Suspended sediment estimation and analysis in river basins with rice paddy fields

2012 ◽  
Vol 66 (5) ◽  
pp. 918-926 ◽  
Author(s):  
E. Lapong ◽  
M. Fujihara ◽  
T. Izumi ◽  
K. Hamagami ◽  
T. Kakihara ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Prediction Models ◽  
Rice Paddy ◽  
Quality Characteristic ◽  
Small Rivers ◽  
Natural Soil ◽  
Agricultural Watersheds ◽  
Regression Equations ◽  
Water Quality Characteristic ◽  
Model Equations

Suspended sediment, which is an important water quality characteristic concerning effluents from agricultural areas, was studied in relatively small rivers that drain agricultural watersheds with considerable rice paddy areas. Suspended sediment load (SL) was observed daily for thirty three months and analysed – applying data stratification. Suspended sediment prediction models were established and the effect of rice transplanting activities on the rivers' SL was estimated. Results showed that data stratification improved the discharge–SL correlation and reduced regression and curve-fitting errors, thereby improving the efficiency of the derived model equations. Clustering the months into the rice- and non-rice transplanting seasons also improved the resulting regression equations, although not statistically significantly. Suspended SL was found to be higher during the rice transplanting season and the activities contributed a considerable amount of suspended sediment during the period, supporting the conjecture that sediments come from sources other than natural soil erosion.

Removal of Humic Substances by Coagulation

1999 ◽  
Vol 40 (9) ◽  
pp. 47-54 ◽  
Author(s):  
C.R. O’Melia ◽  
W.C. Becker ◽  
K.-K. Au
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Complex Formation ◽  
Natural Organic Matter ◽  
Divalent Cations ◽  
Water Source ◽  
Quality Characteristic ◽  
Oxide Surfaces ◽  
Water Quality Characteristic ◽  
Coagulant Dosage

Measurements and modeling of the adsorption of natural organic matter (NOM) on oxide surfaces are presented and compared. Agreement is good and supports the view that the adsorption of NOM on oxides depends significantly on complex formation reactions between specific sites on oxide surfaces and functional groups on the NOM. Coagulant requirements can and often are set by the total organic carbon (TOC) concentration in a water source. Frequently there is a stoichiometric relationship between the required coagulant dosage and the TOC of the water to be treated. Other important factors include pH and the concentration of divalent cations. Ozone may benefit or retard coagulation, depending on coagulant type and the water quality characteristic that is dominant in setting the optimum coagulant dose.

scholarly journals Estimating the suspended sediment yield in a river network by means of geomorphic parameters and regression relationships

2008 ◽  
Vol 12 (1) ◽  
pp. 177-191 ◽  
Author(s):  
S. Grauso ◽  
G. Fattoruso ◽  
C. Crocetti ◽  
A. Montanari
Keyword(s):  
Suspended Sediment ◽  
Sediment Yield ◽  
Central Italy ◽  
Drainage Density ◽  
River Network ◽  
Regression Equations ◽  
Suspended Sediment Yield ◽  
Geomorphic Parameters ◽  
Potential Applicability ◽  
Small River Basin

Abstract. An application of regression relationships depending on geomorphic parameters is proposed to predict the amount of the average annual suspended sediment yield at different sections of the drainage network. Simple and multiple regression relationships, utilising the drainage density and the hierarchical anomaly index as independent variables, based on data from 20 river basins of different size located in Italy, are here tested. An application is also shown for a small river basin located in central Italy where it is possible to compare the obtained suspended sediment yield estimates with reservoirs siltation data. The results confirm the potential applicability of regression equations for estimating the suspended sediment yield depending on the topological behaviours of the river network. A discussion of the reliability of the method for ungauged basins is also provided, which puts in light the necessity of additional tests to support the application of the approach to small size watersheds.

scholarly journals The Development and Evaluation of a Statistical–Dynamical Tropical Cyclone Genesis Guidance Tool

2016 ◽  
Vol 32 (1) ◽  
pp. 27-46 ◽  
Author(s):  
Daniel J. Halperin ◽  
Robert E. Hart ◽  
Henry E. Fuelberg ◽  
Joshua H. Cossuth
Keyword(s):  
Tropical Cyclone ◽  
Prediction Models ◽  
Weather Prediction ◽  
Multiscale Model ◽  
Global Model ◽  
Tropical Cyclone Genesis ◽  
Regression Equations ◽  
Global Models ◽  
Tropical Weather ◽  
Cyclone Genesis

Abstract The National Hurricane Center (NHC) has stated that guidance on tropical cyclone (TC) genesis is an operational forecast improvement need, particularly since numerical weather prediction models produce TC-like features and operationally required forecast lead times recently have increased. Using previously defined criteria for TC genesis in global models, this study bias corrects TC genesis forecasts from global models using multiple logistic regression. The derived regression equations provide 48- and 120-h probabilistic genesis forecasts for each TC genesis event that occurs in the Environment Canada Global Environmental Multiscale Model (CMC), the NCEP Global Forecast System (GFS), and the Met Office's global model (UKMET). Results show select global model output variables are good discriminators between successful and unsuccessful TC genesis forecasts. Independent verification of the regression-based probabilistic genesis forecasts during 2014 and 2015 are presented. Brier scores and reliability diagrams indicate that the forecasts generally are well calibrated and can be used as guidance for NHC’s Tropical Weather Outlook product. The regression-based TC genesis forecasts are available in real time online.

Establishment of optimum regression model and determination of relationships between body measurements and slaughter traits in Japanese quails by path analysis

2015 ◽  
Vol 55 (6) ◽  
pp. 799
Author(s):  
Fatih Uckardes ◽  
Dogan Narinc ◽  
Hande Kucukonder
Keyword(s):  
Path Analysis ◽  
Direct Effect ◽  
Prediction Models ◽  
Carcass Weight ◽  
Coefficient Of Determination ◽  
Multiple Regression Equation ◽  
Path Coefficient ◽  
Regression Equations ◽  
Linear Type ◽  
Japanese Quails

Path analysis was used to investigate direct, indirect and total effects of some morphological measurements on slaughter and carcass traits in Japanese quails. Bodyweight, shank length, shank diameter, breast circumference and body length measurements were taken from 219 Japanese quails. Bivariate correlations between carcass weight and morphological traits in quails ranged from 0.405 to 0.864. The direct effect of bodyweight on carcass weight was the strongest in the study and (path coefficient of 0.85) positively influenced carcass weight (P < 0.01). The direct effect of other linear-type traits on carcass weight was non-significant as revealed by t-test (P > 0.05). These traits were indirectly realised mostly by shank diameter. Thus, they were dropped from the final regression equations to obtain much more simplified prediction models. The optimum multiple regression equation for Japanese quails included bodyweight, with coefficient of determination (R2) of 0.7463. The correlation between characters was determined in more detail by using path analysis in this study. Thus, it was shown that path analysis could be used for selecting a variable. The forecast indices obtained in this study could aid in weight estimation, selection and breeding programs.

Some Limitations of the Models in the Highway Safety Manual to Predict Run-off-Road Crashes

2013 ◽  
Vol 2377 (1) ◽  
pp. 38-48
Author(s):  
Shaw-Pin Miaou
Keyword(s):  
Prediction Models ◽  
Highway Safety ◽  
Roadside Safety ◽  
Highway Safety Manual ◽  
Run Off ◽  
Section Design ◽  
Single Vehicle ◽  
Crash Modification Factors ◽  
Model Equations ◽  
Crash Prediction Models

Crash-prediction models in the current edition of the Highway Safety Manual (HSM) have been developed to predict crash frequency by collision type and severity level for specific types of roadways and sites. Each model is made up of three major components: safety performance functions (SPFs), crash modification factors, and calibration factors. The objective of this study was to identify the limitations of the prediction models in estimating single-vehicle, run-off-road (SVROR) crashes for roadside safety analyses and suggest needed changes and developments. The paper presents a review of the state of the models in HSM and focuses on SPFs. Data from FHWA's safety effects of cross-section design for two-lane roads database were used to gain insight about the characteristics of SVROR crashes and total crashes, and to identify the limitations of the current models in predicting the frequency, type, and severity of SVROR crashes. Three major areas of limitations of SPFs are discussed: (a) assumptions involved in development, (b) variables that are potentially important to roadside design but not considered, and (c) statistical bias and uncertainty of the model equations.

Regression models for the prediction of water quality in the stormwater of urban arid catchmentsA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (2) ◽  
pp. 331-344 ◽  
Author(s):  
M. Nouh ◽  
N. Al-Noman
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Suspended Sediment ◽  
Regression Models ◽  
Stormwater Runoff ◽  
Environmental Engineering ◽  
Regression Equations ◽  
Relative Importance ◽  
Flow Properties ◽  
Water Quality Control

Data from five residential urban arid catchments were used to develop regression equations for predicting mean concentrations of selected heavy metals in the stormwater runoff from duststorm and stormwater flow properties. The selected metals are copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and iron (Fe). The concentrations of the selected metals were predicted through two groups of equations. The first group of equations relates concentrations of suspended sediment with duststorm and stormwater parameters, whereas the second group relates the concentrations of the suspended sediment with those of heavy metals in the stormwater runoff. The results of the predictions encouraged recommendations on the use of the equations in the investigated catchments and identified the relative importance of the stormwater runoff and duststorms on the accumulation and transportation of heavy metals in the stormwater runoff. Based on the obtained results, recommendations concerning water quality control in arid areas are made.

scholarly journals Approach to Evaluation of Quality of Medical Services

2019 ◽  
pp. 41-45
Author(s):  
M. Burichenko ◽  
O. Ivanets
Keyword(s):  
Healthcare Providers ◽  
Quality Of Healthcare ◽  
Medical Institution ◽  
Medical Services ◽  
Regression Equations ◽  
Healthcare Provision ◽  
Quality Of Health Services ◽  
Model Equations ◽  
Fisher’S Criterion

The method of estimation of quality of medical services on the basis of qualimetry depending on subjects of estimation is offered. Subjects evaluated are divided into three groups. For each group, quality indicators are defined that characterize the needs of each group. The evaluators comprise the needs of patients, the management of the medical institution and the state authorities. For each subject, a mathematical equation based on multiparametric regression is developed. The peculiarity of each equation is to take into account the factors influencing the quality of medical services of this particular group. Qualimetric method is used for quantitative assessment of the quality of medical services. The method is based on a set of multiparameter linear regression equations that allow to take into account and analyze the influence of various factors on the quality of medical services, depending on the subjects of evaluation. On the basis of processed statistics, the coefficients for each group were determined. We have checked each regression model for Fisher’s criterion adequacy. Proposed and tested model equations have become the basis for developing a methodology for assessing the quality of medical services. The proposed approach to the assessment of the quality of health services provides an opportunity to quantify the quality of the provision of medical services to consumers in a specific medical institution for different groups of subjects. But it can serve as a means of regulating the quality of healthcare provision by healthcare providers. The proposed approach allows identifying the risks that affect the quality of services. In the case of unsatisfactory quality of these services, based on the proposed approach, identify a group that does not meet the quality requirements and develop measures to address identified deficiencies as required by the international standard.

scholarly journals Assessment of Groundwater Quality in the Jajrood River Basin, Tehran, Iran: A Coupled Physicochemical and Hydrogeochemical Study

2020 ◽  
Vol 9 (3) ◽  
pp. 237-254
Author(s):  
Maeyan Givi ◽  
◽  
Mahsa Jahangiri-Rad ◽  
Hamidreza Tashauoei ◽  
◽  
...  
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
River Basin ◽  
Major Ions ◽  
Monsoon Season ◽  
Oxygen Demand ◽  
Quality Characteristic ◽  
Water Quality Characteristic ◽  
Groundwater Samples ◽  
Subsurface Soil

Background: The physicochemical composition of groundwater is affected by the quantity and quality of surrounding aquifers which are in turn recharging from adjacent river waters. Methods: In the present study, 20 surface and 16 groundwater samples were collected in pre- and post-monsoon season from the Jajrood River basin, Tehran, Iran. The samples were analyzed for 18 physicochemical water quality characteristics to assess the river and groundwater qualities. Hydrogeochemical analyses of groundwater samples were also performed to determine the Water Quality Index (WQI) for drinking and evaluate factors governing the water quality characteristic in the study area. Accordingly, the Piper diagram and Gibbs and Chadha plots were drawn to assess seasonal variations in hydrochemical facies and processes in the basin. Subsurface soil samples were also examined with respect to the structure, elemental composition, and multi-elemental trace analysis. Results: Results showed the abundance of major ions in the order of Ca+2 >Na+>Mg+2>K+ for cations and HCO3- >SO42- >Cl- >NO3- >F- for anions. In general, all drinking groundwater samples met WHO permissible limits except for Chemical Oxygen Demand (COD) and HCO3-. Moreover, the water is categorized as Ca-Mg-HCO3 type. Subsurface soil analyses demonstrated quartz and calcium carbonate as the main phases of soil structure, suggesting the enrichment of groundwater with temporary hardness. Conclusion: Overall, the groundwater quality was suitable for drinking and agricultural activities.

scholarly journals INFLUENCE OF FOREST STAND DENSITY ON PINUS SYLVESTRIS ROUNDWOOD QUALITY IN EVEN-AGED MIXED SCOTS PINE STANDS IN MYRTILLOSA MEL. MESOTROPHIC SITE TYPE

2021 ◽  
Vol 3 ◽  
pp. 208-215
Author(s):  
Ziedonis Miklašēvičs
Keyword(s):  
Pinus Sylvestris ◽  
Tree Species ◽  
Prediction Models ◽  
Wood Quality ◽  
Research Work ◽  
Stand Density ◽  
Forest Stand ◽  
Raw Material ◽  
Quality Characteristic ◽  
Round Wood

Among different development directions for better forest utilization, the purposefully detailed assessment of wood quality as raw material, faciliating improved wood utilization in manufacturing of traditional roundwood products as well as brand new products, proves to be very perspective. Roundwood quality features substantially differ depending on forest stand geographic location, growing site conditions, tending of forest stands and other circumstances [2], [3], [11]. Therefore, the economical estimation of more important tree species in Latvia should not be based only on scientific conclusions made in other countries, so particular research is needed for this purpose. Pine (Pinus sylvestris) is the most widespread tree species in Latvia, therefore a research work provided the characteristic of round wood obtained from pine tree stem is an actual point from several aspects, as it is necessary;to create early prediction models of roundwood quality; to plan harvesting purposes;to create the data basis of economically more relevant domestic tree species;to provide the further development of roundwood quality assessment methods;to estimate the competitiveness of Latvia pine timber in the world marketThe main goal of study is to work out the quality characteristic of pine roundwood manufactured in final felling sites depending on timber formation damages- bark abrasion caused side drought.  

scholarly journals Assessment of rate of penetration of a tunnel boring machine in the longest railway tunnel of Turkey

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Candan Gokceoglu
Keyword(s):  
Multiple Regression ◽  
Prediction Models ◽  
Tunnel Boring Machine ◽  
Regression Equations ◽  
Railway Tunnel ◽  
Tunnel Boring Machines ◽  
Rate Of Penetration ◽  
Tunnel Boring ◽  
Ann Models ◽  
Boring Machines

AbstractOne of the most important issues in tunnels to be constructed with tunnel boring machines (TBMs) is to predict the excavation time. Excavation time directly affects tunnel costs and feasibility. For this reason, studies on the prediction of TBM performance have always been interesting for tunnel engineers. Therefore, the purpose of the study is to develop models to predict the rate of penetration (ROP) of TBMs. In accordance with the purpose of the study, a new database including 5334 cases is obtained from the longest railway tunnel of Turkey. Each case includes uniaxial compressive strength, Cerchar Abrasivity Index, α angle, weathering degree and water conditions as input or independent variables. Two multiple regression models and two ANN models are developed in the study. The performances of the ANN models are considerably better than those of the multiple regression equations. Before deep tunnel construction in a metamorphic rock medium, the ANN models developed in the study are reliable and can be used. In contrast, the performances of the multiple regression equations are promising, but they predict lower ROP values than the measured ROP values. Consequently, the prediction models for ROP are open to development depending on the new data and new prediction algorithms.

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