MRA: Continental scale controls on instream and catchment contributions to greenhouse gas fluxes from rivers

MRA：大陆范围内对河流内和流域温室气体通量贡献的控制

基本信息

批准号：
2106071
负责人：
Emily Bernhardt
金额：
$ 69.95万
依托单位：
Duke University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-01 至 2026-07-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2106071&HistoricalAwards=false
关键词：
MRA Continental scale controls instream

项目摘要

The primary goal of this project is to derive a robust and defensible estimate of the greenhouse gases emitted to the atmosphere from the rivers of the United States and to build predictions of how these gas emissions are likely to change in coming decades. The greenhouse gases emitted from rivers are both delivered from their surrounding watersheds and produced by river organisms. River and watershed characteristics such as river structure, groundwater exchange, algal production, respiration, temperature, and contributing land types can affect the rates at which rivers produce and release carbon dioxide and other greenhouse gases. However, scaling these known factors to continuous, widespread predictions of river greenhouse gas dynamics remains difficult because of limited sampling times and locations across this expansive suite of variables. This data limitation has now been overcome for river monitoring sites included in the National Ecological Observatory Network (NEON). Using data collected from 26 NEON river sites across the United States, researchers will build models of continuous gas emissions. We will take advantage of the wide variation in watershed and channel characteristics across sites to build statistical models that allow us to estimate riverine greenhouse gas fluxes across the entire continent, and to identify those sites where gas emissions are most likely to respond strongly to rising temperatures or altered hydrology. This project will also train early-career scientists, including underrepresented groups, in field ecology and the processing and interpretation of large data sets to make better predictions of global change.This proposal seeks to answer three questions: (1) How do greenhouse gas (GHG) fluxes vary across streams and rivers of the continental U.S.? (2) What channel and catchment properties are associated with the highest riverine releases of carbon dioxide, methane, and nitrous oxide from rivers? and (3) what channel characteristics are associated with the highest instream contribution (e.g., primary production and respiration) to riverine GHG emissions? Using the diverse portfolio of hydrologic, biogeochemical, and geomorphic data collected by the National Ecological Observatory Network (NEON) at its 26 wadeable stream locations, we will leverage level 0 data (including discrete estimates of GHG concentrations and solute chemistry in the channel and in groundwater along with continuous measures of hydrology, pH, conductivity, and dissolved oxygen from the channel) to build robust estimates of annual GHG emissions from all 26 sites. We will link these GHG fluxes with concurrent estimates of stream metabolism, rates of groundwater inflow, and groundwater-surface water GHG exchange, and use reaeration models to discriminate between instream and catchment derived GHG contributions to riverine GHG fluxes. We will refine and test our data-derived models with intensive field work at a subset of NEON sites and at a field site in North Carolina where we conduct detailed empirical research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目的主要目的是对从美国河流发出的温室气体进行强有力且可辩护的估计，并建立对这些气体排放在未来几十年中可能如何变化的预测。从河流发出的温室气体都从周围的流域传递，并由河流生物产生。河流和流域特征，例如河流结构，地下水交换，藻类产量，呼吸，温度和贡献土地类型，可能会影响河流生产和释放二氧化碳和其他温室气体的速率。但是，将这些已知因素缩放到连续的，对河温室气体动力学的广泛预测仍然很困难，因为该变量的抽样时间和位置有限。现在已经克服了国家生态观测网络（NEON）中的河流监测地点的数据限制。使用从美国各地的26个霓虹灯地点收集的数据，研究人员将建立连续气体排放的模型。我们将利用各个地点的分水岭和通道特征的广泛变化，以构建统计模型，使我们能够估算整个大陆的河流温室气体通量，并确定那些最有可能对温度上升或变化的水文学反应强烈反应的地点。该项目还将在现场生态学以及对大型数据集的加工和解释中培训包括代表性不足的群体在内的早期职业科学家，以对全球变化进行更好的预测。该提案寻求回答三个问题：（1）温室气（GHG）磁通量如何在美国大陆美国大陆的河流和河流之间变化？（2）哪些河道和流域特性与河流中二氧化碳，甲烷和一氧化二氮的最高河流释放有关？（3）哪些渠道特征与河流温室气体排放的最高仪表贡献（例如初级生产和呼吸）有关？ Using the diverse portfolio of hydrologic, biogeochemical, and geomorphic data collected by the National Ecological Observatory Network (NEON) at its 26 wadeable stream locations, we will leverage level 0 data (including discrete estimates of GHG concentrations and solute chemistry in the channel and in groundwater along with continuous measures of hydrology, pH, conductivity, and dissolved oxygen from the channel) to build robust estimates of annual所有26个地点的温室气体排放。我们将将这些温室气通量与同时估计的溪流代谢，地下水流入率和地下水面水温ghg交换以及使用重新模型区分河流和流域对河流温室气量的GHG贡献。我们将在霓虹灯站点的子集和北卡罗来纳州的现场现场进行大量现场工作来完善和测试我们的数据衍生的模型，在那里我们进行了详细的实证研究。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来通过评估来通过评估来支持的。