Acta Hydrologica Slovaca最新文献

{"title":"Spatial and temporal variability of Aridity Index in lowland areas of Slovakia","authors":"Viera Rattayová, M. Garaj, K. Hlavčová","doi":"10.31577/ahs-2022-0023.02.0031","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0031","url":null,"abstract":"Changes in precipitation and temperature caused by global warming are reasons for the increasing occurrence of hydrological extremes such as floods or droughts. The aridity index is a significant indicator of local climate changes and is often used for quantifying the long-term climate conditions of a given location. In addition, the values of the aridity index are indicators of the water conditions of the area and their potential tendency to change in humidity. Therefore, understanding the spatio-temporal patterns of the aridity index is a crucial goal for agricultural and water management of watersheds. This research investigates the spatial and temporal variations of the aridity indices at 27 climatological stations situated in the lowland areas of Slovakia. The stations were divided into three main lowland areas according to their spatial location. The United Nations Environmental Program (UNEP) method was used, and 40 years climatological measurements data from the Slovak Hydrometeorological Institute (SHMI) was considered for calculating the monthly and yearly mean values of the aridity index and assessing its spatial and temporal patterns. Trends in the monthly and yearly spatial mean values of the aridity index showed significant variability between selected areas. The annual mean of the aridity index of stations situated in the Juhoslovenská kotlina lowland indicates increasing trends in the aridity index in winter months and in July. In the case of other lowlands, there were no trends in the monthly and yearly values. Other significant differences were observed in the seasonal variability of the mean monthly values of the aridity index in selected areas.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"9 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127181556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of spatial interpolation methods of hydrological data on example of the Pripyat river basin (within Ukraine)","authors":"K. Sokolchuk, M. Sokáč","doi":"10.31577/ahs-2022-0023.02.0025","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0025","url":null,"abstract":"The article considers four methods of spatial interpolation: method of inverse weighted distances (IDW), triangulation (TIN), Spline interpolation and Kriging. The Pripyat basin was chosen as the study area, and the regularities of the spatial distribution of hydrological characteristics across the territory were assessed. For this territory, maps of spatial distribution of the specific discharge by four chosen methods were created; the accuracy of the obtained results was assessed. Based on the results of the work it was determined that the IDW method with a distance coefficient P=2 gives better results for the generalization of hydrological data over the studied area. The next most reliable methods are Kriging, which shows small errors, and Spline, with smooth transitions. The least suitable among the studied methods is TIN method. To study boundaries and territories that are outside the boundaries defined by GIS based on input data, in this case – Pripyat basin, IDW method is recommended to use, while every other can be used to study the central part of the catchment, with different reliability for the boundary territories.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124181823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Empirical models to calculate the snow water equivalent in the high mountain catchments of the Western Carpathians","authors":"L. Holko, M. Danko, Martin Jančo, P. Sleziak","doi":"10.31577/ahs-2022-0023.02.0027","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0027","url":null,"abstract":"Empirical models based on the relationship between snow depth ( SH ) and density ( ρ ) are used to estimate the snow water equivalent ( SWE ) from SH. However, ρ is poorly correlated with SH while the correlation between SH and SWE which can be directly obtained from snow measurements, is much better. We derived models based on the SH-SWE correlations for two datasets obtained in the high mountain catchments in Slovakia (The Low and Western Tatra Mountains). The models consider time (months from January to April) and elevation zones. Evaluation of the models against independent data showed that they are transferrable to other climatic conditions. About a half of estimated point SWE values was well comparable to measured values, i.e. the differences were approximately within ±15%. Substantial overestimation of measured SWE by more than 35% was obtained for about 10% of the values in January when the same equation was used for all elevation zones. Our final validation employed independent data from the High Tatra Mountains. It showed that about 60% of SWE values calculated for the entire snow courses as an average of 20 values calculated by the derived models from SH compared well (±15%) to values obtained by the traditional approach, i. e. as a product of the snow course mean SH (20 measurements) and ρ (3 measurements). Although the results of our models can be comparable to those provided by models based on snow density, due to recurrent use of SH and almost no correlation between SH and ρ, the models based on the SH-SWE relationship represent in our opinion a more correct approach.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122970288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in the hydrological balance in the Litava river basin during the 90-years period 1931–2020","authors":"P. Pekárová, Z. Bajtek, P. Miklánek, J. Pekár, Katarína Jeneiová, J. Ridzoň","doi":"10.31577/ahs-2022-0023.02.0024","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0024","url":null,"abstract":"During last twenty years, a number of extremely dry years have occurred in a number of European river basins. In Slovakia, the lowland streams of southern Slovakia have been particularly affected by drought. One of these streams is the Ipeľ River. In this basin we have three continuous observations of daily flows since 1931: from Krupinica at Plášťovce, Litava at Plášťovce, and from Ipeľ at Holiša station. The first part of the paper is devoted to the statistical analysis of the Litava flow series. In the second part, the hydrological balance in the Litava basin for the three subperiods (1931– 1960, 1961–1990, and 1991–2020) in annual time step has been elaborated. The first thirty years 1931–1960 were the wateriest (runoff was 205 mm). In the last thirty years, the runoff coefficient was only 0.2 (runoff 131 mm) in Litava basin. In the final part of the study, the BILAN balance model (in a monthly step) was used to compute the contribution of several runoff components in the Litava basin during period 1930/31–2019/20. The long-term average baseflow accounts for 40.7% of the total modelled runoff, interflow accounts for 46.8% and direct runoff accounts for 12.5% of the total modelled runoff.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134007893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification of the automated flood forecasting system on the Stryi River","authors":"B. Khrystiuk, L. Gorbachova, V. Shpyg","doi":"10.31577/ahs-2022-0023.02.0026","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0026","url":null,"abstract":"The physical and geographical location of the Stryi River Basin causes the formation of catastrophic floods, which are regularly forming in this region and cause significant material damage and, sometimes, the death of people. The last catastrophic flood took place on the Stryi River in June 2020. Thus, the creation of a modern system for forecasting the streamflow of the Stryi River is a very important task. This paper describes such an automated flood forecasting system (FFS Stryi) that is developed at the Ukrainian Hydrometeorological Institute of the State Emergency Service of Ukraine and the National Academy of Sciences of Ukraine. The basis of the system is the hydrological module NAM of the Rainfall-Runoff software complex MIKE 11 (Denmark), which uses the forecasted weather parameters from the numerical mesoscale atmospheric model WRF ARW v. 3.6.1 (USA). The objective of this study is to verify this system and identify the factors that affect the accuracy of flood forecasting of the Stryi River. The system of streamflow forecasting of the Stryi River uses the continuous series of calculated (historical) levels and discharges, air temperature, precipitation, evaporation, as well as the forecast of meteorological indicators for 5 days. The system is set to work with a three-hour time step in the automatic regime. Verification of FFS Stryi according to the historical meteorological data showed that the system reproduces the streamflow of the Stryi River with satisfactory quality. The accuracy of discharge forecasting depends on the accuracy of weather parameters forecasting and, above all, the quantity of precipitation and the time of their falling out. Errors of hydrological forecasting are caused by an imperfect hydrometeorological network of observations (number of points and frequency of measurement), a digital model of the relief of the Stryi River basin and errors of weather parameters forecasts.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121740700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydraulic conductivity of saturated bed silts in Chotárny channel, ŽO area, Slovakia","authors":"R. Dulovičová, Radoslav Schügerl, Y. Velísková","doi":"10.31577/ahs-2022-0023.02.0020","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0020","url":null,"abstract":"This paper deals with the comparison of two different ways used for determination of saturated hydraulic conductivity values of bed silts located along the Chotárny channel, obtained from field measurements in 2018. The Chotárny channel is one of three selected monitored channels at the ŽO area – the flat lowland with channel network. The permeability of bed silts impacts water flow between surface water in the channel and surrounding groundwater in the scope of their interaction at this area. It is expressed by its value of saturated hydraulic conductivity. The bed silts along Chotárny channel were extracted and obtained by two ways, as disturbed samples and as undisturbed samples. The selection of sampling place was made by thickness of bed silt in the measured profiles. The samples were extracted in three different vertical parts of bed silt – from top, middle and bottom part of bed silt layer. In case of the disturbed samples the empirical formulas based on the grain size analysis were used for determination of saturated hydraulic conductivity value. In case of undisturbed samples was used the falling head method for determination of saturated hydraulic conductivity value. The values of saturated hydraulic conductivity obtained from disturbed samples of bed silts K d were calculated by using of several empirical formulas: 1. Bayer – Schweiger; 2. Špaček I.; 3. Špaček II.; 4. Hazen I.; 5. Bayer; 6. USBR and 7. Orechova. The results in Table 1 show that the valid values K d for Chotárny channel in 2018 were from 1.00x10 -10 to 1.19x10 -04 m s -1 . The recommended formula for calculation of K d of bed silts by empirical formulas in Chotárny channel, based on criterium of the largest number of valid obtained results, is Hazen I. formula. The values of saturated hydraulic conductivity obtained from undisturbed samples of bed silts K u were determined according the relation for calculation of average value of saturated hydraulic conductivity (by falling head method in laboratory). These values are illustrated in Table 2. The values K u for Chotárny channel in 2018 reached values from 7.68x10 -08 – 4.53x10 -05 m s -1 . All the results from both methods of determination of saturated hydraulic conductivity were compared.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127778002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neurohydrological prediction of water temperature and runoff time series","authors":"Zoltán Árpád Liptay","doi":"10.31577/ahs-2022-0023.02.0021","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0021","url":null,"abstract":"In this paper we give an overview of experiments with artificial neural networks on the Hungarian reach of the Danube River carried out by the Hungarian Hydrological Forecasting Service. Two areas were selected: rainfall-runoff modelling and water temperature simulation. The statistical machine learning method is a universal interpolation and classification tool, but showed poor performance when applied for correlation in complex hydrological situations. Despite very strong learning skills of neural networks even a conceptual model gave more consistent and superior results through validation, and the statistic method is more sensitive to overlearning than deterministic methods. Despite deterministic models being superior artificial neural networks still provide satisfactory results that confirms their application.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114763552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of climate change and human factors on the water regime of the Danube Delta","authors":"V. Vyshnevskyi, S. Shevchuk","doi":"10.31577/ahs-2022-0023.02.0023","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0023","url":null,"abstract":"Climate changes in the Danube Delta, as well as changes in water temperature, water runoff and sediment yield, have been identified on the basis of available observational data. It has been shown that the intra-annual distribution of water runoff has become more uniform in recent decades. It decreased in April-May and increased in February-March. At the same time, there has been a significant decrease in sediment transport. Changes due to anthropogenic impact were detected in water runoff in the largest river branches, in particular, the reduction of the share of the Kiliyskyi branch. Over the past 60 years, the water temperature in the Danube Delta has increased significantly, by more than 2°C. In general, the water temperature is higher than the air temperature, especially in autumn. Some features of the delta formation have been identified.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122691496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trend changes and frequency analysis of the annual maximum volumes for various runoff duration on the Morava River at Moravský Svätý Ján","authors":"Veronika Bačová Mitková","doi":"10.31577/ahs-2022-0023.02.0022","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0022","url":null,"abstract":"In the present paper we analyzed, the occurrence of annual maximum runoff volumes with t-day durations for a 99-year series (1920–2020) of mean daily discharge of the Morava River at Moravský Svätý Ján gauge (Slovakia). The runoff volume is, apart from the peak runoff, another very important hydrological characteristic of a river for flood hazard assessment. The maximum runoff volumes with t -day duration were determined. Subsequently, trends of the annual maximum runoff volumes with t -day durations were identified. We analyzed how the annual maximum runoff volumes of the Morava River have changed over the period 1922–2020 and how they have changed over dry and wet periods. The results indicate that the trends of the annual maximum runoff volumes with t -day durations decrease, especially in wet periods. On the Morava River usually the maximum annual discharges occur simultaneously with the annual maximum runoff volume of waves with a given duration t . However, the corresponding values in terms of significance are not equivalent. Based on the exceeding probability curves of the annual maximum runoff volumes, it is possible to determine to the selected volume V tmax for different t-days the probability of its exceeding and return period. The Log-Pearson distribution type III was used to determine the T-year values of the maximum runoff volumes with t-day duration.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126933521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of soil water retention curves based on two programs","authors":"J. Vitková, Lucia Toková, Natália Botková","doi":"10.31577/ahs-2022-0023.02.0017","DOIUrl":"https://doi.org/10.31577/ahs-2022-0023.02.0017","url":null,"abstract":"We compared two methods of modeling soil water retention curves used by scientists in Slovakia. The first modeling was done using the GENRET program and the second using the RETC program. Samples of pure sandy soil and sandy soil with applied biochar in three different particle sizes were used for the simulation. Sandy soil has a very low retention capacity therefore the modeling of soil water retention curves is not easy. Our results showed that the GENRET program can model the curve even at high pressures, which the RETC program modeled only in one variant, but the RETC program had better agreement with measured data. The most significant differences between the programs were at the lowest and highest pressures.","PeriodicalId":321483,"journal":{"name":"Acta Hydrologica Slovaca","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128586569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}