<p>Lakes and wetlands cover a large portion of the earth’s
surface and play a crucial role in hydrology. They provide permanent and
temporary storage for water within the landscape allowing for greater
infiltration and evaporation along with a reduction in peak flooding events. Lakes
and wetlands also provide many other non-hydrological benefits such as their
ability to improve water quality and provide wildlife and fisheries habitat.
Despite their known benefits, wetland destruction has been a prominent issue
for many years. This study quantifies the hydrologic effects of lakes and
wetlands by introducing a parametrization method for hydrologic model simulations
in the North American Land Data Assimilation System (NLDAS) domain. Lake
profiles were created based on the geospatial lake depth-area relationship
through interpolation of known lake depths and areas throughout the domain.
Wetlands were parametrized based on topographic wetness index (TWI) calculated
using high-resolution DEM imagery. Wetland profiles were created using a
binning technique along with the DEM and land use classifications. The Variable
Infiltration Capacity (VIC) macroscale hydrologic grid-based model and its
associated lake and wetland algorithm were used to quantify the effects of
lakes and wetlands on streamflow. Profiles were generated for every
corresponding VIC grid cell in the NLDAS domain, but for this study two
watersheds, the Buttahatchee River in Mississippi and the Black River in North
Carolina, were selected to test the parametrization and quantify the impact of
lakes and wetlands on watershed hydrology. The Buttahatchee River watershed
contains 6.6% lakes and wetlands, which were predominantly clustered near the
stream channel, and the Black River watershed contained 19.2% lakes and
wetlands which were spread out across the entirety of the watershed. Simulated
daily streamflow with and without the lake and wetland algorithm activated was used
to evaluate impacts on flood frequency as well as components of the water
balance. Flood magnitude decreased due to the presence of lakes and wetlands.
This decrease was 5.8% and 29.6% for a 10-year return period flood for the Buttahatchee
River and the Black River sites, respectively. Mean annual flowrate decreased
significantly as a result of lakes and wetlands indicating storage of water in
the lakes and wetlands allowed for a greater degree of evapotranspiration. There
were 1.6% and 10.9% decreases in average streamflow rates as well as
corresponding 0.3% and 4.1% increases in annual evapotranspiration in the Buttahatchee
River and Black River watersheds, respectively. While lakes and wetlands reduce
peak flood events and decrease average streamflow rates through increased storage
and evapotranspiration, the magnitude of these impacts varies based on the
quantity and distribution of lakes and wetlands in the watershed as well as the
climate and vegetation present. </p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/8035178 |
| Date | 11 June 2019 |
| Creators | Stephen J Kines (6630242) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Modeling_the_Impacts_of_Lakes_and_Wetlands_on_Streamflow/8035178 |
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