Effect of climate change on overland flow generation: a case study in central Germany

Abstract

Abstract:The impact of global climate change on runoff components, especially on the type of overland flow, is of utmost significance. High-resolution temporal rainfall plays an important role in determining the hydrological response of quick runoff components. However, hydrological climate change scenario analyses with high temporal resolution are rare. This study investigates the impact of climate change on discharge peak events generated by rainfall, snowmelt, and soil-frost induced runoff using highresolution hydrological modelling. The study area is Schäfertal catchment (1.44 km 2 ) in the lower Harz Mountains in central Germany. The WaSiM-ETH hydrological model is used to investigate the rainfall response of runoff components under near future (2021-2050) and far-distant future (2071-2100) climatic conditions. Disaggregated daily climate variables of WETTREG2010 SRES scenario A1B are used on a temporal resolution of 10 min. Hydrological model parameter optimization and uncertainty analysis was conducted using the Differential Evolution Adaptive Metropolis (DREAM_(ZS)) uncertainty tool. The scenario results show that total runoff and interflow will increase by 3.8% and 3.5% in the near future and decrease by 32.85% and 31% in the far-distant future compared to the baseline scenario. In contrast, overland flow and the number and size of peak runoff will decrease moderately for the near future and drastically for the far-distant future compared to the baseline scenario. We found the strongest decrease for soil-frost induced discharge peaks at 79.6% in the near future and at 98.2% in the far-distant future scenario. It can be concluded that high-resolution hydrological modelling can provide detailed predictions of future hydrological regimes and discharge peak events of the catchment.

Exploring the Dynamics of Transit Times and Subsurface Mixing in a Small Agricultural Catchment

“… (a) The catchment Schäfertal in central Germany. (b) Spatial distribution of the soil types (Anis & Rode, ). (c) Mesh used for the flow modeling, green line indicates the 1D segments for the channel.…”

“…The geomorphology, soils and the structure of the aquifer have been investigated in detail in previous studies (Graeff et al, ; Anis & Rode, ). The hillslopes are dominated by Luvisols and Cambisols (Figure b), with differences between the northern slope and the southern slope caused by different degrees of weathering.…”

Challenges of Reducing Phosphorus Based Water Eutrophication in the Agricultural Landscapes of Northwest Europe

“…In Northern European countries, such as Sweden, projected warmer temperatures will likely shorten the period of persistent snowpack and cause more soil freezing-thawing episodes (Mellander et al, 2007) with increased erosion and loss of particulate P. In German lower mountain ranges snowmelt events are often an important source of sediment and P loss (Ollesch et al, 2005(Ollesch et al, , 2006. Increasing temperatures may therefore shorten periods with snow cover, but could in contrast to Northern Europe also lower surface runoff due to smaller number of snowmelt events (Anis and Rode, 2015). These may mobilize both the dissolved and particulate P. In Norway, the trend in the number of freeze-thaw events depends on altitude, with an increasing number observed in the mountains (Hanssen-Bauer et al, 2009) and a decrease observed in the lower lying agricultural areas along the coast (Bechmann and Eggestad, 2016).…”

Estimating Soil Moisture Patterns with Remote Sensing and Terrain Data at the Small Catchment Scale

“…The use of terrain data in the benchmark model only forces laterally controlled patterns, which result in decreased explanatory power (explained variance) for intermediate catchment conditions. For these conditions, it is evident that the addition of multitemporal vegetation data (TRE 3), used as proxy to detect moisture stress, improves the detection of regions that are affected by stagnant water and different soil characteristics, such as colluvial (finer textured) and peaty soils with shallow groundwater depths that increase spatial heterogeneity on the toeslope and in the valley bottom (Martini et al, 2015; Anis and Rode, 2015). Therefore, the TRE 3 model produces more reliable patterns in the floodplain and toeslope areas where temporally wet regions exist, which was confirmed by qualitative field observations.…”