CAREER: proposal to link catchment hydrologic transport to the evolved architecture of the critical zone

GSTDTAP

项目编号	1654194
	CAREER: proposal to link catchment hydrologic transport to the evolved architecture of the critical zone
	Ciaran Harman
主持机构	Johns Hopkins University
项目开始年	2017
	2017-03-01
项目结束日期	2022-02-28
资助机构	US-NSF
项目类别	Continuing grant
项目经费	155371(USD)
国家	美国
语种	英语
英文摘要	This research aims to better understand the relationship between shallow groundwater and streamflow in the Piedmont of the mid-Atlantic US, and geologically similar landscapes. The work involves a combination of water sampling and subsurface observations in a set of study watersheds in the Maryland Piedmont region, which will feed into analysis and modeling using novel theoretical tools developed by the PI. The results will contribute to allied research efforts to understand the effects of climate variability on water quality where agricultural fertilizer use has generated a legacy of nitrate in groundwater stores. Similarly the results may have implications for our understanding of the effects of long-term climate variability on the movement of water through the weathering bedrock, which has implications for our understanding of the earth?s carbon cycle on geologic timescales. Research and education are integrated into this work in multiple ways. A portion of the funds from the project will be used to enrich the STEM content of summer day camps at the field site, and provide access to the camps for elementary school children from predominantly-African American inner-city Baltimore schools. Hands-on experimental and field hydrology resources will be developed to enrich the undergraduate hydrology curriculum at Johns Hopkins. Open-access virtual workshops, datasets and associated software tools will be developed to train graduate students at other institutions in new methodologies and their potential applications to their field sites. An increasing number of studies suggest that headwater streamflow is derived from the turnover of apparently large volumes of water in the subsurface. However this storage, and the nature of its turnover, is not well understood at the catchment scale. At the same time, investigations into the critical zone are elucidating controls on the structure and properties of the subsurface, including the processes of weathering and fracturing that generate water-filled pore volume. This project aims to link the emergent storage and transport properties of hillslopes and sub-watersheds to the evolved structure of the entire subsurface critical zone. A novel theoretical approach, built on recent advances in time-variable transit time distributions, now allows emergent hillslope-scale relationships between storage, discharge, and age structure to be captured in a single unified function, f_Q. This provides a framework for expressing fundamental hypotheses about the relationship between critical zone structure, climate variability, and hydrologic transport. Hypotheses will be tested in nested field sites in a deeply weathered, fractured watershed in Maryland, where geophysical studies suggest that topographically-induced bedrock fracturing drives the structure of the critical zone. A combination of passive isotope tracer sampling, deep and shallow drilling, borehole geophysical observations and irrigation experiments will be conducted to examine the critical zone structure, test quantitative hypotheses about the nature of f_Q, and examine the potential of this framework as a basis for catchment-scale coupled flow and transport modeling.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/70851
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Ciaran Harman.CAREER: proposal to link catchment hydrologic transport to the evolved architecture of the critical zone.2017.