The Hydro-Economic Modeling of Low-Flow Events on the Middle Elbe: Assessing Socio-Economic Impacts on River Navigation

Low-flow events cause socio-economic impacts in various sectors. However, there are few hydro-economic models to quantify these. This article presents a hydro-economic modeling approach to determine the direct economic damage of low flows to freight and tourist navigation on free-flowing rivers. This includes the description of the required hydrological and economic input variables, a presentation of the calculation approach and the development of the damage functions. Damage and replacement costs were calculated for the study area of the middle Elbe in order to test the model and show how low-flow events affect freight and tourist navigation. Our results indicate that considerable economic losses occur not only during low flows, but also when the reference water levels for navigation are only slightly exceeded over a long period of time. It was also shown that certain river sections are more vulnerable to low-flow events and therefore cause higher costs. The model represents an analytical tool that considers both economic and hydrological aspects. As a part of a holistic risk assessment, it can help decision-makers to understand the interactions between water and the economy and to develop strategies that promote sustainability in water resource management.