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Evaluations des ressources en eau et de leur gestion

Introduction

    Water is essential for life, but humanity faces complex challenges associated with increased demand, variable supply, widespread pollution, and water-related disasters. Water resources, their management and any degradation are important to land resource components in most dryland assessment sites. Water resources degradation and effects of land degradation on water quantity and quality should be assessed in more depth in areas where this is reported to be a critical issue1.

    Water touches every aspect of development and it links with nearly every Sustainable Development Goal (SDG)2. It drives economic growth, supports healthy ecosystems, and is essential and fundamental for life itself3.

    1. What are the resources of water available?

      About 97% of the water on the Earth is salt water and only 3% is fresh water; slightly over 2/3 of this is frozen in glaciers and polar ice caps. The remaining unfrozen freshwater is found mainly as groundwater, with only a small fraction present above ground or in the air. The only natural input to any surface water system is precipitation within its watershed, the total quantity of water in that system at any given time is also dependent on many other factors.

      Storage capacity include lakes, wetlands and artificial revservoirs, the permeability of the soil beneath these storage bodies, the runoff characteristics of the land in the watershed, the timing of the precipitation and local evaporation rates. All of these factors also affect the proportions of water loss. Water reclamation or wastewater reuse is the process of co-use instead of single use of freshwater supplies which can be a water-saving measure. When used, water is eventually discharged back into natural water sources, it can still have benefits to ecosystems, improving streamflow, nourishing plant life and recharging aquifers, as part of the natural water cycle converting wastewater into water that can be reused for other purposes4.

      2. What is of particular concern regarding water resources?

        Estimates indicate that 40% of the world population live in water scarce areas, and approximately ¼ of world’s GDP is exposed to this challenge. By 2025, about 1.8 billion people will be living in regions or countries with absolute water scarcity.

        Already some 2.2 billion people around the world do not have safely managed drinking water services, 4.2 billion people do not have safely managed sanitation services, and 3 billion lack basic handwashing facilities. Gaps in access to water supply and sanitation, growing populations, more water-intensive patterns of growth, increasing rainfall variability, and pollution are combining in many places to make water one of the greatest risks to economic progress, poverty eradication and sustainable development.

        The consequences of such stress are local, national, transboundary, regional, and global in today’s interconnected and rapidly changing world. Consequences will be disproportionately felt by the poorest and most vulnerable.

        As underlined by the World Bank5, lack of access to water supply and sanitation (WSS) constitutes a public health, economic, and environmental emergency across the developing world. Regarding the availability of water resources, of particular concern are:

        1. the effective use of rainwater for direct consumption, for productive purposes and for recharging surface and ground-water supplies;
        2. the reduced water quality through pollution, salinization and overexploitation by domestic, agricultural, forest and industrial uses;
        3. the reduced water quantity / availability for consumption (human and animals) and other uses because of drought or over-exploitation of water sources;
        4. the maintenance of the hydrological regime (i.e. recharge of groundwater, flood control – in catchments and watersheds) which is an important ecosystem service;
        5. the extent and performance of water resources management alongside soil, land use and vegetation management for mitigating effects of desertification, drought, and climate change.

        Urgent action is thus needed to provide sustainable urban and rural water supply and sanitation services to all and contribute to job creation and economic recovery.

        Climate change and population growth are expected to put additional pressure on water resources. The World Bank Group works thus to:

        • (i) Enhance economic growth by improving bulk water supplies for health, sanitation, and the economy; and by encouraging associated job creation; and
        • (ii) Promote more sustainable management and use of water resources in economic stimulus packages and other relief efforts through improvements in water governance6. This in particular to support the Coronavirus (COVID-19) response and recovery.

        Also, according to a WHO/UNICEF technical brief on Safely Managed Water, Sanitation, and Hygiene (WASH)7, by improving facilities and using proven behavior change techniques, WASH services should enable more frequent and regular hand hygiene, one of the most important measures that can be used to prevent infection with the COVID-19 virus. Many co-benefits will be realized by safely managing WASH services and applying good hygiene practices. Such efforts would prevent other infectious diseases, which cause millions of deaths each year.

        3. How evolve water scarcity over time?

          More than 90% of water in water-scarce regions goes today to irrigated agriculture, but this phenomenon has a long history. Water withdrawal can also be very high for certain industries, but consumption is generally much lower than that of agriculture. The major industrial users include hydroelecric dams, thermoelectric power plants, which use water fo cooling, ore and oil refineries, use water in chemical processes and manufacturing plants, which use water as a solvent and in natural gas extraction from shale rock.

          The World Economic Forum listed droughts, lack of rainfall, or pollution as a cause of water scarcity and one of the largest global risks in terms of potential impact over the next decade8. With a global population still growing fast, estimates show that with current practices, the world will face a 40% shortfall between forecast demand and available supply of water by 2030. Water scarcity and drought are playing in aggravating fragility and increasing the risks of conflicts and water-related disasters also account for 70% of all deaths related to natural disasters.

          Many pollutants also threaten water supplies, but the most widespread, especially in developing countries, is the discharge of raw sewage into natural waters; this method of sewage disposal is the most common method in underdeveloped countries, but also is prevalent in quasi-developed countries such as China, India, Nepal and Iran.

          4. How critical is sanitation in this context?

            Sanitation is critical to health, economic growth and the environment. Poor sanitation and contaminated water are also linked to transmission of diseases such as cholera, dysentery, hepatitis A and typhoid. Smart investments in clean water and sanitation is about preventing needless deaths, investing in people and transforming lives. For example, 297,000 children under 5 years die due to diarrhea linked to inadequate WASH. Healthier children would also become healthier adults who could contribute more to the economy. This principle is at the core of the Human Capital Project9 of the World Bank.

            To deliver on their commitment to Sustainable Development Goal (SDG) 6.2 – “Achieving access to adequate and equitable sanitation and hygiene for all by 203010, political commitment and leadership, technological innovations and breakthroughs in service delivery and financing

            5. What is the specific impact of climate change on water resources?

              Climate change expresses itself through water as 9 out of 10 natural disasters are water-related. Water-related climate risks cascade through food, energy, urban and environmental systems. To achieve climate adaptation and development goals, water must be at the core of adaptation strategies.

              Climate change will indeed worsen the situation by altering hydrological cycles, making water more unpredictable and increasing the frequency and intensity of floods and droughts. The roughly 1 billion people living in monsoonal basins and the 500 million people living in deltas are especially vulnerable. Flood damages only from property damage are estimated in $120 billion per year and droughts pose, among others, further constraints to the rural poor, highly dependent on rainfall variability for subsistence.

              To guide effective climate change adaptation, activities should reflect the importance of water management for reducing vulnerability and building climate resilience, prioritizing the following actions:

              • (i) Expand beyond traditional integrated water resources management (IWRM). Efforts to reduce greenhouse gas emissions also depend on access to reliable water resources, as all mitigation actions need water to succeed.
              • (ii) Promote investment and solutions that incorporate management of ‘natural infrastructure’ – the ecosystem services provided by healthy watersheds and coasts – and their benefits for climate-resilient development of the food and energy sectors.
              • (iii) Support actions at scale to build climate resilience by combining watershed management, sustainable infrastructure, and empowerment and learning through adaptive institutions.

              6. How more particularly build resilience to hydro-climatic risks?

                Climate change has made the water cycle far less predictable - and water availability and quality less reliable - threatening communities, livelihoods, and sustainable development11. Climate change is indeed radically altering the water cycle as the world is becoming:

                • Hotter – Higher temperatures are increasing the rate of evaporation from land and plants into the atmosphere, leading to greater demand for irrigation water ;
                • Stormier – The frequency and intensity of hurricanes and cyclones are on the rise, resulting in stronger winds, more precipitation, and more recurrent flooding ;
                • Wetter – Rising sea levels are increasing the risks associated with storm surges and poor drainage in low-lying coastal areas. Higher sea levels also affect the quality of freshwater resources ;
                • Drier – Drought frequency and intensity are increasing, resulting in crop failures, growing water scarcity, and potential famines. Arid zones and deserts will continue to expand ;
                • More polluted – Higher temperatures are intensifying the growth of dissolved nutrients in bodies of water, leading to harmful algal blooms, dead zones, and fish kills.

                7. What is the impact of water resources on economy?

                  Water is a vital factor of all types of production, so diminishing water supplies translates into slower growth. Some regions could see their growth rates decline by as much as 6 % of GDP by 2050 as a result of water-related losses in agriculture, health, income and prosperity.

                  Water supply and sanitation require a huge amount of capital investment in infrastructure such as pipe networks, pumping stations and water treatment works. It was once estimated that the Organisation for Economic Co-operation and Development (OECD) nations would need to invest at least US$ 200 billion/ year to replace aging water infrastructure to guarantee supply, reduce leakage rates and protect water quality12.

                  Ensuring a sufficient and constant supply of water under increasing scarcity is thus essential to achieve global poverty alleviation goals:

                  • (i) Optimizing the use of water through better planning and incentives will help to improve welfare and increase economic growth. Economic instruments such as water permits and prices, if well implemented and enforced, can improve stewardship of water resources.
                  • (ii) Expanding water supply and availability where and if appropriate which is vital. This includes investments in water storage, water reuse and recycling and, where viable, desalinization. These interventions must be accompanied by policies to promote water efficiency and improve water allocation.
                  • (iii) “Water proofing” economies to limit the impact of extremes and uncertainties is also among the top priorities. Better urban planning, expanding crop insurance to protect farmers, and citizen engagement will build resilience and minimize economic impacts of adverse events.

                  Water is also crucial in determining whether the world will achieve the Sustainable Development Goals (SDGs) of the United Nations. The world needs thus a fundamental shift in how:

                  • (i) Understanding Water which means making evidence-based decisions about water using strengthened water data;
                  • (ii) Valuing Water which means recognizing the values that societies accord to water and its uses, taking these into account in political and business decisions including decisions about appropriately pricing water and sanitation services;
                  • (iii) Managing Water which means pursuing integrated approaches to water resource management across local, national, and regional levels.

                  8. How to sustain water resources?

                    Sustaining water resources means improving resource management at the river basin, country, and transboundary levels. Feeding 9 billion people by 2050 will require a 60% increase in agricultural production and a 15% increase in water withdrawals.

                    The fragmentation of this resource also constrains water security. There are 276 transboundary basins, shared by 148 countries, which account for 60% of the global freshwater flow. Similarly, 300 aquifers systems are transboundary in nature, meaning 2 billion people worldwide are dependent on groundwater.

                    The challenges of fragmentation are often replicated at the national scale, meaning cooperation is needed to achieve optimal water resources management and development solutions for all riparians. To deal with these systemic complex and interlinked water challenges, countries will need to improve the way they manage their water resources and associated services.

                    To strengthen water security against this backdrop of increasing demand, water scarcity, growing uncertainty, greater extremes, and fragmentation challenges, clients will need to invest in institutional strengthening, information management, and (natural and man-made) infrastructure development. Institutional tools such as legal and regulatory frameworks, water pricing, and incentives are needed to better allocate, regulate, and conserve water resources.

                    Information systems are needed for resource monitoring, decision making under uncertainty, systems analyses, and hydro-meteorological forecast and warning. Investments in innovative technologies for enhancing productivity, conserving and protecting resources, recycling storm water and wastewater, and developing non-conventional water sources should be explored in addition to seeking opportunities for enhanced water storage, including aquifer recharge and recovery. Ensuring the rapid dissemination and appropriate adaptation or application of these advances will be a key to strengthening global water security.

                    9. What is the specific contribution of the World Bank in the management of this climate/water resources context?

                      The World Bank helps countries ensure sustainability of water use, build climate resilience and strengthen integrated management. It contributes to ensure that water benefits are equitably and sustainably accessible to all. This requires the removal of structural barriers that prevent access to water resources and services, and that limit participation in water institutions and processes. It means ensuring that excluded groups have a voice in water planning and distribution. It provides knowledge, advocacy, technical expertise, and financial support to strengthen water supply services (WSS) and institutions around the world13.

                      The 2030 Water Resources Group (WRG)14 of the World Bank forges Multi-Stakeholder Partnerships, or MSPs, to collectively manage this scarce resource for the benefit of people, ecosystems, and economies. Drawing on the experience of the 2030 WRG these multistakeholder partnerships, their Governing Council has identified the three thematic areas, agriculture, industry and coping with climate change, where water challenges are the most urgent, and where small changes will have the greatest impact. The 2030 WRG also works to leverage the power of appropriate technologies so that possible solutions can be rapidly rolled out to meet the scale of the challenge.

                      In this context, the World Bank works with their clients to design climate-informed and energy-efficient green and grey water projects that sustain water resources, deliver services, and build resilience. They help countries to prepare for and adapt to increasing hydro-climatic risks, and work to slow the pace of climate change by reducing greenhouse gas emissions of water service providers. In this context, they work with the clients to improve water management, providing investment and technical support that builds resilience, reduces emissions, and lowers costs.

                      To promote partnerships between governments, the private sector, and civil society that help countries adapt to climate variability, the World Bank also work to reform institutions and processes so that they become more inclusive and accountable to citizens, reflect greater diversity in their management and staff, and extend services to all.

                      10. What about water resources more specifcally in agriculture?

                        Water in agriculture is central to feeding the planet, providing livelihoods, and building resilience to climate shocks and extremes. It takes around 2,000 – 3,000 litres of water to produce enough food to satisfy one person's daily dietary need15.

                        Irrigation methods such as furrow and overhead sprinkler irrigation are usually less expensive but are also typically less efficient, because much of the water evaporates, runs off or drains below the root zone. Other irrigation methods considered to be more efficient include drip or trickle irrigation, surge irrigation, and some types of sprinkler systems where the sprinklers are operated near ground level16.

                        In their support to the Coronavirus (COVID-19) response and recovery the Water Group of the World Bank17 works to :

                        • (i) ensure continuity of irrigation services that sustain critical agricultural production and
                        • (ii) provide cash injections to rural communities, create job opportunities for the vulnerable, and improve the productivity of agro-environmental assets to build long-term resilience to shocks.

                        11. What are the Source Protection Explorer and the Protecting Water Atlas?

                          With rapid rates of habitat loss, the threat of climate change, and dwindling public resources, there is an increasing need to inform decisions with sound science. Investing in watershed health is a sustainable way to enhance water security.

                          The Source Protection Explorer18 of the World Bank enables users to explore cities that can meet specified pollution reduction targets using conservation actions and the area and cost required to reach these targets. Innovative investments can help address water depletion. Among them, the Water Scarcity Explorer enables users to look at how, where and when water has been used and explore potential strategies to alleviate scarcity within a given basin.

                          The Protecting Water Atlas, where users can explore data and analyses that underpin The Nature Conservancy's global-scale reports. This mapping site is part of a family of spatial decision tools.

                          The Nature Conservancy, along with global, regional and local partners, have in particular developed a powerful spatial decision support tool and suite of web apps, called the Natural Solutions Toolkit19 , that puts scientific information in the hands of public agencies, communities and key stakeholders. This toolkit includes spatial decision tools and web applications to catalyze water conservation.

                          With a common goal of highlighting the value of nature in reducing risk and enhancing resilience in cities, counties, provinces, states, and across nations, the Toolkit provides effective communications in science and technology across environments.

                          12. What are the programs covered by the Toolkit?

                            The variety of programs and projects that use the Toolkit includes:

                            Coastal Resilience which supports practitioners around the world who are working to address coastal hazards, particularly sea level rise and storm surge, with adaptation and risk mitigation solutions;

                            A Freshwater Network which supports U.S. statewide and regional decision-making regarding the status and trends of freshwater resources;

                            A Floodplains by Design which facilitates integrated, multi-benefit floodplain management and flood risk reduction decisions;

                            An Atlas of Ocean Wealth mapping Ocean Wealth explores and maps global ecosystem services such as fishery production, carbon sequestration, natural coastal protection, and recreation and tourism in determining global and regional ocean wealth;

                            A Natural Resource Navigator in New York which allows planners and managers to make climate-smart decisions to sustain natural resources;

                            A Protecting Water Atlas which provides information about the world’s watersheds to advance solutions for securing water quality and quantity for people and nature;

                            The Blueways Conservation decision support tool which supports marine biodiversity conservation by providing a series of apps in support of decision-making processes that enhance the management of our oceans.

                            Natural Climate Solutions (NCS) which provide a snapshot of a country’s potential to mitigate climate change relative to their commitment to the 2015 Paris Agreement. NCS illustrates mitigation pathways that reduce CO2 levels through restoration, avoided conversion, and improved management of forest, wetland, and grassland ecosystems.

                            There is also the Urban Water Blueprint30 which analyzes the state of water in more than 2,000 watersheds and 530 cities worldwide to provide science-based recommendations for natural solutions that can be integrated alongside traditional infrastructure to improve water quality. City and utility leaders who embrace both natural and engineered water infrastructure will not only meet future water demand; they will reshape our planet's landscape for the better.

                            13. What is the Dynamic Water Resources Tool?

                              The Dynamic Water Resources Assessment Tool (DWAT)21 has been under development since 2008 as a part of the activities of World Meteorological Organization (WMO).

                              It is designed to assist long-term planning and policy assessment and development. Its application allows the assessment of land-use changes within the basin over time, and of the impacts on water availability under a wide variety of scenarios, including climate change.

                              This tool is intended to help users, particularly policy specialists and water resource managers, identify current and future water management challenges and compare those with current and past water resources availability. This tool can also help better understand the impacts of past and present water management practices on water resources, as well as the interactions between climate, water and landscape.

                              Its use can contribute to water reform by providing nationally and regionally consistent water resources information and data, such as surface water, groundwater, urban and agricultural water supply and use. Moreover, it can aid in the formulation of government policy and the development of broad-scale strategic plans and decision making.

                              The DWAT is being peer-reviewed by a panel of Commission for Hydrology experts, who are applying it to basins located in different geographical areas, each with different climatic characteristics. This peer-review has the objective of further testing the system to strongly enhance the model reliability.

                              14. What is the role of the Working Group on Integrated Water Resources Management of the UNICE?

                                The Working Group on Integrated Water Resources Management and the Working Group on Monitoring and Assessment of the United Nations Economic Commission for Europe (UNECE)22 are the two main subsidiary bodies established by the Meeting of the Parties.

                                The focus of the work of the Working Group on IWRM is on intersectoral activities to support the implementation of a Convention with regard to the integrated management of transboundary water resources (surface waters and groundwaters).

                                Activities under this Working Group aim to:

                                • prevent, control and reduce transboundary impacts, as defined in the Convention;
                                • promote the ecosystem approach in the framework of integrated water resources management;
                                • promote equitable and reasonable utilization of transboundary waters;
                                • ensure conservation and, where necessary, restoration of water-related ecosystems.

                                Further goals are to:

                                • advance adaptation to climate change in the transboundary context, including flood and drought management;
                                • promote understanding of the water-food-energy-ecosystems nexus and the reconciliation of multiple water uses in transboundary basins;
                                • advance the understanding of the benefits of transboundary cooperation;
                                • prevent accidental water pollution;
                                • facilitate the financing of transboundary water cooperation
                                • facilitate reporting under the Convention and on Sustainable Development Goal indicator 6.5.2.

                                The Working Group also seeks to build and strengthen the institutions responsible for the management of transboundary waters, to facilitate the work of joint bodies and to promote access to information and public participation in decision-making.

                                In the context of the COVID-19 crisis, the Water Convention and the Protocol on Water and Health jointly serviced by WHO-Europe and UNECE help countries by promoting the availability of safe water for all within countries and across borders and sectors.

                                15. What are the purpose of the “Water for Life' Decade” projects of the United Nations?

                                  The development of the UN United Nations World Water Development (WWDR), coordinated by the World Water Assessment Programme (WWAP), is a joint effort of the UN agencies and entities which make up UN-Water, working in partnership with governments, international organizations, non-governmental organizations and other stakeholders. The 2021 edition of the UN WWDR 2021 entitled ‘Valuing Water groups current methodologies and approaches to the valuation of water into five interrelated perspectives:

                                  1. Valuing water sources : in situ water resources and ecosystems;
                                  2. Valuing water infrastructure for water storage, use, reuse or supply augmentation;
                                  3. Valuing water services, mainly drinking water, sanitation and related human health aspects;
                                  4. Valuing water as an input to production and socio-economic activity, such as food and agriculture, energy and industry, business and employment;
                                  5. Other sociocultural values of water, including recreational, cultural and spiritual attributes.

                                  These are complemented with experiences from different global regions; opportunities to reconcile multiple values of water through more integrated and holistic approaches to governance; approaches to financing; and methods to address knowledge, research and capacity needs.

                                  The rationale for the Integrated Water Resources Management (IWRM) approach was that managers, whether in the government or private sectors, have to make difficult decisions on water allocation. More and more they have to apportion diminishing supplies between ever-increasing demands. Drivers such as demographic and climatic changes further increase the stress on water resources. The traditional fragmented approach is no longer viable and a more holistic approach to water management is essential. This approach has now been accepted internationally as the way forward for efficient, equitable and sustainable development and management of the water resources.

                                  The primary goal of the 'Water for Life' Decade 2005-201524 was to promote efforts to fulfil international commitments made on water and water-related issues by 2015. Focus was on furthering cooperation at all levels, so that the water-related goals of the Millennium Declaration, the Johannesburg Plan of Implementation of the World Summit for Sustainable Development and of the Agenda 21 could be achieved.

                                  The challenge was to focus attention on action-oriented activities and policies that ensure the long-term sustainable management of water resources, in terms of both quantity and quality, and include measures to improve sanitation. Achieving the goals required sustained commitment, cooperation and investment on the part of all stakeholders from 2005 to 2015 and far beyond. The United Nations, through its inter-agency coordination mechanism, UN-Water, was responsible for coordinating the project.

                                  Build on the achievements of the previous “Water for Life” Decade, 2005-2015. the objectives of the International Decade for Action on Water for Sustainable Development, 2018-202825 have been defined as

                                  • Advance sustainable development;
                                  • Energize implementation of existing programmes and projects;
                                  • Mobilize action to achieve the 2030 Agenda for Sustainable Development 26.

                                  There should also be a greater focus on:

                                  • The sustainable development and integrated management of water resources for achievement of social, economic and environmental objectives;
                                  • The implementation and promotion of related programmes and projects;
                                  • The furtherance of cooperation and partnerships at all levels to achieve inter-nationally agreed water-related goals and targets, including those in the 2030 Agenda for Sustainable Development.

                                  References
                                  A series of reports of international organizations including The World Bank, the United Nations or the World Meteorological Organization which are mentioned in the text.

                                  1 www.worldbank.org/en/topic/waterresourcesmanagement  and https://wbwaterdata.org/group/sustain-water-resources 
                                  2  www.fao.org/fileadmin/templates/nr/kagera/Documents/LADA_manuals/part2_f.pdf
                                  3 https://en.wikipedia.org/wiki/Water_resources 
                                  4 https://documents.worldbank.org/en/publication/documents-reports/documentdetail/155901614168147480/water-supply-and-sanitation-water-is-at-the-heart-of-development 
                                  5 https://sdgs.un.org/goals 
                                  6  http://documents1.worldbank.org/curated/en/775711614147342979/pdf/Climate-Change-and-Water-Building-Resilience-to-Hydro-Climatic-Risks.pdf
                                  7  http://documents1.worldbank.org/curated/en/677471614162507456/pdf/Social-Inclusion-Promoting-Social-Inclusion-in-the-Water-Sector.pdf
                                  8  https://www.2030wrg.org/wp-content/uploads/2020/11/WRG-Annual-Report_2020_Sprds_12_4.pdf
                                  9  UN Water – Coping with Water Scarcity 2007
                                  10 https://en.wikipedia.org/wiki/Water_resources 
                                  11 https://documents.worldbank.org/en/publication/documents-reports/documentdetail/875921614166983369/water-in-agriculture-towards-sustainable-agriculture 
                                  12 The Protecting Water Atlas ; The World Bank 
                                  13 Natural Solutions Toolkit  
                                  14 https://public.wmo.int/en/water/dynamic-water-resources-assessment-tool 
                                  15 www.unwater.org/publications/un-world-water-development-report-2021/ 
                                  16 www.un.org/waterforlifedecade/background.shtml 
                                  17 www.un.org/waterforlifedecade/background.shtml 
                                  18 www.undp.org/content/undp/en/home/2030-agenda-for-sustainable-development.html 

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