Apply Image Technology to River Level Estimation

2016 ◽  
pp. 87-94
Author(s):  
Ming-Tsung Yeh ◽  
Yun-Jhong Hu ◽  
Chien-Wen Lai ◽  
Chao-Hsing Hsu ◽  
Yi-Nung Chung
Keyword(s):  
River Level

scholarly journals Applying soft computing approaches to river level forecasting

1999 ◽  
Vol 44 (5) ◽  
pp. 763-778 ◽  
Author(s):  
LINDA SEE ◽  
STAN OPENSHAW
Keyword(s):  
Soft Computing ◽  
River Level

Missing values and lack of information in water management datasets: an approach based on Bayesian Networks

2021 ◽  
Author(s):  
Rosa F Ropero ◽  
M Julia Flores ◽  
Rafael Rumí
Keyword(s):  
Extreme Events ◽  
Coastal Area ◽  
Flood Risk ◽  
Missing Values ◽  
Real Data ◽  
Continuous Variables ◽  
Target Variable ◽  
River Level ◽  
Lack Of Information ◽  
Level Variable

<p>Environmental data often present missing values or lack of information that make modelling tasks difficult. Under the framework of SAICMA Research Project, a flood risk management system is modelled for Andalusian Mediterranean catchment using information from the Andalusian Hydrological System. Hourly data were collected from October 2011 to September 2020, and present two issues:</p><ul><li>In Guadarranque River, for the dam level variable there is no data from May to August 2020, probably because of sensor damage.</li> <li>No information about river level is collected in the lower part of Guadiaro River, which make difficult to estimate flood risk in the coastal area.</li> </ul><p>In order to avoid removing dam variable from the entire model (or those missing months), or even reject modelling one river system, this abstract aims to provide modelling solutions based on Bayesian networks (BNs) that overcome this limitation.</p><p><em>Guarranque River. Missing values.</em></p><p>Dataset contains 75687 observations for 6 continuous variables. BNs regression models based on fixed structures (Naïve Bayes, NB, and Tree Augmented Naïve, TAN) were learnt using the complete dataset (until September 2019) with the aim of predicting the dam level variable as accurately as possible. A scenario was carried out with data from October 2019 to March 2020 and compared the prediction made for the target variable with the real data. Results show both NB (rmse: 6.29) and TAN (rmse: 5.74) are able to predict the behaviour of the target variable.</p><p>Besides, a BN based on expert’s structural learning was learnt with real data and both datasets with imputed values by NB and TAN. Results show models learnt with imputed data (NB: 3.33; TAN: 3.07) improve the error rate of model with respect to real data (4.26).</p><p><em>Guadairo River. Lack of information.</em></p><p>Dataset contains 73636 observations with 14 continuous variables. Since rainfall variables present a high percentage of zero values (over 94%), they were discretised by Equal Frequency method with 4 intervals. The aim is to predict flooding risk in the coastal area but no data is collected from this area. Thus, an unsupervised classification based on hybrid BNs was performed. Here, target variable classifies all observations into a set of homogeneous groups and gives, for each observation, the probability of belonging to each group. Results show a total of 3 groups:</p><ul><li>Group 0, “Normal situation”: with rainfall values equal to 0, and mean of river level very low.</li> <li>Group 1, “Storm situation”: mean rainfall values are over 0.3 mm and all river level variables duplicate the mean with respect to group 0.</li> <li>Group 2, “Extreme situation”: Both rainfall and river level means values present the highest values far away from both previous groups.</li> </ul><p>Even when validation shows this methodology is able to identify extreme events, further work is needed. In this sense, data from autumn-winter season (from October 2020 to March 2021) will be used. Including this new information it would be possible to check if last extreme events (flooding event during December and Filomenastorm during January) are identified.</p><p> </p><p> </p><p> </p>

scholarly journals Evaluation of the Upper Paraná River discharge controlled by reservoirs

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 707-716 ◽  
Author(s):  
EE. Souza Filho
Keyword(s):  
Paraná River ◽  
River Level ◽  
Parana River ◽  
River Damming ◽  
Discharge Rates ◽  
Historical Series ◽  
Discharge Regime ◽  
Upper Paraná River ◽  
The Relationship ◽  
Different Levels

The building of large dams in the Upper Paraná River basin altered the discharge regime at the Porto São José River section. The discharge regime has been altered since 1972, but the changes intensified after the Porto Primavera damming, in late 1998. Considering that discharge control affects the relationship between channel and floodplain, this work aimed to evaluate the intensity of the discharge control that resulted from the operation of the Porto Primavera Dam. To achieve this objective, statistical analyses were carried out based on the Porto São José Fluviometric Station historical series of river level readings and discharge, between 1964 and 2007. Results showed that the average discharge increased from 1964 to 1981 and diminished after river damming. The increase of average discharge rates was followed by an increase of the duration of higher discharges at different levels of geomorphologic and limnological importance, and the reduction of average discharge during the last observed period was followed by a disproportionate decrease in the duration of the abovementioned discharges. Moreover, it is clear that the relationship between fluviometric level and fluvial discharge changed, which implies that a certain river level reading represents a higher discharge than necessary before river damming.

scholarly journals QUANTITATIVE ASSESSMENT OF THE MOST DECISIVE FACTORS DETERMINING RIVER LEVEL IN AN ESTUARY

2003 ◽  
Vol 47 ◽  
pp. 961-966
Author(s):  
Keisuke YOKOO ◽  
Shizuo YOSHIDA ◽  
Shuzo NISHIDA ◽  
Norihiko ARAKAWA
Keyword(s):  
Quantitative Assessment ◽  
River Level

Measurement of river level variations with satellite altimetry

1993 ◽  
Vol 29 (6) ◽  
pp. 1839-1848 ◽  
Author(s):  
C. J. Koblinsky ◽  
R. T. Clarke ◽  
A. C. Brenner ◽  
H. Frey
Keyword(s):  
Satellite Altimetry ◽  
River Level

scholarly journals Realignments of the Colorado River by ~2 m.y. of rotational bedrock landsliding: The Surprise Valley landslide complex, Grand Canyon, Arizona

Geosphere ◽  
2021 ◽  
Author(s):  
Jesse E. Robertson ◽  
Karl E. Karlstrom ◽  
Matthew T. Heizler ◽  
Laura J. Crossey
Keyword(s):  
Cross Sections ◽  
Colorado River ◽  
Grand Canyon ◽  
Geologic Mapping ◽  
River Level ◽  
The Past ◽  
The North ◽  
Seismic Triggering ◽  
Depositional Age ◽  
Deer Creek

The Surprise Valley landslide complex is the name used here for a group of prominent river-damming landslides in Grand Canyon (Arizona, USA) that has shifted the path of the Colorado River several times in the past 2 m.y. We document a sequence of eight landslides. Three are Toreva-block landslides containing back-rotated but only mildly disrupted bedrock stratigraphy. The largest of these landslides, Surprise Valley landslide, is hypothesized to have dammed the Colorado River, cut off a meander loop through Surprise Valley, and rerouted the river 2.5 km south to near its present course at the Granite Narrows. Another bedrock landslide, Poncho’s runup, involved a mass detachment from the north side of the river that drove a kilometer-scale bedrock slab across the river and up the south canyon wall to a height of 823 m above the river. A lake behind this landslide is inferred from the presence of mainstem gravels atop the slide that represent the approximate spillway elevation. We postulate that this landslide lake facilitated the upriver 133 Mile slide detachment and Toreva block formation. The other five landslides are subsequent slides that consist of debris from the primary slides; these also partially blocked and diverted the Colorado River as well as the Deer Creek and Tapeats Creek tributaries into new bedrock gorges over the past 1 m.y. The sequence of landslides is reconstructed from inset relationships revealed by geologic mapping and restored cross-sections. Relative ages are estimated by measuring landslide base height above the modern river level in locations where landslides filled paleochannels of the Colorado River and its tributaries. We calculate an average bedrock incision rate of 138 m/m.y. as determined by a 0.674 ± 0.022 Ma detrital sanidine maximum depositional age of the paleoriver channel fill of the Piano slide, which has its base 70 m above the river level and ~93 m above bedrock level beneath the modern river channel. This date is within error of, and significantly refines, the prior cosmogenic burial date of 0.88 ± 0.44 Ma on paleochannel cobbles. Assuming steady incision at 138 m/m.y., the age of Surprise Valley landslide is estimated to be ca. 2.1 Ma; Poncho’s runup is estimated to be ca. 610 ka; and diversion of Deer Creek to form modern Deer Creek Falls is estimated to be ca. 400 ka. The age of the most recent slide, Backeddy slide, is estimated to be ca. 170 ka based on its near-river-level position. Our proposed triggering mechanism for Surprise Valley landslides involves groundwater saturation of a failure plane in the weak Bright Angel Formation resulting from large volumes of Grand Canyon north-rim groundwater recharge prior to establishment of the modern Deer, Thunder, and Tapeats springs. Poncho’s and Piano landslides may have been triggered by shale saturation caused by 600–650 ka lava dams that formed 45 river miles (73 river km; river miles are measured along the Colorado River downstream from Lees Ferry, with 1 river mile = 1.62 river kms) downstream near Lava Falls. We cannot rule out effects from seismic triggering along the nearby Sinyala fault. Each of the inferred landslide dams was quickly overtopped (tens of years), filled with sediment (hundreds of years), and removed (thousands of years) by the Colorado River, as is also the potential fate of modern dams.

scholarly journals Hydro-mechanical behaviour of a sandy silt from a river embankment

2020 ◽  
Vol 195 ◽  
pp. 01033
Author(s):  
Vincenzo Butticè ◽  
Alessio Ferrari ◽  
Carmine G. Gragnano ◽  
Guido Gottardi
Keyword(s):  
Mechanical Behaviour ◽  
Measurement Techniques ◽  
Degree Of Saturation ◽  
Confining Stress ◽  
River Level ◽  
Suction Control ◽  
Sandy Silt ◽  
Axial Translation ◽  
Safety Margins ◽  
River Embankment

The paper presents the results of an experimental campaign aimed at characterizing the hydro-mechanical behaviour of a sandy silt from a river embankment. Due to continuous river level fluctuations and changing climatic and environmental conditions, flood embankment materials experience frequent variations in degree of saturation and suction values. Such variations strongly impact the earthwork performance both in terms of seepage and stability conditions. For these reasons, a detailed characterization of the material behaviour in unsaturated conditions was carried out. Experiments were designed in order to highlight the response of the involved soil in terms of changes in matric suction and confining stress. All tests were performed on undisturbed samples from the embankment. To cover the suction range, which is expected to be significant for the material and assessed through field monitoring, a combination of several suction-control and suction-measurement techniques was used (e.g. negative water column, axial translation, tensiometers). Obtained results enabled (i) to quantify the evolution of the yield stress with suction, (ii) to assess the collapse upon wetting behaviour, (iii) to get detailed information on the water retention behaviour and (iv) to define the relative permeability of the soil. This extensive characterization work serves as a basis for the analysis of the embankment response following river level variations, the final purpose of the research being to establish a reliable methodology and a feasible procedure for the realistic assessment of the safety margins under transient seepage.

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