자료유형  

 학위논문

Control Number  

0017163978

International Standard Book Number  

9798384012177

Dewey Decimal Classification Number  

910

Main Entry-Personal Name  

McDowell, Taylor M.

Publication, Distribution, etc. (Imprint  

[S.l.] : The University of Wisconsin - Madison., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

243 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-02, Section: B.

General Note  

Advisor: Mason, Joseph A.

Dissertation Note  

Thesis (Ph.D.)--The University of Wisconsin - Madison, 2024.

Summary, Etc.  

요약The state of an aeolian system is often dependent on climate and vegetation, and currently, aeolian landscapes in the Great Plains are in a stable state due to vegetation cover. The Great Plains already experiences high interannual variability in precipitation, and this variability is projected to increase with 21st century climate change. These changes will likely affect vegetation in the region, and thus, landscape stability. The spatial patterns and rates of dune activity, dust deposition, and water erosion of loess landscapes have all varied in the past in response to climate change, but the complexity of plant-soil-geomorphic feedbacks limits our ability to link past changes directly to landscape activation. The goal of this dissertation is to better understand unsaturated zone hydrology, its response to climate change and implications for plant available moisture, and geochemical tracers of erosion in two aeolian landscapes, loess tablelands and sand dunes, in Nebraska. In Chapter 1, our objective is to understand how differences in soil hydraulic properties alter the soil hydrology of the two aeolian sediments. We used a numerical unsaturated flow model, Hydrus 1D, to simulate both water flow and root uptake. Compared to the dune sand, the loess had a broader pore-size distribution which resulted in higher volumetric water content, more negative matric potentials, lower hydraulic conductivity for wet soils, and higher hydraulic conductivity for dry soils. Unexpectedly, these differences did not lead to large differences in root uptake between the sediments. Chapter 2 extends the soil moisture modeling for future climate scenarios. Soil moisture was modeled for the same sediments throughout the 21st century. Results demonstrate the value of modeling long-term soil hydrology with a more realistic representation of soil physics, and while there was no clear long-term trend, there were large 10- to 20-year fluctuations between wet and dry periods of soil moisture mirroring the precipitation trends of increased variability. In Chapter 3, we evaluated the use of two geochemical tracers, meteoric 10Be and 137Cs, to estimate millennial- and decadal-scale erosion rates on loess tablelands. Results show that meteoric 10Be has great potential to estimate erosion rates in Holocene loess landscapes.

Subject Added Entry-Topical Term  

Geography.

Subject Added Entry-Topical Term  

Hydrologic sciences.

Subject Added Entry-Topical Term  

Soil sciences.

Subject Added Entry-Topical Term  

Ecology.

Subject Added Entry-Topical Term  

Climate change.

Index Term-Uncontrolled  

Aeolian landscapes

Index Term-Uncontrolled  

Cosmogenic nuclides

Index Term-Uncontrolled  

Erosion

Index Term-Uncontrolled  

Great Plains

Index Term-Uncontrolled  

Soil hydrology

Added Entry-Corporate Name  

The University of Wisconsin - Madison Geography

Host Item Entry  

Dissertations Abstracts International. 86-02B.

Electronic Location and Access  

로그인을 한후 보실 수 있는 자료입니다.

Control Number  

joongbu:656513