Combining Reliability, Resilience, Vulnerability Criteria and Downstream Flood Risk to derive robust Adaptation Strategies of Multi-Reservoir, multiobjective Water Resources System Operation under Climate Change

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Anpassung der Talsperrensteuerung an Klimaänderungen : Bewertung von Leistungsfähigkeit und Robustheit

Reservoirs serve to compensate naturally fluctuating water availability and socio-economically driven water demand. To achieve this, flood water is retained and stored water is released to bridge periods of low flow. The required storage capacity when planning new dams and the operating rules of existing dams are determined on the basis of the observed flows at the site of the reservoir. The flow properties depend on the hydrology of the catchment area, which in turn is influenced by the climatic boundary conditions. Changes in climate therefore directly influence the input data used in reservoir design and the subsequent reservoir performance. A significant change in climate conditions is expected in the future due to the increasing concentration of greenhouse gases in the atmosphere. This raises the question of the impact of climate change on the performance of reservoirs and how adaption measures can be planed and chosen. The performance of reservoirs is evaluated probabilistically by considering the consequences and the probability of failure events. A distinction is made between failures due to floods and failures due to low flows. Probabilistic methods for evaluating the performance of flood protection provided by dams are well-established, whilst the corresponding method to evaluate the performance of dams that protectagainst low flows is newly developed. Combining these two methods makes it possible to determine the overall performance of a dam by means of the integrated water management risk for floods and low flows. The applied methods of stochastic generation of inflow boundary conditions allow us to quasi-continuously capture the potential impact of projected climate change and to map it using the climate impact function, which represents the relationship between climate-induced change of statistical properties of the inflow and the change in the performance of the studied reservoirs. The climate impact function assesses of the robustness of the reservoir. Robustness describes how sensitively the performance of the reservoir responds to changes in the inflow. Comparing the climate impact functions derived for different operation rules enables us to find adaption measures which preserve the performance of the reservoir for a climate-induced change in the inflow boundary conditions

Anpassung der Talsperrensteuerung an Klimaänderungen : Bewertung von Leistungsfähigkeit und Robustheit

Reservoirs serve to compensate naturally fluctuating water availability and socio-economically driven water demand. To achieve this, flood water is retained and stored water is released to bridge periods of low flow. The required storage capacity when planning new dams and the operating rules of existing dams are determined on the basis of the observed flows at the site of the reservoir. The flow properties depend on the hydrology of the catchment area, which in turn is influenced by the climatic boundary conditions. Changes in climate therefore directly influence the input data used in reservoir design and the subsequent reservoir performance. A significant change in climate conditions is expected in the future due to the increasing concentration of greenhouse gases in the atmosphere. This raises the question of the impact of climate change on the performance of reservoirs and how adaption measures can be planed and chosen. The performance of reservoirs is evaluated probabilistically by considering the consequences and the probability of failure events. A distinction is made between failures due to floods and failures due to low flows. Probabilistic methods for evaluating the performance of flood protection provided by dams are well-established, whilst the corresponding method to evaluate the performance of dams that protectagainst low flows is newly developed. Combining these two methods makes it possible to determine the overall performance of a dam by means of the integrated water management risk for floods and low flows. The applied methods of stochastic generation of inflow boundary conditions allow us to quasi-continuously capture the potential impact of projected climate change and to map it using the climate impact function, which represents the relationship between climate-induced change of statistical properties of the inflow and the change in the performance of the studied reservoirs. The climate impact function assesses of the robustness of the reservoir. Robustness describes how sensitively the performance of the reservoir responds to changes in the inflow. Comparing the climate impact functions derived for different operation rules enables us to find adaption measures which preserve the performance of the reservoir for a climate-induced change in the inflow boundary conditions