Doctoral Dissertation Research: Hydro-Ecological Linkages in Urbanizing Watersheds: A Process-Based Assessment of Land-Use Change Impact on Nitrogen Export

博士论文研究：城市化流域的水文生态联系：基于过程的土地利用变化对氮输出影响的评估

• 批准号: 0302703
• 负责人: Christina Tague
• 金额: $ 1.2万
• 依托单位: San Diego State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-15 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0302703&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Hydro; Ecological

The terrestrial-aquatic interface, in particular the riparian ecotone, plays an important role in watershed nitrogen cycling. Because land-use change can significantly alter its capacity to process or retain nitrogen, understanding the linkages between upland nitrogen delivery and ecotone processing is crucial for land-use change impact assessments. This doctoral dissertation research project will address the role of the riparian zone and the stream in the retention, transformation and mobilization of nitrogen. The student will examine the role of riparian and in-stream processing, the effect of spatial arrangement in land use, and the development of remote sensing-based aggregation procedures. The research approach will combine hydro-ecological modeling with remote sensing and field measurements, allowing for addressing relevant processes and related patterns across a range of spatial and temporal scales. The regional hydro-ecological simulation system (RHESSys), a hydro-ecological watershed model, will be coupled within a geographic information system (GIS) to a flow and water quality model for streams. The stream model will be enhanced to account for stream-groundwater interactions and associated nitrogen processing in the hyporheic zone, the subsurface flowpath where stream water mixes with subsurface water. Model development and application will be based on an established RHESSys application and on remote sensing data and field data collected as part of activities at the Baltimore Ecosystem Study Long Term Ecological Research site (BES-LTER). Additional field campaigns will be conducted in support of the modeling activities, including field experiments and stream monitoring.Understanding the linkages between hydrologic and biogeochemical cycling is an important research challenge in global change science. Coupling hydrology and biogeochemistry across multiple spatial-temporal scales is a key approach for meeting this challenge. This study will help bridge this gap in scientific understanding by providing a multidisciplinary, process-based approach for investigating nitrogen export from watersheds. The study should enhance general understanding of spatial-temporal linkages in the landscape between water and biogeochemical cycling and their role in controlling human-induced impacts on ecosystem functioning. The enhanced model should also be of direct value to practitioners who might use it for water- and land-resource management. The research will build on established research endeavors and will integrate with educational and community outreach activities, including the use of high school students and community members as volunteer data collectors. The doctoral candidate will assist interested students in using data they and others collect in science fair projects. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

陆-水界面，特别是河岸交错带，在流域氮素循环中起着重要作用。由于土地利用变化可显著改变其处理或保留氮素的能力，因此了解旱地氮素输送与交错带处理之间的联系对于土地利用变化影响评估至关重要。这项博士论文研究项目将讨论河岸带和溪流在氮的保留、转化和动员中的作用。学生将研究河岸和溪流处理的作用，土地利用中空间安排的影响，以及基于遥感的聚合程序的发展。研究方法将把水生态模拟与遥感和实地测量结合起来，从而能够处理各种空间和时间尺度上的相关过程和相关模式。区域水生态模拟系统(RHESSys)是一个水生态流域模型，将在地理信息系统(GIS)内与河流流量和水质模型相耦合。河流模型将得到改进，以考虑河流-地下水相互作用和地下潜流带中相关的氮处理，地下水流路径是溪水与地下水混合的地方。模型的开发和应用将基于已建立的RHESSys应用程序以及作为巴尔的摩生态系统研究长期生态研究站点(BES-LTER)活动一部分收集的遥感数据和实地数据。将开展更多的实地活动，以支持模拟活动，包括实地实验和河流监测。了解水文和生物地球化学循环之间的联系是全球变化科学中的一项重要研究挑战。在多个时空尺度上耦合水文学和生物地球化学是应对这一挑战的关键途径。这项研究将通过提供一种多学科的、基于过程的方法来调查流域的氮素输出，从而帮助弥合这一科学理解上的差距。这项研究应加强对水和生物地球化学循环在景观中的时空联系及其在控制人类对生态系统功能的影响方面的作用的总体认识。改进后的模型对可能将其用于水资源和土地资源管理的从业人员也应该具有直接价值。这项研究将建立在既定研究努力的基础上，并将与教育和社区推广活动相结合，包括使用高中生和社区成员作为志愿者数据收集者。博士生将帮助感兴趣的学生使用他们和其他人在科学博览会项目中收集的数据。作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立研究生涯。