Refine
Year of publication
Document Type
- Article (26)
- Conference Proceeding (13)
- Part of a Book (11)
- Preprint (1)
Keywords
- 3-D Cartography (2)
- 3D-Kartographie (2)
- VR Cartography (2)
- VR-Kartographie (2)
- 3D (1)
- Cartographic symbols (1)
- GLM (1)
- General Lake Model (1)
- Geovisualization (1)
- Global observatory data (1)
Institute
Regional climate models (RCM) provide site-specific meteorological data at a suitable spatial resolution for the estimation of future climate-driven changes in aquatic ecosystems. In this study, we used meteorological data from the RCM weather-situation-based regionalization method (WETTREG), available for Germany, to force a one-dimensional hydrodynamic lake model to simulate climate-induced changes on the summer thermal stratification of Lake Ammersee in southern Germany. In comparison to the period of 2002–2010, an extension by 22 days of the summer stratification period was simulated for 2042–2050. Further, a vertical shift in the position of metalimnion and thermocline within the lake was not detected, but a slight increase in the metalimnion thickness during mid-summer of 1 m was simulated. Along with these changes in stratification patterns, warming for the epilimnion water temperatures during summer stratification and for the entire water body in winter were simulated for the future. By contrast the hypolimnion temperatures are simulated to decrease during the summer stratification. In addition to simulating future limno-physical aspects, the investigation demonstrates that the RCM data of the WETTREG projection are suitable for conducting climate change impact studies.
Unlike other aquatic continental ecosystems such as lakes, small coastal brooks have not been used as indicators of anthropogenic or climatic impacts. Our study addresses reconstructing the evolution of coastal brooks in the southwest of Spain from the early 17th century to the end of the 20th century using fieldwork, remote sensing, historical sources and microrelief. These brooks have had a continuous regression, losing 84.7% of their length since 1630 AD. From the 17th century to the beginning of the 20th century, climatic factors were responsible for the filling and siltation of the thalweg of brooks with sandy sediments of eolian origin. The alternation of dry and humid periods during the Little Ice Age in southern Spain favoured the mobilisation of sandy sediments in a process of secondary dunification, which was initiated during the 18th century and prominent at the end of the Little Ice Age. This process has coincided with a loss of water availability or an increase of aridity in some lakes and lagoons of southwestern Europe at the end of the 19th century. However, during the second half of the 20th century, the average annual rate of thalweg regression almost quadrupled to 432.2 m∙year-1 mainly due to anthropogenic impacts associated with logging. These changes coincide with the mobilisation of sandy sediment and the erosion of coastal brooks in southwestern Portugal and other continental aquatic ecosystems in southwestern Spain. Therefore, we believe that changes in small coastal brooks can be used as indicators of anthropogenic and climatic impacts and, in the future, as sentinels to study the effects of climatic change just as lakes, reservoirs and rivers are considered.
Simulating water temperatures and stratification of a pre-alpine lake with a hydrodynamic model
(2013)
We report on the calibration of the one-dimensional hydrodynamic lake model Dynamic Reservoir Simulation Model to simulate the water temperature conditions of the pre-alpine Lake Ammersee (southeast Germany) that is a representative of deep and large lakes in this region. Special focus is given to the calibration in order to reproduce the correct thermal distribution and stratification including the time of onset and duration of summer stratification. To ensure the application of the model to investigate the impact of climate change on lakes, an analysis of the model sensitivity under stepwise modification of meteorological input parameters (air temperature, wind speed, precipitation, global radiation, cloud cover, vapour pressure and tributary water temperature) was conducted. The total mean error of the calibration results is −0.23 °C, the root mean square error amounts to 1.012 °C. All characteristics of the annual stratification cycle were reproduced accurately by the model. Additionally, the simulated deviations for all applied modifications of the input parameters for the sensitivity analysis can be differentiated in the high temporal resolution of monthly values for each specific depth. The smallest applied alteration to each modified input parameter caused a maximum deviation in the simulation results of at least 0.26 °C. The most sensitive reactions of the model can be observed through modifications of the input parameters air temperature and wind speed. Hence, the results show that further investigations at Lake Ammersee, such as coupling the hydrodynamic model with chemo-dynamic models to assess the impact of changing climate on biochemical conditions within lakes, can be carried out using Dynamic Reservoir Simulation Model.
Thermal dynamics of lakes has a key role in chemical and biological processes in lakes including nutrient distributions and phytoplankton growth. Applications of hydrodynamic models to lakes can provide insights into possible future alterations in thermal dynamics induced by climate change. In this study we present the calibration and validation of the newest version of the open-source hydrodynamic model GLM (General Lake Model) to the dimictic Lake Ammersee, located in south-east Germany. The simulation of lake water temperatures for the calibration period revealed an overall root mean square error of 0.65 °C and a mean error of 0.08 °C. The seasonal stratification pattern and the annual thermal structure of this dimictic lake were reproduced by the model. The model simulated the presence of winter ice cover for the only year out of eight years simulated, when ice cover was observed. Elevated lake water temperatures were also reproduced in model simulations during a period in 2003 of unusually high air temperatures. Statistical analysis of the model calibration results for Lake Ammersee indicates a fit comparable to, or better than most other well-established hydrodynamic models and provides an opportunity for continuous simulations through periods of ice cover. Our results indicate a major improvement of GLM compared with earlier model versions and demonstrate the applicability of GLM for limnophysical studies, particularly for altered forcing conditions such as climate change.
Modellierungsansatz und Szenarien zur limnologischen Entwicklung des Ammersees im Klimawandel
(2012)
Der Klimawandel in Nürnberg unter Berücksichtigung unterschiedlicher Klimamodelle und –szenarien
(2012)
Der Ammersee im Klimawandel
(2014)