COLLABORATIVE RESEARCH: COUPLED HYDROLOGICAL AND GEOCHEMICAL PROCESS EVOLUTION AT THE LANDSCAPE EVOLUTION OBSERVATORY

合作研究：景观演化观测站的耦合水文和地球化学过程演化

• 批准号: 1417175
• 负责人: Ciaran Harman
• 金额: $ 18.89万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417175&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; COUPLED; HYDROLOGICAL; GEOCHEMICAL

The physical, chemical and biological structures and processes controlling biogeochemical reaction, flow and transport in natural landscapes interact at multiple space and time scales and are difficult to quantify. The current paradigm of hydrological and biogeochemical theory is that process descriptions derived from observations at small scales can be applied to predict at much larger scales, as long as some effective values of the scale dependent parameters can be identified. However, this paradigm is known to be flawed and increasingly frequent calls have been made for new theories that will better link small-scale process understanding with large-scale predictions. Furthermore, natural systems evolve in time in a way that is hard to observe in short-run laboratory experiments or in natural landscapes with unknown initial conditions and time-variant forcing. This project will use carefully designed wetting and drying experiments using stable water isotope tracers at the hillslope scale to determine the structure of flow paths, as well as to quantify water transit time distributions along those flow paths. Chemical analysis of pore waters and hillslope outflow will determine mineral weathering kinetics during these wetting-drying cycles which will be related to observed water transit times. Detailed numerical modeling with a coupled systems model will be used to simulate the flow and reactive transport and the evolution of the porous medium through data assimilation and inverse modeling. This project will observe the way water, rock and life interact and create the organized structure of the soil. These observations will be made at an unprecedented spatial and temporal resolution using the Landscape Evolution Observatory (LEO) at Biosphere 2. LEO consists of three large artificial landscapes built in a climate controlled environment that contain over 1,800 sensors to measure how water flows through these landscapes and interacts with the soil minerals and microbiological ecosystems. The research outcome will contribute to a new generation of modeling tools for quantifying contaminant transport in a changing environment. The result will reconcile the discrepancies between observations of flow and transport phenomena at lab and field scales. Two PhD students and several undergraduate students will be trained in novel hydrologic-geochemical experimentation and Earth systems modeling, and their research will be shared with the 100,000 people that visit Biosphere 2 each year.

自然景观中控制生物地球化学反应、流动和运输的物理、化学和生物结构和过程在多个空间和时间尺度上相互作用，并且难以量化。当前水文和生物地球化学理论的范式是，只要能够确定尺度相关参数的一些有效值，从小尺度观测得出的过程描述就可以应用于更大尺度的预测。然而，众所周知，这种范式存在缺陷，人们越来越频繁地呼吁建立新的理论，以更好地将小规模过程理解与大规模预测联系起来。此外，自然系统随时间演化的方式在短期实验室实验或初始条件未知和时变强迫的自然景观中很难观察到。该项目将使用精心设计的润湿和干燥实验，使用山坡尺度的稳定水同位素示踪剂来确定流动路径的结构，并量化沿这些流动路径的水通过时间分布。孔隙水和山坡流出物的化学分析将确定这些干湿循环期间的矿物风化动力学，这与观察到的水通过时间有关。耦合系统模型的详细数值建模将用于通过数据同化和反演建模来模拟流动和反应输运以及多孔介质的演化。该项目将观察水、岩石和生命相互作用的方式，并创造土壤的组织结构。这些观测将使用生物圈 2 号景观演化观测站 (LEO) 以前所未有的空间和时间分辨率进行。LEO 由在气候控制环境中建造的三个大型人工景观组成，其中包含 1,800 多个传感器，用于测量水如何流经这些景观以及与土壤矿物质和微生物生态系统的相互作用。 研究成果将有助于开发新一代建模工具，用于量化不断变化的环境中的污染物传输。结果将调和实验室和现场尺度的流动和传输现象观察之间的差异。两名博士生和几名本科生将接受新型水文地球化学实验和地球系统建模方面的培训，他们的研究成果将与每年参观生物圈 2 号的 10 万人分享。

项目成果

Direct Observation of Hillslope Scale StorAge Selection Functions in Experimental Hydrologic Systems: Geomorphologic Structure and Preferential Discharge of Old Water

实验水文系统中山坡尺度蓄水选择函数的直接观测：地貌结构与旧水优先排放

• DOI: 10.1029/2020wr028959
• 发表时间: 2022
• 期刊: Water Resources Research
• 影响因子: 5.4
• 作者: Kim, Minseok;Volkmann, Till H. M.;Wang, Yadi;Meira Neto, Antonio A.;Matos, Katarena;Harman, Ciaran J.;Troch, Peter A.
• 通讯作者: Troch, Peter A.