Application of satellite Sentinel-1 radar images for description of ice phenomena on Dębe reservoir

Winter conditions of low air temperature cause development of ice phenomena at rivers and reservoirs, creating often problems in their exploitation. There is a need to continuously monitor the spatial extension of ice phenomena and their different forms. Local water authority (RZGW Warszawa) prepares for rivers under their administration a daily reports on ice conditions in winter. Ice reports are prepared from visual inspection of the RZGW personnel visiting selected sections of the river course. This is specially problematic in holidays and weekends when usually data from observations are missing. In this study it is tested application of microwave remote sensing data from Sentinel-1 platform to observe the development and recession of the ice cover at the Dębe reservoir in winter 2017. Satellite Sentinel-1 radar images are distributed by the European Space Agency (ESA) on the open access policy. These are two satellites A and B which every 2 days collect images in SAR active remote sensing technique. Dębe reservoir was created in 1963 by closing by the barrage Narew river below its confluence with Bug river. Maximum water head is 7.1 m, and average 6.8 m. Area of the reservoir is 30.3 km2 average discharge of Bug river at Wyszków gauge is 162 m3 • s–1, and Narew river at Zambski Kościelne gauge 139 m3 • s–1. Retention time of water in the reservoir is 3–4 days. Comparison of the average water temperature at gauge Zambski Kościelne and Wyszków from the winter half-year of the period 1963–1981 shows the increase of water temperature by 0.5–1 C after the year 1972 when Ostrołęka power station was put in to operation. This difference in the temperature between Narew and Bug rivers is reflected by the ice conditions at the end of winter season. Sentinel-1 SAR instrument emits electromagnetic wavelength of 6 cm (C band), and are use two polarizations VH and VV. Using SNAP program geometric correction and color composite was created for selected images at the beginning and end of ice cover at Dębe reservoir on Narew river, covering period January 5-March 6, 2017. It has been found that interpretation of the Sentinel-1 images is most problematic if we want to detect boundary between open calm water and new fast ice. The flow of pancake ice on January 5, 2017 had been recorded and the pattern of ice distribution compared to flow lines calculated by the hydrodynamic CCHE2D model. Result of the hydrodynamic modeling shows circulation pattern in the widest part of the reservoir where are also the most favorable conditions for lake type of ice cover formation. End of ice cover is represented by the image of February 26, 2017 which shows the Narew river free from ice due to higher temperature of the water. Relatively simple visual interpretation of the Sentinel-1 VH and VV images can by used in the study of ice phenomena on major rivers and lakes

Numerical Modeling of Transport of Thermal Pollution in a River – Case Study

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

GIS approach to estimation of the total phosphorous transfer in the Pilica River lowland catchment

In this paper, the Pilica River catchment (central Poland) is analyzed with a focus on understanding the total phosphorous transfer along the river system which also contains the large artificial Sulejów Reservoir. The paper presents a GIS method for estimating the total phosphorous (TP) load from proxy data representing sub-catchment land use and census data. The modelled load of TP is compared to the actual transfer of TP in the Pilica River system. The results shows that the metrics of connectivity between river system and dwelling areas as well as settlement density in the sub-catchments are useful predictors of the total phosphorous load. The presence of a large reservoir in the middle course of the river can disrupt nutrient transport along a river continuum by trapping and retaining suspended sediment and its associated TP load. Analysis of the indirect estimation of TP loads with the GIS analysis can be useful for identifying beneficial reservoir locations in a catchment. The study has shown that the Sulejów Reservoir has been located in a subcatchment with a largest load of the TP, and this feature helps determine the problem of reservoir eutrphication

How Big Can a Flood of the Vistula River be in Warsaw – Historical and Hydrological Perspective

Zarządzanie zagrożeniem powodziowym to nowa metodologia zmniejszania niebezpieczeństw dla przestrzeni miejskiej. Jednym z ważnych aspektów zagrożenia powodziowego jest ekspozycja na zalanie spowodowana niewłaściwą lokalizacją zabudowań. Planowanie przestrzenne i ocena zagrożenia powodziowego mogą być dokonane na podstawie właściwej informacji o ekstremalnych powodziach. W niniejszym artykule dokonano analizy studium przypadku powodzi Wisły w Warszawie w różnych okresach historycznych, biorąc pod uwagę trzy metodologie oceny wielkości powodzi ekstremalnych w miastach

Sentinel-1 Satellite Radar Images: A New Source of Information for Study of River Channel Dynamics on the Lower Vistula River, Poland

The amount of sediments transported by a river is difficult to estimate, while this parameter could influence channel geometry. It is possible to derive the bedload transport rate per unit width of the river channel by measuring the migration distance of bedform profiles over time and thickness of bedload layer in motion. Other possible methods include instrumental measurements using bedload traps and empirical formulas. It is possible to use remote-sensing techniques to measure the dynamics of bedform movements and geometries. Landsat images and aerial photographs have been used for this. A new source of remote-sensing information is radar satellite images. Sentinel-1 images have a temporal resolution of 2–3 days and spatial resolution of 25 m at middle latitudes, which make them usable on large rivers. The research area is the 814–820 km reach of the Lower Vistula River, where seven alternate sandbars were selected. The bank lines of the sandbars were delineated on Sentinel-1 images sensed during two low-flow periods of 4 August–26 September 2018 and 1 July–31 August 2019, when discharges at low flow were similar. From water stage observations at gauges, water elevations were assigned to every bank line of the alternate sandbars. The following morphometric parameters were calculated: alternate sandbar centers, volumes and longitudinal profile. Average daily movement of the sandbars in the period 4 August 2018–1 July 2019 was calculated as 0.97 m·day−1. A similar alternate sandbar movement velocity was obtained from a study of Sentinel-2 optical satellite images and hydro-acoustic measurements on the Lower Vistula River. Having depth of bedload in motion and alternate sandbar shift velocities, it was possible to calculate the rate of bedload transport according to the Exner approach formula. Rate of bedload transport was estimated as qb = 0.027 kg·s−1·m−1. This study shows a novel use of Sentinel-1 images to study the 3D geometry and movement rate of sandbars

Gis Approach to Estimation of the Total Phosphorous Transfer in the Pilica River Lowland Catchment

In this paper, the Pilica River catchment (central Poland) is analyzed with a focus on understanding the total phosphorous transfer along the river system which also contains the large artificial Sulejów Reservoir. The paper presents a GIS method for estimating the total phosphorous (TP) load from proxy data representing sub-catchment land use and census data. The modelled load of TP is compared to the actual transfer of TP in the Pilica River system. The results shows that the metrics of connectivity between river system and dwelling areas as well as settlement density in the sub-catchments are useful predictors of the total phosphorous load. The presence of a large reservoir in the middle course of the river can disrupt nutrient transport along a river continuum by trapping and retaining suspended sediment and its associated TP load. Analysis of the indirect estimation of TP loads with the GIS analysis can be useful for identifying beneficial reservoir locations in a catchment. The study has shown that the Sulejów Reservoir has been located in a subcatchment with a largest load of the TP, and this feature helps determine the problem of reservoir eutrphicatio

The sedimentation processes in Włocławek Reseryoir

The study discusses accumulation and erosion processes which occurred in the bowl of Włocławek Reservoir in the period 1971-1992, and were analysed using digital batimetric maps. It also provides the results of the work of other authors concerning the assessment of the river sediments accumulated in the reservoir. Analysis of digital batimetric maps has shown that the materiał deposited in Włocławek Reservoir in the years 1971-1992 totalled about 18.3 million m3, which corresponds to approximately 0.87 million m3 of sediments per annum, and means a 4.5% loss of the reservoir's storage capacity. The volume of accumulation and erosion, assessed in this manner, approximates the earlier calculations performed using different research methods; it corroborates the fact that accumulation prevails in the balance of the sediments

Impact of initial conditions on the prediction of the spread of thermal pollution in rivers

The influence of initial conditions on the prediction of the increase of river temperature below the point of release of heated water for a designed power plant has been analysed in this study. The results for different assumed values of river flow and different temperatures of the discharged heated water have been presented. The results have been analysed taking into account existing legal frames. The two-dimensional inhouse RivMix model has been used to simulate the temperature distribution whereas the two-dimensional depth-averaged turbulent open channel flow model CCHE2D has been used to simulate the velocity fields and the water depths for the selected flows of the river

GIS approach to estimation of the total phosphorous transfer in the Pilica River lowland catchment

In this paper, the Pilica River catchment (central Poland) is analyzed with a focus on understanding the total phosphorous transfer along the river system which also contains the large artificial Sulejów Reservoir. The paper presents a GIS method for estimating the total phosphorous (TP) load from proxy data representing sub-catchment land use and census data. The modelled load of TP is compared to the actual transfer of TP in the Pilica River system. The results shows that the metrics of connectivity between river system and dwelling areas as well as settlement density in the sub-catchments are useful predictors of the total phosphorous load. The presence of a large reservoir in the middle course of the river can disrupt nutrient transport along a river continuum by trapping and retaining suspended sediment and its associated TP load. Analysis of the indirect estimation of TP loads with the GIS analysis can be useful for identifying beneficial reservoir locations in a catchment. The study has shown that the Sulejów Reservoir has been located in a subcatchment with a largest load of the TP, and this feature helps determine the problem of reservoir eutrphication