CNH2-S: Water-mediated coupling of natural-human systems: drought and water allocation across spatial scales

在该国许多地区，河流是灌溉、娱乐、城市和发电等用途的主要水源。每种用水都有不同的经济价值。此外，每条河流的取水可能会遵循不同的制度规则体系，例如，私人拥有“水权”，而不是公共的水资源分配制度。在经济和环境可持续性方面，水的价值与当地规则体系相结合的差异可能会导致更多或更少的成果。这些差异的影响在不同的尺度和气候制度中还没有得到很好的理解，但已知的是，在缺水时期，例如干旱，任何差异都会加剧。为了研究这些相互作用，这项研究计划结合了不同河流系统的水文、基础设施和经济模型，并评估了一系列水分配系统的结果。所调查的水分配制度涵盖了从基于既定水权的更严格的制度，到将水用于最高价值用途的制度。建模框架允许在不同的空间尺度上分析系统，以及主要从积雪融化而不是降雨中接收水的河流。随着人口增长和气候变化，用于管理水的规则将需要演变和调整，这突显了这项研究的重要性。在易受干旱影响的美国西部，许多河流系统对水的需求超过了供应。这种短缺需要加强对水可获得性的自然变化与管理这些河流供应系统中的水运动的人类决策之间的联系和反馈的了解。在这些系统中，水被用于农业、娱乐、市政、发电和其他活动--每种活动对水的估值都不同。自然系统的变化，特别是干旱，限制了人类可用水的总量。水分配规则和可用的水基础设施将自然和人类因素联系在一起。拟议的努力将促进对水文、气候和经济过程如何在一系列干旱强度和空间尺度上共同决定水的价值和分配的了解。以往的研究表明，反馈和阈值影响水文系统和社会系统之间的耦合。然而，需要开发和评估先进的建模方法，以更充分地了解人与自然相互作用对不同流域的影响。拟议的研究将开发一个新的系统，用于模拟以水为重点的人与自然耦合系统，该系统利用可操作的水分配模型将水文和经济组成部分联系起来。这一架构将能够直接评估两种截然不同的基于主体的人类行为模型(微观经济规则与基于制度的规则)如何在一系列条件和规模上产生不同的结果。日益增长的水需求和不断变化的气候将需要新的水管理方法，突出了这项研究的重要性。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In many parts of the country, rivers are the primary water source for uses such as irrigation, recreation, cities, and power generation. Each water use has a different economic value. Also, the withdrawal of water from each river may follow a different institutional rule-system, for example private ownership of ‘water rights’ versus a public system of water allocation. Differences in the value of water combined with the local rule-system can lead to more- or less-productive outcomes, both economically and in terms of environmental sustainability. The effects of these differences are not well understood across scales and climate regimes, but it is known that any differences will be exacerbated during periods of water scarcity, e.g. droughts. To investigate these interactions, this research plan combines models of hydrology, infrastructure, and economics for different river systems and evaluates outcomes following a range of water allocation systems. The investigated water allocation systems span a spectrum ranging from more rigid systems based on established water rights, to those in which water goes to the highest-value uses. The modeling framework permits analyzing systems at different spatial scales and for rivers that primarily receive water from snowmelt versus rainfall. As populations grow and climate changes, the rules used to manage water will need to evolve and adapt, underscoring the importance of this research.The demand for water exceeds supply for many river systems in the drought-prone western U.S. This shortfall necessitates enhanced knowledge of the linkages and feedbacks between the natural variations in water availability and the human decisions that govern water movement in these stream-supplied systems. In these systems, water is used for agriculture, recreation, municipal uses, power generation, and other activities—each with a different valuation of water. Variations in the natural system, in particular drought, constrain the total amount of water available for human use. Water allocation rules and available water infrastructure connect the natural and human components. The proposed effort will advance knowledge of how hydrologic, climatic and economic processes jointly determine the value and allocation of water, across a range of drought intensities and spatial scales. Previous studies have shown that feedbacks and thresholds influence the coupling between hydrologic and societal systems. Yet, development and evaluation of advanced modeling approaches is needed to more fully understand the implications of human-natural interactions for different watersheds. The proposed research will develop a new system for modeling water-focused coupled human and natural systems that utilizes an operational water allocation model to link the hydrologic and economic components. This architecture will enable a direct evaluation of how two contrasting agent-based models of human behavior (microeconomic versus institutional-based rules) yield different outcomes across a range of conditions and scales. The growing demands for water and changing climate will require new ways of managing water, highlighting the importance of this research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.