scholarly journals A study on the characteristics and influencing factors of reservoir sedimentation in Wanjiazhai Reservoir

2018 ◽  
Vol 246 ◽  
pp. 01046
Author(s):  
Zhihui Ren ◽  
Ting Wang ◽  
Yuanjian Wang ◽  
Shaojun Qu
Keyword(s):  
Water Level ◽  
Reservoir Operation ◽  
Temporal Distribution ◽  
Measured Data ◽  
Sediment Deposition ◽  
Reservoir Sedimentation ◽  
Spatial And Temporal Distribution ◽  
Timely Manner ◽  
Reservoir Area ◽  
The Impact

Based on measured data of the Wanjiazhai Reservoir in different periods, the characteristics of the spatial and temporal distribution of sedimentation in the reservoir area were preliminarily analyzed and the impact of reservoir operation on this distribution was discussed. Primary conclusions are as followed: in terms of temporal distribution, sedimentation continuously accumulated over the period from 2000 to 2017, with the sediment deposition ratio dramatically decreasing between 2011 and 2017; in terms of spatial distribution, the sedimentation in the reservoir area was mainly concentrated downstream of the WD54 section, with the highest concentration being downstream of the WD23 section. The characteristics of sedimentation distribution in the reservoir area were closely related to inflow and sediment conditions and reservoir operation water level. When the water level was lower than 952 m, the sediment deposition ratio was lower than 0. To further improve the sediment deposition form in the reservoir area, lowering water level and ejecting the sediment are recommended in a timely manner.

Spatial and temporal distribution of early-stage phyllosoma of westren rock lobster, Panulirus cygnus

1980 ◽  
Vol 31 (4) ◽  
pp. 485 ◽  
Author(s):  
DW Rimmer
Keyword(s):  
Early Stage ◽  
Temporal Distribution ◽  
Lunar Cycle ◽  
Stage I ◽  
Western Coast ◽  
Spatial And Temporal Distribution ◽  
Rock Lobster ◽  
Larval Release ◽  
Panulirus Cygnus ◽  
The Impact

Time-series sampling for early-stage phyllosoma of P. cygnus was carried out off the western coast of Australia near the centre of the population of breeding adults. Hatching occurred from November through February in 1973-74 and 1974-75. Spatial distribution of the larvae was similar between the two seasons studied. The density of newly hatched (stage I) phyllosoma was greatest along the off-shore portion of the continental shelf. The majority of larvae moved off shore soon after hatching and the relative abundance of stages 11 and 111 increased with distance off shore. An off-shore extension of the sampling yielded an estimated minimum net rate of off-shore transport of 5.25 km,day for the stage I phyllosoma taken at the station farthest off shore. In 1973-74. larval release increased gradually from a low level in November to a peak in mid January. In 1974-75 larval release commenced at least a month earlier and peaked in late November, tapered off through December, and peaked again in mid January. Water temperature correlated with temporal differences in larval release. Warmer temperatures early in the 1974-75 season apparently induced the onset of breeding early enough to permit a second breeding by some females. There appeared to be no periodicity of hatching related to the lunar cycle. The distribution of early-stage phyllosoma was patchy and the impact of patchiness on quantitative sampling is discussed.

scholarly journals Spatial and temporal distribution of ''curvina'' larvae (Plagioscion squamosissimus HECKEL, 1840) and its relationship to some environmental variables in the upper Paraná River floodplain, Brazil

2003 ◽  
Vol 63 (3) ◽  
pp. 381-391 ◽  
Author(s):  
M. S. T. Baumgartner ◽  
K. Nakatini ◽  
G. Baumgartner ◽  
M. C. Makrakis
Keyword(s):  
Water Level ◽  
Temporal Distribution ◽  
Paraná River ◽  
Spatial And Temporal Distribution ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain ◽  
Spawning Sites

With the objective of studying the spatial and temporal distribution of ''curvina'' Plagioscion squamosissimus larvae and verifying respective spawning sites, monthly sampling was carried out from March 1993 to February 1994 on the Upper Paraná River floodplain. Using a conical-cylindrical plankton net (0.5 mm mesh), samples were taken from the surface of the water bodies, and in the marginal vegetation a strainer and a dragnet (''picaré'') were used. Water samples were collected for environmental variable analysis (temperature, dissolved oxygen, water pH, and electrical conductivity). Water level data were obtained from hydrometric stations. High average density of larvae was found from December 1993 to February 1994 due to high temperature and water level. The Baía sub-area was shown to be the most important in the larvae catch, probably due to its semi-lotic characteristics. Larvae size distribution was shown to be more frequent in the 4.0 mm standard length class, indicating that the sampling stations were next to the spawning sites.

Decision support system for optimal reservoir operation modeling within sediment deposition control

2009 ◽  
Vol 59 (3) ◽  
pp. 479-489 ◽  
Author(s):  
Iwan K. Hadihardaja
Keyword(s):  
Reservoir Operation ◽  
Storage Capacity ◽  
Sediment Deposition ◽  
Optimal Decision ◽  
Operation Model ◽  
Original Design ◽  
Sediment Control ◽  
Hydroelectric Energy ◽  
Sanmenxia Reservoir ◽  
The Impact

Suspended sediment deals with surface runoff moving toward watershed affects reservoir sustainability due to the reduction of storage capacity. The purpose of this study is to introduce a reservoir operation model aimed at minimizing sediment deposition and maximizing energy production expected to obtain optimal decision policy for both objectives. The reservoir sediment-control operation model is formulated by using Non-Linear Programming with an iterative procedure based on a multi-objective measurement in order to achieve optimal decision policy that is established in association with the development of a relationship between stream inflow and sediment rate by utilizing the Artificial Neural Network. Trade off evaluation is introduced to generate a strategy for controlling sediment deposition at same level of target ratio while producing hydroelectric energy. The case study is carried out at the Sanmenxia Reservoir in China where redesign and reconstruction have been accomplished. However, this model deals only with the original design and focuses on a wet year operation. This study will also observe a five-year operation period to show the accumulation of sediment due to the impact of reservoir storage capacity.

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