scholarly journals Comparison of parameters influencing the behavior of concentration of nitrates and phosphates during different extreme rainfall-runoff events in small watersheds

2013 ◽  
Vol 10 (10) ◽  
pp. 12105-12151 ◽  
Author(s):  
J. Moravcová ◽  
T. Pavlíček ◽  
P. Ondr ◽  
M. Koupilová ◽  
T. Kvítek
Keyword(s):  
Water Quality ◽  
Extreme Rainfall ◽  
Strong Relationship ◽  
Storm Events ◽  
Rainfall Runoff ◽  
Small Watersheds ◽  
Summer Storm ◽  
The Impact ◽  
The Relationship ◽  
Runoff Events

Abstract. The behavior of solute concentrations during storm events is completely different from their behaviour under normal conditions, and very often results in hysteresis. This study aim is to explore the relationship between the biogeochemical and hydrological parameters describing natural conditions and the reciprocal interactions between changes in concentration of selected indicators of water quality in water and the discharge dynamics during different types of extreme rainfall-runoff events in the Jenínský stream and the Kopaninský stream catchment (Czech Republic). The relationship between concentrations and runoffs is explained by concentration-discharge hysteretic loops. As the statistical method used for cross analyzing the impact of the parameters there was chosen the RDA analysis. The relationships between the particular parameters were examined separately by conditions of spring snow melt and summer storm events. The results than confirmed the very strong relationship between parameters describing water quality and percentage of stable parts of the catchment and also of infiltration vulnerable sites.

scholarly journals Effect of Maritime Traffic on Water Quality Parameters in Santa Marta, Colombia

2021 ◽  
Vol 9 (5) ◽  
pp. 474
Author(s):  
René Rodríguez-Grimón ◽  
Nestor Hernando Campos ◽  
Ítalo Braga Castro
Keyword(s):  
Water Quality ◽  
Petroleum Hydrocarbons ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Maritime Traffic ◽  
Natural Park ◽  
High Concentrations ◽  
The Impact ◽  
The Relationship ◽  
Multiple Chemical

Since 2013, there has been an increase (>23%) in naval traffic using maritime routes and ports on the coastal fringe of Santa Marta, Colombia. Of major concern, and described by several studies, is the relationship between maritime traffic and coastal contamination. This study proposed a maritime traffic indicator considering the simultaneous effects of several relevant measurements of water quality parameters to estimate the impact of naval activity. The approach involved developing a model including the number of vessels, hull length, and permanence time in berths. In addition, water quality variables, considering climatic seasons, were used to verify association with maritime traffic and touristic activities. The high concentrations of total coliforms (TC) and dissolved/dispersed petroleum hydrocarbons in chrysene equivalents (DDPH) reported by the International Marina of Santa Marta (SM) were affected by the local anthropic activities, including tourism, naval traffic, and urban wastewater discharges. Moreover, our results suggest the occurrence of multiple chemical impacts within Tayrona National Natural Park (PNNT) affecting conservation goals. The estimation of the maritime traffic indicator proposed in this study may be an easy and more complete tool for future studies evaluating the impact of naval activities on environmental quality.

scholarly journals Assessment of Rainfall-Induced Landslide Distribution Based on Land Disturbance in Southern Taiwan

2021 ◽  
Vol 10 (4) ◽  
pp. 209
Author(s):  
Chih-Ming Tseng ◽  
Yie-Ruey Chen ◽  
Chwen-Ming Chang ◽  
Yung-Sheng Chue ◽  
Shun-Chieh Hsieh
Keyword(s):  
Satellite Image ◽  
Extreme Rainfall ◽  
Land Area ◽  
Rainfall Events ◽  
Land Disturbance ◽  
Bare Land ◽  
Southern Taiwan ◽  
The Impact ◽  
Landslide Distribution ◽  
The Relationship

This study explores the impact of rainfall on the followed-up landslides after a severe typhoon and the relationship between various rainfall events and the occurrence, scale, and regional characteristics of the landslides, including second landslides. Moreover, the influence of land disturbance was evaluated. The genetic adaptive neural network was used in combination with the texture analysis of the geographic information system for satellite image classification and interpretation to analyze land-use change and retrieve disaster records and surface information after five rainfall events from Typhoon Morakot (2009) to Typhoon Nanmadol (2011). The results revealed that except for extreme Morakot rains, the greater the degree of slope disturbance after rain, the larger the exposed slope. Extreme rainfall similar to Morakot strikes may have a greater impact on the bare land area than on slope disturbance. Moreover, the relationship between the bare land area and the index of land disturbance condition (ILDC) is positive, and the ratio of the bare land area to the quantity of bare land after each rainfall increases with the ILDC. With higher effective accumulative rainfall on the slope in the study area or greater slope disturbance, the landslide area at the second landslide point tended to increase.

scholarly journals Initial abstraction ratio and Curve Number estimation using rainfall and runoff data from a tropical watershed

RBRH ◽  
2019 ◽  
Vol 24 ◽  
Author(s):  
Luiz Claudio Galvão do Valle Junior ◽  
Dulce Buchala Bicca Rodrigues ◽  
Paulo Tarso Sanches de Oliveira
Keyword(s):  
Conversion Factor ◽  
Poor Performance ◽  
Curve Number ◽  
Storm Events ◽  
Rainfall Runoff ◽  
Initial Abstraction ◽  
Rainfall Depth ◽  
Standard Value ◽  
Tropical Watershed ◽  
Runoff Events

ABSTRACT The Curve Number (CN) method is extensively used for predict surface runoff from storm events. However, remain some uncertainties in the method, such as in the use of an initial abstraction (λ) standard value of 0.2 and on the choice of the most suitable CN values. Here, we compute λ and CN values using rainfall and runoff data to a rural basin located in Midwestern Brazil. We used 30 observed rainfall-runoff events with rainfall depth greater than 25 mm to derive associated CN values using five statistical methods. We noted λ values ranging from 0.005 to 0.455, with a median of 0.045, suggesting the use of λ = 0.05 instead of 0.2. We found a S0.2 to S0.05 conversion factor of 2.865. We also found negative values of Nash-Sutcliffe Efficiency (to the estimated and observed runoff). Therefore, our findings indicated that the CN method was not suitable to estimate runoff in the studied basin. This poor performance suggests that the runoff mechanisms in the studied area are dominated by subsurface stormflow.

scholarly journals Comments on "Researcher bias: The use of machine learning in software defect prediction"

2015 ◽  
Author(s):  
Chakkrit Tantithamthavorn ◽  
Shane McIntosh ◽  
Ahmed E Hassan ◽  
Kenichi Matsumoto
Keyword(s):  
Prediction Model ◽  
Strong Association ◽  
Model Performance ◽  
Strong Relationship ◽  
Defect Prediction ◽  
Explanatory Variables ◽  
Software Defect ◽  
The Impact ◽  
The Relationship ◽  
Selection Of

Shepperd et al. (2014) find that the reported performance of a defect prediction model shares a strong relationship with the group of researchers who construct the models. In this paper, we perform an alternative investigation of Shepperd et al. (2014)’s data. We observe that (a) researcher group shares a strong association with the dataset and metric families that are used to build a model; (b) the strong association among the explanatory variables introduces a large amount of interference when interpreting the impact of the researcher group on model performance; and (c) after mitigating the interference, we find that the researcher group has a smaller impact than the metric family. These observations lead us to conclude that the relationship between the researcher group and the performance of a defect prediction model may have more to do with the tendency of researchers to reuse experimental components (e.g., datasets and metrics). We recommend that researchers experiment with a broader selection of datasets and metrics to combat potential bias in their results.

scholarly journals A multibiomarker approach in rats to assess the impact of pollution on Sinos River, Southern Brazil

2010 ◽  
Vol 70 (4 suppl) ◽  
pp. 1223-1230 ◽  
Author(s):  
C. Rechenmacher ◽  
AM. Siebel ◽  
A. Goldoni ◽  
CR. Klauck ◽  
T. Sartori ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Water Quality ◽  
Dna Damage ◽  
Quality Analysis ◽  
Microbiological Analysis ◽  
Southern Brazil ◽  
Anthropogenic Contamination ◽  
Water Analyses ◽  
The Impact ◽  
The Relationship

The aim of this study was to determine the feasibility of combining water quality analysis with different biomarkers to characterise the relationship between anthropogenic contamination and biotic response in the Sinos River, southern Brazil. Wistar rats were studied using three biomarkers combined with physical, chemical and microbiological analysis to assess the effects of pollution at four sampling sites. The induction of oxidative stress was quantified by MDA levels in peripheral blood, lymphocyte DNA damage was determined using the comet assay, and histopathological changes were analysed in the liver. After sampling, animals were allowed to drink the river water during a 48 hours period. No increase in oxidative stress and DNA damage was observed. However, liver damage was observed in the animals exposed to water samples, indicating that the Sinos River is contaminated with hepatotoxic substances. Water analyses confirmed that water quality decreased downriver.

Effects of vegetation cover on runoff and erosion under simulated rain and overland flow on a rehabilitated site on the Meandu Mine, Tarong, Queensland

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 299 ◽  
Author(s):  
R. J. Loch
Keyword(s):  
Overland Flow ◽  
Extreme Rainfall ◽  
Rainfall Runoff ◽  
Vegetative Cover ◽  
Erosion Rates ◽  
Overland Flows ◽  
Simulated Rain ◽  
Runoff Events ◽  
Flow Study

This research was carried out to quantify the role of vegetative cover in reducing runoff and erosion from rehabilitated mined land. Duplicate plots 1.5 m wide and 12 m long were prepared on a rehabilitated area of the Meandu Mine, Tarong, with vegetative cover of 0, 23%, 37%, 47%, and 100%. The area had a uniform 15% slope, and there were no rill or gully lines present. Simulated rain equivalent to a 1 : 100 year storm was applied to the plots, and runoff and erosion were measured. Infiltration totals and rates increased strongly with increasing vegetative cover. There was visibly greater infiltration under vegetation. Erosion from the simulated storm was greatly reduced by vegetative cover, declining from 30–35 t/ha at 0% vegetative cover to 0.5 t/ha at 47% cover. Reductions in erosion at lower levels of vegetative cover were greater than predicted by the cover/erosion relationship used in the USLE. The dominantly stoloniferous growth habit of the grass at this site may have increased the effectiveness of vegetative cover in this study. To allow the data to be extrapolated to slopes longer than 12 m, a series of overland flows were applied to the upslope boundaries of the plots, simulating flows on slopes up to 70 m long. Detachment and transport of sediment by applied overland flow was similarly reduced by vegetative cover, and results from the overland flow study also indicate that for slopes up to 70 m long with grass cover of 47% or greater, erosion rates will be minimal, even under extreme rainfall/runoff events.

Risk assessment of post-wildfire hydrological response in semiarid basins: the effects of varying rainfall representations in the KINEROS2/AGWA model

2016 ◽  
Vol 25 (3) ◽  
pp. 268 ◽  
Author(s):  
Gabriel Sidman ◽  
D. Phillip Guertin ◽  
David C. Goodrich ◽  
Carl L. Unkrich ◽  
I. Shea Burns
Keyword(s):  
Risk Assessment ◽  
High Risk ◽  
Peak Flow ◽  
Radar Data ◽  
Burned Area ◽  
Rainfall Runoff ◽  
National Monument ◽  
Bandelier National Monument ◽  
The Impact ◽  
Runoff Events

Representation of precipitation is one of the most difficult aspects of modelling post-fire runoff and erosion and also one of the most sensitive input parameters to rainfall-runoff models. The impact of post-fire convective rainstorms, especially in semiarid watersheds, depends on the overlap between locations of high-intensity rainfall and areas of high-severity burns. One of the most useful applications of models in post-fire situations is risk assessment to quantify peak flow and identify areas at high risk of flooding and erosion. This study used the KINEROS2/AGWA model to compare several spatial and temporal rainfall representations of post-fire rainfall-runoff events to determine the effect of differing representations on modelled peak flow and determine at-risk locations within a watershed. Post-fire rainfall-runoff events at Zion National Park in Utah and Bandelier National Monument in New Mexico were modelled. Representations considered included both uniform and Soil Conservation Service Type II hyetographs, applying rain over the entire watershed and applying rain only on the burned area, and varying rainfall both temporally and spatially according to radar data. Results showed that rainfall representation greatly affected modelled peak flow, but did not significantly alter the model’s predictions for high-risk locations. This has important implications for post-fire assessments before a flood-inducing rainfall event, or for post-storm assessments in areas with low-gauge density or lack of radar data due to mountain beam blockage.

scholarly journals Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

2016 ◽  
Vol 13 (6) ◽  
pp. 1863-1875 ◽  
Author(s):  
Zahra Thomas ◽  
Benjamin W. Abbott ◽  
Olivier Troccaz ◽  
Jacques Baudry ◽  
Gilles Pinay
Keyword(s):  
Water Quality ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Human Disturbance ◽  
Nutrient Dynamics ◽  
Agricultural Activity ◽  
Agricultural Catchments ◽  
The Impact ◽  
The Relationship

Abstract. Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43−) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent catchment buffering capacity and the probability of human disturbance provides a useful perspective for evaluating vulnerability of aquatic ecosystems and for managing systems to maintain agricultural production while minimizing leakage of nutrients.

scholarly journals INFLUENCE OF SERVICE QUALITY ON SWITCHING BEHAVIOR MEDIATED BY RELATIONSHIP QUALITY IN SPRING BED RETAILERS IN JABODETABEK

2016 ◽  
Vol 10 (1) ◽  
pp. 59
Author(s):  
Djong Hermanto
Keyword(s):  
Service Quality ◽  
Relationship Quality ◽  
Structural Equation ◽  
Structural Model ◽  
Strong Relationship ◽  
Switching Behavior ◽  
Business Context ◽  
Strongly Agree ◽  
The Impact ◽  
The Relationship

Retailers in the spring bed business have a privilege to choose among the various products offered by various suppliers. Typically, these retailers would have chosen the suppliers whose products are matched with their needs and at the same time could give higher profits. This condition has strengthened the competition in the spring bed industry. In order to face the challenges that come from the retailers’ switching behavior, every supplier has to give a good service quality and build a strong relationship quality with their retailers. In this study, relationship quality was measured by three components: satisfaction, trust and commitment from the retailers to the suppliers.The objective of the study is to analyze the impact of service quality on switching behavior which was mediated by the relationship quality. The components of relationship quality are: satisfaction, trust and commitment. A theoretical framework was developed as the hypotheses for testing the impact of every variables were constructed. The samples of this study were 341 spring bed retailers in Jabodetabek (Jakarta, Bogor, Depok, Tangerang and Bekasi) area. A sixpoint Likert-type scale was used for the questionnaire variables, with 1 = strongly disagree and 6 = strongly agree. The quantitative analysis with Structural Equation Modelling (SEM) was completed using Lisrel 8.8. The structural model of this study could explain the interrelationship among each variables in the model. As a result, from ten hypotheses there were five findings supporting the hypotheses: service quality had an impact on satisfaction, service quality had an impact on trust, satisfaction had an impact on trust, trust had an impact on commitment, and commitment had an impact on commitment. The findings which did not support the hypotheses<br />were: There was no impact of service quality on commitment and switching behavior; there is no impact of satisfaction on commitment and switching behavior; and finally there is no impact of trust on switching behavior. As a conclusion, the result of the study described the importance of service quality in manufactured industry, in the business to business context between spring bed suppliers and retailers. The impact of service quality on the switching behavior was mediated by relationship quality, where commitment was the important component of relationship quality that greatly affecting the strength of service quality impact on switching behavior. For future studies, researchers may explored other model to investigate more variables with more proper indicators, more homogeneous samples and longer period of research

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