL)
corrplot(
  mat_cor,
  method ="color",
  type = "upper",
  addCoef.col ="black")

10.1 Inertia distribution:

. Inertia distribution The inertia of the first dimensions shows if there are strong relationships between variables and suggests the number of dimensions that should be studied. The first two dimensions of analyse express 75.41% of the total dataset inertia ; that means that 75.41% of the individuals (or variables) cloud total variability is explained by the plane. This percentage is high and thus the first plane represents an important part of the data variability. This value is strongly greater than the reference value that equals 54.52%, the variability explained by this plane is thus highly significant (the reference value is the 0.95-quantile of the inertia percentages distribution obtained by simulating 5738 data tables of equivalent size on the basis of a normal distribution). From these observations, it is probably not useful to interpret the next dimensions.

fviz_screeplot(res.pca, addlabels = TRUE, ylim = c(0, 50), title = "Variance expliquée par chaque axe")

Figure: Decomposition of the total inertia The first factor is major: it expresses itself 64.85% of the data variability. Note that in such a case, the variability related to the other components might be meaningless, despite of a high percentage. An estimation of the right number of axis to interpret suggests to restrict the analysis to the description of the first 1 axis. These axis present an amount of inertia greater than those obtained by the 0.95-quantile of random distributions (64.85% against 33.12%). This observation suggests that only this axis is carrying a real information. As a consequence, the description will stand to these axis.

10.2 Dimension Description 1

The labeled individuals are those with the greatest contribution to the construction of the plan.

fviz_pca_var(res.pca, col.var = "cos2", repel = TRUE, title = "Corrélations des variables")

fviz_pca_biplot(res.pca, repel = TRUE, col.var = "green", col.ind = "red", title = "Plan Factoriel ACP")

The dimension 1 opposes individuals such as mali, mauritanie and senegal (to the right of the graph, characterized by a strongly positive coordinate on the axis) to individuals such as serra lionne and liberia (to the left of the graph, characterized by a strongly negative coordinate on the axis). The group in which the individuals mali, mauritanie and senegal stand (characterized by a positive coordinate on the axis) is sharing :

-low values for the variable X.agri.

Figure- Variables factor map (PCA) The labeled variables are those the best shown on the plane.

dimdesc(res, axes = 1:1) $Dim.1

$Dim.1

Description of each cluster by quantitative variables

$1 v.test Mean in category Overall mean sd in category Overall sd p.value X.ind 2.700802 31.375 11.13308 5.225 11.07053 0.006917255 précipit 2.540191 2385.500 1175.61538 257.500 703.53684 0.011079191 X.agri -2.155921 14.950 55.91538 6.550 28.06684 0.031089847

$2 v.test Mean in category Overall mean sd in category Overall sd p.value N_d.infr -2.049270 1969.00000 2539.76923 499.78062 893.26128 0.04043568 flux_fin_x10.6 -2.552973 13.79833 46.68923 13.84761 41.31871 0.01068078

$3 v.test Mean in category Overall mean sd in category Overall sd p.value flux_fin_x10.6 3.042180 92.588 46.689231 26.386445 41.318709 0.002348713 t. 2.924978 32.310 29.523077 1.749606 2.609354 0.003444807 stress_H 2.913426 10.332 5.150769 3.789941 4.870343 0.003574861 N_d.infr 2.699889 3420.400 2539.769231 711.580382 893.261281 0.006936253 qtt_an_eau 2.436877 2373.600 1093.395385 1595.239117 1438.720317 0.014814710 X.agri 2.433963 80.860 55.915385 16.866132 28.066839 0.014934529 X.municip -2.142545 16.840 32.953846 15.734751 20.596811 0.032149691 X.ind -2.178683 2.326 11.133077 2.352434 11.070528 0.029355210 précipit -2.437629 549.400 1175.615385 338.585646 703.536838 0.014783958

#Contribution des variables aux axes

 In a PCA, each axis is built from a combination of variables.  Variables with high contributions are key in defining the axis.  Variables with low contributions have little influence on the axis.  The correlation circle shows which variables explain each axis: • Variables close to the edge of the circle → well represented. • Variables aligned with an axis → important for that axis.  Understanding the contributions helps to properly interpret each axis and to identify the most influential variables.

fviz_pca_contrib(res.pca, choice = "var", axes = 1:2, title = "Contribution des variables aux axes")
## Warning in fviz_pca_contrib(res.pca, choice = "var", axes = 1:2, title =
## "Contribution des variables aux axes"): The function fviz_pca_contrib() is
## deprecated. Please use the function fviz_contrib() which can handle outputs of
## PCA, CA and MCA functions.

fviz_contrib(res.pca, choice = "var", axes = 1, top = 12, title = "Contribution des variables - Axe 1")

fviz_contrib(res.pca, choice = "var", axes = 2, top = 12, title = "Contribution des variables - Axe 2")

Contributions des individus à la Dimension 1

base <- read.csv(file="C:/Users/hp/Desktop/PROJET RTI/R/BASE.csv", header = TRUE, sep = ";",
                 dec = ",", row.names =1)

acp_result <- PCA(base, scale.unit = TRUE, ncp = 5, graph = FALSE)
# 4.3 Contributions des individus à la Dimension 1
fviz_contrib(acp_result, choice = "ind", axes = 1, top = 20)

Contributions des individus à la Dimension 2

# 4.4 Contributions des individus à la Dimension 2
fviz_contrib(acp_result, choice = "ind", axes = 2, top = 20)

a. Quality of the PCA

The first two principal components explain a large proportion of the total variance of the data.

The cumulative percentage of variance captured by Dim1 and Dim2 shows that the PCA faithfully summarizes the information contained in the original data set.

b. Interpretation of Axis 1 (Dim1)

The most contributing variables to Axis 1 are those that differentiate certain countries or observations.

This axis could represent a contrast between (for example) countries with better water access and those with greater difficulties.

c. Interpretation of Axis 2 (Dim2)

Axis 2 is shaped by different variables (such as food security, urbanization rate, etc.).

This axis appears to separate countries based on another major factor (such as level of agricultural development or resource management).

d. Position of variables on the correlation circle

Variables located close to the edge of the circle are very well represented: they explain much of the variability on the two principal axes.

Variables strongly aligned with an axis → key variables for that axis.

e. Distribution of individuals (countries)

Countries or observations placed in the same area of the factor map share similar characteristics.

Countries far from the center are very specific compared to the studied variables.

f. Contribution of variables

Variables with a high contribution (above average) are essential for building the axes.

These variables must be highlighted in the analysis and thematic interpretation.

11 HIERARCHICAL CLASSIFICATION:

The classification was carried out by the Ascending Hierarchical Classification algorithm and produced the following figures. Dendrogram: The dendrogram below shows that 3 main classes are created based on similarities between individuals.

# Réaliser l'ACP sans graphique (base de la classification)
res.pca <- PCA(base, graph = FALSE)

# Extraire les coordonnées des individus
ind_coord <- res.pca$ind$coord

# Calculer la Classification Hiérarchique Ascendante (CHA)
res.hcpc <- HCPC(res.pca, graph = FALSE)

# Afficher le dendrogramme
fviz_dend(res.hcpc, rect = TRUE, show_labels = TRUE, main = "Dendrogramme de la classification")
## Warning: The `<scale>` argument of `guides()` cannot be `FALSE`. Use "none" instead as
## of ggplot2 3.3.4.
## ℹ The deprecated feature was likely used in the factoextra package.
##   Please report the issue at <https://github.com/kassambara/factoextra/issues>.
## This warning is displayed once every 8 hours.
## Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
## generated.

# 4.2 Graphique des individus
fviz_pca_ind(acp_result,
             col.ind = "cos2", # Colorer selon le cos²
             gradient.cols = c("#00AFBB", "#E7B800", "#FC4E07"),
             repel = TRUE)

Figure - Ascending Hierarchical Classification of the individuals. The classification made on individuals reveals 3 clusters. The cluster 1 is made of individuals such as liberia and serra lionne. This group is characterized by :

The hierarchical tree can be plotted on the factor map, with individuals colored according to their clusters.

11.1 Interpretation :

a. Objective of HCA

The Hierarchical Clustering Analysis (HCA) aims to group countries or observations based on their similarity across the analyzed variables.

It complements the PCA by forming homogeneous clusters of individuals (countries) with similar profiles.

b. Reading the dendrogram

The dendrogram is a tree-shaped graph showing how observations are progressively grouped together.

Two observations that merge early (at a low height) are very similar.

Conversely, those that merge later (at a higher height) are more different.

c. Number of clusters

By cutting the dendrogram at an appropriate level (often where there is a large jump in fusion heights), we can define 3 to 5 clusters (or more depending on your results).

Each cluster brings together countries with similar profiles based on the variables studied in the PCA.

d. Description of the clusters

Cluster 1: Countries with high values on certain variables (e.g., better access to drinking water, high urbanization rate, etc.).

Cluster 2: Countries with greater challenges on several indicators (e.g., low water access, low food security…).

Cluster 3: Intermediate countries, showing average levels across the studied variables.

(The exact interpretation depends on your specific dendrogram and country groupings.)

11.2 Hierarchical classification of countries:

After the analysis of the data, it was possible to group the countries according to the criteria.

12 Recommandations GIRE

Strategic Recommendation for IWRM (Integrated Water Resources Management) Based on Your PCA Your PCA and hierarchical classification show that the countries studied are divided into several distinct groups according to their performance or challenges related to water. Based on this, here is an adapted recommendation:

a. Strengthen capacities for countries facing difficulties

In your analysis, countries like Gambia, Benin, Togo, Sierra Leone, and Liberia are positioned far from the best performers on the main axes.

Recommended actions:

Train local stakeholders in sustainable water resource management.

Strengthen hydraulic infrastructures (wells, boreholes, irrigation networks, dams).

Implement water quality monitoring systems.

Support local governance to develop stronger water management plans.

b. Capitalize on leading countries

Countries like Mali, Senegal, Burkina Faso, and Mauritania demonstrate better performances in water use and management.

Recommended actions:

Share best practices between countries (South-South cooperation).

Strengthen cross-border projects (shared rivers, common aquifers).

Support existing initiatives in irrigation and water mobilization.

c. Adapt management strategies according to group profiles

Thanks to the classification, you identified homogeneous groups: different strategies are needed based on local realities.

Recommended actions:

Tailored approaches: a one-size-fits-all program will not be effective.

Prioritize areas with high water vulnerability for quick interventions.

Integrate social and economic dimensions into local water management projects.

d. Use PCA results to target key areas for improvement

Your PCA highlighted the main discriminant variables.

Recommended actions:

Focus actions on the variables that contributed the most to the axes (e.g., access to drinking water, sanitation coverage, irrigation control…).

Implement specific policies based on these key variables.

e. Strengthen resilience to climate change

Countries must integrate climate adaptation into their water management plans.

Recommended actions:

Promote artificial aquifer recharge.

Support water-resilient agriculture.

Develop early warning systems for droughts and floods.

13 Analysis and interpretation of the regression line:

# 1. Effectuer l'ACP (avec les mêmes variables que dans votre analyse)
res_acp <- PCA(RTI[,c("t.","stress_H","flux_fin_x10.6","X.agri","précipit","X.ind","X.municip")], graph=FALSE)

# 3. Créer un dataframe avec les résultats
results <- data.frame(
  Pays = rownames(res_acp$ind$coord),
  Dim1 = res_acp$ind$coord[,1],  # Première dimension
  Dim2 = res_acp$ind$coord[,2],  # Deuxième dimension
  stress_H = RTI$stress_H    # Variable à expliquer
)

# 4. Régression linéaire (stress_H en fonction de Dim1)
model <- lm(stress_H ~ Dim1, data = results)
summary(model)  # Affiche les coefficients et R²
## 
## Call:
## lm(formula = stress_H ~ Dim1, data = results)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -3.9329 -1.7908  0.1664  1.5437  4.0769 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   5.1508     0.6528   7.891 7.44e-06 ***
## Dim1          1.9325     0.2891   6.683 3.45e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 2.354 on 11 degrees of freedom
## Multiple R-squared:  0.8024, Adjusted R-squared:  0.7844 
## F-statistic: 44.67 on 1 and 11 DF,  p-value: 3.452e-05
# 5. Visualisation avec régression
ggplot(results, aes(x = Dim1, y = stress_H)) +
  geom_point(color = "steelblue", size = 3) +  # Points pour chaque pays
  geom_smooth(method = "lm", se = FALSE, color = "red") +  # Ligne de régression
  geom_text_repel(aes(label = Pays), box.padding = 0.5) +  # Labels sans chevauchement
  labs(x = "(temperature)",
       y = "water stress",
       title = "linear regression of water stress") +
  theme_minimal() +
  theme(legend.position = "none")
## `geom_smooth()` using formula = 'y ~ x'

This graph shows a linear regression between water stress and a climatic variable (“temperature/precipitation”), which seems to represent an indicator combining temperature and precipitation. It illustrates how aridity influences water stress in several West African countries.

13.1 Interpretation of the Graph:

This graph shows a linear regression between:

Explanatory variable (x): temperature (horizontal axis)

Variable to explain (y): water stress (vertical axis)

We observe that:

Overall, as temperature increases, water stress also increases.

The relationship appears to be positive linear: an increase in temperature is associated with an increase in water stress.

Senegal and Mauritania show high water stress at high temperatures.

On the other hand, Liberia and Sierra Leone show low water stress at lower temperatures.

Some points, like Mali, are further from the regression line: these are larger residuals.

In summary: Temperature seems to be an important factor influencing water stress in this region.

Regression Line Equation:

The general equation of a regression line is:

Water Stress=a+b×Temperature where:

a = intercept

b = slope of the line

13.2 Implications for Integrated Water Resources Management (IWRM)) :

14 Conclusion

West Africa is currently facing major challenges in terms of water resources management. Between climate variability, inequalities in access, demographic pressures and weak institutional capacities, the region illustrates the growing complexity of water governance in a context of global change. The analysis of water stress levels and climatic conditions shows a clear correlation: Sahelian countries, characterized by an arid climate and limited resources, are the most exposed, while coastal countries, although better provided with water, are not exempt from challenges, particularly in terms of pollution, equitable access and sustainable management. Faced with these challenges, Integrated Water Resources Management (IWRM) is a relevant approach, capable of reconciling the multiple uses of water, strengthening regional cooperation and promoting sustainable practices. However, its implementation is still incomplete, hampered by political, technical and economic difficulties. To be effective, IWRM must be anchored in a participatory, inclusive and cross-border dynamic, supported by coherent public policies, local capacity building, and better coordination between the countries bordering the major basins. Thus, this study highlights the need to integrate climate, social and institutional dimensions into water management strategies. The success of IWRM in West Africa will depend on the ability of states to collaborate, anticipate the impacts of climate change, and mobilize the resources needed to ensure sustainable, equitable, and secure access to water for current and future generations.

15 Références Bibliographiques

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[2] C. Green et S. Baden, « Integrated water resources management: a gender perspective », IDS Bull., vol. 26, no 1, p. 92‑100, 1995.

[3] S. Ardoin-Bardin et al., « Using general circulation model outputs to assess impacts of climate change on runoff for large hydrological catchments in West Africa », Hydrol. Sci. J., vol. 54, no 1, p. 77‑89, 2009.

[4] M. Sidibe et al., « Near-term impacts of climate variability and change on hydrological systems in West and Central Africa », Clim. Dyn., vol. 54, p. 2041‑2070, 2020.

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[6] M. Mul et al., Water resources assessment of the Volta River Basin, vol. 166. International Water Management Institute (IWMI), 2015. [En ligne]. Disponible sur: https://books.google.com/books?hl=fr&lr=&id=jH19CwAAQBAJ&oi=fnd&pg=PR7&dq=Water+Governance:+Legal+and+Institutional+Aspects+of+Natural+Resource+Management+in+West+Africa,%22+IUCN+Environmental+Law+Centre,+Ouagadougou,+Burkina+Faso,+September+25-27,+2002&ots=2HbjKS3eaQ&sig=v-5O-ITMoTANiHbCbyN1B8gZiv8

[7] A. SAMBO, « Perceptions locales et pratiques d’adaptation au changement climatique dans la gestion rationnelle des ressources en eau du Lac Tchad », Geo-Eco Trop, vol. 37, no 2, p. 293‑302, 2013.

[8] C. R. De Kimpe et J.-L. Morel, « Urban soil management: a growing concern », Soil Sci., vol. 165, no 1, p. 31‑40, 2000.

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[10] F. Le Quesne et al., « The role of insurance in integrated disaster & climate risk management: Evidence and lessons learned », 2017, [En ligne]. Disponible sur: https://collections.unu.edu/eserv/UNU:6312/MCII_ACRI__1710020_Online-meta.pdf

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