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Revised Capacities and Sediment Pattern Assessment in Rajaval
and Kharo Reservoirs of Gujarat (India)
-- R K Jaiswal, T Thomas, R V Galkate and S Singh
Information on rate and extent of reservoir sedimentation is essential for taking up appropriate measures
in controlling the sediment inflow, to obtain updated assessment of useful life of the reservoir and to decide
on the optimum reservoir operation schedule based on realistic assessment of available
storage. In the present study, a comparison of sedimentation status was made in Rajaval and Kharo reservoirs situated in
Bhavnagar district of Gujarat. From the analysis, it was observed that 5.043 million cu m of gross storage of
Rajaval reservoir has been lost in 25 years (1982-2007) and the average rate of siltation in this reservoir is
0.202 million cu m/year. In the case of Kharo reservoir, 4.332 million cu m of gross storage has been lost
in 22 years (1985-2007) and the average rate of siltation is 0.197 million cu m/year. The data of silt surveys
in the year 2000 was also used and the pattern of siltation in both reservoirs was analyzed for
evaluation periods, namely, impoundment to 2000 (Evaluation Period-I) and 2000-07 (Evaluation Period-II). From
the analysis, it was observed that the sedimentation rate increased significantly during 2000-07 in both
the reservoirs but Rajaval reservoir needs immediate attention for soil conservation measures because rate
of siltation in this reservoir has doubled during this period. The spatial distribution of sediment in
both reservoirs indicated more deposition in upper part due to flat topography in that region.
© 2010 IUP. All Rights Reserved.
Relationship Between Storage Coefficient
and Catchment Area Using Hec-hms
for Southern Region of Sarawak
-- Kuok King Kuok, Po-Chan Chiu,
Chai Min Chung and Tiong Huo Chuang
This paper presents the simulation of hourly rainfall-runoff relationship with appropriate
hydrologic parameters on selected three catchments; Bedup, Batu Gong and Rayu catchments, located at
southern region of Sarawak, Malaysia. Hydrologic model selected for this study is Hydrologic Engineering
Centre-Hydrologic Modeling System (HEC-HMS). The model parameters were optimized with combination
of initial and constant loss, Clark unit hydrograph, recession baseflow and Muskingum routing
methods. Each of these hydrologic parameters was calibrated automatically through optimization manager
function that built within HEC-HMC model. To ensure the robustness of optimal parameters obtained,
each catchment will be validated with three independent storm events. The
accuracy of simulation results was measured with coefficient of correlation and peak error. Two
methods were applied to obtain time of concentration
(Tc) and storage coefficient
(R), which are the fundamental parameters for Clark instantaneous unit hydrograph. First method was obtained through
optimization manager function that build within HEC-HMS, and second method was through calculation according
to Hydrological Procedure No. 5 (1974). The results revealed that the optimized Tc and R are very close
with calculated Tc and R. The relationship between R and catchment area (A) was then established through
a linear equation. The relationship between R and A for southern region of Sarawak is represented as R = 0.0535A - 1.4093. Establishment of this equation will enable the hydrologists and researchers to estimate
the Tc and R values by just determining the catchment area, especially for the ungauged catchments at
southern region of Sarawak.
© 2010 IUP. All Rights Reserved.
Effect of Fencing on Morphological, Chemical
and Physical Attributes of Soils
in an Agricultural Catchment in N-w Tract of India
-- M S Hadda, Dapinder Pal Singh,
M Vashistha and Narinder Mohan
Soil erosion by water poses a serious threat to agricultural production in the northwestern tract of
India which has weak and ecologically degraded land, undulating terrain and structurally poor soils.
Absence of fencing has been one of the main features of cultivation in the area. Keeping these points in view,
the effect of fencing was studied on morphological, chemical and physical attributes of soils in the tract.
The most significant and critical differences, however, observed were decrease in thickness of A-horizon
, organic matter content and increase in clay content in severely eroded profiles than that in
moderately eroded profiles in the area. With increase in effective soil depth, saturated hydraulic conductivity,
Mean Weight Diameter (MWD) and organic C content decreased with respect to A-horizon depth.
However, Cation Exchange Capacity (CEC) showed an inconsistent trend in subsurface layered depths as
compared to A-horizon (surface layer) of the studied profiles. The organic C content was 108.3% and 72.7% and
total soil N was 54.3% and 38.9% less for the subsurface layer ( 30-60 cm ) as compared to the surface layer
(0-5 cm) in fenced and non-fenced areas, respectively. The available phosphorus content was
significantly higher by 9.5% in fenced than that in non-fenced treatment, respectively. The resistance to penetration
was 237.5% and 98.6% more in 10-15 cm layer than that in 0-5 and 5-10 cm layers, respectively through
fencing. The most useful indicators from the point of view of assessing soil quality in the area are organic c, total
N, bulk density and total porosity.
© 2010 IUP. All Rights Reserved.
InfoWorks Collection System-Based
Hydrodynamic Modeling in Sibu Town
-- Ting Sie Chun, Frederik Joseph Putuhena and Salim Said
InfoWorks Collection System (CS) with its embedded Geographic Information System (GIS) applications
is an approach of one-dimensional hydrodynamic modeling tool that used to identify the causes of
inundation. Sungai Merah residential area covered an area of 0.47
km2 in Sibu Town of Sarawak State, located
within the Seduan River basin, which is a flood-prone area with relatively flat and typically low-lying
floodplain. The simulated model, used for the integrated assessment of flood conditions in the study area; for
risk-based design of flood protection measures and hence as a decision support tool for flood risk
management. Additionally, flood mitigation in the study area is part of the Sibu Town urban water management
system, which proposed 3.7 m high levee to be constructed along the Seduan River to protect the residential
area from tidal impact. Tidal gates are also provided to overcome the internal drainage problems.
The hydrodynamic modeling showed its capability in identifying the effectiveness of the levee for 2, 5, 10
and 20 years Average Recurrence Interval (ARI).
© 2010 IUP. All Rights Reserved.
Physicochemical Properties of Tropical Forest Soil
-- Ahmad Makmom Abdullah,
Nurul Azzura Shahadan and Marzuki Ismail
Pasoh Forest Reserve (PFR), which is located in Malaysia at
2° N and 102° E, is far from any
industrialized or urbanized areas, suitable for providing background information on tropical forest soil properties.
Hence, the objective of the study was to determine the physicochemical properties of the PFR soils. Three plots of
9 ´ 9 m were established and divided into 1
´ 1 m subplots. Two subplots of dimension 1
´ 1 m were sampled in each plot resulting in a total of six subplots selected for soil analysis. A pit of 1 m deep was
dug out and soil samples were taken from every 10 cm layer until 1 m depth. Soil acidity (pH), moisture
content, bulk density, electrical conductivity, available phosphate
(PO42-), available sulphate
(SO42-), exchangeable acidity, exchangeable Al and H, exchangeable base cations, Effective Cation Exchangeable Capacity
(ECEC) and base saturation were determined. The results indicated that the soil profile was characterized by A,
E, EB, and B horizon with respective characteristics. Mean base saturation values of the PFR soils were
78.77 ± 3.78% and strongly correlated with the exchangeable Ca. The physicochemical properties of the PFR
soil is similar to the previous studies and presumably unaffected by anthropogenic and natural activities.
© 2010 IUP. All Rights Reserved.
RESEARCH NOTE
Evaluation of Biofertilizers on Growth
and Biomass Accumulation of Coleus vettiveroides
-- B Mamatha, T N Shivananda, K Sudhir,
A N Ganeshamurthy and Savitha M Murthy
© 2010 IUP. All Rights Reserved.
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November '10
