東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back to Search results for [ null ]

Switch To: Labeled | MARC Mode | ISBD

An Improved Understanding of Ecohydr...

Dwivedi, Ravindra.

Linked to FindBook

Google Book

Amazon

博客來

An Improved Understanding of Ecohydrological and Geochemical Functioning of a Mountainous Site Using Multiple Methods and Multiple Tracers.

Record Type:	Electronic resources : Monograph/item
Title/Author:	An Improved Understanding of Ecohydrological and Geochemical Functioning of a Mountainous Site Using Multiple Methods and Multiple Tracers./
Author:	Dwivedi, Ravindra.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2019,
Description:	259 p.
Notes:	Source: Dissertations Abstracts International, Volume: 80-08, Section: B.
Contained By:	Dissertations Abstracts International80-08B.
Subject:	Hydrologic sciences. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10975490
ISBN:	9780438838062

An Improved Understanding of Ecohydrological and Geochemical Functioning of a Mountainous Site Using Multiple Methods and Multiple Tracers.
Dwivedi, Ravindra.

An Improved Understanding of Ecohydrological and Geochemical Functioning of a Mountainous Site Using Multiple Methods and Multiple Tracers. - Ann Arbor : ProQuest Dissertations & Theses, 2019 - 259 p.

Source: Dissertations Abstracts International, Volume: 80-08, Section: B.

Thesis (Ph.D.)--The University of Arizona, 2019.

This item must not be sold to any third party vendors.

High elevation mountainous catchments are often important sources of water for downstream arid and semi-arid basins. However, a better understanding of the ecohydrological and geochemical functioning of these mountainous systems is presently limited due to sparse observations at these sites which experience extreme climatic and topographic gradients. Therefore, high density observations are needed to improve our understanding of water sources and the temporal and spatial behavior of flow paths in mountainous ecosystems. This study utilizes multi-year observations of hydrologic fluxes, storages, conservative tracers, chemical compositions and water residence times from a mountainous site located within the Santa Catalina Mountains Critical Zone Observatory (SCM-CZO), Tucson, Arizona, to first develop and evaluate competing conceptual models of seasonal streamflow generation. A conceptual model involving four endmembers (precipitation, soil water, shallow and deep groundwater) provided the best match to observations. Subsequently, the long-term isotopic and hydrometric observations for various potential source waters were used to identify sources of water that support mountainous ecosystems during both wet and dry seasons. It was found that the sources of water for both streamflow and vegetation water demand was the same, i.e., there was no evidence supporting the ecohydrological water source separation hypothesis for the selected field site. Finally, improved practical methods for estimating catchment-scale response functions such as transit time distribution (TTD) and evapotranspiration time distribution (ETTD) are presented. The proposed methods are resistant to gaps in tracer time series. It was found that a gamma type TTD best matches the observations when using either very short (e.g., δ18O) or relatively older groundwater age tracers (e.g., 3H). Furthermore, the estimated ETTD type for the field site showed a composite ETTD type with a piston flow type for low periods (< 0.1 year) and a gamma type with long-tails for higher periods. Therefore, this work improves understanding of hydrologic structure and function of the CZ in a mountainous catchment in a sub-humid setting.

ISBN: 9780438838062Subjects--Topical Terms:

3168407
Hydrologic sciences.

An Improved Understanding of Ecohydrological and Geochemical Functioning of a Mountainous Site Using Multiple Methods and Multiple Tracers.
LDR:03375nmm a2200337 4500 001 2208784
005 20191025102413.5
008 201008s2019 ||||||||||||||||| ||eng d
020 $a 9780438838062
035 $a (MiAaPQ)AAI10975490
035 $a (MiAaPQ)arizona:16684
035 $a AAI10975490
040 $a MiAaPQ $c MiAaPQ
100 1 $a Dwivedi, Ravindra. $3 3435833
245 1 3 $a An Improved Understanding of Ecohydrological and Geochemical Functioning of a Mountainous Site Using Multiple Methods and Multiple Tracers.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2019
300 $a 259 p.
500 $a Source: Dissertations Abstracts International, Volume: 80-08, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
500 $a Advisor: Meixner, Thomas.
502 $a Thesis (Ph.D.)--The University of Arizona, 2019.
506 $a This item must not be sold to any third party vendors.
520 $a High elevation mountainous catchments are often important sources of water for downstream arid and semi-arid basins. However, a better understanding of the ecohydrological and geochemical functioning of these mountainous systems is presently limited due to sparse observations at these sites which experience extreme climatic and topographic gradients. Therefore, high density observations are needed to improve our understanding of water sources and the temporal and spatial behavior of flow paths in mountainous ecosystems. This study utilizes multi-year observations of hydrologic fluxes, storages, conservative tracers, chemical compositions and water residence times from a mountainous site located within the Santa Catalina Mountains Critical Zone Observatory (SCM-CZO), Tucson, Arizona, to first develop and evaluate competing conceptual models of seasonal streamflow generation. A conceptual model involving four endmembers (precipitation, soil water, shallow and deep groundwater) provided the best match to observations. Subsequently, the long-term isotopic and hydrometric observations for various potential source waters were used to identify sources of water that support mountainous ecosystems during both wet and dry seasons. It was found that the sources of water for both streamflow and vegetation water demand was the same, i.e., there was no evidence supporting the ecohydrological water source separation hypothesis for the selected field site. Finally, improved practical methods for estimating catchment-scale response functions such as transit time distribution (TTD) and evapotranspiration time distribution (ETTD) are presented. The proposed methods are resistant to gaps in tracer time series. It was found that a gamma type TTD best matches the observations when using either very short (e.g., δ18O) or relatively older groundwater age tracers (e.g., 3H). Furthermore, the estimated ETTD type for the field site showed a composite ETTD type with a piston flow type for low periods (< 0.1 year) and a gamma type with long-tails for higher periods. Therefore, this work improves understanding of hydrologic structure and function of the CZ in a mountainous catchment in a sub-humid setting.
590 $a School code: 0009.
650 4 $a Hydrologic sciences. $3 3168407
650 4 $a Environmental science. $3 677245
650 4 $a Geochemistry. $3 539092
690 $a 0388
690 $a 0768
690 $a 0996
710 2 $a The University of Arizona. $b Hydrology. $3 1019590
773 0 $t Dissertations Abstracts International $g 80-08B.
790 $a 0009
791 $a Ph.D.
792 $a 2019
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10975490