1 Introduction

The strategic and overall objective of this study is to enhance the resilience, prosperity, and quality of life from a holistic perspective by developing a holistic roadmap for a sustainable water future, with a community consensus, focusing on transboundary and shared water resources basins where water resources could contribute for a sustainable water future in a basin such as the Nile River basin. Specific objectives are to enhance synergies and cooperation among Nile River basin countries; build mutual trust among practitioners with different nationalities, ethnic group, backgrounds, gender, and perspectives; involve practitioners and polycentric perspective; promote low-complexity, community-based participatory driven by actionable knowledge, and best practice; identify related impact on water future and related demographics, ecological, environmental, political, economic, social, and technological (DEEPEST) holistic framework and context; improve the foresight of future multidimensional water-related issues; promote transdisciplinary water resources planning and related global goals; prepare basin strategies for the development, address optimal water priorities, drivers, benefits, timeframe, and measures for the water-related sectors through the formulation and implementation of the roadmapping process; pave the way to enable innovative water-related technologies, knowledge, and infrastructure both to explore and to support decisions; highlight innovative solutions that could be applicable to improve water resilience; provide an added value of water resources for informed water-related sustainable development strategies and policies for all large rivers, and especially Nile River.

Large Rivers Recently, many researchers have significant contributions to the subject of large rivers.

In Africa, the floodplain’s wetlands are found on large rivers. Examples include Rufiji, Kilombero, the Zambezi, Luangwa, Kafue, the Cubango, Okavango, and the Mara rivers. The Zambezi River with 2574-km-long is the fourth longest in Africa. It is located in Zambia, Angola, Botswana, and Namibia, and has a border with Zimbabwe, Zambia, and Mozambique. The wetland impacts on the flow regime of large African rivers were modeled (Makungu and Hughes 2021). Statistical down-scaling model (SDSM), a stochastic weather model, was used to both assess climate change, and to adapt water, agriculture, and energy in a large river basin (Gebrechorkos et al. 2020).

In Asia, The Yangtze (Changjiang) River is the longest in both China and Asia and the third longest globally. Its length is 6300 km, its average discharge is 30,146 m3/s, and its basin size is 1,808,500 km2. The Yangtze River is a large dammed river. Damming and human activities have disturbed freshwater, biotic, and abiotic factors in the Yangtze River (Sun et al. 2021). The Yellow River, located in China, is the sixth longest river globally where its length is 5464 km. The Yellow River has a complex large basin. The alternative allocation effect in the Yellow River by setting the blue water footprint (BWF) on blue water scarcity (BWS) for each sub-catchment was investigated (Albers et al. 2021). Climate change has a significant impact on the Yellow River basin, especially rainfall events and its related water and sediment yield (Xu et al. 2021). The Brahmaputra River is a large transboundary braided “river”. It flows from Tibet, and then India, to Bangladesh. It is 3848 km long, the 15th longest, and by discharge the 9th largest river globally. Its discharge was modeled using the WRF-Hydro model (Dubey et al. 2021). Human, hydrological, and hydrogeological systems for intensive agriculture in a large river basin were spatial and temporal analyzed to strengthen water management (Erhu et al. 2020). Geospatial analysis was used to simulate total suspended solids (TSS) in a large transboundary river. The model reliability was improved using hydrologic signatures (Ly et al. 2020).

In Australia, the Murray River is the longest. Its length is 2508 km, its average discharge is 767 m3/s, and its basin size is 1,061,469 km2. The impact of multi-decadal floods on aquatic macroinvertebrates was modeled based on hydrological, water quality, and climate data, in the Murray River (Le et al. 2021).

In Europe, a climate change assessment of the Nemunas River basin was provided using two Representative Concentration Pathways (RCPs). The Nemunas/Nioman/Neman River, a large transboundary river, has a total length of 937 km. The Nemunas are located in Eastern Europe, in Belarus, Lithuania, and Russia, in the European Union (EU) territory. The two used RCPs were one of the intermediate stabilization pathways RCP4.5 and one high pathway RCP8.5 (Čerkasova et al. 2021). The necessity of a minimum discharge for hydropower generation and ecological benefits in Ume River, its length is 460 km and located in Sweden, a large regulated river, was documented (Widén et al. 2021).

In North America, the hydrological exchange flows (HEFs) for the Columbia River, is 2,000 km long and located in North America, a transboundary river flows through the United States and Canada, a large complex regulated river was studied particularly river–aquifer interface, hydrologic forcing, hydrodynamic, hydrogeologic, geomorphologic, contaminant plume, physical features, hydrogeological structure, and biogeochemical processes (Song et al. 2021). Hybrid precipitation datasets were proposed for better hydrological modeling in the Saskatchewan River, its length is 1,939 km in Canada (Wong et al. 2021).

In South America, the largest river by discharge and drainage basin and the second longest globally is the Amazon River. It is located in Peru, Colombia, and Brazil Countries. From its Source in Peru to its Mouth in Brazil, its length is 6400 km. Its discharge ranges from a minimum equal to 180,000 m3/s to a maximum equal to 340,000 m3/s, and an average equal to 209,000 m3/s (6591 km3 per year). Its width ranges from a minimum equal to 1 km to a maximum equal to 100 km. Its depth ranges from a minimum equal to 20 m to a maximum equal to 100 m. The Amazon basin area is 7,000,000 km2. The Amazon River’s sustainability could be ensured by indigenous communities and international authorities. The future interdisciplinary research to ensure its conservation could include freshwater biodiversity, ecosystem, wastewater discharge, overfishing, local communities, and agriculture (Henao et al. 2020).

The Nile River The Nile River is not only one of the large rivers in the world but also the longest river on Earth. The Nile has had great positive impacts in terms of the effectiveness of human civilizations from the dawn of history. The river has a complex water resources (WRs) system. It has a total length of approximately 6650 km. The Nile River basin drains an area estimated at 3,349,000 square kilometers. The river's regime is controlled by some dams, situated on the main Nile or its tributaries. The Nile River’s behavior has a vital characteristic in the life of the Nile people. A good flood causes a good harvest and meant subsequent adequate food.

Historically, the Nile River had potentially posed serious opportunities for peace and security throughout the Nile basin region. Now, Climate change and global change could cause significant harm to the Nile basin region, particularly, downstream communities. Indeed, water security and food security could be jeopardized due to climate change. Nile communities, especially, downstream communities are not only dependent on the river for their livelihood but also their very existence depends on the river itself.

The Nile basin comprises three broad subsystems in 11 countries. The Nile subsystems are the Eastern Nile, the Equatorial Nile, and the Main Nile. The river basin could be divided into ten sub-basins. The Equatorial Nile comprises Lake Victoria, Albert Nile, Victoria Nile, Bahr el Jebel, Bahr el Ghazal, and White Nile sub-basins. The Eastern Nile comprises Tekeze–Atbara, Blue Nile, and Baro–Akobo–Sobat sub-basins. Northern of Lake Nasser up to the Nile Delta, the main Nile represents a northern section of the Nile River. The average annual precipitation and average annual potential evapotranspiration in the sub-basin are presented in Table 1.

Roadmapping process (RMP) A roadmap is an integrative tool that supports interaction, support, and reinforcement across many disciplines and sciences (humanities, environmental, medical, biological, social, physical, and engineering sciences). Roadmaps identify competitive advantages by attributing future activities that represent the nodes of a roadmap to the appropriate organizations. Roadmaps assist in research and development (R&D) funding decisions by locating the optimal path to a goal that is most cost-efficient and/or least time-consuming. The roadmaps could identify necessary strategies and critical steps to realize the required result.

Table 1 The precipitation and evapotranspiration in the Nile sub-basin
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Technology roadmapping (TRM) is an effective methodology in foresight, future research, and technology forecasting. TRM has been applied among companies, organizations, and government projects to achieve strategic objectives. A literature review on the TRM and strategy has been presented (Douglas Pedro de Alcantara and Mauro Luiz Martens 2019). Technology roadmapping plays a focal role in technology and innovation at a wide range of national levels. In developing countries, technological learning not innovation could be the key technology development engine. An appropriate architecture for technology roadmaps including technological learning and technological capabilities could be identified rather than an ordinary technology roadmap. Technology roadmapping has been presented (Ghazinoory et al 2017). Some instructions for global foresight practice have been developed (Cagnin and Könnölä 2014). Organizations can build roadmaps clarifying different paths for technology development and describing their strategies. The roadmap could define the initial survey, desirable objectives, expert identification, technology alternatives, scenario analysis, hierarchical decision model, and future technology estimation. A strategic roadmapping for robotics technologies based on multicriteria technology assessment has been presented (Daim et al 2018).

A set of independent roadmaps could be interconnected in an overall roadmap describing science, technologies, innovations, industries, products, markets, policies, economics, the environment, and societies. The concept of modular roadmapping provides an integrated foresight to connect independent roadmaps. Although any roadmap indicates several paths of the future and shapes a unique module, modularity for integrated roadmapping facilitates systematically linking expertise regarding overarching challenges. An innovative roadmapping project explaining modular roadmapping has been presented (Sauer et al. 2017).

A roadmap could be a method for regional and international prosperity and economic and technological cooperation. Organizations have utilized the roadmap technique to develop their strategy, planning, and foresight activities. Recently, many researchers have investigated RMP and introduced many contributions in this field. The industrial and technological roots of roadmapping have been provided (Kerr and Phaal 2020). The main principles for successful strategic roadmapping to obtain the strategic benefits promised have been described (Siebelink et al 2021). Many applications for roadmaps in different fields have been introduced. Applications in predicting trends of future development and blockchain technology have been developed (Zhang et al 2021). A roadmap’s metamodel has been developed using model-based roadmapping (MB-RM) (Yuskevich et al 2021). How public agencies could use roadmaps to develop ecosystem policy roadmap has been explored (Gomes et al 2021).

The roadmapping process (RMP) is a common foresight technique. Many other techniques (Delphi technique, morphological analysis, decision matrix, interviews, and prioritization analysis) could contribute to integrating strategic and technical views in a technology roadmap (TRM). A method to strengthen the Delphi technique by constructing TRM based on both a decision matrix and interviews with experts has been proposed (Junior et al 2018). An efficient roadmapping practice for standardization has been proposed (Ho and O'Sullivan 2017). As common foresight techniques, efforts to integrate both the roadmapping process and scenario planning were done. The combined technique attempts to capture the advantages and strengths of both and minimize their disadvantage and limitations. The scenario-driven road mapping process has been presented (Hussain et al 2017).

2 Materials and methods

2.1 Study area: Nile River basin

The methodical follow-up, review, and monitoring of progress toward the global goals (GGs) and targets using specified indicators are vital to the success of enabling the environment and achieving sustainable development. To satisfy the requirements, and commitments of the 2030 Agenda, Nile River basin countries have submitted their regional indicators. Sustainable Development Goal 6 (SDG 6) is concerned with water and sanitation. SDG 6 could assess safe drinking water, wastewater, sanitation, and ecosystems. In some cases, there is no data submitted and further information could be needed for transboundary river and/or lake basins. The selected sustainable development indicators and the information sources are presented in Table 2. Nile basin data to track progress towards SDG 6 are shown in Table 3.

Table 2 The selected QOL indicators and the information sources
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Table 3 Nile basin data to track progress towards SDG 6
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2.2 Roadmapping process (RMP) and foresight discipline

Foresight is a promising academic discipline with a methodical framework that draws from many other established academic disciplines and fields and/or human expertise. The foresight process could be defined as how to explore and prioritize optimal pathways to the future utilizing both past knowledge and present actions.

Recently, many scholars have explored some foresight techniques and processes. Examples included horizon scanning (Batisha 2022), megatrends analysis (Bojovic and McGregor 2023), scenario planning (Natcher et al. 2022), visioning (Jittrapirom et al. 2023), Delphi method (Maekawa et al. 2022; Xin et al. 2022), cross-impact analysis (Kartseva et al. 2020; Ghasemian et al. 2020), expert panel (Rovera et al. 2023; Dreizin et al. 2023), narrative inquiry (Singhal and Prakash 2023; Gibson et al. 2023), causal layered analysis (Talebian and Talebian 2018), appreciative inquiry (Flavell 2023), conference model (Miyachi et al. 2021), environmental scanning (García-Carbonell et al. 2021), text mining (Neves et al. 2023), future wheel (Nielsen et al. 2023), trend impact analysis (Taghizadeh et al. 2023), wild cards (Takala and Heino 2017), substitution analysis (Le et al. 2022), and road mapping (Ding and Hernández 2023).

The roadmapping process (RMP) could be considered one of the most promising foresight techniques. Recently, the application of the roadmapping process (RMP) has been increased in science and technology (S&T), development, industry, health, media, and government organizations.

2.3 The general framework of the roadmaps

Generally, roadmaps are created by futurists to communicate future visions to different stakeholders. The foresight of strategic decisions and prioritizing objectives are the typical application of the roadmaps. RMP enables futurists to generate ideas, prioritize goals and necessities, evaluate schedules, and monitor progress. Roadmapping techniques could monitor employee, customer, and third-party feedback. RMP enables futurists to foresight, innovate for and reshape the sustainable future. Futurists could specify missions, allocate resources, engage stakeholders, and modify workflows. In addition, futurists could manage a future vision for a project, product, or scheme through its lifecycle. Various roadmaps could be viewed, updated, and managed in a master plan. The roadmaps empower futurists to assign tasks, track milestones, identify the critical path, automate workflows, manage resources, and change views. The roadmaps suggest the best possible path forward and offer a flash forward to a sustainable future. The main types of roadmaps are shown in Table 4.

Table 4 The main types of roadmaps
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The roadmap Elements An arrangement of four explicit and implicit elements is the minimum sufficient to establish a roadmap. This set includes bars, diamonds, arrows, and keys. Bars could use to represent activities, projects, platforms, concepts, future programs, and other entities that occur over a while. 'Tapered bars' could be applied to show the likely range of start and completion dates (e.g., 10% and 90% confidence levels). Diamonds could use to represent decision points, milestones, objectives, and forecasts that occur at a single point in time. Arrows could use to represent linkages, connect roadmap elements, to map relationships. Keys could apply to represent any colors, acronyms, and line styles used to read the roadmap. The implicit element may use to represent the best practice. The implicit element cannot be easily shown as related by other means such as the value of color.

Static roadmaps and dynamic roadmaps Concerning a particular point in time, roadmaps can be classified into static roadmaps or dynamic roadmaps. A static Roadmap represents an invariable viewpoint at a particular point in time. Static roadmaps consider a single route to value or a few scenarios. A static roadmap dismisses uncertainty too quickly and ignores management's ability to switch paths depending on how the future unfolds. A dynamic roadmap shows how to foresight the future when to accelerate the future when to go for broke when to stop it. The dynamic roadmaps recognize that management can learn about and adapt to changing conditions. The dynamic roadmap offers a more complete, realistic foresight of the future, which often justifies a higher valuation. Dynamic roadmapping allows for minimizing risk and optimizing value, showing greater potential. The dynamic roadmapping tool may be required in many cases. Roadmaps could be sufficiently produced using any technique for diagramming and visualizing data.

Push roadmap and Pull roadmap The roadmap of Nile River sustainability could be classified as a “push” or “pull” roadmap. In general, futurists could use a “push” roadmap to design their visions and plans on a logical path for a sustainable future, “pushing” forward from the present situation to a sustainable future. On the other hand, the futurists in the Nile basin countries could use a “pull” roadmap to identify the optimal path to a project or goal, and “pull” the prerequisite activities backward toward the desired result from a suitable situation.

The roadmapping process (RMP) scope The roadmapping process (RMP) includes technical and non-technical issues, investigation of standard gaps, the establishment of priorities, developing action plans, design of system architectures, enhancing system architecture, publication, and implementation, and after that reviewing monitoring, and follow-up actions. The roadmap could expand the scope of innovations, including social ideas for effecting positive change in cultures, behaviors, and mentalities.

2.4 The roadmapping process for the large and/or transboundary rivers

The roadmapping process (RMP) for a sustainable water future in large rivers such as the Nile River involves several phases such as the identification of preliminary fundamental concepts, standards, visions, goals, standardization activities, and assessment of the national, regional, and international environments. It is a major transformative tool to change the unsustainable paths at the regional level of the Nile basin. An effective roadmap requires unprecedented cooperation for enabling water governance, the right allocation, and sufficient financial and human resources. It depends on building more sustainable societies and human capacities, promoting women and youth participation, and the participation of groups concerned with harnessing water science, technology, and water innovations. Continuous monitoring and follow-up to review the roadmap's outcomes and results are mandatory for suggesting corrective measures and adopting methods and techniques for conscious sustainable water harvesting and consumption.

The roadmapping process (RMP) could be defined as an optimal path from vision, policy, and strategy to an informed, effective actionable plan. In the context of the large rivers and transboundary water development, the key actions in the roadmapping process could be summarized as initiation and identification, steering committee composition, team Building and teamwork, stakeholder involvement, situational analysis, visioning and vision articulation, goals shaping, scenario planning and principal pillars, simulating global goals, the adoption and promotion, communications plan, and ultimately continuous improvement and ensuring the quality of life.

1. Initiation and identification

The initiation and identification stage determine who should initiate the process, stakeholder consultation, and political support, identify available resources, and assess best practices applied in other river basins.

2. Steering committee composition

The steering committee could be composed of one or more representatives appointed by each river basin state to provide the teamwork with appropriate guidance and support, review the proposals and reports prepared by the teamwork, and monitor the implementation within their respective states.

3. Team building and teamwork

The teamwork could focus on organizing the overall roadmapping process; initiating specific activities, coordinating meetings, procuring expertise and resources, and supporting working groups.

4. Stakeholder involvement

The stakeholder involvement could start with the identification of stakeholders, assessment of their interests, their potential contributions to the roadmapping process, and their relative influence and importance.

5. Situational analysis

The situational analysis will focus on the existing water situation system in terms of the sustainability principles and the global goals, evaluating the water requirement of different development alternatives, wastewater disposal, and impacts on terrestrial, forests, and aquatic ecosystems, socio-economic aspects, pinpoint potential conflicts, their severity and implications, and risks and hazards, posed by flood and drought occurrence.

6. Visioning and vision articulation

The vision articulation for enhancing the quality of life in the Nile River basin is an expression of its peoples’ aspirations in how they could optimize their benefits from the river and its water resources and related political, economic, social, and ecosystems.

7. Goals shaping and Roadmap layers

The goals shaping could be formulated in the context of the main pillars. The main roadmap layers are hydrological, man-made systems, and ecosystems. Hydrological layers focus on major hydrological systems (e.g., large rivers, transboundary shared rivers, the river basin, major regions, rivers, streams, tributaries, and distributaries, river delta regions, coastal systems, freshwater lakes, “reservoirs”, man-made lakes, shallow brackish lagoons, swamp, wetlands, and Mediterranean Sea). Man-made layers focus on (climate change, water level, hydraulic structures, and dams, energy, water losses “barriers”, people and population, irrigation and cultivation, and navigation). Ecosystem layers focus on (biodiversity, plant, and animal life).

8. Scenario planning and principal pillars

The scenarios could be formulated in the context of the principal pillars: enabling environment (ensuring political, people, and community satisfaction, and economic feasibility); political framework for different hydrological systems, (transboundary rivers, tributaries, lakes, reservoirs, etc.) and different social, economic, environmental, and ecosystems, (climate change, biodiversity, plant and animal life, people and population, irrigation and cultivation, navigation, energy, hydraulic structures and dams); enabling legal framework (the principle of equitable and reasonable utilization) for different riparian states, and the most significant water demand sectors and large water consumers (agricultural irrigation, aquaculture, livestock, household, industry, electricity, hydropower generation), and to mitigate competition for water among water consumers and/or riparian states, and mitigate overall water scarcity; and institutional arrangement, financing arrangements, and management instruments (organizing different functions effectively, water management, water allocation, water delivery, etc.), and optimizing options for each action.

9. Simulating global goals

Examining compatibility with global goals for all the riparian states, and most important the river basin as a whole with great emphasis on all ecosystems, and hydrological systems. In light of global goals, the key considerations could be reducing poverty, achieving food security, ensuring healthy lives, empowering women, ensuring water, energy, work for all, promoting sustainable agriculture, resilient infrastructure and cities, sustainable industrialization, and economic growth, reducing inequality, combating climate change, land degradation, desertification, biodiversity loss, conserving river and lakes resources, protecting forests, terrestrial ecosystems, promoting peaceful riparian states, communities, and societies, and revitalizing the regional partnership for health river and sustainable development.

10. The adoption and promotion

All riparian states and political leaders’ participation are of extreme importance to gain acceptance, satisfaction, and success for the roadmap. During the roadmapping process (RMP), effective communication is significant to keep communities informed.

Each riparian state should ratify the endorsement of the roadmap.

11. Communications plan

The communications plan identifies the target audiences, key messages, and awareness materials and set out the process for dissemination of core messages to all riparian states and stakeholders.

11. Continuous improvement and ensuring the quality of life.

Initiating performance indicators to measure the progress of implementation; defining milestones to highlight remarkable achievements; building informed policy for practical opportunities that could achieve continuous improvement; and enhancing the quality of life in the river basin should be documented.

2.5 Constructing of the Nile River sustainability roadmap

A detailed roadmap could be produced in short and focused meetings. Workshops could provide a useful mechanism to bring together the range of stakeholders who should be involved in more complex cases. This enables communication, data collection, and creativity, especially in the early stages. RMP utilizing a workshop approach in organizations has been developed (UNFCCC 2013). The process uses the low-tech approach of ‘post-it’ notes to capture key information and map this on the outline roadmap structure as shown in Fig. 1. The roadmap supports a mechanism for consultation with key stakeholders and discussion with customers, clients, providers, and suppliers.

Fig. 1
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The flow diagram of the roadmapping process

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Roadmap specialists should be aware of objectives, requirements, constraints, potential routes, capabilities, and technological options. A summarized version of this approach showing the key planning and workshop steps involved are shown in Table 5. Generally, the roadmap framework should be populated with information, drawing on the program and technical documentation supported by expert knowledge and discussion within the group. Then, roadmaps may be produced using a Software-as-a-Service (SaaS) (web-hosted software) such as Aha!; Craft; Lucidchart; Onedesk; ProductPlan; TrendsRadius; and Smartsheet (Appendix A).

Table 5 Key activities in RMP
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2.6 Key characteristics of multi-layered roadmap

At the early stages, multi-layered roadmaps are probable to have gaps and inconsistencies, but the quality of the multi-layered roadmap could improve over time as the strategic plan matures. Table 6 explains the best practice and key features of the multi-layered roadmap.

Table 6 Key features of a multi-layered Roadmap
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3 Results

3.1 Master roadmapping outcomes for the Nile River

The river’s roadmap is designed as a generic multi-layered roadmap that could be applied at different scales—at local, national, regional, and transboundary levels. The Nile River’s roadmap could strengthen the river system, management strategies, alternative development, sharing knowledge, and support successful decision-making. It is a comprehensive tool for integrating complex environmental, political, technological, social, and economic objectives thus extremely facilitating multi-sector, multi-objective WRs planning, particularly at the river basin level. It was designed to facilitate complex WRs planning. It provided toolsets for scenario management and multi-criterion decision-making. Components of the master RMP for the Nile River system are presented in Table 7. The multi-layers included Hydrology, the Nile basin, major regions, rapids, rivers, streams, tributaries, and distributaries, water losses “barriers”, swamps and wetlands, “Al-Sudd marshes”, freshwater lakes, hydraulic structures and dams, energy, man-made lakes “reservoirs”, shallow brackish lagoons, water level, irrigation and cultivation, plant and animal life, biodiversity, navigation, people and population, Nile delta region, coastal systems, climate change, Mediterranean sea. For the roadmap of the Nile River system, the sublayers of biodiversity “plant and animal life” layer included the vegetation sublayer, fish’s sublayer, and reptile’s sublayer.

Table 7 Components of master RMP for Nile River system
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3.2 A multi-layered roadmapping for a sustainable Nile River future

For a sustainable future of complex large rivers, a multi-layered roadmapping technique could be applied. Examples of layers for such a roadmap are water governance, water cooperation, water and climate, water, sustainable development, and the 2030 agenda, water scarcity, groundwater, agriculture, water in landscapes, water, sanitation and hygiene (WASH), the impact of global epidemics, youth, gender, indigenous knowledge, human rights, and conflicts (Russo-Ukrainian war, plunge in Sino-US relations, etc.), and unconventional water. A multi-layered roadmapping for a sustainable Nile River future is summarized in Fig. 2.

Fig. 2
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A multi-layered roadmapping for upgrading the quality of life (QOL)

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3.3 The sustainability roadmap for the Nile River

The River sustainability roadmap has several important key features. The main present pillars are the “water-related aspects”, “non-water aspects”, and the benefits assessment, based on the Benefit Opportunity Assessment Tool (BOAT) developed by the International Union for Conservation of Nature (IUCN) (IUCN 2020). The two main future pillars are proactive resilience for the Nile River and its basin in times of global change and innovative Nile River and basin future opportunities. Nile River system’s “water-related aspects” includes freshwater lakes, rivers, streams, tributaries, man-made lakes, reservoirs, lagoons, shallow brackish lagoons, water losses, (evaporation, seepage and aquatic vegetation), and estuary (Mediterranean Sea). Nile River system’s “non-water aspects” includes swamps, wetlands, delta, biodiversity (plant, fishes, reptiles), hydraulic structures and dams, and human activities (cultivation, irrigation, and navigation).

According to the principles of (BOAT), the main benefits of a river system are economic, ecological, socio-economic, regional, and political (peace and security) cooperation. Economic benefits and opportunities could include irrigated agriculture, aquaculture, water-based tourism, energy generation, agro-based industries, and work opportunities. Ecosystem benefits and opportunities could include terrestrial habitats, aquatic ecosystems (fish, vegetation, bird, reptile, etc.), and biodiversity. Social benefits and opportunities could include minimizing poverty, inequalities, health risks, waterborne disease, and water-related disasters, and maximizing work opportunities and social welfare.

Regional economic cooperation benefits and opportunities could include enhancing the practice of transporting cross-border investments, citizens, labor, goods, services, markets, and infrastructure networks. Peace and security benefits and opportunities could include identifying a shared water vision, strengthening political and diplomatic relations, and permanent consolidation of political stability and peace. On the other hand, future opportunities include hydrological, ecological, economic, political, catalytic, and beyond the river. New WRs opportunities could be developed within the Nile basin. The Jonglei Canal could be a good example. The idea of the Jonglei Canal project was to minimize evaporation losses from the upper Nile (especially, the swamps, in the Sudd, the Sobat, and Bahr el Ghazal sub-basins). Future benefits include optimizing river flow, watersheds, and WRs; strengthening biodiversity, wetlands, and water and soil quality; increasing agricultural, hydropower production and trade; strengthening cooperation, and regional trade and markets, construction of infrastructure (waterways, roads, and railways; and maximizing regional collaboration, transportation, and tourism. The key characteristics of the Nile River sustainability roadmap are shown in Fig. 3.

Fig. 3
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The key characteristics of the Nile River sustainability roadmap

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3.4 Policy implications

The wise policy of rivers (especially, large rivers, and/or transboundary shared rivers) could create sustainable opportunities right across all riparian states. The present informed political and economic river-related actions could promote maximizing rivers-based collaboration among the riparian states, and different and competitive sectors of the economy, to ensure future-sustained rivers, and freshwater resources. The policy actions could focus on international policy objectives such as the Global Goals and Africa 203, actionable knowledge driven by practice in the Nile River basin. From a political perspective, the effective and informed roadmapping process (RMP) could improve the political knowledge of shared water resources in the context of the large and/or transboundary rivers. The direct policy implication is to effectively define challenges, threats, weaknesses, gaps, risks, needs, strengths, and opportunities in all riparian states. From a holistic political perspective, promoting optimal river and water resources policy options, enhancing evidence-based river planning, improving future river-related opportunities, combating threats, and demonstrating the cross-boundary and up-scaling the river services have the priorities.

From the political economy perspective, the rivers and related water resources are much more complicated. Water and related natural ecosystems could be considered as the source of food, feed, fiber, manufactured agricultural goods, hydropower, river transport, and water recreation. The informed policy actions could ensure water security, food security, and biodiversity conservation, in the river basin. The policy actions could enhance hydrological systems, ecosystems, and the socio-economical contexts in the basin. The policy actions could contribute to mitigating vulnerable communities in the basin. The political benefits and multiple opportunities must be thoroughly assessed to ensure well-being and economic prosperity.

All riparian states (from upstream to downstream) should ensure inclusive cooperation to counteract asymmetries. Political and hydrological partnerships should engage all social and ethnic groups, especially, vulnerable groups to support upstream–downstream cooperation. Political protocols could be developed to optimize the added value of informed river strategies and policies. In designing the policy framework, innovative, low-complexity, user-friendly, low-cost, interconnected, and multidimensional actions could have priority. If the policy actions focus on enhancing the capacity for proactive innovation policy development, the prosperity, resilience, cooperation, and synergizing of the riparian states, through a transdisciplinary policy approach could be the outcomes. On the other hand, a participatory policy approach could facilitate a shared vision for all riparian states and communities through sharing values, concepts, hopes, goals, needs, co-invest, markets, funding, challenges, cultural backgrounds, and scientific knowledge. To be effective, the participatory policy approach should be built on confidence, coordination, and trust. Stakeholders, project practitioners, scientists with different backgrounds skills, and perspectives, should be involved.

4 Discussion

The large rivers basins management necessitates not only arrow focus on hydrology and/or economics but also ecological, social, and political systems. The water and environmental management of large rivers necessitate many ecological, social, and political inputs and factors from all stakeholders (Campbell 2016). The river basin sustainability has a highly positive impact from regional, continental, and global perspectives. Controlling Nile River discharge converts the river into a man-made channel and exacerbates transboundary conflicts. Environmental solutions based on water quality and environmental benefits rather than hydrological solutions based on river discharge (water quantities) were suggested (Pacini & Harper 2016).

In the Nile River basin (NRB), hydrological processes are impacted by climate change at the basin scale. Competing WRs demand to put more pressure on water planners. Many scholars (Almazroui et al. 2020; Mengistu et al. 2021; Dosio et al. 2019; Haile et al 2017; Wagena et al. 2016; Legesse 2016; Getachew et al. 2021; Alaminie et al. 2021) have studied the precipitation changes in different watersheds, basins, and regions. The focus has been on the Lake Tana basin, Upper Blue Nile Basin (UBNB), Nile River basin (NRB), and East Africa. Area (km2) ranged from 15,000 in the Tana basin to 3.35 million in UBNB. Different climate models have been run such as Coupled Model Intercomparison Project Phase 5 (CMIP5) and Phase 6 (CMIP6) supervised by the WCRP Working Group on Coupled Modeling (WGCM), World Climate Research Programme (WCRP), and General Circulation Models (GCMs), the regional climate model COSMO-CLM developed by the Climate Limited-area Modeling Community (CLM-Community), Geophysical Fluid Dynamics Laboratory GFDL-GCM, ECHAM (general circulation model (GCM)], and Canadian Earth System Model (CanESM2). Different periods have been studied starting from 1948 until 2100. Scenarios have included the shared socio-economic pathway (SSP), and the Representative Concentration Pathway (RCP). Emissions Scenarios have been developed by the Intergovernmental Panel on Climate Change (IPCC) to assess long-term climate change, impacts, and mitigation. The Special Report on Emissions Scenarios (SRES) covers the driving forces of future emissions (technological, social, demographic, and economic). Four sets of scenarios described the future of the world in different cases. The scenarios are A1 (very rapid economic growth), A2 (very heterogeneous world and regional economic development), B1 (a convergent world and information and service economy), and B2 (local solutions to sustainable development). Some projected percent changes in precipitation (Almazroui, 14.2 to 24.5; Mengistu, − 10.8 to − 19.0; Dosio, increasing; Legesse, − 10.6 to − 17.5; Haile, decreasing; Wagena, 11.0 to 11.7; Getachew, 25; and Alaminie, slightly increasing) could impact water yield.

The roadmapping process (RMP) for a sustainable water future could involve several phases; identification of preliminary fundamental concepts, standards, visions, goals, and standardization activities; assessment of both national and international environments including technical and non-technical issues; investigation of standard gaps; establishment of priorities; developing action plans; designing and enhancing system architecture; publication; implementation; reviewing, monitoring, and follow-up.

The roadmap for river sustainability is a beacon for foreseeing future river scenarios, a long-term catalyst for environmental sustainability. It is advanced paraphernalia to invest and maximize WRs and to coexist harmoniously. The sustainability roadmap aims to ensure a sustainable river future, maximize the total production of a drop of water, maximize comprehensive sustainable profitability in the sectors and fields related to WRs, particularly the environment, economy, and society, and enable water governance. It could enhance the efficiency of harvesting and consumption of water and natural resources, reduce water waste, strengthen capacities and policies, build more sustainable and well-being societies, ensure sustainable industrialization, confront the challenges facing the river basin, and achieve the common goals for all groups, communities, peoples, and countries concerned with the basin. The roadmap is focused on increasing the competitiveness of the river basin. It is a major transformative force to change the unsustainable paths at the regional level of the Nile basin. The roadmap could solve the challenges facing the process of sustainable water development, and enable scientists, researchers, and innovators to develop water sciences and technologies to support sustainable economic transformation and green growth.

The roadmap requires unprecedented cooperation for enabling water governance, good allocation, and financial and human resources. It depends on building more sustainable societies and human capacities, promoting women and youth participation, and the participation of groups concerned with harnessing water science, technology, and water innovations. To ensure a sustainable river future, facilitating the water development and dissemination of relevant water technologies should be applied. Monitoring, and tracking of pollutants from different water consumers, analyzing data for use in the recycling and restoration of natural resources, and creating partnerships between stakeholders should be applied. It is a must to develop skills, maximize water innovation, and promote smart investment in water science and technology. The roadmap could expand the scope of innovations, including social ideas for effecting positive change in cultures, behaviors, and mentalities. Continuous monitoring and follow-up to review the outcomes and results are mandatory for suggesting corrective measures and adopting methods and techniques for conscious sustainable water consumption and conscious sustainable water harvesting.

The main return of the roadmap is to optimize the river development, activate and promote trade, face and solve the challenges of climate change, and face the decline of biodiversity. The return includes maximizing the utilization of WRs, hydropower, and raw materials. The road map for river sustainability is a lighthouse for achieving the objectives of the countries and peoples in a sustainable river future and optimal, effective, and wise use of water and related natural resources. The road map is a cooperative future mechanism for anticipating a sustainable river future, formulating sectoral policies and strategies related to WRs, and foreseeing the returns and benefits of the circular water economy. It could facilitate cooperation mechanisms among the countries and peoples. A roadmap is a tool for integrating, spreading water awareness, building circular water work models, and shifting towards sustainable and water-resilient societies.

5 Conclusions

The Nile River is the lifeline that supports fraternity, cooperation, and participation in the development, management, and optimization of the Nile's water. The hydrologic regime of the river will be severely impacted by climate change (CC). Therefore, a total and comprehensive road map must be established to manage the water worth of the river from source to estuary and identify crises and opportunities, and foresee the future from a regional perspective for all the riparian states. The road map, supported by the involvement of civil society, and the participation of all concerned groups and stakeholders, could create a common vision that leads to sustainable solutions that serve all people. Based on the sustainability roadmap, a master plan, action plans, programs, and mechanisms could be formulated to activate the sustainability vision, build trust, prevent harm to any of the concerned parties, and achieve a win–win sustainable future for all. The road map could be served as a basis for cooperation and partnership between the riparian states and peoples, in a manner that ensures the preservation of the environmental, social, and economic aspects of the river. The road map could be formulated with the participation of scholars, experts, and technicians from all scientific disciplines. The road map could be constructed based on international law, contemporary regional integration, and common interests and goals. Cultural and environmental diversity and the population mass should be considered as additional opportunities. The road map could facilitate the necessary policies and actions for the sustainable WR’s future. RMP could enable the optimization of water uses and analyze the share of the agricultural sector to achieve the most feasible sustainable economic return. Optimizing the use of the Nile water, strengthening the cooperation between the riparian states, and reducing water losses along the path of the river are feasible outcomes from RMP. The roadmap could enable water security and a sustainable water future (SWF) under conditions of scarcity, climatic changes, and expected pandemics. The road map could play an effective role in the sustainable water future (SWF) that is based on knowledge, and whose features have been shaped by highly developed and modern technological means such as artificial intelligence, the Internet of things, digital transaction technology, and nanotechnology. The road map represents a way that guarantees the quality of life (QOL) for current and future generations. The sustainability roadmap could be a lighthouse to establish the concept of the ethical dimension of rational management of water and environmental resources and to achieve the comprehensive ethical charter of water-related practices along the river.

The analysis could avoid weaknesses and promote strengths if a strategic, political, economic, and hydrological foresight knowledge base is more holistic and future-oriented. Strengthening future expectations could be improved by engaging advanced thinking processes tools, and future reality trees. Prospective alternatives, opportunities, feasibility, barriers, and challenges should be further investigated and utilized. The more advanced scenarios related to the pathways of science technology, research, development, political polarization, political competition, unconventional water, innovative water technologies, agriculture, infrastructure, civilization, social structures, economic indicators (global, regional, national, and local), trade, energy, land-use, climate change could mitigate the shortcomings.

The insights for future research could be summarized into two main pillars. The first is the advances in the road mapping process (RMP), and the second is the possible application domains. Concerning the roadmapping process (RMP), other foresight techniques could enrich the roadmapping process. Some good examples are horizon scanning to enhance systematic scans for signals of change; megatrends analysis to improve patterns and trends; scenario planning to involve plausible futures; and visioning to describe the preferred futures. On the other hand, the future application domain could involve other hydrological systems. Other shared (transboundary) surface water (rivers) resources could be successful case studies. A most prominent example is shared (transboundary) groundwater (aquifer) resources. On the other side, the application domain could involve other transboundary and shared systems. A good example is the exploitation of shared energy resources (e.g., exploration, drilling, and/or production of natural gas or oil (petroleum) fields). A practical case study is the establishment of the East Mediterranean Gas Forum (EMGF) to set a shared vision to optimize the exploitation of natural gas resources in the East Mediterranean region. The same methodology could be applied as an efficient political mechanism, especially, in mitigating the transboundary environmental dilemmas. Prominent examples include transboundary (water resources/acid rain/air/greenhouse gases, etc.) pollution. Other transboundary environmental dilemmas could include poverty and immigration, desertification, and biodiversity loss.