@article{DeusdaraLealSamprognaMohorCuartasetal.2022, author = {Deusdar{\´a}-Leal, Karinne and Samprogna Mohor, Guilherme and Cuartas, Luz Adriana and Seluchi, Marcelo E. and Marengo, Jose A. and Zhang, Rong and Broedel, Elisangela and Amore, Diogo de Jesus and Alval{\´a}, Regina C. S. and Cunha, Ana Paula M. A. and Gon{\c{c}}alves, Jos{\´e} A. C.}, title = {Trends and climate elasticity of streamflow in south-eastern Brazil basins}, series = {Water}, volume = {14}, journal = {Water}, number = {14}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w14142245}, pages = {25}, year = {2022}, abstract = {Trends in streamflow, rainfall and potential evapotranspiration (PET) time series, from 1970 to 2017, were assessed for five important hydrological basins in Southeastern Brazil. The concept of elasticity was also used to assess the streamflow sensitivity to changes in climate variables, for annual data and 5-, 10- and 20-year moving averages. Significant negative trends in streamflow and rainfall and significant increasing trend in PET were detected. For annual analysis, elasticity revealed that 1\% decrease in rainfall resulted in 1.21-2.19\% decrease in streamflow, while 1\% increase in PET induced different reductions percentages in streamflow, ranging from 2.45\% to 9.67\%. When both PET and rainfall were computed to calculate the elasticity, results were positive for some basins. Elasticity analysis considering 20-year moving averages revealed that impacts on the streamflow were cumulative: 1\% decrease in rainfall resulted in 1.83-4.75\% decrease in streamflow, while 1\% increase in PET induced 3.47-28.3\% decrease in streamflow. This different temporal response may be associated with the hydrological memory of the basins. Streamflow appears to be more sensitive in less rainy basins. This study provides useful information to support strategic government decisions, especially when the security of water resources and drought mitigation are considered in face of climate change.}, language = {en} } @article{RottlerVormoorFranckeetal.2021, author = {Rottler, Erwin and Vormoor, Klaus Josef and Francke, Till and Bronstert, Axel}, title = {Hydro Explorer}, series = {River research and applications}, volume = {37}, journal = {River research and applications}, number = {4}, publisher = {Wiley}, address = {New York}, issn = {1535-1459}, doi = {10.1002/rra.3772}, pages = {544 -- 554}, year = {2021}, abstract = {Climatic changes and anthropogenic modifications of the river basin or river network have the potential to fundamentally alter river runoff. In the framework of this study, we aim to analyze and present historic changes in runoff timing and runoff seasonality observed at river gauges all over the world. In this regard, we develop the Hydro Explorer, an interactive web app, which enables the investigation of >7,000 daily resolution discharge time series from the Global Runoff Data Centre (GRDC). The interactive nature of the developed web app allows for a quick comparison of gauges, regions, methods, and time frames. We illustrate the available analytical tools by investigating changes in runoff timing and runoff seasonality in the Rhine River Basin. Since we provide the source code of the application, existing analytical approaches can be modified, new methods added, and the tool framework can be re-used to visualize other data sets.}, language = {en} } @article{Ayzel2018, author = {Ayzel, Georgy V.}, title = {Runoff predictions in ungauged arctic basins using conceptual models forced by reanalysis data}, series = {Water Resources}, volume = {45}, journal = {Water Resources}, publisher = {Pleiades Publ.}, address = {New York}, issn = {0097-8078}, doi = {10.1134/S0097807818060180}, pages = {S1 -- S7}, year = {2018}, abstract = {Due to global warming, the problem of assessing water resources and their vulnerability to climate drivers in the Arctic region has become a focus in the recent years. This study is aimed at investigating three lumped hydrological models to predict daily runoff of large-scale Arctic basins in the case of substantial data scarcity. All models were driven only by meteorological forcing reanalysis dataset without any additional information about landscape, soil, or vegetation cover properties of the studied basins. Model parameter regionalization based on transferring the whole parameter set showed good efficiency for predictions in ungauged basins. We run a blind test of the proposed methodology for ensemble runoff predictions on five sub-basins, for which only monthly observations were available, and obtained promising results for current water resources assessment for a broad domain of ungauged basins in the Russian Arctic.}, language = {en} } @article{WeldeabRuehlemannBookhagenetal.2019, author = {Weldeab, Syee and R{\"u}hlemann, Carsten and Bookhagen, Bodo and Pausata, Francesco S. R. and Perez-Lua, Fabiola M.}, title = {Enhanced Himalayan glacial melting during YD and H1 recorded in the Northern Bay of Bengal}, series = {Geochemistry, geophysics, geosystems}, volume = {20}, journal = {Geochemistry, geophysics, geosystems}, number = {5}, publisher = {American Geophysical Union}, address = {Washington}, issn = {1525-2027}, doi = {10.1029/2018GC008065}, pages = {2449 -- 2461}, year = {2019}, abstract = {Ocean-land thermal feedback mechanisms in the Indian Summer Monsoon (ISM) domain are an important but not well understood component of regional climate dynamics. Here we present a O-18 record analyzed in the mixed-layer dwelling planktonic foraminifer Globigerinoides ruber (sensu stricto) from the northernmost Bay of Bengal (BoB). The O-18 time series provides a spatially integrated measure of monsoonal precipitation and Himalayan meltwater runoff into the northern BoB and reveals two brief episodes of anomalously low O-18 values between 16.30.4 and 160.5 and 12.60.4 and 12.30.4 thousand years before present. The timing of these events is centered at Heinrich event 1 and the Younger Dryas, well-known phases of weak northern hemisphere monsoon systems. Numerical climate model experiments, simulating Heinrich event-like conditions, suggest a surface warming over the monsoon-dominated Himalaya and foreland in response to ISM weakening. Corroborating the simulation results, our analysis of published moraine exposure ages in the monsoon-dominated Himalaya indicates enhanced glacier retreats that, considering age model uncertainties, coincide and overlap with the episodes of anomalously low O-18 values in the northernmost BoB. Our climate proxy and simulation results provide insights into past regional climate dynamics, suggesting reduced cloud cover, increased solar radiation, and air warming of the Himalaya and foreland areas and, as a result, glacier mass losses in response to weakened ISM. Plain Language Summary Indian Summer Monsoon rainfall and Himalayan glacier/snow melts constitute the main water source for the densely populated Indian subcontinent. Better understanding of how future climate changes will affect the monsoon rainfall and Himalayan glaciers requires a long climate record. In this study, we create a 13,000-year-long climate record that allows us to better understand the response of Indian Summer Monsoon rainfall and Himalayan glaciers to past climate changes. The focus of our study is the time window between 9,000 and 22,000 years ago, an episode where the global climate experienced large and rapid changes. Our sediment record from the northern Bay of Bengal and climate change simulation indicate that during episodes of weak monsoon, the melting of the Himalayan glaciers increases substantially significantly. This is because the weakening of the monsoon results in less cloud cover and, as a result, the surface receives more sunlight and causes glacier melting.}, language = {en} } @article{AyzelVarentsovaErinaetal.2019, author = {Ayzel, Georgy and Varentsova, Natalia and Erina, Oxana and Sokolov, Dmitriy and Kurochkina, Liubov and Moreydo, Vsevolod}, title = {OpenForecast}, series = {Water : Molecular Diversity Preservation International}, volume = {11}, journal = {Water : Molecular Diversity Preservation International}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w11081546}, pages = {17}, year = {2019}, abstract = {The development and deployment of new operational runoff forecasting systems are a strong focus of the scientific community due to the crucial importance of reliable and timely runoff predictions for early warnings of floods and flashfloods for local businesses and communities. OpenForecast, the first operational runoff forecasting system in Russia, open for public use, is presented in this study. We developed OpenForecast based only on open-source software and data-GR4J hydrological model, ERA-Interim meteorological reanalysis, and ICON deterministic short-range meteorological forecasts. Daily forecasts were generated for two basins in the European part of Russia. Simulation results showed a limited efficiency in reproducing the spring flood of 2019. Although the simulations managed to capture the timing of flood peaks, they failed in estimating flood volume. However, further implementation of the parsimonious data assimilation technique significantly alleviates simulation errors. The revealed limitations of the proposed operational runoff forecasting system provided a foundation to outline its further development and improvement.}, language = {en} } @article{DidovetsLobanovaBronstertetal.2017, author = {Didovets, Iulii and Lobanova, Anastasia and Bronstert, Axel and Snizhko, Sergiy and Maule, Cathrine Fox and Krysanova, Valentina}, title = {Assessment of Climate Change Impacts on Water Resources in Three Representative Ukrainian Catchments Using Eco-Hydrological Modelling}, series = {Water}, volume = {9}, journal = {Water}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w9030204}, pages = {18}, year = {2017}, abstract = {The information about climate change impact on river discharge is vitally important for planning adaptation measures. The future changes can affect different water-related sectors. The main goal of this study was to investigate the potential water resource changes in Ukraine, focusing on three mesoscale river catchments (Teteriv, UpperWestern Bug, and Samara) characteristic for different geographical zones. The catchment scale watershed model—Soil and Water Integrated Model (SWIM)—was setup, calibrated, and validated for the three catchments under consideration. A set of seven GCM-RCM (General Circulation Model-Regional Climate Model) coupled climate scenarios corresponding to RCPs (Representative Concentration Pathways) 4.5 and 8.5 were used to drive the hydrological catchment model. The climate projections, used in the study, were considered as three combinations of low, intermediate, and high end scenarios. Our results indicate the shifts in the seasonal distribution of runoff in all three catchments. The spring high flow occurs earlier as a result of temperature increases and earlier snowmelt. The fairly robust trend is an increase in river discharge in the winter season, and most of the scenarios show a potential decrease in river discharge in the spring.}, language = {en} } @article{MohrCoppusIroumeetal.2013, author = {Mohr, Christian Heinrich and Coppus, Ruben and Iroume, Andres and Huber, Anton and Bronstert, Axel}, title = {Runoff generation and soil erosion processes after clear cutting}, series = {Journal of geophysical research : Earth surface}, volume = {118}, journal = {Journal of geophysical research : Earth surface}, number = {2}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9003}, doi = {10.1002/jgrf.20047}, pages = {814 -- 831}, year = {2013}, abstract = {Timber harvesting by clear cutting is known to impose environmental impacts, including severe disturbance of the soil hydraulic properties which intensify the frequency and magnitude of surface runoff and soil erosion. However, it remains unanswered if harvest areas act as sources or sinks for runoff and soil erosion and whether such behavior operates in a steady state or evolves through time. For this purpose, 92 small-scale rainfall simulations of different intensities were carried out under pine plantation conditions and on two clear-cut harvest areas of different age. Nonparametrical Random Forest statistical models were set up to quantify the impact of environmental variables on the hydrological and erosion response. Regardless of the applied rainfall intensity, runoff always initiated first and yielded most under plantation cover. Counter to expectations, infiltration rates increased after logging activities. Once a threshold rainfall intensity of 20mm/h was exceeded, the younger harvest area started to act as a source for both runoff and erosion after connectivity was established, whereas it remained a sink under lower applied rainfall intensities. The results suggest that the impact of microtopography on surface runoff connectivity and water-repellent properties of the topsoil act as first-order controls for the hydrological and erosion processes in such environments. Fast rainfall-runoff response, sediment-discharge-hystereses, and enhanced postlogging groundwater recharge at catchment scale support our interpretation. At the end, we show the need to account for nonstationary hydrological and erosional behavior of harvest areas, a fact previously unappreciated in predictive models.}, language = {en} }