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Content:
Vol.
10. No. 1 Spring 2010
Vol.
9, No.2
Fall 2009
Vol.
9, No.1 Spring 2009
Vol. 8, No.2
Fall 2008
Vol.
8, No.1 Spring 2008
Vol.
7, No. 2 Fall 2007
Vol.
7, No. 1 Spring 2007
Vol.
6, No. 2 Fall 2006
Vol.
6, No. 1 Spring 2006
Vol. 5, No. 2 Fall 2005
Vol.
5, No. 1 Spring 2005
Vol.
4, No. 2 Fall 2004
Vol.
4, No. 1 Spring 2004
Vol.
3, No. 2 Fall 2003
Vol.
3,
No. 1 Spring
2003
Vol. 2,
No. 2 Fall 2002
Vol. 2,
No. 1 Spring 2002
Vol. 1, No. 1 Fall 2001
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ABSTRACT
An unprecedented eight hurricanes (Charley, Frances, Ivan,
Jeanne, Dennis, Katrina, Rita and Wilma) affected South Florida
in 2004 and 2005. These storms resulted in high property losses,
high rainfall, high surface water flows, rise in lake water
levels and damage to water management infrastructure. The last
storm to hit was Hurricane Wilma which passed through the
central section of South Florida from the west to the east as a
Category 2 hurricane with gust wind speed as high as 180 km h-1
and widely affected the area. Apart from the extensive costly
wind damage, rainfall from Wilma affected the South Florida
Water Management System. One of the risks associated with
hurricanes in South Florida is the potential for wave erosion
damage to the Herbert Hoover Dike on Lake Okeechobee and
consequences of a breach. The Herbert Hoover Dike was damaged by
Hurricane Wilma. Analysis of wind direction and speed over the
region and estimated storm surge and wave setup of 4.68 m on the
Lake Okeechobee levee corresponds with water mark and levee
damage observations. Water level data is presented showing the
lake drawdown at upwind and the wave setup downwind. Atmospheric
pressure change over the region during the hurricane is
presented. Water quality of the lake was affected due to settled
sediment re-suspension and increase in phosphorus in the water
column. Spatial monthly mean total suspended solids
concentration increased from 19 mg L-1 to 131 mg L-1
(689 percent), while spatial monthly mean total phosphorus
concentration increased from 201 µg L-1 to 305 µg L-1
(152 percent). The hurricane uprooted and dislocated vegetation
from wetlands and littoral zones of lakes. Canals and water
control structures were filled with uprooted vegetation and
other debris resulting in limited flood conveyance.
N. R. Deshpande, B.D. Kulkarni, A. K. Verma and
B.N. Mandal
ABSTRACT
Annual extreme rainfall series of 1-3 day durations at stations
located inside the Indus basin in India were subjected to
statistical analysis in order to estimate point Probable Maximum
Precipitation (PMP) and maximum rainfall of different return
periods for the durations of 1-3 days. Daily rainfall data of
210 stations ranging from 1901-2000 (with varying data length)
has been considered for the present study. Rainfall distribution
of the basin on seasonal and annual scale has been examined.
Spatial patterns of 1-3 day extreme rainfall over the basin have
been presented which showed
that low values of extreme rainfall are located in the Ladakh
region located in the northern parts of the basin, while region
lying in the Himachal Pradesh (Sutlej river basin) experienced
heavy rainfall. Over the entire basin, point PMP estimates were
found to range from about 5 to 98 cm for 1-day, 7 to 137 cm for
2-day and 8 cm to 163 cm in 3-day durations. Highest values of
point PMP for 1-3 day durations were found to correspond to
Kilba station in the Sutlej basin.
Extreme Value Type-I (EV1) distribution has been fitted to 1-3
day extreme rainfall series and various return period values
were estimated.
Using the same fit it was found that,
PMP estimates for 1-3 day durations, have return period
of the order of
1000-year.
Extreme rainfall features and estimates of point PMP and maximum
rainfall for different return periods documented in this study
will be useful for designing and planning the water resources
projects in the basin.
Abstract:
The
technical and institutional performance evaluation of Geray
Irrigation Scheme was made in order to identify management
practices for implementation to improve the system operation and
the performance of the irrigation system. The evaluation was
made based on the selected performance indicators such as
conveyance efficiency, application efficiency, water delivery
performance, and maintenance indicators. The availability of
institutional and support services were also investigated
through a questionnaire administered to beneficiary farmers and
other stakeholders. The results obtained showed that the main
and tertiary canal conveyance efficiencies were 92 and 82
percents respectively. Many of the secondary and tertiary canals
are poorly maintained and many of the structures are
dysfunctional. Application efficiency monitored on three
farmers’ plot located at different ends of a given secondary
canal ranges from 44 to 57 percent. Water delivery
performance was only 71% showing a very substantial reduction
from the design of the canal capacity. Maintenance indicator
evaluated in terms of water level change (31.9%) and
effectiveness of the infrastructures showed that the scheme
management was in a very poor shape. Dependability of the scheme
evaluated in terms of duration and irrigation interval showed
that the scheme is performing below the intended level. The 47%
of the land initially planned for development is currently under
irrigation while there is no change in the water supply
indicating that the sustainability of the scheme is in doubt.
The cooperative support services that had been rendered to the
beneficiaries in the past four years were found to be minimal.
Moreover, there were few indicators that show the production was
market oriented. The evaluation clearly revealed the fact that
conflict resolution remains to be the duty of the local
community authorities and Water User Associations (WUA) has no
legal right to enforce its bylaws. In conclusion, the overall
technical adequacy of the scheme is rated very poor requiring
tremendous mobilization of the community to sustainably manage
it. Proper institutional setup needs to be in place, and WUA
needs to be more empowered in order to enforce its by-laws.
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JoSHJournal
of Spatial Hydrology
ISSN: 1530-4736