Performance of a one-dimensional hydraulic model for the calculation of stranding areas in hydropeaking rivers

Abstract

Fish stranding is a critical issue in rivers with peaking operations. The ability to accurately predict potential stranding areas can become a decisive factor to assess environmental impacts and to plan mitigation measures. The presented work shows that common procedures suggested in the literature in the use of one-dimensional (1D) models for flood zone mapping are not always applicable to compute stranding areas. Specific and easy-to-understand guidance needs to be given for smaller-scale issues. We provide specific guidelines to accurately predict potential stranding areas in a cost-effective manner. By analysing four different river morphologies in detail in a peaking river, we find that the optimal geometry effort (number of cross sections) does not necessarily coincide with the maximum and it varies between channel types according to river physical characteristics such as sinuosity and channel complexity. The use of a 1D model can provide good estimates with an optimal geometry layout