管理共享资源：世界银行集团对水资源管理的支持（方法文件）

Managinga Shared Resource: The World Bank Group’s Support February 19, 2026 1.Background and Context WhyEvaluateWaterResourceManagement? 1.1Water is fundamental to nearly every dimension of development—foodproduction, energygeneration,publichealth, industrial output, andoverallresilience(IPCC 2022;Smith 2022;UnitedNations2024).1Yet water resources are under growingstress from population growth, economic expansion, climate change, and environmental 1.2Water resource management (WRM), as applied in this evaluation, refers to thepractical “system of systems” through which countries manage their water resources.These include hydrological systems (the water that exists and moves through rivers,aquifers, and basins), information systems (how countries measure, track, and projectwater availability), institutional systems (laws, policies, regulations, basin organizations, 1.3Although WRM is closely linked to water services (such as water supply,sanitation, and irrigation service delivery) and to the broader concept of water security,it is conceptually distinct.Effective WRM governs the resource base—its stocks, flows,and variability—on which water services, agriculture, and ecosystems depend. In theWorldBank Group’s water strategy,WRMplays a foundational role acrossall threestrategic pillars: it supports Water for People by enabling reliable and equitable service 1.4At the global level, progress in strengthening WRM is tracked throughSustainable Development Goal (SDG) target 6.5.1, which monitors countries’implementation of integrated approaches to WRM.4Progress toward SDG 6.5.1 has been 1.5Strengthening WRM is central to achieving theBank Group’s mission of endingpoverty on a livable planet.Water helps shape macroeconomic performance, socialoutcomes, and countries’ capacity to manage climate-related shocks (UNESCO 2020).World Bank (2016) estimated that the economic effects of water scarcity,5intensified byclimate change, could reduce GDP growth by more than 6percent by 2050 in some 1.6At the household and community level, the consequences of inadequate WRMare profound.Droughts and water shocks experienced in early childhood have long-term, and even intergenerational impacts, resulting in stunted growth, reducedschooling, and lower income well into adulthood (Damania et al. 2017; Hyland and Russ2019). Recent evidence underscores the growing social and economic risks of waterinsecurity: water deficits are estimated tohaveaccountedfor about 10percent of the rise The Economics of Water Resource Management 1.7WRM requires coordination among users who draw on a shared resource.Whenwater is shared and access is difficult to control, individual decisions about use canimpose costs on others, even if those decisions are privately rational (Garrick 2015).Without effective allocation rules and enforcement,the result is oftenoveruse, for collective resource management are more effective when theyincorporate clearlydefined boundaries, participatory decision-making, and graduated sanctions. Whensupported by appropriate management systems, water’s renewable nature can allow 1.8Water availability varies across space and time, shaping how water resources areplanned, allocated, and managed.Availability changes with short-term weatherpatterns, seasonal cycles, and large-scale climate patterns such as the El Niño–SouthernOscillation,6and is becoming more variable and uncertain due to climate change (Smithet al. 2019). Water resources also rarely align with administrative boundaries. As aresult, WRM responsibilities are distributed across many institutions both horizontally 1.9These characteristics give rise to three interrelated challenges: achievingallocative efficiency, productive efficiency, and distributional equity.Together, thesechallenges determine how well societies transform a finite and variable resource intoone that sustains economic growth and improves welfare. Allocative efficiency concernshow water flows to its highest-value uses across sectors and users.7Productive efficiencyconcerns how efficiently water is used within each sector to minimize waste and 1.10Translating these economic principles into policy is a complex task becauseWRM typically pursues multiple objectives simultaneously. As a result, well-alignedinstitutions, incentives, and infrastructure investments are necessary for improvedWRM outcomes.Improving allocative efficiency, productive efficiency, and measures, for example, coordinating regulatory reforms that clarify rights andresponsibilities with pricing or incentive mechanisms that influence user behavior andinfrastructure investments that expand or stabilize supply. Coherent bundles of The Global Challenge 1.11Water risks, such as waterstress and variability,are widespread andintensifying.Climate change is rapidly intensifying the water cycle; causing moreextreme floods and droughts; worsening water scarcity (which affects more than half theworld's population yearly); and threatening