This research investigated human induced land use patterns, land cover change and
hydrologic response in mountain watersheds. The hypothesis was that the spatial pattern
of land use patches in a watershed influences runoff generating mechanisms, and thus
affects peak flows and stream ecosystems. The goal was to increase the understanding of
the influence of landscape pattern on environmental process, and thus provide a scientific
basis for the design of urban development that maintains the structure and function of
biological communities along a stream system. The study was a first attempt to apply the
methods of landscape pattern analysis from landscape ecology to hydrology and stream
response. Previous analyses in hydrology have not explicitly considered the spatial
arrangement of land use/cover patterns in the watershed. Although statistical
relationships between landscape pattern and stream discharge were not achieved because
of limitations of the hydrological modelling, this study laid the groundwork for the
realization of this goal.
The geographic information system (GIS) software Maplnfo, and a hydrologic model
based on the Rational Method, were used to investigate the relationships between land
use patterns and their effect on the hydrology of four steep mountain stream systems in
the Greater Vancouver region of British Columbia. Accepted land use/ cover categories
and landscape metrics were used to quantify and characterise landscape change, across
time (1946-1995) and between watersheds. Composite runoff coefficients ( Q were
calculated for each land use, and a five-year peak stream discharge (Q) that took the
changing landscape into consideration was modelled. Stream pattern, total impervious
surface (TLA), and road networks were assessed as part of the description of the
landscape.
This thesis considered relationships between: discharge and percent land use area;
discharge and total imperviouss area; discharge and landscape pattern; and percent land
use area and landscape pattern. It was found that calculated discharge, percent
impervious, and developed area increased across all watersheds across all time periods.
The number of road crossings on the creek mainstem and total road length in the
watersheds increased with percentage of developed area in the watersheds, and there was
a linear relationship between C coefficient and the length of roads in the watershed.
Development emerged in discrete patches, generally in the more accessible and flatter
regions of the basin. Patch shape metrics followed an increasing trend with development
levels between zero and twenty percent. However, between twenty and fifty percent
developed the metrics scattered and did not have an apparent trend. This was likely due to
a shift in the landscape matrix from forest cover to development. Increased development
was associated with fragmentation of the landscape because more land use/cover
categories were present in the watershed. This created a situation where average patch
size decreased, patch diversity and density increased, and the watersheds had a
fragmented appearance. Developed patches generally had a more complex shape than
forest patches. The likelihood of finding a forest patch adjacent to a developed patch
decreased as development increased.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/10961 |
| Date | 11 1900 |
| Creators | Shepherd, Jennifer Lise |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Relation | UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] |
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