SWAT-based runoff modeling in complex catchment areas: Theoretical background and numerical procedures

This paper shows the structure of the SWAT-based model used in modeling of the 'rainfallrunoff' process. The SWAT model is hydro-dynamic and physically-based model for application in complex and large basins. Model inputs are as follows: rainfall, air temperature, soil characteristics, topography, vegetation, hydrogeology and other relevant physical parameters. The model is based on five linear reservoirs as follows: reservoir of the vegetation cover, snow accumulation and melting, surface reservoir, underground reservoir and surface runoff reservoir. The model uses GIS tools for preprocessing and post-processing. The basic modeling unit is the hydrologic response unit (HRU), defined as the network of elementary hydrologic areas with the selected discretization, measure of which is dependent upon the desired accuracy, as well as upon data accuracy. The total runoff on the exit profile of the catchment is computed by convolution of the sum of runoffs (surface and base runoffs). The model can be applied at the daily and hourly level of discretization and used for multiannual simulations. Illustration of operation of the SWAT based model will be presented on a selected part of the River Drina basin (with the total area of around 20.000 km2).

Fluid dynamic forces in the main steam pipeline of thermal power plant upon stop valves closure

A steam turbine trip is followed by a prompt closure of stop valves in front of the turbine and consequently to a pressure rise in the main steam pipeline. This steam hammer transient leads to the generation of intensive fluid dynamic forces that act along the pipeline axis and induce additional dynamic loads on the main steam pipeline. It is a common practice to assume a simultaneous closure of all stop valves in the safety analysis of the main steam pipeline. In the present paper computer simulations and analyses of the fluid dynamic forces are performed for several scenarios that take into account the possibility of delayed closure of the stop valve in front of the turbine. The influence of the failure of the steam by-pass line opening is considered too. The results show that the delay of the stop valve closure increases the maximum intensity of fluid dynamic force in the pipeline segment in front of the stop valve and decreases the intensity of fluid dynamic forces in segments along the pipeline. The failure of the by-pass line to open leads to prolonged steam pressure and fluid dynamic forces oscillation in pipeline segments. The simulations were performed with the in-house computer code based on the method of characteristics for the solving of the hyperbolic system of PDE that represent the mass, momentum and energy balance equations of the 1-D, compressible and transient fluid-flow. The obtained results are a support to safety analyses of thermal power plants under transient conditions

Fluid dynamic forces in the main steam pipeline of thermal power plant upon stop valves closure

A steam turbine trip is followed by a prompt closure of stop valves in front of the turbine and consequently to a pressure rise in the main steam pipeline. This steam hammer transient leads to the generation of intensive fluid dynamic forces that act along the pipeline axis and induce additional dynamic loads on the main steam pipeline. It is a common practice to assume a simultaneous closure of all stop valves in the safety analysis of the main steam pipeline. In the present paper computer simulations and analyses of the fluid dynamic forces are performed for several scenarios that take into account the possibility of delayed closure of the stop valve in front of the turbine. The influence of the failure of the steam by-pass line opening is considered too. The results show that the delay of the stop valve closure increases the maximum intensity of fluid dynamic force in the pipeline segment in front of the stop valve and decreases the intensity of fluid dynamic forces in segments along the pipeline. The failure of the by-pass line to open leads to prolonged steam pressure and fluid dynamic forces oscillation in pipeline segments. The simulations were performed with the in-house computer code based on the method of characteristics for the solving of the hyperbolic system of PDE that represent the mass, momentum and energy balance equations of the 1-D, compressible and transient fluid-flow. The obtained results are a support to safety analyses of thermal power plants under transient conditions

USING INTERNET OF THINGS IN MONITORING AND MANAGEMENT OF DAMS IN SERBIA

This paper discusses harnessing Internet of Things in monitoring and managing dams in Republic of Serbia. Large dams are of major importance, primarily because of their use for electricity, but risks which are associated with it should be greatly taken into account. There is a need to consolidate information related to dam facilities in order to use them for dam management in Republic of Serbia. An information system has been developed based on existing systems, allowing utilization of intelligent network sensors. The aim of paper is to describe possibilities Internet of Things application within specific system for dam safety management. In order to facilitate the inclusion of a large number of intelligent sensors, a new data acquisition module for communication with sensors in the monitoring network is defined. The system should provide on time alerting in the case that the security parameters deviate from expected values

General platform for hydro-information systems – a review of concept

This paper provides insight into the Institute's long-standing engagement in the design and implementation of hydroinformatics systems in Serbia and the region. The introduction provides a definition of the hydroinformatics system and different areas of application, as well as an overview of the best practices in the world. An overview of the general platform that was created based on experience in the development of different systems has been presented here. We have described the functionalities integrated into a single software platform based on mathematical models and computational services. Various practical examples of application by the Institute are presented with the specifics of implementation in line with the purpose and characteristics of the studied systems. The conclusion highlights the role of applied hydroinformatics systems and the effects of application by users. Possible further development and implementation directions in water management and hydropower systems in Serbia and the region have been also presented.Conference in the honour of 75 years of the Jaroslav Černi Water Institute, held in the Serbian Academy of Sciences and Arts, October 19-20th, 2022

Evolution of cataract surgery: Smaller incision - less complications

Background/Aim. Cataract surgery has become one of the safest procedures in medicine thanks to advances in technology and surgical techniques. Although minimal, we still witness different complications. The aim of this study was to compare visual outcome and complication rate in different techniques of cataract surgery, ie in cataract surgeries with various corneal incision width. Methods. The study included 3,457 consecutive patients, ie 4,670 eyes that had undergone cataract surgery. The used surgical techniques were: extracapsular cataract extraction, phacoemulsification/ forceps IOL implantation, phacoemulsification/ injector IOL implantation, microincision cataract surgery (MICS). Patient follow up was 6 months. Patients were evaluated for: visual aquity, corneal astigmatism, cellular reaction in the anterior chamber, IOL position. Results. Uncorrected visual aquity 30 days postoperatively was ≥ 0.5 in 30% of the eyes - ECCE; 54.7% of the eyes - phacoemulsification/forceps IOL implantation; 63.0% of the eyes - phacoemulsification/injector IOL implantation; 5/8 of the eyes - MICS. Endophthalmitis was detected in 0.15% of the eyes - ECCE and 0.1% of the eyes - phacoemulsification/forceps IOL implantation. In eyes with phacoemulsification/injector IOL implantation or microincision cataract surgery (MICS) there were no cases of endophthalmitis. After a 6-month period intraocular lens were dislocated in 7.2% of the eyes - ECCE, and 0.6% of the eyes - phacoemulsification/PMMA IOL. There was no IOL dislocation in other surgical techniques. Conclusion. Shorter corneal incision implies less complications, less operative trauma, faster visual rehabilitation and better visual outcome

DEM-based GIS algorithms for automatic creation of hydrological models data

In this paper the authors discuss the Digital Elevation Model (DEM) based GIS algorithms, applicable for automatic creation of input data needed by hydrological models. The expected source of DEM data are standard digital data sets that a modeler can purchase from the official data sources. The DEM has to be cleared from errors and prepared for standard hydrology usage as the depression less version, or a version of DEM where only small depressions are filled-in, while larger depressions are extracted as separate objects. The slopes and aspects are calculated from such DEM. The flow accumulation image is created using slopes and aspects and using information about large ponds. From flow accumulation image the surface drainage network is extracted with user-specified density. Based on slopes and aspects, the catchment is delineated into subcatchments, the areas drained by each river segment. Finally, the model-specific parameters like length of flow segment along the terrain and along the river to the subcatchment outlet, slope of those segments, subcatchment shape factor, or subcatchments mean or weighted slope are calculated. Paper explains the used algorithms and emphasizes the problems one can encounter during the usage of DEM data using examples from River Drina catchment. Finally, the authors comment on overall usability of presented GIS algorithms, especially if purchased data are of low quality.

SWAT-based runoff modeling in complex catchment areas: Theoretical background and numerical procedures

This paper shows the structure of the SWAT-based model used in modeling of the 'rainfallrunoff' process. The SWAT model is hydro-dynamic and physically-based model for application in complex and large basins. Model inputs are as follows: rainfall, air temperature, soil characteristics, topography, vegetation, hydrogeology and other relevant physical parameters. The model is based on five linear reservoirs as follows: reservoir of the vegetation cover, snow accumulation and melting, surface reservoir, underground reservoir and surface runoff reservoir. The model uses GIS tools for preprocessing and post-processing. The basic modeling unit is the hydrologic response unit (HRU), defined as the network of elementary hydrologic areas with the selected discretization, measure of which is dependent upon the desired accuracy, as well as upon data accuracy. The total runoff on the exit profile of the catchment is computed by convolution of the sum of runoffs (surface and base runoffs). The model can be applied at the daily and hourly level of discretization and used for multiannual simulations. Illustration of operation of the SWAT based model will be presented on a selected part of the River Drina basin (with the total area of around 20.000 km2).

Svrljiška oblast u praistoriji, antici i srednjem veku

La région de Svrljig en Serbie orientale – préhistoire, antiquité et moyen âge / Сврљишкa oблaст у прaицтoриjи, aнтици срeдњeм вeку, Бeoгрaд 2012 у цeлини двojeзичнa мoнoгрaфиja нa фрaнцускoм и српскoм jeзику у издaњу Бaлкaнoлoшкoг институтa СAНУ и Културнoг цeнтрa Сврљиг у сaрaдњи сa Фрaнцуским институтoм у Србиjи и Oпшинoм Сврљиг, прeдстaвљa jeдинствeни пoдухвaт дa сe први пут, у oквиру jeднoг мoнoгрaфскoг дeлa, нaучнo oбрaди jeднa пoмaлo нeпрaвeднo зaпoстaвљeнa и вaжнa нaучнa тeмa. Нaимe, рeкoнструишe сe свeукупнa прoшлoст брojних људских зajeдницa кoje су нaсeљaвaлe ширoкe oблaсти Сврљишкe кoтлинe и дoлинe Сврљишкoг Tимoкa. Нaвeдeнa oблaст нa истoку дaнaшњe Србиje, дo дaнaс у нaучнoм смислу умнoгoмe terra incognita, дугo je прeдстaвљaлa изaзoв и нужнoст зa сaдржajaн истрaживaчки рaд, кojи нe трeтирa искључивo лoкaлни тeмaтски oквир вeћ нaпрoтив, кojи укључуje, нa oснoву ширих пoимaњa, брojнe интeрaкциje сa свим сусeдним oблaстимa кoje чeстo дeфинишeмo кao цeнтрaлни Бaлкaн, нa срeдoкрaћи кoмуникaциja измeђу Jaдрaнa и Дунaвa. Хрoнoлoшки oквир тeмe изузeтнo je рaзуђeн и oбухвaтa хeтeрoгeнa врeмeнскa рaздoбљa прaистoриje, aнтикe, визaнтиjскe eпoхe, срeдњeг вeкa и турскe дoминaциje. Teмaтски, тeкст je пoдeљeн нa вишe сaдржajних пoглaвљa кoja сe oднoсe нa: прирoднe oдликe, истoриjaт истрaживaњa, прaистoриjу (кaмeнo дoбa и мeтaлнo дoбa), aнтичку eпoху, крaj aнтикe, срeдњи вeк дo oслoбoђeњa oд Tурскe влaсти и oптицaj нoвцa у Сврљишкoj oблaсти крoз истoриjу. Moнoгрaфиja сaдржи и бoгaт кaтaлoг брojнoг нeпубликoвaнoг пoкрeтнoг aрхeoлoшкoг мaтeриjaлa кojи je рaзврстaн пo типу и хрoнoлoшким oдрeдницaмa, кao и нaучни aпaрaт пoпут рeгистрa пojмoвa, кaрaтa и илустрaциja. Сви пoкрeтни и нeпoкрeтни aрхeoлoшки нaлaзи кojи сe у oвoj мoнoгрaфиjи први пут изнoсe нa увид ширoj jaвнoсти, прoизвoд су вишeгoдишњих систeмaтских aрхeoлoшких истрaживaњa у сврљишкoj oблaсти. Tрeбa нaпoмeнути дa су кључни сeгмeнти oвe мoнoгрaфиje, пoсвeћeни вaжним и нeрeшeним нaучним питaњимa o кojимa су услeд нeдoстaткa aрхeoлoшких истрaживaњa, a кaткaд и услeд нeдoвoљнoг пoзнaвaњa ситуaциje нa тeрeну, изнoшeни тeшкo oдрживи нaучни стaвoви. Teкст укaзуje нa нoвe чињeницe и прeдлaжу сe рeшeњa кoja у прoгрeсивнoм смислу рeвидирajу пojeдинe устaљeнe вишeдeцeниjскe стaвoвe. Пoсeбнo бисмo истaкли слeдeћe тeмe: Прeкoнoшкa пeћинa кao вишeслojни прaистoриjски лoкaлитeт, Tрибaлскa нeкрoпoлa Сигнaл и Timacum Maius – убикaциja римскoг нaсeљa нa итинeрaрскoм путу Lissus–Naissus–Ratiaria и прeдлoг нoвoг тумaчeњa пoдaтaкa кoje сaoпштaвajу aнтичкe путнe кaртe – итинeрaри