| 1. |
- Ameli, Ali A.
(författare)
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Controls on subsurface transport of sorbing contaminant
- 2017
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Ingår i: Hydrology Research. - : IWA PUBLISHING. - 1998-9563 .- 2224-7955 .- 0029-1277. ; 48:5, s. 1226-1239
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Tidskriftsartikel (refereegranskat)abstract
- Subsurface transport of a sorbing contaminant is poorly understood and characterized. Here, a new semi-analytical saturated-unsaturated flow and transport model is coupled to a kinetic sorption algorithm to assess the impact of changes in the subsurface permeability architecture and flow rate on sorption characteristics. The model outputs reveal the pronounced effect of the rate of vertical decline in K-s on the frequency of occurrence and spatial distribution of subsurface sorption as well as the timing and rate of sorbing contaminants discharged into stream. Sorption potential is weakened with infiltration rate. The impact of infiltration rate on the decline in sorption potential becomes more accentuated as the degree of subsurface vertical heterogeneity in saturated hydraulic conductivity increases. Porosity pattern also impacts sorption characteristics; but its effects highly depend upon the degree of vertical heterogeneity in Ks. The results and methodology presented in this paper have potential implications for assessing water quality in integrated groundwater-surface water systems as well as designing remediation systems.
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| 2. |
- Baresel, Christian, et al.
(författare)
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Diffuse subsurface zinc loads from mining areas in the Dalälven River Basin, Sweden
- 2009
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 0029-1277 .- 2224-7955. ; 40:5, s. 445-453
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Tidskriftsartikel (refereegranskat)abstract
- The zinc load from the Dalalven River to the Baltic Sea is greater than for any other watercourse in Sweden. This paper investigates zinc mass flows into and through the Dalalven River from major mining areas within its drainage basin. Reported zinc mass flow data for this river are re-analyzed using an input-output flow analysis approach. Results show major inconsistencies in previous data interpretations which totally neglected possible zinc mass load contributions from the groundwater system to the river. This paper quantifies significant subsurface zinc load contributions that are consistent with all independently available data. Furthermore, a possible explanation for why these subsurface contributions may have been missed in previous studies and by the prevailing Swedish environmental monitoring system is provided. The study indicates that the input-output flow analysis approach may be generally useful for identifying and quantifying diffuse, unmonitored and uncertain pollutant load contributions from ground- to surface water systems.
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| 3. |
- Bengtsson, Lars
(författare)
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Daily and hourly rainfall distribution in space and time - conditions in southern Sweden
- 2011
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 0029-1277 .- 2224-7955. ; 42:2-3, s. 86-94
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Tidskriftsartikel (refereegranskat)abstract
- Very extreme events occur randomly in space and in time. In this paper daily precipitation from more than 200 stations within a 10 000 km(2) region in the very south of Sweden is analysed. While there is a relation between moderate daily precipitation and annual precipitation, the most extreme events are found to be independent of annual precipitation and also of altitude and distance to the sea. The most extreme events are distributed evenly over the region. Variations of the climate are considered. For three cities daily storms are analysed for a period of 89 years. No trend over time is found of the daily high precipitation. Hourly storms are analysed for four stations within the city of Malmo. The probability of concurrent events is rather high, but there is little correlation between the rain intensities at the different stations during the most intense events.
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| 4. |
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| 5. |
- Bengtsson, Lars
(författare)
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Preface
- 2008
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 0029-1277 .- 2224-7955. ; 39:4
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Tidskriftsartikel (refereegranskat)
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| 6. |
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| 7. |
- Bengtsson, Lars
(författare)
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The dependence of the consumption of dissolved oxygen on lake morphology in ice covered lakes.
- 2020
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 0029-1277 .- 2224-7955. ; 51:3, s. 381-391
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Tidskriftsartikel (refereegranskat)abstract
- The consumption of oxygen in ice covered lakes is analyzed and related to biological oxygen demand and sediment oxygen demand. An approach for computing dissolved oxygen concentration is suggested assuming horizontally mixed waters and negligible vertical dispersion. It is found that the depletion of dissolved oxygen is mainly due to the transfer of oxygen at the water/sediment interface. The morphology of a lake is very important for how fast the dissolved oxygen concentration is reduced during winter.
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| 8. |
- Berndtsson, Ronny
(författare)
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Classification of groundwater chemistry in Shimabara, using self-organizing maps
- 2017
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 0029-1277 .- 2224-7955. ; 48:3, s. 840-850
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Tidskriftsartikel (refereegranskat)abstract
- Shimabara City in Nagasaki Prefecture, Japan, is located on a volcanic peninsula that has abundant groundwater. Almost all public water supplies use groundwater in this region. For this reason, understanding groundwater characteristics is a pre-requisite for proper water supply management. Thus, we investigated the groundwater chemistry characteristics in Shimabara by use of self-organizing maps (SOMs). The input to SOM was concentrations of eight major groundwater chemical components, namely Cl−, NO3−, SO42–, HCO3−, Na+, K+, Mg2+, and Ca2+ collected at 36 sampling locations. The locations constituted private and public water supply wells, springs, and a river sampled from April 2012 to May 2015. Results showed that depending on the chemistry, surface water and groundwater could be classified into five main clusters displaying unique patterns. Further, the five clusters could be divided into two major water types, namely, nitrate- and non-polluted water. According to Stiff and Piper trilinear diagrams, the nitrate-polluted water represented Ca-(SO4 + NO3) (calcium sulfate nitrate) type, while the non-polluted water was classified as Ca-HCO3 (calcium bicarbonate) type. This indicates that recharging rain water in the upstream areas is polluted by agricultural activities in the mid-slope areas of Shimabara.
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| 9. |
- Bertini, Claudia, et al.
(författare)
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An entropy-based approach for the optimization of rain gauge network using satellite and ground-based data
- 2021
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 2224-7955 .- 0029-1277. ; 52:3, s. 620-635
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Tidskriftsartikel (refereegranskat)abstract
- Accurate and precise rainfall records are crucial for hydrological applications and water resources management. The accuracy and continuity of ground-based time series rely on the density and distribution of rain gauges over territories. In the context of a decline of rain gauge distribution, how to optimize and design optimal networks is still an unsolved issue. In this work, we present a method to optimize a ground-based rainfall network using satellite-based observations, maximizing the information content of the network. We combine Climate Prediction Center MORPhing technique (CMORPH) observations at ungauged locations with an existing rain gauge network in the Rio das Velhas catchment, in Brazil. We use a greedy ranking algorithm to rank the potential locations to place new sensors, based on their contribution to the joint entropy of the network. Results show that the most informative locations in the catchment correspond to those areas with the highest rainfall variability and that satellite observations can be successfully employed to optimize rainfall monitoring networks.
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| 10. |
- Bian, Guodong, et al.
(författare)
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Detection and attribution of flood responses to precipitation change and urbanization : A case study in Qinhuai River Basin, Southeast China
- 2020
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 0029-1277 .- 2224-7955. ; 51:2, s. 351-365
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Tidskriftsartikel (refereegranskat)abstract
- Both flood magnitude and frequency might change under the changing environment. In this study, a procedure combining statistical methods, flood frequency analysis and attribution analysis was proposed to investigate the response of floods to urbanization and precipitation change in the Qinhuai River Basin, an urbanized basin located in Southeast China, over the period from 1986 to 2013. The Mann–Kendall test was employed to detect the gradual trend of the annual maximum streamflow and the peaks over threshold series. The frequency analysis was applied to estimate the changes in the magnitude and frequency of floods between the baseline period (1986–2001) and urbanization period (2002–2013). An attribution analysis was proposed to separate the effects of precipitation change and urbanization on flood sizes between the two periods. Results showed that: (1) there are significant increasing trends in medium and small flood series according to the Mann–Kendall test; (2) the mean and threshold values of flood series in the urbanization period were larger than those in the baseline period, while the standard deviation, coefficient of variation and coefficient of skewness of flood series were both higher during the baseline period than those during the urbanization period; (3) the flood magnitude was higher during the urbanization period than that during the baseline period at the same return period. The relative changes in magnitude were larger for small floods than for big floods from the baseline period to the urbanization period; (4) the contributions of urbanization on floods appeared to amplify with the decreasing return period, while the effects of precipitation diminish. The procedure presented in this study could be useful to detect the changes of floods in the changing environment and conduct the attribution analysis of flood series. The findings of this study are beneficial to further understanding interactions between flood behavior and the drivers, thereby improving flood management in urbanized basins.
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