Global climate model (GCM) outputs from Coupled Model Inter-comparison Project Phase 5 (CMIP5) were widely used to investigate climate change impacts last 10 years. It is important to know whether Coupled Model Inter-comparison Project Phase 6 (CMIP6) is more reliable than CMIP5. Number of studies compared GCMs from two CMIPs in simulating climate variables, but they are not in the field of hydrology for large quantities of watersheds. The objective of this study is to compare CMIP5 and CMIP6 climate model projections in projecting hydrological changes between future (2071–2100) and historical (1976–2005) periods and inter-model variability of hydrological impacts for the future period over 343 catchments in China's mainland. The results show that the GCMs in CMIP6 show more increase in daily mean temperature and mean annual precipitation. However, GCMs in CMIP6 and CMIP5 show similar increases in mean and peak streamflow. Moreover, GCMs in CMIP6 show less inter-model variability for streamflow in southern and northeastern China, but more in central China, which is consistent to that for precipitation after bias correction. Overall, this comparison provides the consistency of future change and uncertainty in predicted streamflow with climate simulations, which bring confidence for hydrological impact studies using CMIP6.
{"title":"A comparison of CMIP5 and CMIP6 climate model projections for hydrological impacts in China","authors":"Yawen Lei, Jie Chen, L. Xiong","doi":"10.2166/nh.2023.108","DOIUrl":"https://doi.org/10.2166/nh.2023.108","url":null,"abstract":"\u0000 Global climate model (GCM) outputs from Coupled Model Inter-comparison Project Phase 5 (CMIP5) were widely used to investigate climate change impacts last 10 years. It is important to know whether Coupled Model Inter-comparison Project Phase 6 (CMIP6) is more reliable than CMIP5. Number of studies compared GCMs from two CMIPs in simulating climate variables, but they are not in the field of hydrology for large quantities of watersheds. The objective of this study is to compare CMIP5 and CMIP6 climate model projections in projecting hydrological changes between future (2071–2100) and historical (1976–2005) periods and inter-model variability of hydrological impacts for the future period over 343 catchments in China's mainland. The results show that the GCMs in CMIP6 show more increase in daily mean temperature and mean annual precipitation. However, GCMs in CMIP6 and CMIP5 show similar increases in mean and peak streamflow. Moreover, GCMs in CMIP6 show less inter-model variability for streamflow in southern and northeastern China, but more in central China, which is consistent to that for precipitation after bias correction. Overall, this comparison provides the consistency of future change and uncertainty in predicted streamflow with climate simulations, which bring confidence for hydrological impact studies using CMIP6.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43504573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengyu Xu, Canyu Yuan, Xianghu Li, Yaling Lin, Hongxiang Fan
Extreme precipitation is very sensitive to climate change. Global warming will significantly affect the frequency and intensity of extreme precipitation and further affect the spatio-temporal pattern of disaster-causing risk of extreme precipitation. This study analyzes the spatio-temporal trends of extreme precipitation and projects its disaster-causing risk under different climate scenarios in the Yangtze River Basin from 2021 to 2100. The results indicate that the extreme precipitation in the Yangtze River Basin shows an increasing trend in the future. Annual precipitation (PRCPTOT) increases by 33.05–42.56% under five scenarios compared with the historical period. The future change in heavy precipitation (R95p) also shows a significant increase, but heavy rain days (R50) and 5-day maximum precipitation (RX5day) decrease. The disaster-causing risk of extreme precipitation in the Yangtze River Basin is mainly Levels III and IV, accounting for 57.23–65.99% of the total basin area. The area with Level V is mainly distributed in the Poyang Lake Basin and the lower main stream of the Yangtze River. Moreover, the changes in disaster-causing risk of extreme precipitation are mainly manifested in the decrease of areas with low risk (Levels I and II) and the increase of areas with medium risk (Levels III and IV) in different periods.
{"title":"Projection of disaster-causing risk of extreme precipitation in the Yangtze River Basin based on CMIP6","authors":"Chengyu Xu, Canyu Yuan, Xianghu Li, Yaling Lin, Hongxiang Fan","doi":"10.2166/nh.2023.141","DOIUrl":"https://doi.org/10.2166/nh.2023.141","url":null,"abstract":"\u0000 Extreme precipitation is very sensitive to climate change. Global warming will significantly affect the frequency and intensity of extreme precipitation and further affect the spatio-temporal pattern of disaster-causing risk of extreme precipitation. This study analyzes the spatio-temporal trends of extreme precipitation and projects its disaster-causing risk under different climate scenarios in the Yangtze River Basin from 2021 to 2100. The results indicate that the extreme precipitation in the Yangtze River Basin shows an increasing trend in the future. Annual precipitation (PRCPTOT) increases by 33.05–42.56% under five scenarios compared with the historical period. The future change in heavy precipitation (R95p) also shows a significant increase, but heavy rain days (R50) and 5-day maximum precipitation (RX5day) decrease. The disaster-causing risk of extreme precipitation in the Yangtze River Basin is mainly Levels III and IV, accounting for 57.23–65.99% of the total basin area. The area with Level V is mainly distributed in the Poyang Lake Basin and the lower main stream of the Yangtze River. Moreover, the changes in disaster-causing risk of extreme precipitation are mainly manifested in the decrease of areas with low risk (Levels I and II) and the increase of areas with medium risk (Levels III and IV) in different periods.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45189683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mengru Zhang, Xiaoli Yang, M. Pan, Linyan Zhang, Xiuqin Fang, J. Sheffield
The characteristics of meteorological drought in different river basins in China have clear spatio-temporal differences and the difference between watersheds is also reflected in the influence mechanism of meteorological drought. This study investigated the meteorological drought risk under different future emission scenarios, based on the Coupled Model Intercomparison Project 6 (CMIP6). Furthermore, we explored the influence of precipitation and temperature on meteorological drought in different basins of China in the future. Meanwhile, the uncertainty associated with CMIP6 in different watersheds is also considered. In the future, the frequency of meteorological drought events mainly shows a decreasing trend, but the drought intensity and duration increase. In China, the rate of probability change in drought's intensity was greater than drought duration and the probability distribution of drought characteristics is significantly different between the historical and the future periods. Under the low and medium emission scenarios (SSP126 and SSP245), the Joint Recurrence Period of future drought intensity and duration increases and the Recurrence Period decreases in the western and north-eastern basins. Precipitation plays a major role in the meteorological drought, especially in the northeast and southeast basins of China.
{"title":"Spatio-temporal characteristics and driving factors of the meteorological drought across China based on CMIP6","authors":"Mengru Zhang, Xiaoli Yang, M. Pan, Linyan Zhang, Xiuqin Fang, J. Sheffield","doi":"10.2166/nh.2023.130","DOIUrl":"https://doi.org/10.2166/nh.2023.130","url":null,"abstract":"\u0000 The characteristics of meteorological drought in different river basins in China have clear spatio-temporal differences and the difference between watersheds is also reflected in the influence mechanism of meteorological drought. This study investigated the meteorological drought risk under different future emission scenarios, based on the Coupled Model Intercomparison Project 6 (CMIP6). Furthermore, we explored the influence of precipitation and temperature on meteorological drought in different basins of China in the future. Meanwhile, the uncertainty associated with CMIP6 in different watersheds is also considered. In the future, the frequency of meteorological drought events mainly shows a decreasing trend, but the drought intensity and duration increase. In China, the rate of probability change in drought's intensity was greater than drought duration and the probability distribution of drought characteristics is significantly different between the historical and the future periods. Under the low and medium emission scenarios (SSP126 and SSP245), the Joint Recurrence Period of future drought intensity and duration increases and the Recurrence Period decreases in the western and north-eastern basins. Precipitation plays a major role in the meteorological drought, especially in the northeast and southeast basins of China.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46924459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Clemenzi, D. Gustafsson, Wolf-Dietrich Marchand, B. Norell, J. Zhang, R. Pettersson, V. Pohjola
Snow in the mountains is essential for the water cycle in cold regions. The complexity of the snow processes in such an environment makes it challenging for accurate snow and runoff predictions. Various snow modelling approaches have been developed, especially to improve snow predictions. In this study, we compared the ability to improve runoff predictions in the Överuman Catchment, Northern Sweden, using different parametric representations of snow distribution. They included a temperature-based method, a snowfall distribution (SF) function based on wind characteristics and a snow depletion curve (DC). Moreover, we assessed the benefit of using distributed snow observations in addition to runoff in the hydrological model calibration. We found that models with the SF function based on wind characteristics better predicted the snow water equivalent (SWE) close to the peak of accumulation than models without this function. For runoff predictions, models using the SF function and the DC showed good performances (median Nash–Sutcliffe efficiency equal to 0.71). Despite differences among the calibration criteria for the different snow process representations, snow observations in model calibration added values for SWE and runoff predictions.
{"title":"Impact of snow distribution modelling for runoff predictions","authors":"I. Clemenzi, D. Gustafsson, Wolf-Dietrich Marchand, B. Norell, J. Zhang, R. Pettersson, V. Pohjola","doi":"10.2166/nh.2023.043","DOIUrl":"https://doi.org/10.2166/nh.2023.043","url":null,"abstract":"\u0000 Snow in the mountains is essential for the water cycle in cold regions. The complexity of the snow processes in such an environment makes it challenging for accurate snow and runoff predictions. Various snow modelling approaches have been developed, especially to improve snow predictions. In this study, we compared the ability to improve runoff predictions in the Överuman Catchment, Northern Sweden, using different parametric representations of snow distribution. They included a temperature-based method, a snowfall distribution (SF) function based on wind characteristics and a snow depletion curve (DC). Moreover, we assessed the benefit of using distributed snow observations in addition to runoff in the hydrological model calibration. We found that models with the SF function based on wind characteristics better predicted the snow water equivalent (SWE) close to the peak of accumulation than models without this function. For runoff predictions, models using the SF function and the DC showed good performances (median Nash–Sutcliffe efficiency equal to 0.71). Despite differences among the calibration criteria for the different snow process representations, snow observations in model calibration added values for SWE and runoff predictions.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41794703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Haxton, G. Vesuviano, Samuel Pucknell, T. Kjeldsen
The current reservoir safety guidance within the UK recommends the use of the FSR/FEH rainfall-runoff model to estimate PMF (probable maximum flood) peak flows for reservoirs within the highest risk category (A). However, the FSR/FEH model has been superseded by the ReFH2 rainfall-runoff model for all other flood risk purposes in the UK. This study develops a new modelling framework for PMF estimation using ReFH2 by translating the assumptions made within the current FSR/FEH PMF procedure and applying these within the ReFH2 rainfall-runoff model. Peak flows from the methodology are compared with those from the FSR/FEH model for 400+ catchments. The study highlights the potential for ReFH2 to be used as the rainfall-runoff model for all return periods, up to and including the PMF, thereby paving the way for using the ReFH2 model for reservoir safety studies.
{"title":"Probable maximum flood: the potential for estimation in the UK using ReFH2","authors":"T. Haxton, G. Vesuviano, Samuel Pucknell, T. Kjeldsen","doi":"10.2166/nh.2023.117","DOIUrl":"https://doi.org/10.2166/nh.2023.117","url":null,"abstract":"\u0000 The current reservoir safety guidance within the UK recommends the use of the FSR/FEH rainfall-runoff model to estimate PMF (probable maximum flood) peak flows for reservoirs within the highest risk category (A). However, the FSR/FEH model has been superseded by the ReFH2 rainfall-runoff model for all other flood risk purposes in the UK. This study develops a new modelling framework for PMF estimation using ReFH2 by translating the assumptions made within the current FSR/FEH PMF procedure and applying these within the ReFH2 rainfall-runoff model. Peak flows from the methodology are compared with those from the FSR/FEH model for 400+ catchments. The study highlights the potential for ReFH2 to be used as the rainfall-runoff model for all return periods, up to and including the PMF, thereby paving the way for using the ReFH2 model for reservoir safety studies.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45595040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benjamin Exton, F. Hassard, Angel Medina Vaya, R. Grabowski
Organic pollution continues to contaminate river water and degrade aquatic ecosystems worldwide. In heavily modified river systems with high organic loading, sewage fungus, a heterotrophic biofilm, can form on the riverbed. The aim of this study was to determine how the polybacterial community of riverbed biofilms changes prior to and during a sewage fungus outbreak to inform the development of novel biomonitoring approaches. Riverbed biofilm samples were collected from a site that experienced sewage fungus outbreaks previously and an upstream control, following a BACI design. The polybacterial community was characterized using targeted amplicon sequencing (16s rRNA). The results indicate that the community became dominated by two genera prior to and during the sewage fungus outbreak, Rhodoferax and Sphaerotilus, which accounted for 32.8 and 14.2% of the relative abundance. When aggregated at a higher taxonomic level, the genetic data show that the community was comprised largely of bacteria from a single family, Comamonadaceae, totalling 64.1% of the relative abundance. Statistically significant differences in the polybacterial community over time and between impact and control sites provide initial evidence that genetic-based fingerprinting could be a promising biosentinel approach to identify organic pollution inputs and monitor their ecological impact.
{"title":"Polybacterial shift in benthic river biofilms attributed to organic pollution – a prospect of a new biosentinel?","authors":"Benjamin Exton, F. Hassard, Angel Medina Vaya, R. Grabowski","doi":"10.2166/nh.2023.114","DOIUrl":"https://doi.org/10.2166/nh.2023.114","url":null,"abstract":"\u0000 Organic pollution continues to contaminate river water and degrade aquatic ecosystems worldwide. In heavily modified river systems with high organic loading, sewage fungus, a heterotrophic biofilm, can form on the riverbed. The aim of this study was to determine how the polybacterial community of riverbed biofilms changes prior to and during a sewage fungus outbreak to inform the development of novel biomonitoring approaches. Riverbed biofilm samples were collected from a site that experienced sewage fungus outbreaks previously and an upstream control, following a BACI design. The polybacterial community was characterized using targeted amplicon sequencing (16s rRNA). The results indicate that the community became dominated by two genera prior to and during the sewage fungus outbreak, Rhodoferax and Sphaerotilus, which accounted for 32.8 and 14.2% of the relative abundance. When aggregated at a higher taxonomic level, the genetic data show that the community was comprised largely of bacteria from a single family, Comamonadaceae, totalling 64.1% of the relative abundance. Statistically significant differences in the polybacterial community over time and between impact and control sites provide initial evidence that genetic-based fingerprinting could be a promising biosentinel approach to identify organic pollution inputs and monitor their ecological impact.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45553390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Bahmanpouri, D. Termini, S. Barbetta, M. Dionigi, T. Moramarco
Hydraulic complexity metrics referred to as M1 and M2 play an important role when it comes to the analysis of habitat metrics. In the present paper, the significance of these parameters is analysed by using laboratory data as well as field observations along the Tiber River in Italy. Based on the laboratory data, the estimated parameters allow us to characterize the high/low-velocity areas. Based on field observations, larger magnitudes of M1 are linked to the zones with large changes in cross-sectional flow velocity. Larger magnitudes of M2 are observed at the left bank of the channel for all flow conditions, suggesting locations with larger kinetic energy consumption for aquatic organisms. Overall, the findings of the present research would be of particular interest in quantifying biologically important flow patterns occurring at different spatial scales within different streams and flow conditions.
{"title":"Significance of hydraulic complexity parameters M1 and M2 based on the laboratory and field data","authors":"F. Bahmanpouri, D. Termini, S. Barbetta, M. Dionigi, T. Moramarco","doi":"10.2166/nh.2023.089","DOIUrl":"https://doi.org/10.2166/nh.2023.089","url":null,"abstract":"\u0000 Hydraulic complexity metrics referred to as M1 and M2 play an important role when it comes to the analysis of habitat metrics. In the present paper, the significance of these parameters is analysed by using laboratory data as well as field observations along the Tiber River in Italy. Based on the laboratory data, the estimated parameters allow us to characterize the high/low-velocity areas. Based on field observations, larger magnitudes of M1 are linked to the zones with large changes in cross-sectional flow velocity. Larger magnitudes of M2 are observed at the left bank of the channel for all flow conditions, suggesting locations with larger kinetic energy consumption for aquatic organisms. Overall, the findings of the present research would be of particular interest in quantifying biologically important flow patterns occurring at different spatial scales within different streams and flow conditions.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44531710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mobilia, A. Longobardi, Donato Amitrano, G. Ruello
Urban growth will lead cities to adopt best management practices in order to mitigate the relevant effects, such as an amplification of the hydrological cycle. The use of synthetic-aperture radar (SAR) imagery allowed us to demonstrate, over a period of 20 years (1995–2016), a massive urban development with a 70% increase in the built-up area in the Sarno River basin, in southern Italy, the most polluted river in Europe. Contextually, with the collection of an archive of damaging hydrological events that occurred during the same period, it was possible to identify a potential cause–effect relationship between their statistically significant temporal increase and the increase in the impervious area at the catchment scale provided by satellite imagery analysis. In order to restore the pre-urban development hydrological conditions, a scenario analysis was undertaken where the Storm Water Management Model was used to simulate the hydrological effect of a green roof retrofitting landscape design. SAR imagery was furthermore used to explore the potential retrofitting surfaces, leading to the definition of three different conversion scenarios, accounting for 5, 30, and 100% of potential retrofitting surfaces. The study demonstrated that…..
{"title":"Land use and damaging hydrological events causing temporal changes in the Sarno River basin: potential for green technologies mitigation by remote sensing analysis","authors":"M. Mobilia, A. Longobardi, Donato Amitrano, G. Ruello","doi":"10.2166/nh.2023.036","DOIUrl":"https://doi.org/10.2166/nh.2023.036","url":null,"abstract":"\u0000 Urban growth will lead cities to adopt best management practices in order to mitigate the relevant effects, such as an amplification of the hydrological cycle. The use of synthetic-aperture radar (SAR) imagery allowed us to demonstrate, over a period of 20 years (1995–2016), a massive urban development with a 70% increase in the built-up area in the Sarno River basin, in southern Italy, the most polluted river in Europe. Contextually, with the collection of an archive of damaging hydrological events that occurred during the same period, it was possible to identify a potential cause–effect relationship between their statistically significant temporal increase and the increase in the impervious area at the catchment scale provided by satellite imagery analysis. In order to restore the pre-urban development hydrological conditions, a scenario analysis was undertaken where the Storm Water Management Model was used to simulate the hydrological effect of a green roof retrofitting landscape design. SAR imagery was furthermore used to explore the potential retrofitting surfaces, leading to the definition of three different conversion scenarios, accounting for 5, 30, and 100% of potential retrofitting surfaces. The study demonstrated that…..","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44658175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While it is known that antecedent conditions and rainfall profiles contribute to the nonlinearity of streamflow response and that hydrograph shape can be dependent on the nature of rainfall inputs, how antecedent conditions (with similar rainfall inputs) impact hydrograph shape is less known. Here, a data-based mechanistic (DBM) approach is applied to quantify hydrograph shape, in terms of timing and volume, for the purposes of comparing hydrographs across 17 micro-basins at selected localities in upland UK over a 4-year period. The analysis demonstrates the nonlinearity of storm response for small catchments and revealed that with low antecedent conditions and/or small rainfall inputs there was a high variance in hydrograph shape quantifiers and that these variances decrease (at rates micro-basin dependent) as the micro-basins became wetter or as the storms increased in size, potentially converging to a more stable response.
{"title":"Rainfall–streamflow response times for diverse upland UK micro-basins: quantifying hydrographs to identify the nonlinearity of storm response","authors":"D. Mindham, K. Beven, N. Chappell","doi":"10.2166/nh.2023.115","DOIUrl":"https://doi.org/10.2166/nh.2023.115","url":null,"abstract":"\u0000 While it is known that antecedent conditions and rainfall profiles contribute to the nonlinearity of streamflow response and that hydrograph shape can be dependent on the nature of rainfall inputs, how antecedent conditions (with similar rainfall inputs) impact hydrograph shape is less known. Here, a data-based mechanistic (DBM) approach is applied to quantify hydrograph shape, in terms of timing and volume, for the purposes of comparing hydrographs across 17 micro-basins at selected localities in upland UK over a 4-year period. The analysis demonstrates the nonlinearity of storm response for small catchments and revealed that with low antecedent conditions and/or small rainfall inputs there was a high variance in hydrograph shape quantifiers and that these variances decrease (at rates micro-basin dependent) as the micro-basins became wetter or as the storms increased in size, potentially converging to a more stable response.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42138365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Droughts are defined by a prolonged absence of moisture. For making drought assessments, a drought index is a crucial tool. This study aims to compare drought characteristics across the Central Main Ethiopian Rift using three drought indices – the Standardized Precipitation Index (SPI), the Reconnaissance Drought Index (RDI), and the Standardized Precipitation Evapotranspiration Index – from 1980 to 2017 at six climate sites in spring, summer, and a 6-month period (March–August). With 1 and 5% significance levels, the modified Mann–Kendall and Sen's Slope estimators were used to determine trend and magnitude, respectively. The temporal fluctuations of the three drought indices revealed that droughts are frequent, unpredictable, and random. Furthermore, they behaved similarly and had significant links. At most places, the drought indices found no significant trends. However, in the spring season, Butajira (by the three indices) and Wulbareg (by the SPI) showed significantly decreasing trends (increasing drought severity), with change rates ranging from −0.03 to −0.04/year. A comparison of drought characteristics from 1980–1998 and 1999–2017 droughts have been more severe and frequent in recent decades, with spring being more prevalent than summer. This study, which employed a variety of drought indices, could assist water resource planners in better understanding drought events.
{"title":"A comparative study of drought characteristics using meteorological drought indices over the central main Ethiopian Rift","authors":"W. Hailesilassie, T. Ayenew, S. Tekleab","doi":"10.2166/nh.2023.091","DOIUrl":"https://doi.org/10.2166/nh.2023.091","url":null,"abstract":"\u0000 Droughts are defined by a prolonged absence of moisture. For making drought assessments, a drought index is a crucial tool. This study aims to compare drought characteristics across the Central Main Ethiopian Rift using three drought indices – the Standardized Precipitation Index (SPI), the Reconnaissance Drought Index (RDI), and the Standardized Precipitation Evapotranspiration Index – from 1980 to 2017 at six climate sites in spring, summer, and a 6-month period (March–August). With 1 and 5% significance levels, the modified Mann–Kendall and Sen's Slope estimators were used to determine trend and magnitude, respectively. The temporal fluctuations of the three drought indices revealed that droughts are frequent, unpredictable, and random. Furthermore, they behaved similarly and had significant links. At most places, the drought indices found no significant trends. However, in the spring season, Butajira (by the three indices) and Wulbareg (by the SPI) showed significantly decreasing trends (increasing drought severity), with change rates ranging from −0.03 to −0.04/year. A comparison of drought characteristics from 1980–1998 and 1999–2017 droughts have been more severe and frequent in recent decades, with spring being more prevalent than summer. This study, which employed a variety of drought indices, could assist water resource planners in better understanding drought events.","PeriodicalId":55040,"journal":{"name":"Hydrology Research","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45296160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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