CAREER: A Multi-Scale Approach to Assessment of Climate Change Impacts on Hydrologic and Geomorphic Response of Watershed Systems within an Uncertainty Framework

目前评估气候变化对流域系统影响的方法是不充分的：它们是基于临时选择的气候模式；它们关注的尺度非常粗糙，与当地（通常是河流河段或洪泛平原）尺度上人类活动和生态系统服务的现实脱节；而且，它们没有对流域模型和对未来的预测相关的不确定性作出任何评估。本研究将通过跨学科建模、实地观测以及户外、讲座和实验室教育活动的综合计划，弥合流域系统的多尺度、时空连通性，并解决与流域系统预测相关的不确定性。该项目将把重点放在密歇根州，那里的一些观测指标已经显示出与气候变暖相一致的趋势，包括冬季变短、年平均气温升高、强降水事件频率更高。在该项目的研究部分，一些案例研究将沿着南-东南？北西北气候、水文、农业活动梯度。除了综合大量现有数据集外，还将进行气候强迫和水流状况特征的现场监测，以便为模式评价提供数据。来自世界气候研究计划的耦合模式相互比较项目的气候变化预测的多模式集合将使用化石密集型？中期?，较低级别的？未来二氧化碳排放情景（根据政府间气候变化专门委员会的定义）。推断出的概率信息将用于评估气候变化对流域系统的影响。2039年)，中期(2040年？2069年)和世纪末(2070年？2099年)时期。具体而言，将使用多尺度、基于物理的流域地表/地下过程和流动流体动力学建模框架，并通过嵌套动力学建模功能进行整合，为案例研究流域调查水文和水动力制度基本特征的变化。与气候预估偏差和流域模式不准确性相关的全部不确定性将被量化。本研究产生的一套广泛的缩小比例的气候预测数据以及水文和水动力模型的产出，将提供气候变化补偿和减缓规划所需的全面信息。该项目的外联部分将实施教育活动，重点是加强一级学校七年级学生的科学课程，提高人们对人类活动对流域过程的影响的认识。为期一周的暑期学校的教育活动重点将放在密歇根、威斯康辛和明尼苏达部落中得不到充分服务和代表性不足的美国土著青年学生群体上。通过整合研究和推广计划，该项目将使水文科学界、中学生、本科生和研究生受益。全球气候模型是用来探索地球如何？美国的气候将在未来不同的人类活动情景下演变。这些模式的输出用于气候影响研究。这些研究的典型应用涉及数百至数千平方英里地区的大规模水文变量；它们很少能提供相关的不确定性；目前，还没有研究能够解决未来对水流动力特性或漫滩淹没的影响。然而，大多数气候变化补偿和缓解战略需要与人类活动规模和生态系统服务相关的信息，这些信息通常侧重于流域、溪流、农田等。它们还需要对与预测未来有关的不确定性进行估计，以便在气候预测不准确的情况下做出更明智的决策。为了响应这些社会需求，这项研究将以多模式预估的形式最大限度地利用现有的气候变化信息，并开发出推断气候变化预测不确定性的方法。与以前的研究相比，该项目将综合一系列水文/水动力学模型和观测数据，以建立在整个流域系统中传播气候信号信息的能力：从源头（源）地区到河流通道，以及流量特征的细节。为了确保模型应用的问题得到明确的解决，并且研究结果产生实际影响，案例研究将在整个密歇根州开展。此外，这个CAREER项目将整合教育活动，重点是加强服务不足/代表性不足的学生群体（低收入家庭和美洲原住民）的科学课程，旨在增强他们成为未来领导者的心态，并将科学和工程作为他们的职业选择

The current ways of assessing the impacts of climate change on watershed systems are inadequate: they are based on ad hoc selection of climate models; they focus on metrics at very coarse scales detached from the reality of human activities and ecosystem services at the local (often the stream reach or floodplain) scales; and they do not yield any assessment of uncertainty associated with watershed modeling and projections into the future. This research will bridge the multi-scale, space-time connectivity of watershed systems and address uncertainty associated with their predictions through a comprehensive program of inter-disciplinary modeling and field observations and outdoor, lecture, and lab educational activities. The project will focus on the state of Michigan, where a number of observed metrics already demonstrate trends consistent with a warming climate, including shorter winters, higher mean annual temperatures, and higher frequency of heavy precipitation events. In the research component of the project, a number of case studies will be developed throughout the state along the south-southeast ? north-northwest climatic, hydrologic, and agricultural activities gradient. In addition to a synthesis of a large array of existing data sets, in situ monitoring of climatic forcing and characteristics of flow regime will be carried out to provide data for model evaluation. Multi-model ensembles of climate change projections from the World Climate Research Programme's Coupled Model Intercomparison Project will be downscaled using ?fossil-intensive?, ?mid-?, and ?lower-level? future emission scenarios of carbon dioxide (defined according to the Intergovernmental Panel on Climate Change). The inferred probabilistic information will be used to assess climate change impacts on watershed systems for early (2010?2039), mid- (2040?2069), and late century (2070?2099) periods. Specifically, changes in essential characteristics of hydrological and hydrodynamic regimes will be investigated for the case study basins using a multi-scale, physically-based framework of modeling watershed surface/subsurface processes and flow hydrodynamics, integrated through a capability of Nested Dynamics Modeling. The total uncertainty associated with biases of climate projections and inaccuracies of a watershed model will be quantified. An extensive data set of downscaled climate projections and outputs of hydrologic and hydrodynamic modeling generated in this research will provide a comprehensive volume of information required in climate change compensation and mitigation planning. The outreach component of the project will implement educational activities focusing to enhance the science class program of 7th graders in Title I schools and increase awareness of the consequences of human activities on watershed processes. The emphasis of educational activities of a week-long summer-school will be placed on underserved and underrepresented groups of students of Native American youth of Michigan, Wisconsin, and Minnesota tribes. Through the integration of research and outreach programs, the project will benefit the hydrological sciences community, middle-school, undergraduate, and graduate students.Global climate models are the tools used for exploring how earth?s climate will evolve in future under different scenarios of human activity. Outputs of these models are used in climate impact studies. The typical applications of these studies concern large-scale hydrologic variables for areas of hundreds-to-thousands of square miles; very rarely they can provide the associated uncertainty; currently, there are no studies that can address future impacts on flow hydrodynamic characteristics or floodplain inundation. Yet, most of climate change compensation and mitigation strategies require information that is relevant to scales of human activities and ecosystem services, which typically focus on watersheds, streams, agricultural fields, etc. They also require an estimate of uncertainty associated with projection into the future to make better informed decisions in conditions of climate projection inaccuracies. Responding to these societal needs, this research will use maximum available information on climate change in the form of multi-model projections and develop methodologies that will infer uncertainty of climate change predictions. In contrast to previous studies, the project will synthesize a range of hydrologic/hydrodynamic models and observational data to create capabilities for propagating information on climate signals through the entire watershed system: from headwater (source) areas to stream channels, and to the details of flow characteristics. To ensure that the issues of model applications are addressed specifically and that research findings make a practical impact, case studies will be developed throughout the state of Michigan. Furthermore, this CAREER project will integrate educational activities focusing to enhance the science class program of underserved/underrepresented student groups (low income families and Native Americans) targeting to empower their mind-sets to become future leaders and pursue science and engineering as their career choices