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1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Seasonal dynamics of sediment in the Ciemiega River

100%
Debicki R., Glinski P., Kuczynski A.
Zeszyty Problemowe Postępów Nauk Rolniczych
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1996
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tom 436
Dynamics of sediment amount in the Ciemiega river water during three months of the 1996 vegetative period and its comparison with similar data from 1975 are discussed in this paper. A spectrophotometric method was used to determine water turbidity as a measure of sediment concentration in water.
2
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Estimating long term sediment yields from sediment core analysis

86%
Kennie P., Bogen J., Olsen H. C.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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2010
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tom 42
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nr 1
115-126
Sediment cores from lakes and reservoirs can be used to estimate sediment yields. In proglacial lakes, the bed sediment typically accumulates as varves, reflecting changes in seasonal and annual sedimentation. This report compares the results from two different methods of measuring suspended sediment transport in a Norwegian glacial river and lake. Sediment yields obtained from a study of sediment cores in the proglacial lake Nigardsvatn along with measurements of the delta topset were compared with a 25-year record of sediment transport based on automatic water sampling and water discharge measurements at a monitoring station at the inflowing river. During the period from 1980 to 2005, analyses of sediment cores taken from the lake bed along with measurements and grain size distribution analysis of the delta indicated that a volume of 175,670 to 202,697 m3 was deposited in the lake Nigardsvatn and corresponding river delta. The year 1980 was selected as a convenient starting point because a large-magnitude flood with a 100-year recurrence interval occurred at the end of 1979, leaving an easily recognizable sediment layer and accurate reference point. Sediment cores were taken at a total of 24 locations throughout the lake and 25 locations in the delta. The densities of the sediment cores were found to vary between 1.3 and 1.5 g/cm3 during the period examined in this study, giving a total suspended sediment load of between 175,670 and 202,697 tons. The measurements carried out at the sediment station in the glacier melt-water river gave a value of 294,800 tons during the same period. A final value of 211,100 tons is calculated from the monitoring station results after deduction of the sediment fraction which passes through the lake without being deposited. This gives a discrepancy between the two methods of 8,403 to 35,430 tons (4–20%). This can be partially attributed to the difficulties of measuring the water discharge in the unstable glacier meltwater river. In conclusion, sediment cores may be used to extrapolate or correct measurements from sediment monitoring stations over longer periods but caution should be made when considering single years.
3
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Spatial analysis of vegetal cover and sediment yield in Tapacura river catchment based on remote sensing and GIS

86%
Silva R. M., Santos C. A. G., Gico Lima Montenegro S. M., Silva L. P.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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2010
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tom 42
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nr 1
5-16
Mapping and assessment of erosion risk is an important tool for planning of natural resources management, allowing researchers to propose modifi cation in land-use properly and implement more sustainable management strategies in the long-term. The Tapacurá river catchment, located in Pernambuco State, Northeastern Brazil, is one of the planning units for management of water resources of Recife Metropilitan Region (RMR), and it is divided into 12 sub-basins. The objective of this study is to evaluate the spatial variability of vegetal cover and sediment yield in this basin through remote sensing and GIS techniques. Maps of the erosivity (R), erodibility (K), topographic (LS), cover-management (C) and support practice (P) factors were derived from the digital elevation model (DEM), climate database, and soil and NDVI maps, taking into account information available in the literature. In order to validate the simulation process, Sediment Delivery Ratio (SDR) was estimated. The obtained NDVI map showed vegetation loss during the analyzed period, indicating a distinct contrast between loss and gains of vegetation index. The vegetation and sediment yield mapping showed to be a useful tool for environmental monitoring and management, which can provide satisfactory results when jointly used. The results suggest a mean SDR around 0.9 and estimate the sediment yield as 23.98 ton/ha/month.
4
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Suspended sediment concentration and yield in snowmelt flood events in a small lowland river

86%
Hejduk A., Banasik K.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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2010
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tom 42
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nr 1
61-68
Results of investigation on suspended sediment delivery from small lowland, agriculturally used catchment of Zagożdżonka River, located in central Poland, during snowmelt periods of 2001– –2007 are presented. The study catchment‘s area, upstream of the well equipped gauging station at Czarna, is 23.4 km2. Suspended sediment concentration and sediment yield has been calculated and analysed for 15 snowmelt flood events. The relationship between suspended sediment concentration and the discharge has been analyzed. It has been found that the relation, in majority of the cases, has the form of clockwise hysteresis, however the existance of other types of hysteresis i.e. anticlockwise and “8” shape, have been also confi rmed. Signifi cant relation between suspended sediment yield and runoff volume of snowmelt flood events has been also found.
5
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Efficacy of time-area method in simulating temporal variation of sediment yield in Chehelgazi watershed, Iran

86%
Khaledi Darvishan A. V., Sadeghi S. H. R., Gholami L.
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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2010
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tom 42
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nr 1
51-60
The proper prediction of temporal and spatial variation of sediment yield from the watershed is a need for sediment control, river engineering and soil and water conservation studies. The present study was therefore planned to simulate the sediment graphs for Chehelgazi watershed in Gheshlagh dam upstream in Kurdistan Province, Iran, by using Time-Area Method. Towards this attempt, the study watershed was divided into 7 time-area segments based on the time of concentration. The soil erosion in each segment was estimated using the USLE and then routed to the main outlet using sediment delivery ratio as a function of land slope in two adjacent time-areas. The temporal variation of sediment was ultimately predicted with the help of lag time of sediment arrival to the outlet and the concept of superposition for 11 storm events, which occurred during winter 2006 and spring 2007. The comparison between estimated sediment graphs with corresponding observed ones verifi ed the weak capability of the model in simulation of sediment graphs under consideration. The results also verifi ed the calibration necessity of the model to achieve appropriate estimation for important components of the sediment graphs. The results of the calibration fi nally proved the considerable capability of the model in predicting of total volume of sediment yield with respective estimation and verifi cation errors of 30.93 and 33.40%.
6

SWAT based runoff and sediment yield modelling: a case study of the Gumera watershed in the Blue Nile basin

72%
Asres M. T., Awulachew S. B.
International Journal of Ecohydrology and Hydrobiology
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2010
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tom 10
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nr 2-4
Land degradation caused by soil erosion (sheet and rill erosion) and soil fertility decline is a serious threat in the Ethiopian highlands, especially in the Gumara watershed. In this study the SWAT (Soil and Water Assessment Tool) model was applied to the Gumara watershed to predict sediment yield and runoff, to establish the spatial distribution of sediment yield and to test the potential of watershed management measures to reduce sediment loadings from hotspot areas. The model was calibrated using five years of flow and sediment records and validated using data for the next three years. Out of 30 SWAT sub-basins, 18 sub-watersheds (72%) were identified as erosion prone areas contributing to a mean annual sediment load ranging from 11 to 22 t ha-1 yr-1. The model was used to evaluate the potential of vegetation filter strips of various widths to reduce sediment production from critical micro watersheds. The installation of vegetation filter strips on vulnerable land was shown to result in a 58 to 74% reduction in sediment yield for strip widths of 5 m and 10 m respectively.
7
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The zoning of the erosion intensity and sediment yield using the geographic information systems and remote sensing, with the application of the MPSIAC model (Case study: Syazakh dam basin, Kurdistan)

72%
Emamgholi M., Shahedi K., Khaledian V., Babaee K.
International Letters of Natural Sciences
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2014
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tom 04
The aim of the present research was to estimate erosion and sediment and to formulate a map of the basin's erosion intensity using the satellite data, GIS technique and to compare the hydrometric stations' statistics. Using the Land sat satellite images among the results obtained from these data through (TM, ETM+), coverage index (NDVI) as well as a combination of bands 2, 3 and 4 for determining the type of land use and for assessing the soil texture in terms of regional aerial images tone and in accordance with the physiographic of the basin through sampling the soil texture , the map of the basin's texture was obtained. Assessing the surface and river erosion was also conducted using the aerial images and field visits. Given the data obtained and the model being applied, the special sediment rate in the basin was 5/19 tons per hectare, while the overall sediment rate obtained for the entire basin was estimated 5496533 tons in a year. Meantime, the observed and estimated value in the hydrometric station of Nesare Olya for as much as 553230 tons in a year shows a less than 1 % difference in the entire estimation of the sediments accumulated in the back of the dam while its sediment load rate estimation as much as 5/16 tons per hectare shows a 0/03 difference rate for the station.
8
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Runoff, sediment yield and erodibility characteristics of some soils of central Eastern Nigeria under simulated rainfall

72%
Igwe C. A.
International Agrophysics
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2000
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tom 14
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nr 1
9

The influence of the small reservoirs on the amount of suspended sediment in a stream and the sediment yield value

72%
Szewranski S.
Electronic Journal of Polish Agricultural Universities. Series Environmental Development
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2002
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tom 05
|
nr 2
The presented paper is an edited version of Ph.D thesis of the same title and by the same author. The investigations were carried out in a small agricultural catchment area in the hydrological years 1998/1999-1999/2000. Four cross sections, above and below two small ponds of the total area of 0.8 ha, were subjected to daily bathometrical and hydrological measurements. For each hydrological year, the total suspended loads both supplied and carried out from the ponds were determined. The accumulation rate was analysed against the changeable water discharge and supplied sediment load. The changes in sediment yield values were analysed against the archive data from the years 1977/78-1993/94 in which no ponds were present in the area covered by the studies.
10

Dr-usle: A computer model for predicting sediment yield from small watersheds using the universal soil loss equation

72%
Gorski D., Banasik K.
Zeszyty Naukowe Akademii Rolniczej we Wrocławiu. Inżynieria Środowiska
|
1992
|
tom 01
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