Quantifying hydrologic change in tropical peatlands
Abstract/Contents
- Abstract
- Tropical peatlands are a globally significant carbon sink that store over 100 Gt of carbon. In pristine peatlands, this sink is enabled by unique hydrologic characteristics that keep peat soils waterlogged year-round, in turn slowing down the decomposition of organic matter and protecting peat soil from burning. But Southeast Asian peatlands, which store about half of all tropical peatland carbon, have experienced extensive deforestation, drainage, and conversion to agricultural use in recent decades. Already, this degradation has resulted in devastating impacts. Deadly fires during drought years release massive amounts of carbon dioxide and smoke, and there is also evidence of increased decomposition rates throughout the region. Climate change threatens to further disrupt the hydrologic and carbon balance in peatlands. In this dissertation, I quantified changes in Southeast Asian peatland hydrology by developing the first datasets for two key hydrologic variables: surface soil moisture and drainage canals. This was made possible with new satellite-based sensors and advances in retrieval algorithms and computer vision. In Chapter 2, I showed that soil moisture can be measured with sufficient accuracy using data from NASA's Soil Moisture Active Passive satellite (counter to previous understanding), and found it can be used for predicting peat fire risk up to a month later. In Chapter 3, I created the first regional map of drainage canals. I found that drainage density correlates with higher carbon emissions rates, and counter to previous assumptions, does not correlate one-to-one with land use. In Chapter 4, I built a model to predict future soil moisture regimes under climate change, and found that drier climatic conditions may cause significant decreases in soil moisture, implying more severe fire regimes in the future. Thus, this dissertation provides new tools for studying and modeling changes in peatland hydrology, and the implications that these changes have for earth's carbon cycle.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2022; ©2022 |
| Publication date | 2022; 2022 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Dadap, Nathan Cyril |
|---|---|
| Degree supervisor | Konings, Alexandra |
| Thesis advisor | Konings, Alexandra |
| Thesis advisor | Gorelick, Steven |
| Thesis advisor | Naylor, Rosamond |
| Degree committee member | Gorelick, Steven |
| Degree committee member | Naylor, Rosamond |
| Associated with | Stanford University, Department of Earth System Science |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Nathan Cyril Dadap. |
|---|---|
| Note | Submitted to the Department of Earth System Science. |
| Thesis | Thesis Ph.D. Stanford University 2022. |
| Location | https://purl.stanford.edu/wy241yc9025 |
Access conditions
- Copyright
- © 2022 by Nathan Cyril Dadap
- License
- This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).
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