CNH: Collaborative Research: Northern Gulf of Mexico Hypoxia and Land Use in the Watershed: Feedback and Scale Interactions

每年在墨西哥湾北部形成一个缺氧区，对海岸和海洋渔业以及当地经济产生负面影响。这个区域的空间范围大约是国家缺氧行动计划目标的三倍。对这些缺氧条件的原因和后果的科学评估表明，来自密西西比河上游流域和俄亥俄河流域溪流系统的氮和磷负荷是该区域的大小和持续时间的重要贡献者。土地利用（主要来自农业）是这些养分负荷的主要驱动因素，是这些流域50多万个体生产者作出决定的结果。然而，仅仅了解生物地球化学过程不足以理解这个复杂系统的动力学。该项目通过开发数据丰富的综合模型，重新审视了这个庞大系统的自然和人类动态，这些模型捕捉了不同情景下与扩大个人对流域的影响相关的时空非线性。这项研究将产生第一个完整的模型系统，通过环境和水文成分，在上密西西比、俄亥俄和田纳西盆地的田间规模上，追踪农业土地利用决策，到下游水质影响，包括墨西哥湾缺氧区的大小。独特的是，建模工作将结合来自市场的反馈，以及来自自适应管理形式的公共政策的反馈。该项目将展示如何使用进化算法的强大工具整合人类和自然过程模型。在美国和其他许多国家，缺氧是沿海栖息地日益严重的环境问题。从本研究中开发的通用建模框架将为解决海湾缺氧和水质问题的政策设计和实施提供有效工具，并在景观中确定具有成本效益的保护措施。该项目将加强五个不同机构的科学家之间的跨学科合作，并将支持研究生和本科生的培训。

Each year an oxygen-depleted (hypoxia) zone forms in the Northern Gulf of Mexico, negatively impacting coast and marine fisheries and local economies. The spatial extent of this zone is about three times the target goal of the national Hypoxia Action Plan. The scientific assessment of causes and consequences of these hypoxic conditions indicates that both nitrogen and phosphorous loadings from the Upper Mississippi River Basin and Ohio River Basin stream systems are significant contributors to the size and duration of the zone. Land use, primarily from agriculture, is a key driver of these nutrient loadings and is the result of decisions made by more than 500,000 individual producers in those river basins. However, understanding the biogeochemical processes alone is insufficient to understanding the dynamics of this complex system. This project takes a fresh look at the natural and human dynamics of this enormous system by developing integrated and data-rich models that capture the spatial and temporal non-linearity associated with scaling up the impacts from individuals to the watershed under different scenarios. The research will produce the first complete modeling system that traces agricultural land-use decisions, made at the field scale in the Upper Mississippi, Ohio, and Tennessee Basins through both environmental and hydrologic components, to downstream water quality effects, including the size of the hypoxic zone in the Gulf of Mexico. Uniquely, the modeling effort will incorporate feedbacks via the market, and feedbacks via public policy in the form of adaptive management. This project will demonstrate how to integrate human and natural process models using the powerful tools of evolutionary algorithms. Hypoxia is a growing environmental problem for coastal habitats elsewhere in the United States and many other countries. The development of a general modeling framework from this research will provide an effective tool for the design and implementation of policy to address both Gulf hypoxia and water quality concerns, and identify cost-effective placement of conservation practices within the landscape. This project will strengthen an interdisciplinary collaboration among scientists at five different institutions, and will support the training of graduate and undergraduate students.