Application of a flow-measurement structure for sediment-laden streams

2009 ◽  
Vol 36 (9) ◽  
pp. 1539-1543
Author(s):  
Mustafa Göğüş ◽  
A. Cüneyt Gerek ◽  
A. Burcu Altan-Sakarya

Generally, measurement of flow in natural streams is accomplished by measuring the flow depth. Hence, the relationship between the water level and discharge should be obtained in advance. However, in streams with high sediment load, the bottom level may change due to sediment deposition, preventing the single relation between water level and discharge. This paper summarizes the application of a flow-measurement structure for sediment-laden streams. The proposed structure is designed and built in Turkey and has been under operation since 1998 without any sedimentation problem. The agreement between the real data obtained from the structure and the theoretical rating curve is quite reasonable.

2018 ◽  
Vol 40 ◽  
pp. 04024 ◽  
Author(s):  
Nils Rüther ◽  
Rui Aleixo ◽  
Massimo Guerrero ◽  
Sigurd Sørås ◽  
Siri Stokseth

This study presents a series of acoustic current Doppler profiler (ADCP) measurements, which are converted into suspended load concentrations (SSC). Depending on the particle size distribution (PSD), the sound backscatter and its attenuation are used to determine a theoretical minimal and physical upper limit of the SSC. The SSC are displayed over time and compared with the evolution of the water level during the same time interval. The present study shows that it is possible to have continuous measurements of SSC and water level with a horizontally installed two beam equipped ADCP and discusses the potential of such a continuing times series measurement for application in hydraulic engineering and research. However, the presented data set shows also that the calibration and the filtering of the raw data has to be improved and that further investigations are needed. After data verification, it will be possible to calculate the yearly sediment load and investigate physical behaviour of SSC concentration as a function of water level and discharge.


2000 ◽  
Vol 23 (3) ◽  
pp. 541-544 ◽  
Author(s):  
José Alexandre Felizola Diniz-Filho ◽  
Mariana Pires de Campos Telles

In the present study, we used both simulations and real data set analyses to show that, under stochastic processes of population differentiation, the concepts of spatial heterogeneity and spatial pattern overlap. In these processes, the proportion of variation among and within a population (measured by G ST and 1 - G ST, respectively) is correlated with the slope and intercept of a Mantel's test relating genetic and geographic distances. Beyond the conceptual interest, the inspection of the relationship between population heterogeneity and spatial pattern can be used to test departures from stochasticity in the study of population differentiation.


Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 170
Author(s):  
Michal Holčapek ◽  
Nicole Škorupová ◽  
Martin Štěpnička

The article develops further directions stemming from the arithmetic of extensional fuzzy numbers. It presents the existing knowledge of the relationship between the arithmetic and the proposed orderings of extensional fuzzy numbers—so-called S-orderings—and investigates distinct properties of such orderings. The desirable investigation of the S-orderings of extensional fuzzy numbers is directly used in the concept of S-function—a natural extension of the notion of a function that, in its arguments as well as results, uses extensional fuzzy numbers. One of the immediate subsequent applications is fuzzy interpolation. The article provides readers with the basic fuzzy interpolation method, investigation of its properties and an illustrative experimental example on real data. The goal of the paper is, however, much deeper than presenting a single fuzzy interpolation method. It determines direction to a wide variety of fuzzy interpolation as well as other analytical methods stemming from the concept of S-function and from the arithmetic of extensional fuzzy numbers in general.


2018 ◽  
Vol 45 (1) ◽  
pp. 82-96 ◽  
Author(s):  
Fuqiang Li ◽  
Baotian Pan ◽  
Zhongping Lai ◽  
Hongshan Gao ◽  
Xianjiao Ou

Abstract The partial bleaching of the luminescence signal prior to deposition results in age overestimation, and can be a problem in delineating fluvial evolution within an OSL chronological framework. The Inner Mongolian reaches of the Yellow River are characterised by a high sediment load and complex sources of sediments. To test the incomplete bleaching occurring in this type of environment, the residual doses and the luminescence signal characteristics of different particle size fractions from 14 modern fluvial sediment samples were investigated. Furthermore, 26 OSL ages derived from drilling cores were compared with 11 radiocarbon ages. Our results show that the residual equivalent doses principally range between 0.16 and 0.49 Gy for silt grains, and between 0.35 and 3.72 Gy for sand grains of modern samples. This suggests that medium-grained quartz has been well bleached prior to deposition, and is preferable to coarse-grained quartz when dating fluvial sediments in this region. The results also show that the De values of coarse-grained fractions display a stronger correlation with distance downstream. In addition, a comparison of OSL and radiocarbon ages from drilling cores establishes further confidence that any initial bleaching of these sediments was sufficient. As a result, we believe that the studied fluvial samples were well bleached prior to deposition.


2019 ◽  
Vol 7 (2) ◽  
pp. 157-165
Author(s):  
Andi Setiawan ◽  
Edi Susanto
Keyword(s):  

Liku kalibrasi debit  merupakan kurva yang menunjukkan hubungan antara tinggi muka air dan debit sungai sehingga dapat digunakan untuk memprediksi besarnya debit pada sungai tersebut. Tujuan penelitian ini adalah untuk mendapatkan persamaan liku kalibrasi debit di DAS Deli. Penelitian ini dilakukan dengan mengukur debit air sungai dan mengambil data tinggi muka air menggunakan alat water level logger dengan pengamatan minimal dua kali dalam seminggu. Debit air sungai pada lokasi penelitian memiliki nilai yang bervariasi yaitu 0,74 - 3,28 m3/detik dengan rata-rata 1,06 m3/detik. Penentuan persamaan liku kalibrasi debit menggunakan beberapa metode yaitu linier, polinomial, berpangkat, logaritmik, dan eksponensial. Hasil dari penelitian diperoleh bahwa persamaan dengan metode polinomial orde dua memiliki tingkat korelasi (r) dan RMSE yang terbaik dengan nilai r 0,986 dan nilai RMSE 0,011. Persamaan rating curve yang diperoleh adalah Q = 18,97(h)2 – 1,372(h) + 0,190.


2021 ◽  
Vol 8 ◽  
Author(s):  
Tianshu Gu ◽  
Lishi Wang ◽  
Ning Xie ◽  
Xia Meng ◽  
Zhijun Li ◽  
...  

The complexity of COVID-19 and variations in control measures and containment efforts in different countries have caused difficulties in the prediction and modeling of the COVID-19 pandemic. We attempted to predict the scale of the latter half of the pandemic based on real data using the ratio between the early and latter halves from countries where the pandemic is largely over. We collected daily pandemic data from China, South Korea, and Switzerland and subtracted the ratio of pandemic days before and after the disease apex day of COVID-19. We obtained the ratio of pandemic data and created multiple regression models for the relationship between before and after the apex day. We then tested our models using data from the first wave of the disease from 14 countries in Europe and the US. We then tested the models using data from these countries from the entire pandemic up to March 30, 2021. Results indicate that the actual number of cases from these countries during the first wave mostly fall in the predicted ranges of liniar regression, excepting Spain and Russia. Similarly, the actual deaths in these countries mostly fall into the range of predicted data. Using the accumulated data up to the day of apex and total accumulated data up to March 30, 2021, the data of case numbers in these countries are falling into the range of predicted data, except for data from Brazil. The actual number of deaths in all the countries are at or below the predicted data. In conclusion, a linear regression model built with real data from countries or regions from early pandemics can predict pandemic scales of the countries where the pandemics occur late. Such a prediction with a high degree of accuracy provides valuable information for governments and the public.


The correct assessment of amount of sediment during design, management and operation of water resources projects is very important. Efficiency of dam has been reduced due to sedimentation which is built for flood control, irrigation, power generation etc. There are traditional methods for the estimation of sediment are available but these cannot provide the accurate results because of involvement of very complex variables and processes. One of the best suitable artificial intelligence technique for modeling this phenomenon is artificial neural network (ANN). In the current study ANN techniques used for simulation monthly suspended sediment load at Vijayawada gauging station in Krishna river basin, Andhra Pradesh, India. Trial & error method were used during the optimization of parameters that are involved in this model. Estimation of suspended sediment load (SSL) is done using water discharge and water level data as inputs. The water discharge, water level and sediment load is collected from January 1966 to December 2005. This approach is used for modelled the SSL. By considering the results, ANN has the satisfactory performance and more accurate results in the simulation of monthly SSL for the study location.


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