B. Łapeta, E. Kuligowska, Paulina Murzyn, P. Struzik
This paper presents the evolution of the mesoscale convection system as seen on satellite images during all stages: pre-convection, initiation, and maturity. The evolution of any atmospheric phenomenon can be monitored effectively only when the data available have adequate temporal and spatial resolution. In case of convective storms the resolution should be minutes and kilometers. Therefore, data from the METEOSAT geostationary satellite, with 5-minute and 15-minute intervals were used operationally to monitor the storm of 11 August 2017; this was a most destructive storms, concentrated in several districts of the Pomeranian, Greater Poland, and Kuyavian-Pomeranian voivodeships. Analysis demonstrated that some alarming features, like cold rings or cold U/V shapes, can be visible on the single channel satellite images, without even referring to specific convective products. However, the nowcasting of the convective phenomena requires careful analysis of several dedicated products, including stability indices and water vapor content in the troposphere. It has been shown that with comprehensive analysis of the information provided by the different satellite images and satellite derived products, it is possible to draw conclusions about the severity of the observed storms as well as the probability of the occurrence of the extreme weather at the ground.
{"title":"Monitoring the 11 August 2017 storm in central Poland with satellite data and products","authors":"B. Łapeta, E. Kuligowska, Paulina Murzyn, P. Struzik","doi":"10.26491/mhwm/144590","DOIUrl":"https://doi.org/10.26491/mhwm/144590","url":null,"abstract":"This paper presents the evolution of the mesoscale convection system as seen on satellite images during all stages: pre-convection, initiation, and maturity. The evolution of any atmospheric phenomenon can be monitored effectively only when the data available have adequate temporal and spatial resolution. In case of convective storms the resolution should be minutes and kilometers. Therefore, data from the METEOSAT geostationary satellite, with 5-minute and 15-minute intervals were used operationally to monitor the storm of 11 August 2017; this was a most destructive storms, concentrated in several districts of the Pomeranian, Greater Poland, and Kuyavian-Pomeranian voivodeships. Analysis demonstrated that some alarming features, like cold rings or cold U/V shapes, can be visible on the single channel satellite images, without even referring to specific convective products. However, the nowcasting of the convective phenomena requires careful analysis of several dedicated products, including stability indices and water vapor content in the troposphere. It has been shown that with comprehensive analysis of the information provided by the different satellite images and satellite derived products, it is possible to draw conclusions about the severity of the observed storms as well as the probability of the occurrence of the extreme weather at the ground.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78504034","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}
Mariusz Figurski, G. Nykiel, A. Jaczewski, Z. Baldysz, M. Wdowikowski
Precise simulations of severe weather events are a challenge in the era of changing climate. By performing simulations correctly and accurately, these phenomena can be studied and better understood. In this paper, we have verified how different initial and boundary conditions affect the quality of simulations performed using the Weather Research and Forecasting Model (WRF). For our analysis, we chose a derecho event that occurred in Poland on 11 August 2017, the most intense and devastating event in recent years. High-resolution simulations were conducted with initialization at 00 and 12 UTC (11 August 2017) using initial and boundary conditions derived from the four global models: Global Forecast System (GFS) from the National Centers for Environmental Prediction (NCEP), Integrated Forecast System (IFS) developed by the European Center for Medium-Range Weather Forecasts (ECMWF), Global Data Assimilation System (GDAS) and ERA5. For the last, we made separate calculations using data at the pressure and model levels. The results were evaluated against surface and radar data. We found that the simulations that used data from the GDAS and GFS models at 12 UTC were the more accurate, while ERA5 gave the worst predictions. However, all models were characterized by a low probability of detection and a high number of false alarms for simulations of extreme precipitation and wind gusts.
{"title":"The impact of initial and boundary conditions on severe weather event simulations using a high-resolution WRF model. Case study of the derecho event in Poland on 11 August 2017","authors":"Mariusz Figurski, G. Nykiel, A. Jaczewski, Z. Baldysz, M. Wdowikowski","doi":"10.26491/mhwm/143877","DOIUrl":"https://doi.org/10.26491/mhwm/143877","url":null,"abstract":"Precise simulations of severe weather events are a challenge in the era of changing climate. By performing simulations correctly and accurately, these phenomena can be studied and better understood. In this paper, we have verified how different initial and boundary conditions affect the quality of simulations performed using the Weather Research and Forecasting Model (WRF). For our analysis, we chose a derecho event that occurred in Poland on 11 August 2017, the most intense and devastating event in recent years. High-resolution simulations were conducted with initialization at 00 and 12 UTC (11 August 2017) using initial and boundary conditions derived from the four global models: Global Forecast System (GFS) from the National Centers for Environmental Prediction (NCEP), Integrated Forecast System (IFS) developed by the European Center for Medium-Range Weather Forecasts (ECMWF), Global Data Assimilation System (GDAS) and ERA5. For the last, we made separate calculations using data at the pressure and model levels. The results were evaluated against surface and radar data. We found that the simulations that used data from the GDAS and GFS models at 12 UTC were the more accurate, while ERA5 gave the worst predictions. However, all models were characterized by a low probability of detection and a high number of false alarms for simulations of extreme precipitation and wind gusts.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88165867","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}
The Cunge-Muskingum routing model is one of the most popular and widely used models for hydrologic channel flood routing. The application of Cunge-Muskingum model to an ungauged basin is hindered by the lack of hydro-meteorological data. In the present study, a method is proposed to predict the outflow hydrograph of an ungauged basin as a solution to this problem. The Cunge-Muskingum method is modified, considering the non-prismatic complex natural channel. The Soil Conservation Service Curve Number rainfall-runoff model is employed to obtain the inflow and lateral inflow hydrographs of the ungauged basins, and the Modified Cunge-Muskingum model is employed to anticipate the flood hydrograph at the outlet of the ungauged basin. The proposed approach is employed to the Kulsi River Basin, India, hypothetically treated as an ungauged basin, and the results are compared with the observed data at the outlet of the basin. The performance of the model is evaluated based on RMSE (50.34 m3/s), peak flow error (39.73%), peak flow time error (–3.44%), total volume error (7.36%), relative error (7.36%), mean absolute error (33.5%), correlation coefficient (0.785), coefficient of efficiency (0.59) and Kling-Gupta efficiency (0.66).The results reveal that the proposed Modified Cunge-Muskingum model is an efficient predictor of the flood hydrograph at the outlet of the ungauged basin.
{"title":"Prediction of flood hydrograph using the modified Cunge-Muskingum method in an ungauged basin: a case study in the Kulsi river basin, India","authors":"B. Bharali, U. Misra","doi":"10.26491/mhwm/143249","DOIUrl":"https://doi.org/10.26491/mhwm/143249","url":null,"abstract":"The Cunge-Muskingum routing model is one of the most popular and widely used models for hydrologic channel flood routing. The application of Cunge-Muskingum model to an ungauged basin is hindered by the lack of hydro-meteorological data. In the present study, a method is proposed to predict the outflow hydrograph of an ungauged basin as a solution to this problem. The Cunge-Muskingum method is modified, considering the non-prismatic complex natural channel. The Soil Conservation Service Curve Number rainfall-runoff model is employed to obtain the inflow and lateral inflow hydrographs of the ungauged basins, and the Modified Cunge-Muskingum model is employed to anticipate the flood hydrograph at the outlet of the ungauged basin. The proposed approach is employed to the Kulsi River Basin, India, hypothetically treated as an ungauged basin, and the results are compared with the observed data at the outlet of the basin. The performance of the model is evaluated based on RMSE (50.34 m3/s), peak flow error (39.73%), peak flow time error (–3.44%), total volume error (7.36%), relative error (7.36%), mean absolute error (33.5%), correlation coefficient (0.785), coefficient of efficiency (0.59) and Kling-Gupta efficiency (0.66).The results reveal that the proposed Modified Cunge-Muskingum model is an efficient predictor of the flood hydrograph at the outlet of the ungauged basin.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"65 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87354407","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}
In recent times, undesirable climatic conditions have been attributed to climate change. The intensity of rainfall has amplified extremely, causing floods in many areas worldwide. It is desirable to regulate and minimize the consequences of floods and excess downpour. Using geospatial data for the development of hydraulic models and mapping of simulation results has become standard practice for floodplain assessment. The objective of the current investigation is to use one-dimensional floodplain modeling of the Bhima River between Lonikand and Rahu using the RAS-mapper tool (HEC-RAS). The modeled river reach is about 67 km long, near the Pune administrative division of Maharashtra, India. The hydrodynamic flow computations were carried out for the years 2005 and 2017. A total of 595 cross sections along the main river was employed for hydrodynamic flow simulations. In this study, cross-sections and past observed flood data have been used to develop a 1-D integrated hydraulic model of the Bhima River. The simulated water levels are also validated with observed water levels and found to be reasonably correlated.
{"title":"Hydrodynamic flow modelling and effect of roughness on river stage forecasting","authors":"A. Kambekar, Shweta Patil","doi":"10.26491/mhwm/140234","DOIUrl":"https://doi.org/10.26491/mhwm/140234","url":null,"abstract":"In recent times, undesirable climatic conditions have been attributed to climate change. The intensity of rainfall has amplified extremely, causing floods in many areas worldwide. It is desirable to regulate and minimize the consequences of floods and excess downpour. Using geospatial data for the development of hydraulic models and mapping of simulation results has become standard practice for floodplain assessment. The objective of the current investigation is to use one-dimensional floodplain modeling of the Bhima River between Lonikand and Rahu using the RAS-mapper tool (HEC-RAS). The modeled river reach is about 67 km long, near the Pune administrative division of Maharashtra, India. The hydrodynamic flow computations were carried out for the years 2005 and 2017. A total of 595 cross sections along the main river was employed for hydrodynamic flow simulations. In this study, cross-sections and past observed flood data have been used to develop a 1-D integrated hydraulic model of the Bhima River. The simulated water levels are also validated with observed water levels and found to be reasonably correlated.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"135 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86735509","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}
This study provides an assessment of the current and future changes (in terms of both direction and value) in air temperature, precipitation, snow, wind and their extremes over the territory of Belarus using information from 42 meteorological stations and 92 regional circulation model (RCM) simulations with the highest available horizontal resolution (EUR-11). Three representative concentration pathway scenarios, namely, RCP2.6, RCP4.5 and RCP8.5, are considered. Results demonstrate that in recent decades, temperature has increased over the territory of Belarus by 1.3 ° C, with the largest increase occurring during the cold season (2.1-2.3 ° C). Ensemble scenarios project further increases in air temperature in the current century by +0.5-1.5°C , +2.8°C, and +5.2°C under the RCP2.6, RCP4.5 and RCP8.5 scenarios, with the largest increase during the cold season under the RCP8.5 scenario. The annual means were observed to increase (insignificantly) by 5-7% and the summer precipitation extremes exhibited a 20-25% growth in recent decades. Moreover, dry conditions have intensified in Belarus, particularly during the growing season. Further increases in precipitation of 10-15% across Belarus are projected to occur in all seasons under the RCP4.5 and RCP8.5 scenarios. Simulation models predict greater increases in single day rainfall events compared to their multiday precipitation counterparts. The greatest increases in maximal dry period length (by 1-2) are expected to occur in summer and autumn. The models project the general decrease in snowfall across Belarus to continue into the current century, with a reduction in snow precipitation days of 10-30 days. Despite the reduced wind strength (by 0.9-1.0 m · s -1 ) since the 1970s over the territory of Belarus, the ensemble model reveals slight nonsignificant changes in seasonal and annual wind strengths until the end of the century. Significant changes of 1-3 days under varying directions of the wind regime were observed for days with a strong breeze and storms.
{"title":"Estimates of current and future climate change in Belarus based on meteorological station data and the EURO-CORDEX-11 dataset","authors":"I. Danilovich, B. Geyer","doi":"10.26491/MHWM/139386","DOIUrl":"https://doi.org/10.26491/MHWM/139386","url":null,"abstract":"This study provides an assessment of the current and future changes (in terms of both direction and value) in air temperature, precipitation, snow, wind and their extremes over the territory of Belarus using information from 42 meteorological stations and 92 regional circulation model (RCM) simulations with the highest available horizontal resolution (EUR-11). Three representative concentration pathway scenarios, namely, RCP2.6, RCP4.5 and RCP8.5, are considered. Results demonstrate that in recent decades, temperature has increased over the territory of Belarus by 1.3 ° C, with the largest increase occurring during the cold season (2.1-2.3 ° C). Ensemble scenarios project further increases in air temperature in the current century by +0.5-1.5°C , +2.8°C, and +5.2°C under the RCP2.6, RCP4.5 and RCP8.5 scenarios, with the largest increase during the cold season under the RCP8.5 scenario. The annual means were observed to increase (insignificantly) by 5-7% and the summer precipitation extremes exhibited a 20-25% growth in recent decades. Moreover, dry conditions have intensified in Belarus, particularly during the growing season. Further increases in precipitation of 10-15% across Belarus are projected to occur in all seasons under the RCP4.5 and RCP8.5 scenarios. Simulation models predict greater increases in single day rainfall events compared to their multiday precipitation counterparts. The greatest increases in maximal dry period length (by 1-2) are expected to occur in summer and autumn. The models project the general decrease in snowfall across Belarus to continue into the current century, with a reduction in snow precipitation days of 10-30 days. Despite the reduced wind strength (by 0.9-1.0 m · s -1 ) since the 1970s over the territory of Belarus, the ensemble model reveals slight nonsignificant changes in seasonal and annual wind strengths until the end of the century. Significant changes of 1-3 days under varying directions of the wind regime were observed for days with a strong breeze and storms.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"11 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84305161","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}
Predicting flood discharges in the rivers of an ungauged basin is tedious because essential hydrological data is lacking. In mountainous countries like Nepal, the design of hydraulic structures in these steeply sloped rivers is of prime importance for flood control, as well as for electricity generation where hydraulic head is gained over short, steep reaches. This study illustrates a variety of approaches that can be used to perform flood frequency analysis of typical ungauged mountainous rivers, where discharge data are available from hydrologically similar catchments. The various methods are evaluated by comparing the goodness of fit of an array of hydrologic distribution functions. From each probability density function or regional empirical method, we predict the multi-year return periods for floods, information that is generally required to design the hydraulic structures. The analysis was done based on the annual maxima, peaks above threshold, and widely used regional empirical methods. This analysis was accomplished using the discharge data of Nayapul station near Jhapre Bagar collected from the Department of Hydrology and Meteorology, Government of Nepal, Kathmandu. The analysis and results of this study paved the way for the hydraulic design of water systems in the ungauged study region and demonstrated how the information acquired can be used for water resource management in catchments with similar hydrologic features.
{"title":"Flood frequency analysis for an ungauged Himalayan river basin using different methods: a case study of Modi Khola, Parbat, Nepal","authors":"B. Acharya, B. Joshi","doi":"10.26491/mhwm/131092","DOIUrl":"https://doi.org/10.26491/mhwm/131092","url":null,"abstract":"Predicting flood discharges in the rivers of an ungauged basin is tedious because essential hydrological data is lacking. In mountainous countries like Nepal, the design of hydraulic structures in these steeply sloped rivers is of prime importance for flood control, as well as for electricity generation where hydraulic head is gained over short, steep reaches. This study illustrates a variety of approaches that can be used to perform flood frequency analysis of typical ungauged mountainous rivers, where discharge data are available from hydrologically similar catchments. The various methods are evaluated by comparing the goodness of fit of an array of hydrologic distribution functions. From each probability density function or regional empirical method, we predict the multi-year return periods for floods, information that is generally required to design the hydraulic structures. The analysis was done based on the annual maxima, peaks above threshold, and widely used regional empirical methods. This analysis was accomplished using the discharge data of Nayapul station near Jhapre Bagar collected from the Department of Hydrology and Meteorology, Government of Nepal, Kathmandu. The analysis and results of this study paved the way for the hydraulic design of water systems in the ungauged study region and demonstrated how the information acquired can be used for water resource management in catchments with similar hydrologic features.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"46 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81816782","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}
Based on the results of regular monitoring and remote sensing data the patterns of water temperature and ice regime of the Dnipro River within Kyiv, as affected by global warming and a hydropower plant, were identified. The characteristic features of this stretch of the river are increasing water temperature, and the decreasing thickness and duration of ice cover. The largest water temperature increase is in summer, with a somewhat smaller increase in autumn. The increase of water temperature in spring is much less than the increase in air temperature. In summer, the gradient of water temperature increase is a little bit less than that of air temperature. In autumn, the gradient of water temperature increase is larger than the gradient of air temperature increase. From April to August the lowest water temperature is usually observed near the Kyivska hydropower plant (HPP), which is located upstream. During this period the water temperature downstream from HPP increases. The uneven daily operation of HPP causes the alternation of areas with different temperature along the Dnipro River. In the cold season the water temperature in the Dnipro River is usually higher than in other nearby urban water bodies. Freezing of the water area usually starts from the small and shallow lakes and ponds. The main branch of the Dnipro River freezes last. On the whole, the sequence of ice melting on the waterbodies is the reverse of the freezing process. The longest ice cover duration in spring is observed in the bays with small water exchange, mainly located at a large distance from Kyivska HPP.
{"title":"Temperature and ice regimes of waterbodies under impacts of global warming and a hydropower plant","authors":"V. Vyshnevskyi","doi":"10.26491/MHWM/127538","DOIUrl":"https://doi.org/10.26491/MHWM/127538","url":null,"abstract":"Based on the results of regular monitoring and remote sensing data the patterns of water temperature and ice regime of the Dnipro River within Kyiv, as affected by global warming and a hydropower plant, were identified. The characteristic features of this stretch of the river are increasing water temperature, and the decreasing thickness and duration of ice cover. The largest water temperature increase is in summer, with a somewhat smaller increase in autumn. The increase of water temperature in spring is much less than the increase in air temperature. In summer, the gradient of water temperature increase is a little bit less than that of air temperature. In autumn, the gradient of water temperature increase is larger than the gradient of air temperature increase. From April to August the lowest water temperature is usually observed near the Kyivska hydropower plant (HPP), which is located upstream. During this period the water temperature downstream from HPP increases. The uneven daily operation of HPP causes the alternation of areas with different temperature along the Dnipro River. In the cold season the water temperature in the Dnipro River is usually higher than in other nearby urban water bodies. Freezing of the water area usually starts from the small and shallow lakes and ponds. The main branch of the Dnipro River freezes last. On the whole, the sequence of ice melting on the waterbodies is the reverse of the freezing process. The longest ice cover duration in spring is observed in the bays with small water exchange, mainly located at a large distance from Kyivska HPP.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"16 3 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79705339","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}
The importance of the Dniester River in the socio-economic life of Moldova and Ukraine necessitates research into the main trends in the river’s runoff characteristics and dynamics, especially now, when climate change is significantly altering the water regime of rivers. This paper presents a solution for the problems of identifying the main trends in daily maximum river discharge by seasons and months for various calculation intervals. Two calculation intervals (1981-1998; 1999-2015) with different climatic conditions are considered. Each interval corresponds to one complete cycle of river water discharge. Climatic conditions as a result of global warming are changing differently in the mountains and on the plain, therefore, the identification of trends was performed separately for the alpine and lowland parts of the Dniester River annual runoff formation zone. The search for statistically significant trends was carried out by means of the MannKendall test. The analysis of the frequency of maximum discharges (peak over threshold; POT3) was performed for selected rivers in the studied area. The earlier period (1981-1998) showed statistically significant positive trends for both alpine and lowland rivers of the Upper Dniester. The later period (1999-2015) differed, exhibiting exclusively negative significant trends in daily peaks both by months and by seasons. This result indicates a persistent tendency toward decreasing maximum water runoff for all rivers of the Upper Dniester catchment. There were no statistically significant trends in the frequency of floods.
{"title":"Trends in monthly, seasonal, and annual fluctuations in flood peaks for the upper Dniester River","authors":"S. Melnyk, N. Loboda","doi":"10.26491/mhwm/126705","DOIUrl":"https://doi.org/10.26491/mhwm/126705","url":null,"abstract":"The importance of the Dniester River in the socio-economic life of Moldova and Ukraine necessitates research into the main trends in the river’s runoff characteristics and dynamics, especially now, when climate change is significantly altering the water regime of rivers. This paper presents a solution for the problems of identifying the main trends in daily maximum river discharge by seasons and months for various calculation intervals. Two calculation intervals (1981-1998; 1999-2015) with different climatic conditions are considered. Each interval corresponds to one complete cycle of river water discharge. Climatic conditions as a result of global warming are changing differently in the mountains and on the plain, therefore, the identification of trends was performed separately for the alpine and lowland parts of the Dniester River annual runoff formation zone. The search for statistically significant trends was carried out by means of the MannKendall test. The analysis of the frequency of maximum discharges (peak over threshold; POT3) was performed for selected rivers in the studied area. The earlier period (1981-1998) showed statistically significant positive trends for both alpine and lowland rivers of the Upper Dniester. The later period (1999-2015) differed, exhibiting exclusively negative significant trends in daily peaks both by months and by seasons. This result indicates a persistent tendency toward decreasing maximum water runoff for all rivers of the Upper Dniester catchment. There were no statistically significant trends in the frequency of floods.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"121 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82169949","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}
This research focuses on objective assessment of bioclimatic conditions through analyses of biometeorological indices based on Harrington’s desirability function. Evaluation criteria for the Harrington desirability function during winter are: Bodman’s winter severity index (S), equivalent-efficient temperatures (EETA), index of wind cooling (K0), and wind chill temperature (WC). These metrics were integrated into one complex, generalized desirability index for winter (DW). For the summer period, equivalentefficient temperatures of Missenard (EЕT) index, radiation equivalent-effective temperature (PEET) and Heat Index (HI), were combined to form a desirability index for summer (DS). Zoning of the territory by e integrating the indices (DW/DS) portrays the seasonal and spatial differentiation of bioclimatic conditions over Ukraine. These differences were used to highlight the most favorable and unfavorable regions (zones) for humans and, accordingly, the level of bioclimatic resources for each region. In winter across Ukraine, four zones with different levels of weather comfort were identified, with only three zones in summer. For both seasons meteorological conditions are mostly comfortable based on human thermal state. Zone 3, with satisfactory bioclimatic resources and comfortable weather, is the largest of all zones in both winter and summer, making up 49.61% and 61.0% Ukraine’s territory, respectively. Average values of climatic characteristics were calculated for the specified zones for both seasons (1981-2010).
{"title":"Bioclimatic zoning of the territory of Ukraine based on human thermal state assessment","authors":"L. Malytska, S. Moskalenko","doi":"10.26491/mhwm/125755","DOIUrl":"https://doi.org/10.26491/mhwm/125755","url":null,"abstract":"This research focuses on objective assessment of bioclimatic conditions through analyses of biometeorological indices based on Harrington’s desirability function. Evaluation criteria for the Harrington desirability function during winter are: Bodman’s winter severity index (S), equivalent-efficient temperatures (EETA), index of wind cooling (K0), and wind chill temperature (WC). These metrics were integrated into one complex, generalized desirability index for winter (DW). For the summer period, equivalentefficient temperatures of Missenard (EЕT) index, radiation equivalent-effective temperature (PEET) and Heat Index (HI), were combined to form a desirability index for summer (DS). Zoning of the territory by e integrating the indices (DW/DS) portrays the seasonal and spatial differentiation of bioclimatic conditions over Ukraine. These differences were used to highlight the most favorable and unfavorable regions (zones) for humans and, accordingly, the level of bioclimatic resources for each region. In winter across Ukraine, four zones with different levels of weather comfort were identified, with only three zones in summer. For both seasons meteorological conditions are mostly comfortable based on human thermal state. Zone 3, with satisfactory bioclimatic resources and comfortable weather, is the largest of all zones in both winter and summer, making up 49.61% and 61.0% Ukraine’s territory, respectively. Average values of climatic characteristics were calculated for the specified zones for both seasons (1981-2010).","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"5 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87376194","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}
This paper simulates the responses of water budget components to doubled CO2 (2 × 378 ppm) concentration in the atmosphere with atmospheric and oceanic surface warming of 2°C. Simulations employed version 4.7 of the Regional Climate Model of the International Centre for Theoretical Physics (ICTP). Two six-year experiments were each repeated twice with the same model physics and parameterizations. The control experiment held the CO2 concentration at 378 ppm (no warming), while the other experiment specified doubled CO2 concentration and warming. The results showed a positive response (60-100% increase) to doubled CO2 for precipitation, runoff, and storage terms in Sierra Leone, Burkina Faso, Guinea Bissau, and the ocean area between 3 and 13°N. However, there was a negative response (up to 60%) for northern Senegal, southern Mali, and northern Nigeria. The reductions in water fluxes were observed mostly on the leeward side of the highlands. Evapotranspiration showed a negative response (1-20%) to doubled CO2 on the land north of 20°N. Burkina Faso and southern Mali responded oppositely to doubled CO2, despite their spatial proximity.
{"title":"Simulating the Influence of doubled CO2 on the water budget over West Africa using RegCM4.7","authors":"M. Adeniyi","doi":"10.26491/mhwm/125198","DOIUrl":"https://doi.org/10.26491/mhwm/125198","url":null,"abstract":"This paper simulates the responses of water budget components to doubled CO2 (2 × 378 ppm) concentration in the atmosphere with atmospheric and oceanic surface warming of 2°C. Simulations employed version 4.7 of the Regional Climate Model of the International Centre for Theoretical Physics (ICTP). Two six-year experiments were each repeated twice with the same model physics and parameterizations. The control experiment held the CO2 concentration at 378 ppm (no warming), while the other experiment specified doubled CO2 concentration and warming. The results showed a positive response (60-100% increase) to doubled CO2 for precipitation, runoff, and storage terms in Sierra Leone, Burkina Faso, Guinea Bissau, and the ocean area between 3 and 13°N. However, there was a negative response (up to 60%) for northern Senegal, southern Mali, and northern Nigeria. The reductions in water fluxes were observed mostly on the leeward side of the highlands. Evapotranspiration showed a negative response (1-20%) to doubled CO2 on the land north of 20°N. Burkina Faso and southern Mali responded oppositely to doubled CO2, despite their spatial proximity.","PeriodicalId":42852,"journal":{"name":"Meteorology Hydrology and Water Management-Research and Operational Applications","volume":"397 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72435840","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}
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