Assessing flow intermittence in France under climate change

2020 ◽  
Author(s):  
Aurélien Beaufort ◽  
Quentin Bottet ◽  
Guillaume Thirel ◽  
Eric Sauquet
Keyword(s):  
Climate Change ◽  
Empirical Model ◽  
Headwater Streams ◽  
Low Flow ◽  
Additional Stress ◽  
Discrete Observations ◽  
Aquatic Life ◽  
Current Climate ◽  
Intermittent Rivers ◽  
Flow Intermittence

<p>With climate change, perennial headwater streams are expected to become intermittent and intermittent rivers to dry more often due to more severe droughts, placing additional stress on aquatic life and new constraints for water management.</p><p>In this study, we quantify the changes in river flow intermittence across France over the 21st century. Using global hydrological model calibrated on gauging stations is certainly hazardous to assess changes in flow intermittence at a fine resolution (i.e. in headwater streams). Here, we suggest a modelling framework supported by field observations performed on a large number of French intermittent streams:</p><p>- we used discrete observations from the ONDE network set up by the French Biodiversity Agency recording summer low‐flow levels once a month. ONDE sites are located on headwater streams with a Strahler order strictly less than five and evenly distributed throughout France;</p><p>- a model developed by Beaufort et al. (2017) was adapted to simulate the regional probability of drying of headwater streams (RPoD) under climate change. This empirical model is based on regional relationships established between the non-exceedance frequencies of daily discharges and the proportion of drying statuses observed at ONDE sites. Calibration was performed against the discrete flow states available at 3300 ONDE sites between May and October from 2012 to 2018. The model used daily discharges simulated at 568 gauging stations by the GR6J rainfall-runoff model (Pushpalatha et al., 2011).</p><p>An ensemble of 26 high-resolution projections has been derived from GCM simulations under RCP2.6 and RCP8.5 emission scenarios, applying an advanced delta change approach (van Pelt et al., 2012). Daily discharge time series at the 568 gauging stations obtained from GR6J with the GCM-driven forcings have been used as inputs of the empirical model to estimate RPoD under future climate conditions.</p><p>Characteristics of flow intermittence between May and October have been studied over France divided into 22 Hydro-EcoRegion. Results for the periods 2021-2050 and 2071-2100 show an increase in RPoD with time. The mean RPod over the whole period May–October is 12% at the national scale under the current climate, compared to 20% and 23% on average all RCPs together for the periods 2021-2050 and 2071-2100, respectively. The changes are significant in regions with historically high probability of drying. On the other hand, no change is detected in the Alps. This last result is debatable since, in these areas and under the current climate, low flows are mostly observed in winter, the ONDE sites are sparse and the model predicting RPoD shows the worst performance.</p><p>References:</p><p>Beaufort et al.: Extrapolating regional probability of drying of headwater streams using discrete observations and gauging networks, Hydrol. Earth Syst. Sci., 22(5), 3033–3051, 2018.</p><p>Pushpalatha et al.: A downward structural sensitivity analysis of hydrological models to improve low-flow simulation, J. Hydrol., 411, 66–76, 2011.</p><p>van Pelt et al.: Future changes in extreme precipitation in the Rhine basin based on global and regional climate model simulations, Hydrol. Earth Syst. Sci., 16, 4517–4530, 2012.</p>

scholarly journals Extrapolating regional probability of drying of headwater streams using discrete observations and gauging networks

2017 ◽  
Author(s):  
Aurélien Beaufort ◽  
Nicolas Lamouroux ◽  
Hervé Pella ◽  
Thibault Datry ◽  
Eric Sauquet
Keyword(s):  
Headwater Streams ◽  
Regional Scale ◽  
National Level ◽  
Ephemeral Streams ◽  
Field Observations ◽  
Discrete Observations ◽  
Data Set ◽  
Intermittent Rivers ◽  
The Impact ◽  
Flow Intermittence

Abstract. Headwater streams represent a substantial proportion of river systems and have frequently flows intermittence due to their upstream position in the network. These intermittent rivers and ephemeral streams have recently seen a marked increase in interest, especially to assess the impact of drying on aquatic ecosystems. The objective of this paper is to quantify how discrete (in space and time) field observations of flow intermittence help to extrapolate the daily probability of drying at the regional scale. Two empirical models based on linear or logistic regressions have been developed to predict the daily probability of intermittence at the regional scale across France. Explanatory variables were derived from available daily discharge and groundwater level data of a dense gauging/piezometer network, and models were calibrated using discrete series of field observations of flow intermittence. The robustness of the models was tested using (1) an independent, dense regional data set of intermittence observations, (2) observations of the year 2017 excluded from the calibration. The resulting models were used to simulate the regional probability of drying in France: (i) over the period 2011–2017 to identify the regions most affected by flow intermittence; (ii) over the period 1989–2017, using a reduced input dataset, to analyze temporal variability of flow intermittence at the national level. The two regressions models performed equally well between 2011 and 2017. The accuracy of predictions depended on the number of continuous gauging/piezometer stations and intermittence observations available to calibrate the regressions. Regions with the highest performance were located in sedimentary plains, where the monitoring network was dense and where the regional probability of drying was the highest. Conversely, worst performances were obtained in mountainous regions. Finally, temporal projections (1989–2016) suggested highest probabilities of intermittence (> 35 %) in 1989–1991, 2003 and 2005. A high density of intermittence observations improved the information provided by gauging stations and piezometers to extrapolate the spatial distribution of intermittent rivers and ephemeral streams.

scholarly journals Extrapolating regional probability of drying of headwater streams using discrete observations and gauging networks

2018 ◽  
Vol 22 (5) ◽  
pp. 3033-3051 ◽  
Author(s):  
Aurélien Beaufort ◽  
Nicolas Lamouroux ◽  
Hervé Pella ◽  
Thibault Datry ◽  
Eric Sauquet
Keyword(s):  
Temporal Variability ◽  
Headwater Streams ◽  
Regional Scale ◽  
National Level ◽  
Ephemeral Streams ◽  
Field Observations ◽  
Discrete Observations ◽  
Intermittent Rivers ◽  
The Impact ◽  
Flow Intermittence

Abstract. Headwater streams represent a substantial proportion of river systems and many of them have intermittent flows due to their upstream position in the network. These intermittent rivers and ephemeral streams have recently seen a marked increase in interest, especially to assess the impact of drying on aquatic ecosystems. The objective of this paper is to quantify how discrete (in space and time) field observations of flow intermittence help to extrapolate over time the daily probability of drying (defined at the regional scale). Two empirical models based on linear or logistic regressions have been developed to predict the daily probability of intermittence at the regional scale across France. Explanatory variables were derived from available daily discharge and groundwater-level data of a dense gauging/piezometer network, and models were calibrated using discrete series of field observations of flow intermittence. The robustness of the models was tested using an independent, dense regional dataset of intermittence observations and observations of the year 2017 excluded from the calibration. The resulting models were used to extrapolate the daily regional probability of drying in France: (i) over the period 2011–2017 to identify the regions most affected by flow intermittence; (ii) over the period 1989–2017, using a reduced input dataset, to analyse temporal variability of flow intermittence at the national level. The two empirical regression models performed equally well between 2011 and 2017. The accuracy of predictions depended on the number of continuous gauging/piezometer stations and intermittence observations available to calibrate the regressions. Regions with the highest performance were located in sedimentary plains, where the monitoring network was dense and where the regional probability of drying was the highest. Conversely, the worst performances were obtained in mountainous regions. Finally, temporal projections (1989–2016) suggested the highest probabilities of intermittence (> 35 %) in 1989–1991, 2003 and 2005. A high density of intermittence observations improved the information provided by gauging stations and piezometers to extrapolate the temporal variability of intermittent rivers and ephemeral streams.

Estimation of the annual runoff distribution of the Siverskyi Donets River Basin in the period of current climate change

2020 ◽  
Author(s):  
Hanna Bolbot ◽  
Vasyl Grebin
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Annual Runoff ◽  
Low Flow ◽  
Left Bank ◽  
Spring Flood ◽  
Current Period ◽  
Current Climate ◽  
Annual Runoff Distribution ◽  
The Right

<p>The most urgent tasks facing hydrologists of Ukraine and the world include identifying patterns of rivers hydrological regime against the background of global warming, and assessing these changes. Changes in the annual runoff distribution under climate change impact require separate investigation of anthropogenically altered catchments, such as the Siverskyi Donets River Basin. Siverskyi Donets is the largest river in Eastern Ukraine and the main source of water supply for Kharkiv, Luhansk and Donetsk regions.</p><p>The annual runoff distribution of the Siverskyi Donets River Basin was evaluated by two periods: to the beginning of pronounced climatic changes and the current period. The research is proposed for three water year types: wet year, average year and dry year. The Siverskyi Donets Basin is a complicated water body with peculiar physico-geographical conditions, because of that annual runoff distribution is somewhat different for the left-bank tributaries, right-bank tributaries and, in fact, the Siverskyi Donets River itself.</p><p>It is found that the most runoff of the wet year for both periods is in the spring months. The current period is characterized by a much smaller runoff of spring flood (from the volume of annual runoff) than in the previous period. The annual runoff distribution is offset. Some differences can be observed between the left and right tributaries. For the left-bank tributaries, which has less anthropogenic load, climate change has led to a significant increase of winter and summer-autumn low flow periods. On the right tributaries of the Siverskyi Donets, which are flowing within the industrial part of the Donbass, the low flow period has not changed, or even decreased. Such situation is due to the decrease of mine water disposal because of the industrial production decrease in the region.</p><p>The largest part of the annual runoff in the average year falls on February and March. In the current period, the spring flood has decreased, but the summer and autumn low flow period has increased. The left-bank tributaries runoff during the winter low period is decrease. Instead, the runoff attributable to the autumn and winter low period has increased for the right-bank tributaries and the Siverskyi Donets itself.</p><p>Analyzing the runoff distribution of dry year, we can conclude that the most wet is February. At present, in dry years, spring flood practically are not allocated from the hydrograph; the baseflow months runoff significantly increased. The volume of winter runoff of the Siverskyi Donets River Basin is increased. Actually, for the Siverskyi Donets River the runoff of the summer period has increased and the runoff of the winter and autumn periods has decreased at the present stage.</p><p>The annual runoff distribution of the Siverskyi Donets River Basin in the current climate change has undergone significant changes: the spring flood has decreased and the summer-autumn low flow has increased.</p>

scholarly journals Water and Ice Regime of te Mayma River (the Altay Mountains) in the Context of the Current Climate Change

2019 ◽  
Author(s):  
Keyword(s):  
Climate Change ◽  
Background Level ◽  
Annual Runoff ◽  
Climatic Conditions ◽  
Soil Freezing ◽  
Low Flow ◽  
Winter Warming ◽  
Current Climate ◽  
Average Maximum ◽  
Ice Regime

The paper considers changes in the annual and seasonal runoff, as well as the ice regime of the Mayma River in response to changing climatic conditions in the catchment area during the period of 1940–2016. Significant positive trends, especially occurring during the winter months, have been identified in the long-term course of annual and seasonal air temperatures. A significant decrease in precipitation rate is observed in the cold period of the year. According to the analysis of the hydrological characteristics for the periods of 1940–1975 (the background period) and of 1976–2016 (the period of contemporary climate change), the annual runoff for the Mayma River basin shows a downward trend against the background of the observed climatic changes. The decrease in annual flow is the result of a decrease in the flood flow. Thus, with the observed winter warming and a decrease in the amount of solid precipitation, the average maximum discharge for the wettest month (April) decreased by 35 % in the period of 1976–2016 with respect to the background level of the 1940–1976 period. Winter warming contributes to less soil freezing and replenishment of groundwater during periods of winter thaw and intensive snowmelt, which lead to an increase in runoff in the last winter months and the first months of summer-autumn low-flow periods. Winter warming manifested itself in the ice mode of the river Mayma. Since the beginning of the period of the current climate change (1976) there has been an observed decrease in the duration of ice freeze-up and a shift towards later freezing dates and earlier break-up dates.

scholarly journals Impacts of climate change on the seasonality of low flows in 134 catchments in the River Rhine basin using an ensemble of bias-corrected regional climate simulations

2013 ◽  
Vol 17 (10) ◽  
pp. 4241-4257 ◽  
Author(s):  
M. C. Demirel ◽  
M. J. Booij ◽  
A. Y. Hoekstra
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Regional Climate ◽  
Future Climate ◽  
Low Flow ◽  
River Rhine ◽  
Emission Scenarios ◽  
Low Flows ◽  
Current Climate ◽  
The Future

Abstract. The impacts of climate change on the seasonality of low flows were analysed for 134 sub-catchments covering the River Rhine basin upstream of the Dutch-German border. Three seasonality indices for low flows were estimated, namely the seasonality ratio (SR), weighted mean occurrence day (WMOD) and weighted persistence (WP). These indices are related to the discharge regime, timing and variability in timing of low flow events respectively. The three indices were estimated from: (1) observed low flows; (2) simulated low flows by the semi-distributed HBV model using observed climate as input; (3) simulated low flows using simulated inputs from seven combinations of General Circulation Models (GCMs) and Regional Climate Models (RCMs) for the current climate (1964–2007); (4) simulated low flows using simulated inputs from seven combinations of GCMs and RCMs for the future climate (2063–2098) including three different greenhouse gas emission scenarios. These four cases were compared to assess the effects of the hydrological model, forcing by different climate models and different emission scenarios on the three indices. Significant differences were found between cases 1 and 2. For instance, the HBV model is prone to overestimate SR and to underestimate WP and simulates very late WMODs compared to the estimated WMODs using observed discharges. Comparing the results of cases 2 and 3, the smallest difference was found for the SR index, whereas large differences were found for the WMOD and WP indices for the current climate. Finally, comparing the results of cases 3 and 4, we found that SR decreases substantially by 2063–2098 in all seven sub-basins of the River Rhine. The lower values of SR for the future climate indicate a shift from winter low flows (SR > 1) to summer low flows (SR < 1) in the two Alpine sub-basins. The WMODs of low flows tend to be earlier than for the current climate in all sub-basins except for the Middle Rhine and Lower Rhine sub-basins. The WP values are slightly larger, showing that the predictability of low flow events increases as the variability in timing decreases for the future climate. From comparison of the error sources evaluated in this study, it is obvious that different RCMs/GCMs have a larger influence on the timing of low flows than different emission scenarios. Finally, this study complements recent analyses of an international project (Rhineblick) by analysing the seasonality aspects of low flows and extends the scope further to understand the effects of hydrological model errors and climate change on three important low flow seasonality properties: regime, timing and persistence.

Influence of climate change on low flow conditions. Case study: Laborec River, eastern Slovakia

2021 ◽  
Author(s):  
Katarzyna Kubiak-Wójcicka ◽  
Martina Zeleňáková ◽  
Peter Blištan ◽  
Dorota Simonová ◽  
Agnieszka Pilarska
Keyword(s):  
Climate Change ◽  
Low Flow ◽  
Flow Conditions

scholarly journals Water Temperature and Hydrological Modelling in the Context of Environmental Flows and Future Climate Change: Case Study of the Wilmot River (Canada)

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2101
Author(s):  
Christian Charron ◽  
André St-Hilaire ◽  
Taha B.M.J. Ouarda ◽  
Michael R. van den Heuvel
Keyword(s):  
Climate Change ◽  
Water Temperature ◽  
Environmental Flows ◽  
Low Flow ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Water Abstraction ◽  
Surface Water Flow ◽  
Modelling Studies ◽  
Rcp 8.5

Simulation of surface water flow and temperature under a non-stationary, anthropogenically impacted climate is critical for water resource decision makers, especially in the context of environmental flow determination. Two climate change scenarios were employed to predict streamflow and temperature: RCP 8.5, the most pessimistic with regards to climate change, and RCP 4.5, a more optimistic scenario where greenhouse gas emissions peak in 2040. Two periods, 2018–2050 and 2051–2100, were also evaluated. In Canada, a number of modelling studies have shown that many regions will likely be faced with higher winter flow and lower summer flows. The CEQUEAU hydrological and water temperature model was calibrated and validated for the Wilmot River, Canada, using historic data for flow and temperature. Total annual precipitation in the region was found to remain stable under RCP 4.5 and increase over time under RCP 8.5. Median stream flow was expected to increase over present levels in the low flow months of August and September. However, increased climate variability led to higher numbers of periodic extreme low flow events and little change to the frequency of extreme high flow events. The effective increase in water temperature was four-fold greater in winter with an approximate mean difference of 4 °C, while the change was only 1 °C in summer. Overall implications for native coldwater fishes and water abstraction are not severe, except for the potential for more variability, and hence periodic extreme low flow/high temperature events.

scholarly journals Soil microbial inoculation during flood events shapes headwater stream microbial communities and diversity

2021 ◽  
Author(s):  
Florian Caillon ◽  
Katharina Besemer ◽  
Peter Peduzzi ◽  
Jakob Schelker
Keyword(s):  
Microbial Diversity ◽  
Bacterial Diversity ◽  
Soil Water ◽  
Headwater Streams ◽  
High Flow ◽  
Low Flow ◽  
Flood Events ◽  
Flow Conditions ◽  
Soil Microbial ◽  
Microbial Inoculation

AbstractFlood events are now recognized as potentially important occasions for the transfer of soil microbes to stream ecosystems. Yet, little is known about these “dynamic pulses of microbial life” for stream bacterial community composition (BCC) and diversity. In this study, we explored the potential alteration of stream BCC by soil inoculation during high flow events in six pre-alpine first order streams and the larger Oberer Seebach. During 1 year, we compared variations of BCC in soil water, stream water and in benthic biofilms at different flow conditions (low to intermediate flows versus high flow). Bacterial diversity was lowest in biofilms, followed by soils and highest in headwater streams and the Oberer Seebach. In headwater streams, bacterial diversity was significantly higher during high flow, as compared to low flow (Shannon diversity: 7.6 versus 7.9 at low versus high flow, respectively, p < 0.001). Approximately 70% of the bacterial operational taxonomic units (OTUs) from streams and stream biofilms were the same as in soil water, while in the latter one third of the OTUs were specific to high flow conditions. These soil high-flow OTUs were also found in streams and biofilms at other times of the year. These results demonstrate the relevance of floods in generating short and reoccurring inoculation events for flowing waters. Moreover, they show that soil microbial inoculation during high flow enhances microbial diversity and shapes fluvial BCC even during low flow. Hence, soil microbial inoculation during floods could act as a previously overlooked driver of microbial diversity in headwater streams.

Sign in / Sign up

Export Citation Format

Share Document