Collaborative Research: Modeling DOC dynamics from landscapes to coasts: hydrological connectivity and estuary processes

知识价值：陆地生态系统中溶解有机碳(DOC)的来源、功能和去向，以及它从景观到海洋的运输过程，人们只了解了一部分。在这项拟议的研究中，统计和基于地理信息系统的传输模型被用来研究陆地生态系统和河流中DOC的动态变化。研究目标包括三个方面：1)分析次流域尺度下地表DOC对河流DOC贡献的空间变异性。2)确定受自然和人为影响的DOC长(几十年)和短(天至月)波动背后的传输和转化机制。3)从河流的反射率、浊度和叶绿素的遥感数据预测DOC浓度。在过去的几年里，收集了大量的野外数据，包括30个子流域5年的每月DOC测量、高时空分辨率的河流观测和遥感图像。有了这些数据，该小组将主要依靠一种将统计建模和基于地理信息系统的运输建模相结合的方法。具体地说，他们将1)使用自适应变系数混合模型从统一的土地利用类型中得出每月DOC负荷。2)建立了基于地理信息系统的排水河网DOC质量传输模型。3)利用变系数泛函线性模型和非参数函数模型对DOC进行了遥感预测；4)利用两个特定流域的独立数据集对上述模型进行了验证。该项目对地球科学的贡献在于加深了对DOC输出过程的理解，这些过程受到人类活动、自然事件、流域特征和气候之间相互作用的影响。统计方面的贡献在于创新的估计和推断程序，特别适用于这种复杂的地球科学数据。更广泛的影响：这项拟议的研究将提高对从陆地到沿海水域的碳出口过程的科学理解。这个项目的资助可能会改变公众对S的看法，即他们在沿海社区的行动的影响。这项研究将产生一种适合于研究流域特性、人类活动、自然事件和气候变化之间相互作用的建模技术。该项目为所有参与的学生提供学习机会。这项研究的方法、模型和数据将被整合到广泛学科(统计学、生物地球化学、遥感、水文学和建模)的本科生和研究生教学计划中。通过两个不同研究机构的平等合作，该合作为学生提供了接触尖端建模技术和环境科学的途径。特别是，这两名女性专业人员将成为指导女研究生以自己的经验成为未来的科学家(统计学家和地球科学家)同行的宝贵财富。与沿海碳研究相关的教学材料将通过现有的教育项目和Bridge网站开发和传播。这些外展工作将从COSEE-新英格兰和流域-综合科学伙伴关系(GK-12)计划的早期经验中受益匪浅。

Intellectual Merit: The origin, function, and fate of dissolved organic carbon (DOC) in terrestrial ecosystems and its transport processes from landscapes to sea are only partially understood. In this proposed research, statistical and GIS-based transport models are used to study DOC dynamics in terrestrial ecosystems and rivers. The research objectives are three-fold: 1) To analyze the spatial variability of DOC contributions from land surfaces to streams at sub-basin scales. 2) To identify the transport and transformation mechanisms behind long (decades) and short (days to months) term DOC fluctuations due to natural and anthropogenic influences. 3) To predict DOC concentration from remote sensing reflectance, turbidity and chlorophyll in rivers. In the past several years, a large amount of field data, has been collected including 5-years of monthly DOC measurements in 30 sub-basins, high spatial and temporal resolution riverine observations, and remote sensing imagery. Equipped with these data, the team will rely mainly on an approach that integrates statistical modeling and GIS-based transport modeling. Specifically, they will 1) Use an adaptive varying coefficient mixture model to derive monthly DOC loads from uniform land use types. 2) Construct a GIS-based transport model for routing DOC mass in the drainage stream network. 3) Use a varying coefficient functional linear model and nonparametric functional model to predict DOC through remote sensing 4) Validate the above models with independent data sets from two specific river watersheds. The geosciences contribution from this project lies in the improved understanding of the DOC export processes influenced by interactions among human activities, natural events, watershed characteristics, and climate. The statistical contribution lies in the innovative estimation and inference procedures that are particularly adapted to this complex geoscience data. Broader impacts: This proposed research will improve the scientific understanding of carbon export processes from land to coastal waters. Funding of this project will potentially change the public?s perception of the influence of their actions in coastal communities. This research will result in a modeling technique that is suitable for studying interactions among watershed properties, human activities, natural events and climate change. The project provides learning opportunities for all participating students. The methods, models, and data from this research will be integrated into undergraduate and graduate teaching programs in a broad range of disciplines (statistics, biogeochemistry, remote sensing, hydrology, and modeling). The collaboration offers students access to cutting edge modeling techniques and environmental sciences through an equal partnership of two diverse research institutions. Especially, the two female PIs will be valuable assets in guiding female graduate students to become future fellow scientists (statisticians and geo-scientists) with their own experiences. Coastal carbon research-related instructional materials will be developed and disseminated through existing educational programs and The Bridge website. These outreach efforts will strongly benefit from early experience on the COSEE-New England and Watershed-Integrated Sciences Partnership (GK-12) programs.