scholarly journals Erosion index formulation with respect to reservoir life in the upper Citarum watershed

2018 ◽  
Vol 147 ◽  
pp. 03002
Author(s):  
Bakhtiar
Keyword(s):  
Sediment Yield ◽  
Assessment Tool ◽  
Average Value ◽  
Erosion Index ◽  
Dead Storage ◽  
The Mean ◽  
The Relationship ◽  
Water Assessment ◽  
Annual Sediment

This study aimed to formulate erosion index in the upper Citarum watershed with respect to the Saguling reservoir life. Soil and Water Assessment Tool model was incorporated to simulate hydrological processes in the catchment. From the calibration and validation results, the model is considerably of good performance. The simulated sediment inflow at Nanjung outlet was then extrapolated to determine the sediment inflow into the reservoir. The study revealed that the average value of sediment inflow into the reservoir is 29.24 tonnes/ha/year just below the tolerable erosion limit of 30 tonnes/ha/year assumed by Hammer (1981). It was also found that the relationship between sediment yield and sediment inflow is non linear. Erosion index is formulated as the ratio between the mean annual sediment yield generated in the watershed and the mean annual sediment yield that leads dead storage to be full in the designated life of the reservoir. Erosion index equals to 1.0 indicates that the dead storage will be full in the designated life of the reservoir. A classification of erosion index can be subsequently be made based on erosion index and reservoir life relationship.

scholarly journals Estimating sediment yield at Kaduna watershed, Nigeria using soil and water assessment tool (SWAT) model

Heliyon ◽  
2019 ◽  
Vol 5 (7) ◽  
pp. e02106 ◽  
Author(s):  
J. Daramola ◽  
T.M. Ekhwan ◽  
J. Mokhtar ◽  
K.C. Lam ◽  
G.A. Adeogun
Keyword(s):  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Water Assessment ◽  
Soil And Water

Occupational load as a risk factor for clinically relevant base of thumb osteoarthritis

2020 ◽  
Vol 77 (3) ◽  
pp. 168-171 ◽  
Author(s):  
Jennifer Moriatis Wolf ◽  
Aleksandra Turkiewicz ◽  
Isam Atroshi ◽  
Martin Englund
Keyword(s):  
Sex Education ◽  
Conditional Logistic Regression ◽  
Occupational Tasks ◽  
Standard Classification ◽  
Matched Case ◽  
The Mean ◽  
Thumb Carpometacarpal ◽  
The Relationship ◽  
Control Study

ObjectiveIt is postulated that increased load from pinch and grasp in occupational tasks increases the risk of thumb carpometacarpal (CMC1) osteoarthritis (OA). We sought to characterise the relationship between doctor-diagnosed CMC1 OA and occupation in a large working population.MethodsWe performed a matched case–control study using a Swedish healthcare register. We identified residents aged 30–65 years in 2013 with physician-diagnosed CMC1 OA from 1998 to 2013. We matched four controls per person with CMC1 OA by age, sex, education and postcode. Swedish Standard Classification of Occupations was used to assign occupation. Occupation was categorised as light, light–moderate, moderate and heavy labour. We used conditional logistic regression to estimate ORs with 95% CIs.ResultsWe identified 3462 patients with CMC1 OA and matched 13 211 controls. The mean age of the CMC1 OA group was 63 (SD 7) years, with 81% women. The ORs for CMC1 OA in men were 1.31 (95% CI 0.96 to 1.79) for light–moderate, 1.76 (95% CI 1.29 to 2.40) for moderate and 2.00 (95% CI 1.59 to 2.51) for heavy compared with light work. Women had ORs for CMC1 OA of 1.46 (95% CI 1.32 to 1.61) for light–moderate, 1.27 (95% CI 1.10 to 1.46) for moderate and 1.31 (95% CI 1.07 to 1.59) for heavy compared with light work.ConclusionsThe association between increased manual load in occupation and risk of CMC1 OA is more pronounced in men than in women, likely due to higher workload in the heavy labour category.

scholarly journals Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters

2017 ◽  
Author(s):  
Changchun Huang ◽  
Lin Yao ◽  
Hao Yang ◽  
Chen Lin ◽  
Tao Huang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Inland Waters ◽  
Mean Values ◽  
Inland Water ◽  
Carbon And Nitrogen ◽  
Average Value ◽  
The Mean ◽  
The Relationship ◽  
Global Carbon

Abstract. We examined the relationship between, and variations in, particulate organic carbon (POC) and particulate organic nitrogen (PON) based on previously acquired ocean and inland water data. Some new points were found beside the traditional latitude, depth and temperature dependence of POC, PON and POC/PON. The global average value of POC/PON (7.54±3.82) is higher than the Redfield ratio (6.63). The mean values of POC/PON in south and north hemisphere are 7.40±3.83 and 7.80±3.92, respectively. The high values of POC/PON appeared between 80° N~90° N (12.2±7.5) and 70° N~80° N (9.4±6.4), and relatively low POC/PON were found from 20 °N (6.6±2.8) to 40 °N (6.7±2.7). The latitudinal dependency of POC/PON in the northern hemisphere is much stronger than in the southern hemisphere. Variations of POC/PON in inland water also showed similar latitude-dependency of POC/PON in ocean water, but significantly regulated by lake’s morphology, trophic state and climate, etc. factors. Higher POC and PON could be expected in the coastal water, while POC/PON significantly increased from 6.89±2.38 to 7.59±4.22 in north hemisphere with the increasing rate of 0.0024/km. The coupling relationship between POC and PON in oceans is much stronger than in inland waters. Variations in POC, PON and POC/PON in inland waters should receive more attention due to the importance of these values to global carbon and nitrogen cycles and the indeterminacy of the relationship between POC and PON.

scholarly journals Assessment and Mitigation of Streamflow and Sediment Yield under Climate Change Conditions in Diyala River Basin, Iraq

Hydrology ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 63 ◽  
Author(s):  
Mahmoud S. Al-Khafaji ◽  
Rana D. Al-Chalabi
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
Climate Models ◽  
Assessment Tool ◽  
Coefficient Of Determination ◽  
Base Period ◽  
Important Challenge ◽  
Diyala River ◽  
The Impact ◽  
Water Assessment

The impact of climate change on the streamflow and sediment yield in the Derbendkhan and Hemrin Watersheds is an important challenge facing the water resources of the Diyala River in Iraq. The Soil and Water Assessment Tool (SWAT) was used to project this impact on streamflow and sediment yield until year 2050 by applying five climate models for scenario A1B involving medium emissions. The models were calibrated and validated based on daily observed streamflow and sediment recorded for the periods from 1984 to 2013 and 1984 to 1985, respectively. The Nash–Sutcliffe efficiency and coefficient of determination values for the calibration (validation) were 0.61 (0.53) and 0.6 (0.62) for Derbendkhan and Hemrin, respectively. In addition, the average of the future predictions for the five climate models indicated that the streamflow (sediment yield) for the Derbendkhan and Hemrin Watersheds would decrease to 49% (43.7%) and 20% (30%), respectively, until 2050, compared with the observed flow of the base period from 1984 to 2013. The spatial analysis showed that 10.4% and 68% of the streamflow comes from Iraqi parts of the Derbendkhan and Hemrin Watersheds, respectively, while 10% and 60% of the sediment comes from the Iraqi parts of the Derbendkhan and Hemrin Watersheds, respectively. Deforestation of the northern part of the Hemrin Watershed is the best method to decrease the amount of sediment entering the Hemrin Reservoir.

scholarly journals Future impacts of climate change on sediment influx rate in hydropower reservoir using SWAT

2021 ◽  
Vol 880 (1) ◽  
pp. 012024
Author(s):  
A Z Abdul Razad ◽  
S H Shamsuddini ◽  
A Setu ◽  
L Mohd Sidek
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
Sediment Load ◽  
Assessment Tool ◽  
Annual Rainfall ◽  
Historical Period ◽  
Catchment Management ◽  
Influx Rate ◽  
Control Plan ◽  
Annual Sediment

Abstract Climate change causes more frequent and intense rainfall events, leading to severe erosion in the catchment and sediment transferred into rivers and reservoirs. This study focus on long term sediment load in major rivers in Cameron Highlands and prediction of annual sediment inflow into Ringlet Reservoir from 2000 to 2030. Soil Water Assessment Tool (SWAT) is used as the simulation tool, utilising future gridded rainfall 2017 to 2030 under CCSM and future land use 2030. Future annual rainfall is minimum at 1551 mm (in 2030) and maximum at 3150 mm (in 2029). The future projected annual sediment load into Ringlet Reservoir from 2017 to 2030 is averaged at 354,013 m3/year, ranging from 216,981 to 461,886 m3/year. Comparing between the historical period of 2000 to 2016 and future projection (2017–2030), annual sediment load shows an increase of 12 %. To combat the increase sediment yield, catchment management such as erosion control plan, drainage and runoff control must be developed to minimise sediment yield and subsequent effect of high sediment load transport via rivers and drainage network.

scholarly journals Modelling streamflow and sediment yield using Soil and Water Assessment Tool: A case study of Lidder watershed in Kashmir Himalayas, India

2021 ◽  
Author(s):  
Sarvat Gull ◽  
Shagoofta Rasool Shah
Keyword(s):  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Model Performance ◽  
Study Data ◽  
Influence Strategies ◽  
Similar Characterization ◽  
Fitting Algorithm ◽  
Water Assessment ◽  
Soil And Water

Abstract The conjunction of heavy snowfall during winters and intensive rainfall during monsoons along with the mountainous topography expose the Lidder watershed to serious erosion and flood aggravation issues. Barely any attempts have been made for an in-depth examination of Lidder watershed for precise estimation of sub-basin level runoff and erosion. In this study Soil and Water Assessment Tool (SWAT) was calibrated using Sequential Uncertainty Fitting algorithm (SUFI-2) for modelling streamflow and sediment yield of the Lidder watershed. Daily runoff and sediment event data from 2003–2013 were used in this study; data from 2003–2008 was used for calibration and 2009–2013 for validation. Model performance was evaluated using various statistical tools which showed good results revealing excellent potential of SWAT model to simulate streamflow and sediment yield for both calibration and validation periods. The annual rate of average upland sediment drawn from the watershed was approximately 853.96 Mg/ha for an average surface runoff of 394.15 mm/year. This study identifies the vulnerable areas of the Lidder watershed which can be thoroughly examined by decision-makers for effective management and planning. Further, the calibrated model can be applied to other watersheds with similar characterization to influence strategies in the management of watershed processes.

scholarly journals A BATHYMETRY-BASED RESERVOIR SEDIMENTATION EVALUATION

2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Ayodele Olanrewaju Ogunlela ◽  
Odunayo Babatunde Omole ◽  
Kamorudeen Olaniyi Yusuf
Keyword(s):  
Sediment Yield ◽  
Assessment Tool ◽  
Clay Soil ◽  
Swat Model ◽  
Reservoir Sedimentation ◽  
Mean Values ◽  
Soil Sediment ◽  
The Mean ◽  
Rate Of Sedimentation ◽  
The University

Reservoir sedimentation is a serious problem that normally reduces the capacity of a dam (reservoir) for water storage over a given period of time. This can lead to insufficient availability of water for domestic uses, irrigation and hydropower. This study was conducted to determine the rate of sedimentation, sediment yield and the capacity of the University of Ilorin dam (Ilorin, Nigeria) between June 2007 and June 2014. Geographic Information System (GIS), Global Positioning System (GPS), canoe and lead-line techniques were used for the measurement of depth of the reservoir of the dam. Soil and Water Assessment Tool (SWAT) model was used to simulate the sediment yield. The initial capacity of the dam after construction in 2007 was 1.800 x 106 m3 but this capacity was reduced to 1.411 x 106 m3 in 2014 due to sedimentation. The sediment was found to be clay soil which covered 389,170 m3 of the reservoir and the mean bulk density of the clay soil sediment was 1139 kg/m3. The mean values of clay, silt and sand contents of the sediment yield were 46.5, 35.6 and 17.9 %, respectively. The annual sediment yield was high in the reservoir due to farming activities at the upstream end of the dam, annual rate of sedimentation was 12.78 m3/ha/yr and sediment yield was 14,557.14 kg/ha/yr. Farming activities should be prevented at the upstream of the dam and dredging should be done every 10 years when 30.87% of the storage capacity would be occupied by sediment.

scholarly journals Land Use/Cover Change and their Impacts on Streamflow in Kikuletwa Catchment of Pangani River Basin, Tanzania

2019 ◽  
Vol 38 (2) ◽  
pp. 171-192
Author(s):  
Upendo E. Msovu ◽  
Deogratias M.M. Mulungu ◽  
Joel K. Nobert ◽  
Henry Mahoo
Keyword(s):  
Land Use ◽  
Assessment Tool ◽  
Landsat Imagery ◽  
Swat Model ◽  
Base Flow ◽  
Percentage Increase ◽  
Policy Makers ◽  
Future Prediction ◽  
Water Assessment

Streamflow perturbation is highly prevalent in Kikuletwa catchment. However, little is known concerning land use/cover change (LULCC) with regard to streamflow perturbation in the catchment. This study aims to detect the historical and predict future LULCC and assess their impacts on streamflow amounts using the Soil and Water Assessment Tool (SWAT) model. Supervised classification of Landsat imagery data for 1985, 2000 and 2015 years was done in ERDAS 14 Imagine software. Future prediction of LULCC was done using Module for Land Use Change Evaluation (MOLUSCE) tool, a QGIS plug-in. An accuracy ranging from 79% to 82% was obtained for all steps. The results revealed that, from 1985 to 2000; 1985 to 2015; 1985 to 2030 and 1985 to 2050 the percentage of area change in cultivated land is +21.1%; +29.2%; +38.2% and +42.7%, respectively; forest is - 2.3%, -3.1%, -3.8% and -5.8%, respectively; and shrubland is -6.3%, -10%, -15.7% and - 16%, respectively. The performance of SWAT model during calibration were 0.74, 0.75, 0.51 and -0.5% for NSE, R2, RSR and PBIAS, respectively. The impacts of LULCC indicated that, between 1985 to 2000; 1985 to 2015; 1985 to 2030 and 1985 to 2050, the percentage increase in average simulated annual flow is 4.7%, 6.8%, 12.6% and 19.3%, respectively. Surface runoff increased from 25.2 mm (baseline) to 34.5 mm (36.9%); 36.2 mm (42.4%); 41.4 mm (64.3%) and 47.6 mm (88.9%), respectively. Base flow decreased marginally from 82.2 mm (baseline) to 79 mm (-3.8%); 77.8 mm (5.4%); 75.4 mm (-8.3%) and 73.9 mm (- 10.1%), respectively. Thus, apart from climate effects, streamflow perturbation in the catchment is also related to disturbances of catchment influences such as LULCC as revealed in this study. The study is useful for land planners and water resources managers and policy makers in managing resources sustainably. 

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