Dam construction has increased exponentially over the past century, primarily in
temperate environments. While the impacts of dams in temperate regions have been
well-documented, a parallel level of research on dam impacts has not been achieved in
tropical environments. The overall objective of this research was to understand the
hydrologic impacts of dams in Costa Rica, a representative case study in a tropical
environment. To achieve this objective, the following specific objectives were
developed: 1) examine the spatial and temporal trend of large dam development within
the country; 2) assess large-scale hydrologic impacts (at the national scale); 3) analyze
downstream flow of individual dams to determine regional impacts.
Analysis of the spatial trend of dam development utilized a geographic
information system. The spatial distribution showed no apparent relation to hydroclimate,
and additional land-use analysis indicated that basins containing large dams are
primarily covered by either forest or crop.
Assessment of large-scale impacts used potential reservoir storage to represent
the hydrologic impact. Results indicate that large dams in Costa Rica are having a relatively low impact on the surface water component of the hydrologic cycle compared
to temperate regions. However, this analysis revealed that two dams, Arenal and
Sandillal, are having a disproportionately significant impact on their individual basins.
Analysis of flow regime for individual dams followed standard hydrologic
analyses of comparing pre- and post-dam discharge data. Variables analyzed included
mean, minimum, and peak flows. Results of these analyses revealed that the Arenal-
Corobic-Sandillal dam project have resulted in severe disruption to downstream
hydrology for all three dams. In contrast, downstream of Ventanas Dam changes in
downstream discharge were smaller than those documented for dams in temperate
regions.
The results of this research indicate that dam impacts in the tropics may be very
different from those documented in temperate environments. Consequently, theories
developed for temperate areas regarding expected dam impacts may not apply to tropical
regions. This has important implications for hydrology, geomorphology and ecology.
This study should serve as a step toward development of a more generalized theory of
dam impacts in the tropics.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3237 |
| Date | 12 April 2006 |
| Creators | Laurencio, Laura Richards |
| Contributors | Chin, Anne |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 2676699 bytes, electronic, application/pdf, born digital |
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