CREST-PRF: Constraining Spatiotemporal Nutrient Dynamics Along An Arid-Land River Continuum

科学与技术卓越研究中心博士后研究奖学金（CREST- prf）项目支持具有重大潜力的CREST中心研究人员，并为他们提供培训和研究经验，以拓宽视野，促进跨学科互动，并使他们在科学界处于领导地位。这个CREST- prf项目与新墨西哥大学CREST水与环境中心（CWE）的研究重点一致。该项目的目的是确定溶解有机碳组成的纵向变化如何在多个空间（河段到河流）和时间（小时到年）尺度上控制旱地河流网络的养分吸收动态和输出。干旱地区供养着世界上大约三分之一的人口和世界上一半的农业。由于多种相互竞争的压力因素（如水坝、不断脱水、火灾灰输入和蒸散量增加）以及对水资源的过度依赖，旱地河流系统通常弹性较差，更容易受到水质退化（包括富营养化）的影响。该项目的成果将为评估干旱河流系统中碳和营养物质的命运和运输提供工具，并为在粮食、水和能源联系的背景下制定旨在改善干旱大都市地区营养物质循环的多部门解决方案提供科学知识。拟议的研究将持续监测硝酸盐，磷酸盐，溶解有机碳和辅助水质参数，使用最先进的传感器技术，沿河流连续两年跨越四个数量级的年平均流量，~2000米的高度和~500公里的河流长度。每三周将在传感器站点进行高信息量实验，以量化碳和养分吸收率，同时对溶解有机碳组成进行实验室分析。该研究方法利用“大数据”的力量，将连续传感器数据、现场实验和实验室测量与时间序列分析和基于数据的建模技术相结合。该项目收集的有关整个河网的化学、生物、水文和生态之间相互联系的时空综合信息将生成数据集和建模方法，为淡水资源的适应性管理提供信息，并为干旱陆地河流的总最大日负荷制定指导方针。将连续测量与复杂环境参数相关联的新型代理关系的发展具有巨大的潜力，可以改变目前对流域养分循环的理解，并推进淡水生物地球化学。

The Centers of Research Excellence in Science and Technology-Postdoctoral Research Fellowship (CREST-PRF) track within the CREST program supports beginning CREST Center investigators with significant potential and provides them with training and research experiences that will broaden perspectives, facilitate interdisciplinary interactions and establish them in positions of leadership within the scientific community. This CREST-PRF project is aligned with the research focus of the CREST Center for Water and the Environment (CWE) at the University of New Mexico. The objective of this project is to determine how longitudinal changes in the composition of dissolved organic carbon control nutrient uptake dynamics and export in arid-land river networks at multiple spatial (reach to river) and temporal (hours to years) scales. Arid lands support approximately a third of the world's population and half of the world's agriculture. Due to multiple competing stressors (e.g., dams, constant dewatering, fire ash inputs and increased evapotranspiration), and overreliance on water resources, arid-land river systems are typically less resilient and more vulnerable to water quality degradation, including eutrophication. Results from this project will provide tools to assess the fate and transport of carbon and nutrients in arid river systems, and scientific knowledge to support the development of multi-sector solutions aimed at improving nutrient recycling in arid metropolitan areas, within the context of the food, water and energy nexus.The proposed research will continuously monitor nitrate, phosphate, dissolved organic carbon, and ancillary water quality parameters using state-of-the-art sensor technology for two years along a river continuum spanning four orders of magnitude in mean annual discharge, ~2000 m in altitude and ~500 km of stream length. High-information-yield experiments to quantify carbon and nutrient uptake rates will be conducted every three weeks at the sensor sites along with laboratory analysis of dissolved organic carbon composition. The research approach harnesses the power of "big data" by combining continuous sensor data, field experiments, and laboratory measurements with time-series analysis and data-based modeling techniques. Spatiotemporally comprehensive information about the interconnections between chemistry, biology, hydrology and ecology along an entire river network collected by this project will generate datasets and modeling approaches to inform adaptive management of freshwater resources and establish guidelines for total maximum daily loads in arid land rivers. Development of novel proxy relationships correlating continuous measurements to complex environmental parameters holds great potential to transform current understanding of watershed nutrient cycling and advance freshwater biogeochemistry.