Model study of an outlet control structure used in wetland management
Loading...
Date
1991
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of New Brunswick
Abstract
Ducks Unlimited Canada uses o u t l e t c o n t r o l s t r u c t u r e s to
create and manage waterfowl habitat i n New Brunswick. An
o u t l e t control structure i s a hybrid hydraulic s t r u c t u re
c o n s i s t i n g of four adjustable weirs mated to a corrugated
metal culvert w i t h a p r e f a b r i c a t e d r e i n f o r c e d concrete box.
The hydraulic operating c h a r a c t e r i s t i c s of these o u t l et
c o n t r o l structures were studied through three approaches.
F i e l d v i s i t s were made to three prototype structures and
measurements of operational parameters were made. A one-sixth
scale physical model of the f o u r - f o o t culvert diameter
s t r u c t u r e was constructed and t e s t e d . A numerical model using
e x i s t i n g weir and c u l v e r t theory was devised and r u n .
The above three methods y i e l d e d three sets of r a t i n g curves
( r e s e r v o i r elevation versus discharge through the h y b r id
s t r u c t u r e ) . These r a t i n g curves were compared t o each other
and to the Ducks Unlimited design curve.
The prototype observations, physical model, and numerical
model r e s u l t s agreed very w e l l . These three also coincided
w i t h the Ducks Unlimited design curve at low discharge rates,
but the p h y s i c a l and numerical models both p r e d i c t higher
discharges for a given head than the design curve at high
discharge rates.
E f f o r t s were made to i n v e s t i g a t e methods to f u r t h er
increase the discharge through the s t r u c t u r e f o r a given head
on the weirs, but more experimentation i s recommended.