💧 WASH Investment Research Portal

arXiv:2601.14836v2 Announce Type: replace-cross Abstract: The interlamellar space in van der Waals materials has served as a test bed for studies of strongly confined fluid and ion transport. Despite theoretical and experimental progress, it remains unclear how electrostatic correlations arising from interactions between the confined, hydrated ions and the substrate layer can be reconciled with non-equilibrium ionic transport and the substrate's morphological response. Here, we investigate field-driven ionic conduction in sodium- and water-intercalated layered manganese oxides ($\mathrm{MnO_2}$), a self-intercalated metal oxide nanofluidic system, as a model intrinsically-intercalated van der Waals solid, using nonequilibrium all-atom molecular dynamics simulations that explicitly capture ion-water correlations and layer morphology. We demonstrate that electric-field bias induces spontaneous nanoscale segregation of water within the interlayer space, producing coexisting hydrated and weakly hydrated ionic domains coupled to local lattice distortions. This feedback between hydration and morphology gives rise to heterogeneous transport pathways and leads to a non-monotonic dependence of ionic conductivity on water content. Suppressed conduction arises either from layer collapse at low water levels or from ionic hop blockage by excess water at high water levels. Concurrently, ionic transport exhibits a maximum at intermediate levels of intercalated water, where less hydrated ions can move at the boundaries of strongly hydrated ion clusters. While such non-monotonicity could explain the experimentally observed memristive response of $\mathrm{MnO_2}$ single crystals, these findings also provide a molecular-level mechanism linking intercalated water levels to ionic metal oxide nanofluidic systems, suggesting general design principles for robust, water-assisted ionic conductors.

dc.title: Training Workshop on the Small Reservoirs Dashboard: From Data to Decision dc.contributor.author: Akpoti, Komlavi; Appiah, Sarah dcterms.abstract: This report documents a training workshop on the Small Reservoirs Dashboard held at the University for Development Studies (UDS), Nyankpala Campus, Ghana. Developed under the CGIAR Sustainable Animal and Aquatic Foods Program, the dashboard integrates information on more than 2,000 reservoirs across northern Ghana, combining satellite time-series analysis, field survey data from over 900 sites, and geospatial aquaculture suitability assessments. The workshop equipped students and faculty with practical skills to analyse reservoir water dynamics, multiple-use functions, and aquaculture potential. It also generated valuable feedback and identified opportunities for integrating the dashboard into research, teaching, extension services, and evidence-based planning to support sustainable aquaculture and water resource management in northern Ghana. cg.contributor.programAccelerator: Sustainable Animal and Aquatic Foods

dc.title: Closing the Measurement Gap: The Water Security for Health and Livelihoods (WaSHeL) Indicator for Standardizing the Integrated Measurement of Household Water Security dc.contributor.author: Buisson, Marie-Charlotte; Salmawobil, Joseph; Zane, Giulia dcterms.abstract: While water insecurity is multifaceted, current indicators fail to capture all dimensions of water on welfare and livelihoods. Existing experiential scales primarily focus on some dimensions, often domestic water access, while productive uses, governance, climate risks, and adaptation responses remain underrepresented. The Water Security for Health and Livelihoods (WaSHeL) indicator closes this critical measurement gap. This concise 13-item experiential instrument integrates domestic and productive water insecurity, social consequences, governance exclusion, adaptation strategies, and climatic uncertainty. Grounded in an eight-dimension water security framework drawing on established definitions, WaSHeL captures the systemic and structural dimensions that shape household water security. Designed for rapid implementation with binary responses and a 12-month recall period consistent with the Food Insecurity Experience Scale framework, WaSHeL has been embedded in the 2025 Ghana Living Standards Survey as the first nationally representative experiential measure of integrated household water security. Its sub-index structure supports policy targeting, monitoring, evaluation, learning, and impact assessment across water, agriculture, and climate programs. The instrument is available for integration into household surveys across country and program contexts, and researchers, national statistics officers, and program evaluators are invited to contact the authors to adopt the module. cg.contributor.programAccelerator: Sustainable Animal and Aquatic Foods; Sustainable Farming

dc.title: Unlocking local knowledge production for global water systems analysis dc.contributor.author: Buytaert, Wouter; Tilahun, Seifu A.; Paschalis, Athanasios; Bonetti, Sara; Vishwakarma, Bramha; Crespo, Patricio; Drenkhan, Fabian; Agyei-Mensah, Samuel; Ochoa-Tocachi, Boris; Mijic, Ana; Arcucci, Rossella; Moseley, Ben; Howard, Ben dcterms.abstract: Global freshwater systems are critically threatened by environmental change and overexploitation, stressing the need for novel, transformative solutions. As social-hydrological systems are diverse and complex, water-related risks and decision-making needs are often strongly embedded in a locally specific context. Therefore, such solutions need to be informed by solid scientific evidence while remaining tailored to local realities, knowledge, and practices. However, the current generation of global water system models struggles to produce evidence that is accurate, tailored, and actionable at the local scale. Here we outline an approach to support local knowledge co-production and its integration with existing and emerging data sources in global water system models. We focus on three knowledge sources that are currently underrepresented in global modelling approaches: non-statutory monitoring, citizen observations, and local knowledge. We show how data science methods such as semantic data models, distributed workflows, and machine learning can be leveraged to develop novel knowledge integration pipelines. These pipelines explicitly represent data provenance and track epistemic and aleatoric uncertainties across heterogeneous data sources. When combined with flexible modelling frameworks, this approach provides a blueprint for next generation simulation systems that bridge global modelling and local decision-making. Such systems enable the identification, prioritization, and targeted reduction of local knowledge gaps, thereby enhancing the relevance and legitimacy of global water assessments for regional and community-level action.

dc.title: Scaling Climate-Resilient Irrigation: Partnership Alignment, Coordinated Pathways, and Learning in Nigeria dc.contributor.author: Oluwaseun, Ojeleye Adebayo; Oke, Adebayo; Balana, Bedru; Kirui, Oliver K.; Tilahun, Seifu A.; Owolabi, Mubaraq Adetunji; Calvin, Ojeleye dcterms.abstract: The Scaling Climate-Resilient Irrigation Workshop, held in Abuja on March 24, 2026, provided a strategic pathway to address Nigeria’s irrigation deficit and strengthen year-round agricultural production. Under the CGIAR Scaling for Impact (S4I) Program, IWMI and IFPRI presented a three-year roadmap for 2026–2028 to accelerate the adoption of solar-based irrigation solutions, particularly through farmer-led irrigation development. The program targets 120,000–150,000 smallholder farmers across priority northern states, marking a shift from isolated pilot interventions to coordinated, large-scale deployment. A central message from a workshop on Scaling Resilient Irrigation in Nigeria was that scaling solar irrigation requires more than technology alone; it depends on an integrated ecosystem that connects farmers, finance, technology providers, policymakers, and institutions. Stakeholders identified weak institutional coordination as a major constraint, despite the availability of relevant technologies, programs, and financing opportunities. Financial institutions emphasized that organizing farmers into clusters and cooperatives is essential for reducing investment risk and improving access to affordable finance. Drawing on lessons from India’s large-scale solar irrigation experience, participants advocated a coordinated demand–finance–technology–linkage approach, supported by smart subsidies, tariff waivers, or affordable credit. The workshop concluded with commitments to strengthen coordination, digital extension services, localized financing models, and partnerships to establish a sustainable national system for climate-resilient irrigation. cg.contributor.programAccelerator: Scaling for Impact

dc.title: What is the Evidence on the Implementation of Intersectoral Freshwater-Wastewater Swaps in the World?: A Systematic Map Protocol dc.contributor.author: El-Shafai, Saber A.; Mateo-Sagasta, Javier; Orabi, Mohamed O.; Livoreil, Barbara; Valero Gutierrez del Olmo, Enrique; Eales, Jacqualyn dcterms.abstract: Water scarcity is rising due to population growth, economic expansion, and climate change (Schewe et al., 2014; Gosling and Arnell, 2016; Liu et al., 2017; Lahham et al., 2022; Eldabbagh and Nicol, 2025). This shortage sparks intense sectoral competition, worsened by increasing pollution (van Vliet et al., 2021). Three main strategies address this gap: reducing demand through efficiency and productivity, generating "new" water (through desalination or wastewater treatment), and realigning resources through reallocation. (Qadir et al., 2007; World Bank 2018; He et al 2021; Ricart et al 2021; Mateo-Sagasta et al., 2022; Velpuri et al 2023). A promising but understudied approach is the Freshwater-Wastewater Swap (FWS). This mechanism involves an intersectoral arrangement in which a freshwater donor sector reallocates part of its freshwater to other sectors or to the environment in exchange for a non-conventional water source as a substitute. This arrangement may be formal (contractual, regulated) or informal (customary, negotiated). Intersectoral FWS can involve any combination of the following six water-use sectors: (1) Agricultural; (2) Municipal/urban; (3) Industrial; (4) Cooling; (5) Recreational; and (6) Environmental. Any sector can act as freshwater donor, alternative water supplier, or freshwater recipient. Although some existed specific cases of FWS have been partially assessed (Danso et al 2018, Drechsel et al 2018, Heinz et al 2011.), there is no global synthesis describing what types, how many and where these exchanges have been implemented and documented. Such information is essential to understand external factors (e.g., policies, institutions, economic incentives, perceptions) and internal factors (e.g., quantity and quality of water exchanged, infrastructure, technologies) that made the FWS possible and effective. This study aims to map global cases of the FWS and extract lessons that can support decisions in countries which intend to promote this approach, such as Jordan (Tawfik et al 2023).

dc.title: Co-Creation Workshop on Inclusive Business Models for Cage Aquaculture in Small Reservoirs – Bolgatanga, Ghana dc.contributor.author: Salmawobil, Joseph; Appiah, Sarah; Zane, Giulia dcterms.abstract: A co-creation workshop held by IWMI in Bolgatanga on 9 June 2026, as part of the Sustainable Animal and Aquatic Foods (SAAF) Science Program, brought together 44 stakeholders—including farmers, investors, hatchery operators, financiers, and regulators—to review IWMI’s cage aquaculture pilots in small reservoirs and co-design investment models for scaling up the approach in Ghana’s Upper East Region. After reviewing results and lessons from pilots conducted in the North East Region by IWMI, CSIR-Water Research Institute, and the Fisheries Commission of Ghana, participants compared four potential business models: community–private partnerships; full investor ownership with community members hired as labor; contract farming; and passive investment. They discussed the feasibility, opportunities, and challenges of each model in the Upper East context. The workshop revealed strong interest in investing in aquaculture in small reservoirs. Seventy-nine percent of participants indicated that they would be willing to invest their own resources to finance, at least partly, an aquaculture project. As a next step, IWMI and CSIR-Water Research Institute will provide technical assistance to potential investors, beginning with assessments of the suitability of small reservoirs where they may be interested in investing. The aim is to support the development of one or two pilot aquaculture businesses in 2026, generating practical lessons for future scaling. cg.contributor.programAccelerator: Sustainable Animal and Aquatic Foods

dc.title: Revitalizing Community and Household Irrigation in Ethiopia: Policy Considerations for Improved Performance dc.contributor.author: Ayana, Mekonen; Tiruneh, Yibeltal; Kedir, Yusuf; Abegaz, Fentaw; Mohammed, Mulugeta; Tesfaye, Henok; Awol, Elisa; Haileslassie, Amare dcterms.abstract: This policy brief is the result of concerted efforts by the Ethiopian Institute of Agricultural Research (EIAR), Regional Research Systems, Regional Bureaus of Agriculture, the Ministry of Agriculture, IWMI, and members of the Agricultural Water Management Task Force coordinated by the Ministry of Agriculture. Despite continued expansion of irrigation in Ethiopia, many existing community- and household-managed schemes underperform, limiting the benefits of irrigation investments. Evidence from previous IWMI/CGIAR research and a nationwide EIAR assessment of 75 community-managed and 39 household-managed schemes across diverse agroecological zones and river basins provides the evidence base for this policy brief. The findings highlight the need to balance further expansion of irrigated areas with improving the performance and sustainability of existing schemes. Priority actions include establishing a national irrigation performance monitoring and benchmarking system; targeting rehabilitation and modernization based on scheme performance and importance; strengthening operation and maintenance through improved service delivery and partnerships with youth enterprises and private providers; strengthening Water User Associations and irrigation-specific technical support; and scaling appropriate technologies, including solar-powered irrigation, efficient irrigation systems, water-control and measurement devices, and digital decision-support tools. Together, these measures can increase agricultural productivity and water-use efficiency while making irrigation services more reliable, sustainable, and inclusive. cg.contributor.programAccelerator: Scaling for Impact

dc.title: Policy Coherence for Water Security in the Karamoja–Turkana Complex Between Uganda and Kenya: Aligning Institutions, Incentives, and Investments for a Changing Drylands Region dc.contributor.author: Nicol, Alan; Abalo, Jackie Akot; Nakiru, Lucky Sarafina; Thuo, Simon

dc.title: Policy Coherence for Water Security in the Karamoja–Turkana Complex between Uganda and Kenya: Aligning Institutions, Incentives, and Investments for a Changing Drylands Region dc.contributor.author: Nicol, Alan; Abalo, Jackie Akot; Nakiru, Lucky Sarafina; Thuo, Simon

dc.title: Evidence Charts the Future of Freshwater Biodiversity Conservation dc.contributor.author: Boon, Philip J.; Ridley, Francesca A.; Adhya, Tiasa; Baigún, Claudio; Böhm, Monika; Harrison, Ian; Jähnig, Sonja C.; Quintana, Yasmín; Simaika, John dcterms.abstract: Evidence is essential for promoting freshwater conservation and selecting appropriate conservation actions. This article examines the importance of evidence for freshwater conservation, available sources, how evidence is used, geographical coverage, and the challenges in obtaining evidence. Two databases containing published evidence, namely, Conservation Evidence (CE) and the Collaboration for Environmental Evidence (CEE), were systematically searched and evaluated. Evidence in CE is geographically skewed, with most studies coming from North America and Europe. The IUCN Red List requires evidence to assign species to threat categories, but is limited in its ability to track conservation success. IUCN Green Status can be used to assess the impact of conservation actions on species recovery, but suffers from some of the limitations of Red List assessments. Evidence is also required to select freshwater areas for protection, and for monitoring their condition over time, accompanied by an increasing recognition of the value of using evidence from Indigenous communities to support international agreements. Persistent barriers to the use of evidence for promoting freshwater conservation include weak baselines, short monitoring horizons, mismatched spatial scales, reliance on subjective opinion when analysing evidence, and under-reporting of failures. These and other barriers are addressed in several concluding recommendations. cg.contributor.programAccelerator: Multifunctional Landscapes

dc.title: Multi-Scale Assessment of Irrigation Water Use and Supply in the Amibara Irrigation Scheme, Ethiopia Using Landsat-Derived Evapotranspiration and Field Data dc.contributor.author: Mekonnen, Kirubel; Tadesse, Mulugeta; Velpuri, Naga Manohar; Abdella, Mohammed; Dessalegn, Mengistu; Leh, Mansoor; Akpoti, Komlavi; Owusu, Afua; Likessa, Ashenafi; Seid, Abdulkarim dcterms.abstract: Accurate estimation of irrigation water use and supply is essential for effective irrigation management, yet irrigation withdrawals remain largely unmetered and unreported in many schemes. This study applied a remote sensing–based approach to quantify irrigation water use and supply in the Amibara Irrigation Scheme, Ethiopia. The irrigation component of crop evapotranspiration (Blue ET) was partitioned from a high-resolution Landsat-based ETa product using the Water Accounting Plus (WA+) framework. Blue ET estimates were then integrated with irrigation efficiency parameters to derive remote sensing–based irrigation supply (RbIS) at block, canal and scheme scales. Crop type maps for 2010 and 2024 and a digitized irrigation layout provided the spatial basis for assessing irrigation performance using relative evapotranspiration (RET) and relative irrigation supply (RIS) metrics. Crop mapping revealed a substantial decline in the gravity-fed irrigated area from 9941 ha in 2010 to 4532 ha in 2024. RbIS showed reasonable agreement with reported irrigation supply in 2010 (R² = 0.58) and measured supply in 2024 (R² = 0.77), although supply was consistently underestimated. The extent of irrigation water deficits increased between 2010 and 2024, with the proportion of cotton blocks experiencing water deficits rising from 40% to 67%. Key informant interviews and focus group discussions corroborated the observed irrigation water deficits in 2024, supporting the remote sensing–based assessment. Moreover, RET and RIS revealed spatial variability in irrigation performance across irrigation canals, suggesting potential under and over-supply of irrigation. Overall, the proposed approach provides a scalable framework for assessing irrigation water use and supply in data-scarce irrigation schemes.

dc.title: Solar Irrigation Technology Is Ready to Scale, but Is the System? dc.contributor.author: Tafesse, Yonas; Admasu, Zeleke Belay; Oke, Adebayo; Wamba, Elizabeth

dc.title: Impacts of Landscape Restoration and Long-Term Land Use Change on Ecosystem Services: Evidence from a Case Study in Ethiopia dc.contributor.author: Mokria, Mulugeta; Hagazi, Niguse; Hailemariam, Gebrehiwot; Abiyu, Abrham; Mekuria, Wolde; Kassa, Habtemariam; Tadele, Malefia; Gedle, Assefa; Minang, Peter dcterms.abstract: Land degradation threatens food security, water resources, and biodiversity by eroding soil health and productivity. In Ethiopia, restoration initiatives like exclosures are widely implemented, yet most studies fail to integrate plot-level ecological evidence with landscape-scale land use and land cover (LULC) dynamics. Furthermore, few studies combine these biophysical trends with long-term economic valuation of ecosystem services (ES) and local knowledge to quantify ES trade-offs. Using the Sire-Dodota district of Ethiopia, as a case study, we (i) evaluated the localized ecological performances of communal exclosures relative to LULC-driven ecosystem service (ES) changes, (ii) quantified spatial and temporal (22 years) LULC impacts on ecosystem service values (ESVs), and (iii) assessed community perceptions of restoration outcomes. We combined vegetation inventories, spatial analysis, household surveys, focus group discussions, and value transfer methods across plot and landscape scales. Our results reveal a clear socio-ecological paradox across scales. At the plot-scale, community-managed exclosures significantly enhanced biomass accumulation and biodiversity, establishing a robust empirical baseline for ecological recovery. At the landscape scale, however, LULC-based ESVs increased over 22 years, driven by gains of US$80.6 million from agricultural lands and US$1.3 million from forest lands, alongside a US$3.4 million decline in shrubland ESVs. These increases are potential values rather than realized ecosystem service flows, masking systemic losses in regulating and supporting services as short-term agricultural expansion dominates valuation outcomes. Social data from 393 households strongly corroborate these patterns. While communities consistently recognized localized ecological recovery, they favored agroforestry integration over static exclosures to offset high opportunity costs of restricted access. Together, these findings caution against reliance on uncontextualized macro-scale economic indicators and underscore the need for integrated, multifunctional landscape strategies that align ecological recovery with livelihood needs. We, therefore, recommend establishing a national, open-access ESV meta-database linked to Ethiopia's Land Degradation Neutrality (LDN) targets, alongside future multi-decadal monitoring of below-ground carbon and soil biodiversity, and the cost-benefit performance of blended finance restoration models. cg.contributor.programAccelerator: Multifunctional Landscapes

dc.title: সু#রবেনর (ছাট ও মাঝাির পুক2ের (দশীয়(পানা ও (ছাট মাছ চােষর 9িশ:ণ সহািয়কা dc.contributor.author: Mondal, Anit; Wanasinghe, W. W. M. Apsara P. K.; Roy, Aparna; Sathiskumar, Abinaya; Karnatak, Gunjan; Thangjam, Nirupada; Samanta, Srikanta; Maity, Suman Kumar; Roy, Amitava; Taron, Avinandan dcterms.abstract: This training manual provides practical guidance for farmers on environmentally sustainable and economically viable pond-based fish farming, with a particular focus on integrating Small Indigenous Species (SIS) with carp polyculture. It explains the nutritional importance of SIS as a rich source of essential micronutrients and highlights their role in improving household food and nutrition security. The manual introduces the characteristics of commonly cultured SIS, the rationale for integrated fish farming, and the different types of ponds suitable for aquaculture. It presents step-by-step instructions on pond preparation, water quality management, fertilization, liming, natural food production, and biosecurity measures. Farmers are also guided on species selection, stocking density, fingerling transportation and stocking methods, feed and nutrient management, growth monitoring, pond maintenance, disease prevention and control, and flood protection. The manual concludes with recommendations on harvesting techniques and scheduling to maximize productivity and profitability. Designed as a practical resource, it aims to strengthen farmers' technical knowledge and promote sustainable aquaculture practices that enhance fish production, improve nutrition, diversify livelihoods, and increase resilience while minimizing environmental impacts. cg.contributor.initiative: One Health cg.contributor.programAccelerator: Sustainable Animal and Aquatic Foods

dc.title: The Drought Action Catalyst: A Country Platform for Anticipatory, Financed, Government-led Drought Resilience dc.contributor.author: Amarnath, Giriraj; Schmitter, Petra S.; Fakhruddin, Bapon; Agrawal, Ashish; Ravindranath, Darshini; Hafeez, Mohsin dcterms.abstract: Drought is a systemic economic risk, costing an estimated USD 307 billion annually and projected to affect 75% of the world's population by 2050—yet 88% of weather-related disaster finance still arrives after the damage is done, even though every dollar invested proactively can generate returns up to tenfold. This imbalance is not primarily a funding-volume problem but a market-formation failure: what most drought-prone countries lack is a pipeline of investable, governable propositions backed by triggers, risk profiles, and verification mechanisms that finance can commit against. The Drought Action Catalyst, launched by the International Water Management Institute (IWMI) on behalf of CGIAR at UNCCD COP16, builds precisely this pipeline. More than a delivery mechanism, it is a programmatic climate-finance architecture—a country platform that converts NAP and NDC drought priorities into country-owned investment pipelines, uses concessional finance to derisk early action, and aligns with the country-platform models supported by the GCF and MDBs. Working inside national institutions through three pillars—monitoring and early warning; vulnerability and risk profiling; and preparedness and anticipatory action—it delivers mandated drought governance, risk-informed policy, financed early-action protocols, inclusive digital advisory systems, and trained national teams, with full transfer to national ownership by 2030. Its financing architecture realigns public capital toward anticipatory action while structuring four underutilized pools of non-public capital into an investment-ready pipeline. The Catalyst seeks USD 10 million in seed co-financing (2026–27) to confirm four to five pilot countries and deliver evidence for UNCCD COP17 and negotiations toward a global drought regime. cg.contributor.programAccelerator: Climate Action

dc.title: Positioning the Drought Action Catalyst for Drought Resilience: A Strategic Framework dc.contributor.author: International Water Management Institute dcterms.abstract: Drought is the only major natural hazard slow enough to be anticipated, yet the one for which the world remains least prepared. Costing an estimated USD 307 billion annually and projected to affect 80% of the global population by 2050, drought continues to be met with reactive spending—88% of weather-related disaster funding flows after the event—even though every dollar invested in preparedness can return up to tenfold. This Strategic Framework, developed by the International Water Management Institute (IWMI) on behalf of CGIAR, positions the Drought Action Catalyst as the mechanism to close this gap. Introduced at UNCCD COP16 (Riyadh, December 2024), the Catalyst converts decades of proven science, digital innovation, and global partnership into government-led drought action through three interconnected pillars: monitoring and early warning; vulnerability and risk profiling; and preparedness and anticipatory action. The framework presents the Catalyst's rationale, capabilities, Theory of Change, operational model, investment approach, partnership landscape, and roadmap to 2030. Its foundation is the joint capability of IWMI and CGIAR Centers across all three pillars—combining IWMI's operational drought monitoring systems, such as SADMS and MENAdrought, with CGIAR's integrated expertise in agriculture, livestock, socioeconomics, and food systems. Digital innovations, notably the multilingual SukhaRakshak AI advisory system and decision-support dashboards, extend last-mile delivery to farmers. Deployment is demand-driven and locally led through codesigned National Drought Action Templates, with gender equality and social inclusion embedded throughout. Framed as a time-bound accelerator with an explicit exit strategy, the Catalyst aims to transfer full ownership to national institutions by 2030. The framework is addressed to governments, donors, and development partners considering participation or investment in this shared vision: a world where no community is caught unprepared by drought. cg.contributor.programAccelerator: Climate Action

dc.title: The Micrometeorology of Conservation Agriculture Cropping Systems dc.contributor.author: Mupangwa, Walter; Walker, S.; Tesfuhuney, W.; Smith, H.; Zaman-Allah, Mainassara dcterms.abstract: Conservation agriculture (CA) is widely recognized as a climate-smart practice for strengthening the adaptative capacity and resilience of farming systems in the face of climate variability. A key pathway through which CA contributes to resilience lies in its regulation of micrometeorological variables, such as temperature, humidity, and wind, within cropping systems and plant canopies. These factors are intricately linked to crop development, influencing biomass accumulation and interacting with localized atmospheric dynamics throughout the growing season. CA systems offer distinct advantages over conventional tillage by conserving soil moisture, which becomes vital during dry periods. The moderated evaporation of water from the soil surface contributes to maintaining elevated humidity levels within the canopy, thus buffering plants against moisture stress. Furthermore, higher soil water contents under CA moderate heat exchange between the soil and the atmosphere, leading to more stable and favourable canopy temperatures. CA also promotes optimal crop stand density, which improves the interception of solar radiation and stabilizes the transfer of heat and moisture within the crop canopy. This canopy structure tempers with wind flow, creating more uniform conditions that support photosynthesis and enhance productivity. On a broader scale, CA contributes to climate mitigation efforts through greater carbon sequestration compared to conventional systems. These combined effects underscore CA’s ability to create a microclimate that supports both crop performance and environmental sustainability. This review synthesizes current evidence on these micrometeorological benefits of conservation agriculture over conventional systems. The objective of the review was to assess the effect of CA practices on micrometeorological variables (air and soil temperature, soil moisture, humidity, sunlight, greenhouse gas fluxes) in soil environment and within crop canopy. Such evidence can inform the scaling of CA practices in efforts to build climate-resilient agricultural landscapes. Furthermore, the review information contributes towards effective microclimate monitoring and the development of appropriate climate change mitigation and adaptation strategies. cg.contributor.programAccelerator: Multifunctional Landscapes

dc.title: Intersecting Barriers, Uneven Gains: Analysis of Ethiopia’s Enterprise Environment for Women and Youth dc.contributor.author: Nigussie, Likimyelesh; Enokenwa Baa, Ojongetakah; Nortje, Karen dcterms.abstract: This review examines how Ethiopia’s enabling environment shapes women’s and youth’s enterprise inclusion and what this means for responsible scaling across three Scaling for Impact (S4I) Area of Work2 solution-track delivery systems. In this report, enterprise environment refers to the formal and informal enabling conditions that shape enterprise entry, formalization, operation, adaptation, growth, resilience, and benefit control. The review examines barriers across policy and regulation, financial-market access, market coordination, institutional capacity, Gender Equality and Social Inclusion (GESI), and climate-finance. It uses Solar Powered Irrigation System (SPIS), agro-advisory, and forage-feed pathways as analytical design-testing areas for assessing delivery-system usability, inclusion risks, and enterprise outcomes. The review uses a scoping approach with systematic elements, an Ethiopia-only analytical scope, and a mixed evidence base combining screened academic literature with separately reviewed policy, strategy, roadmap, and grey-literature documents. It applies GESI, intersectionality, feminist political economy, and enterprise lifecycle lenses to examine not only which barriers exist, but how they operate, whom they affect, and how they shape enterprise entry, formalization, operation, adaptation, growth, resilience, and benefit control. The central finding is that barriers to enterprise development in Ethiopia are interconnected and mutually reinforcing rather than discrete. These barriers include regulatory requirements, collateral constraints, weak institutional support, fragmented market coordination, GESI-related constraints, and climate-finance barriers that require cautious interpretation because the evidence on eligibility, transaction costs, instruments, scale, and long-term enterprise outcomes remains limited. These interactions are especially consequential for differently positioned women and youth whose access to assets, information, mobility, time, institutional support, and decision-making power is uneven. For S4I, these barriers matter because scaling may expand reach while reproducing unequal access, weak agency, unmanaged labour and risk burdens, limited voice, and uneven control over benefits. In SPIS, these barriers shape access to finance, technology, water, suppliers, services, and irrigation markets. In agro-advisory scaling, they affect whether content, channels, language, timing, feedback, and service linkages become actionable. In forage-feed innovations, they shape access to livestock assets, training, labour arrangements, cooperative support, markets, and control over benefits. Evidence is not equally direct across the three pathways: SPIS is the relatively stronger evidence-informed design-testing area, while agro-advisory and forage-feed implications are supported more indirectly and should be treated as design considerations requiring further testing. The report therefore recommends using solution-track-specific screening criteria before expansion, so that S4I decisions are based on credible evidence of inclusive access, sustained use, manageable labour and risk, agency, and benefit control rather than reach or adoption alone. Evidence is strongest for policy and regulation, financial-market access, institutional capacity, and GESI, but weaker for climate-finance, long-term reform outcomes, and some solution-track-specific effects. Consequently, the three pathways should be treated as design-testing areas, not as already validated inclusive-scaling models. cg.contributor.programAccelerator: Scaling for Impact

IntroductionLand use and land cover (LULC) change is rapidly redrawing the environmental landscape of coastal Bangladesh.MethodsThis study integrates Landsat-based classification, machine learning-based approaches, and Markov Chain simulation to assess historical and future LULC dynamics in Chattogram District.ResultsRandom Forest classification achieved overall accuracies of 95.96%, 90.45%, and 94.25% for 2006, 2015, and 2025, respectively. Results reveal substantial cropland expansion (+32,375 ha) and continued growth of built-up land, accompanied by declines in vegetation, waterbodies, and bare land. Random Forest demonstrated strong predictive performance, achieving an out-of-bag (OOB) accuracy of 92.63% and a skill score of 0.9171. By 2035, cropland and built-up land are projected to increase to 43.95% and 4.63%, respectively, while vegetation, waterbody, and transitional land-cover classes continue to decline.DiscussionThese findings provide empirical evidence to support sustainable land-use planning and environmental management in coastal-urban systems.

Sustainable irrigation for smallholders requires strategies that minimize and optimize land, water, and energy use while remaining resilient to climate change. The study uses the Land-Water-Energy (LWE) nexus and long-term climate trends to assess smallholder irrigation performance. The Land-Water-Energy Nexus Index (LWENI) assesses the sustainability of four smallholder irrigation systems in Vhembe District. Six normalized indicators for the availability and accessibility of land, water, and energy resources were scored on a 0–1 scale and then aggregated with equal weighting. The standardized composite LWENI scores ranged from 0.53 (Rambuda) to 0.74 (Mphaila), indicating performance ranging from moderately unsustainable to moderately sustainable. These results suggest that smallholder irrigation farmers operate in a zone of functional yet fragile resource integration. The spider diagram visualization shows substantial internal imbalances, with distorted forms indicating inadequate integration of LWE resources, notably land dependency at the expense of electricity infrastructure and a dependable water supply. These trends highlight irrigation issues for smallholders, including siloed management that limits production and resilience. Climatic data analysis (1980–2024) revealed significant seasonal precipitation variability with weak linear increases (3.89 mm/year, R2 = 0.01, p < 0.04), while maximum temperatures showed a significant warming trend (0.04 °C/year, R2 = 0.10, p < 0.01), contributing to increased aridity, as indicated by a 0.01 decline in the Climate Moisture Index. The correlation analysis between LWENI components and climate variables revealed significant positive associations between local maximum temperature trends and both water availability (R2 = 0.98, p = 0.022) and water accessibility (R2 = 0.99, p = 0.013), a pattern interpreted as a monitoring signal rather than a causal finding, given the small sample of four schemes. The combined LWENI and climatic evaluations show that Vhembe District irrigation schemes face resource imbalances, inconsistent energy supply, and increasing climatic unpredictability. Land tenure provides some stability, but water and energy shortages, rising temperatures, and erratic precipitation threaten agricultural production and food security. Infrastructure rehabilitation, solar-powered systems, climate-smart practices, and integrated LWE nexus planning may increase resource efficiency, resilience, and sustainability for these semi-arid smallholder farmers.

Northern Ghana faces persistent dry-season water insecurity despite receiving substantial seasonal rainfall. This critical narrative review examines why wet-season rainfall does not consistently translate into dependable dry-season water access and compares practical responses across land, infrastructure, aquifer, and governance scales. Evidence from 65 peer-reviewed and selected institutional sources shows that the problem is not explained by a single regional groundwater recharge failure. It arises from the interaction of limited and highly seasonal effective recharge, rapid runoff and high evapotranspiration, strong local variability in fractured and weathered aquifers, weak storage and infrastructure reliability, and maintenance, financing, governance, and land-tenure constraints. Regional groundwater recharge estimates, therefore, describe broad replenishment conditions, but they do not by themselves indicate whether groundwater is accessible to a particular community or a borehole. The comparative synthesis shows that no intervention is universally superior. Rehabilitation of viable boreholes and surface water storage reservoirs can offer a rapid route to restore existing services where the assets remain hydrologically viable, although it does not increase recharge and will not remain effective without maintenance reform. Contour bunds and stone lines have strong field evidence for slowing runoff on suitable cultivated slopes, while zaï pits and half-moons are better targeted to crusted and degraded plots where labour and soil amendments are available. Soil cover, agroforestry, and farmer-managed natural regeneration provide complementary land-restoration and livelihood benefits, but tree density and tenure influence whether infiltration gains outweigh transpiration and adoption costs. Sand dams, recharge basins, managed aquifer recharge, and aquifer storage and recovery offer higher storage potential at selected sites, yet require hydrogeological screening, water-quality safeguards, finance, monitoring, and institutional coordination. The review concludes that improving dry-season water security requires a sequenced, site-specific portfolio rather than one regional technology. Immediate priorities are diagnosis and rehabilitation of hydrologically viable assets, followed by locally matched runoff-control and soil-restoration measures. Engineered recharge should proceed through monitored pilots where aquifer, floodwater, water-quality, and governance conditions are favourable. Across all options, performance should be judged by dependable and equitable dry-season service, not only by estimated recharge. This combined framing links hydrological variability with infrastructure conditions, livelihoods, and institutional capacity.

Arid and semi-arid regions, encompassing nearly half of Earth’s land surface, face escalating water scarcity due to precipitation variability, high evaporative demand, and climate change-induced extremes. While groundwater has historically buffered surface water deficits, widespread overexploitation has precipitated aquifer depletion, land subsidence, and water quality deterioration. Conventional irrigation practices—characterized by low water-use efficiency and weak governance—exacerbate these pressures. This review synthesizes principles and multi-scale applications of rainwater harvesting (RWH) as a strategic complement to conventional water management. It examines technical synergies between decentralized RWH systems and managed aquifer recharge (MAR), demonstrating their combined potential to alleviate stress on overexploited groundwater reserves. We address four objectives: (1) analyzing how increasing precipitation variability and extreme climatic events destabilize agricultural systems and exacerbate water risk; (2) evaluating technical and managerial inefficiencies in conventional irrigation; (3) highlighting cascading environmental, economic, and social costs of groundwater overdraft; and (4) proposing an integrated RWH–MAR framework to enhance water availability, improve ecosystem resilience, and contribute to sustainable agricultural intensification. Our findings show that integrating RWH with efficient irrigation, agroecological practices, and supportive governance can significantly improve water-use efficiency and system resilience. Advancing this approach requires a paradigm shift treating rainwater as a managed resource within a unified hydrological cycle. We conclude that revitalizing rainwater harvesting constitutes a cornerstone for building sustainable agricultural systems and ensuring food security under increasing climatic uncertainty. Key advantages of our integrated framework include: (i) reduced reliance on energy-intensive groundwater extraction; (ii) enhanced water availability during critical crop growth stages; (iii) improved groundwater quality through natural filtration mechanisms; and (iv) strengthened institutional capacity through participatory governance and community engagement.

Background and aimAccurate estimation of reference evapotranspiration (ET0) is fundamental to irrigation scheduling, crop water requirement computation, and hydrological modeling in semi-arid agricultural regions. The FAO-56 Penman–Monteith (FAO-56 PM) method, the globally recommended standard, demands complete meteorological datasets that are rarely available across India's irrigation command areas. This study evaluates whether simplified empirical ET0 methods can provide operationally reliable estimates in place of FAO-56 PM under the semi-arid, monsoonal conditions of the Jayakwadi Command Area (JCA), Maharashtra, India.MethodsA 34-year monthly synthetic meteorological dataset (1990–2024) was constructed for five representative virtual stations distributed across the head reach zone of JCA, using interpolated India Meteorological Department (IMD) climatological statistics and NASA-POWER reanalysis data, with independent validation against records from the Maharashtra Water Resources Department. Eight empirical ET0 methods were evaluated against the FAO-56 PM benchmark: three radiation-based methods [Makkink (Mak), Abtew (Abt), Priestley–Taylor (PT)] and five temperature-based methods [Hargreaves–Samani (HS), Thornthwaite (Tho), Hamon (Ham), Linacre (Lin), and Blaney–Criddle (BC)]. Model performance was assessed across annual and four seasonal time scales (spring, summer, autumn, winter) using Nash–Sutcliffe Efficiency (NSE), Relative Error (Re), Normalized Root Mean Square Error (NRMSE), coefficient of determination (R2), and Percent Bias (PBIAS).ResultsRadiation-based models consistently outperformed temperature-based models. On a seasonal scale, Abtew achieved the highest summer performance (NSE = 0.937, Re = 0.007, NRMSE = 0.076) and strong spring accuracy (NSE = 0.664). Makkink performed best in winter (NSE = 0.886) and autumn (NSE = 0.630). Temperature-based models produced consistently negative NSE values at the annual scale, rendering them unreliable for annual ET0 estimation. All eight models showed negative NSE annually, confirming that seasonal disaggregation is essential for empirical model selection in this region. High R2 values for Priestley–Taylor (up to 0.986) did not translate to low bias or error, underscoring that correlation alone is an insufficient performance criterion.ConclusionsMakkink and Abtew, both requiring only solar radiation as their primary input, offer practical, data-light alternatives to FAO-56 PM for operational ET0 estimation across the JCA. Model selection should be guided by season and available data rather than applied uniformly. Future work should incorporate field-measured ET data and explore machine learning-based residual correction to further enhance estimation accuracy.

Flooding is commonly approached as a hydrological disaster, followed by emergency relief, disease surveillance, and environmental clean-up. This approach appears incomplete because floodwater rapidly connects contaminated land, failed sanitation systems, agricultural areas, industrial facilities, water-supply infrastructure, ecosystems, and households. Flood-driven water contamination should therefore be understood as a preventable public-health infrastructure failure rather than an unavoidable aftermath of inundation. This Perspective argues that the health consequences of flooding are shaped not only by the intensity of rainfall or flood depth, but also by the pollutant burden already present in a catchment, the condition of water and sanitation systems, the security of drinking-water sources, and the ability of institutions to translate environmental warnings into timely protective action. The paper proposes flood-ready water and health systems as an integrated public-health model that links upstream pollution prevention, flood-triggered water-quality surveillance, water-safety planning, equitable risk communication, healthcare preparedness, and environmental-health governance. The model treats aquatic ecosystem integrity and safe drinking-water access as interconnected determinants of population health. It also recognizes that vulnerable communities are disproportionately exposed when flooding damages wells, sanitation facilities, water-treatment infrastructure, health facilities, and housing. Strengthening flood resilience therefore requires more than post-flood disinfection and relief supplies. It requires preventive investments that reduce contaminant mobilization, preserve essential water services, identify unsafe sources rapidly, and protect communities before exposure becomes a disease emergency.

IntroductionUrban drainage systems in flood-prone riverine cities are often designed mainly for pluvial flooding, while pluvial-fluvial interactions and river backwater are neglected. This limitation is critical in developing cities where stormwater is conveyed through open-channel and roadside drains whose performance depends on terrain elevation, road elevation, and channel geometry. Existing optimization approaches have largely focused on closed conduit systems or low-impact development placement and can become computationally expensive for large networks.MethodsThis study develops a rank based sequential SWMM simulation optimization framework for large-scale open drainage design under a specified compound rainfall and river-stage scenario. The framework minimizes total channel excavation volume using a constraint-based rank sequential search. Three strategies are included: (i) hierarchical network ranking from upstream to downstream to enforce non-decreasing capacity and reduce the search space; (ii) hydraulic feasibility constraints keeping peak water depth below design channel depth; and (iii) river backflow constraints for elevated river stages.ResultsThe framework is applied to two watersheds in North Guwahati, Assam, India, affected by Brahmaputra backwater. The optimized design covers a 128.33 km drainage network over a 43.50 km2 urban area under a scenario-based compound flood boundary comprising a 5-year design storm and a fixed river stage of 49.5 m. Optimization completed in 11.7 h after 3,156 SWMM evaluations.DiscussionAn independent HEC-RAS 2D rain-on-grid cross-check confirmed the hydraulic consistency of the optimized design under the same compound rainfall-river-stage scenario. The framework provides a computationally tractable, compound-flood-aware approach for open-drain master planning in data-scarce riverine cities.

IntroductionIndia's water dynamics are characterized by intricate challenges arising from rapid population growth, institutional deficiencies, and environmental degradation. These factors lead to significant disparities in Water, Sanitation, and Hygiene (WASH), further entrenching social inequalities and obstructing sustainable development. The study emphasizes that securing fundamental water needs is critical for enabling broader community empowerment, governance innovation, and technological interventions, which are essential components for achieving a resilient and sustainable WASH system.MethodsTo address WASH challenges holistically, this study adopts Maslow's Theory of Human Motivation and a theoretical conceptual policy review, recognizing access to safe water as a primary physiological need essential for societal advancement. These theoretical perspectives help unravel how unmet basic needs impede higher-level social, economic, and environmental progress. Maslow's model offers a compelling way to analyze and enhance Indian government programmes related to water and sanitation by linking people's motivations with water governance.ResultsThe study creates a comprehensive and people-centred policy framework. This research identifies comprehensive pathways that stakeholders can leverage to address India's evolving water and sanitation concerns while promoting sustainable development.DiscussionThis study discusses how Maslow's model provides a powerful lens to interpret why multifaceted solutions like community engagement and institutional reform are essential for building resilience and ensuring equitable water access and addressing water disparities in the country.

ObjectiveEutrophication caused by nitrogen and phosphorus pollution is a major global environmental problem. However, understanding remains insufficient regarding the fine-scale spatial heterogeneity of pollution sources and the key driving factors of their spatial changes in large and medium-sized river basins, which hinders the formulation of targeted pollution control strategies.MethodsTo fill this gap, this study constructed a comprehensive analysis framework integrating remote sensing and hydrological analogy. We systematically analyzed the spatial distribution of nutrients in 60 subcatchments of the Jinjiang River Basin, identified high-pollution risk areas, and quantitatively analyzed the relative contributions of point sources (PS) and non-point sources (NPS).ResultsThe results show that: (1) Nitrogen and phosphorus pollution are widespread throughout the basin, with nitrogen pollution being particularly prominent. 48.3% of monitoring sections in the rainy season and 33.3% in the dry season have nutrient concentrations exceeding the threshold for algae reproduction, posing significant eutrophication risks. (2) Farmland and urban land are the main sources of total nitrogen (TN) and total phosphorus (TP). Farmland NPS pollution accounts for 43.2% of the TN load. Urban land (PS) is the primary source of TP load, accounting for 38.4% of the contribution. (3) High-pollution risk areas are mainly concentrated in three core regions: the downstream urban corridor, the Nan'an Industrial Zone, and the upstream tea garden area.ConclusionsBased on these results, targeted measures are proposed: upgrading urban wastewater treatment facilities, implementing stricter industrial discharge standards, and promoting sustainable agricultural practices in farmland and tea gardens. The spatial priority identification method developed in this study provides a scientific, reliable, and replicable basis for determining priority intervention areas in similar river basins.