Sustainable development of floodplain territories of regulated rivers. Part I: Modeling complex structure dynamics

This two-part study presents an approach to designing a sustainable management system for the environmental socio-economic systems (ESESs) of floodplain territories based on modeling their structure dynamics and hydrotechnical projects on their hydrological regime stabilization. The objective of management is to achieve and maintain the optimal stationary complex structure of a floodplain territory, which is characterized by the best design-achievable correspondence between the functional purpose of its fragments and the nature of their spring flooding. The approach rests on the complex structure dynamics model of a floodplain territory that combines variable hydrological and permanent functional properties. This dynamic model, supplemented by an expert model of the socio-economic potentials of the floodplain territory state, yields optimal parameters of hydrotechnical and socio-economic projects. Implementing the approach for a particular floodplain ESES involves optimization, expert assessment, geoinformation and numerical hydrodynamic modeling, high-performance computing, and the statistical analysis of natural observation data and the results of computational experiments. The retrospective, modern, and forecasted complex structures of the northern part of the Volga–Akhtuba floodplain are numerically built considering the spatial heterogeneity of the riverbed degradation effect of the Volga. These numerical results are used to develop an algorithm for finding the parameters of hydrotechnical projects to ensure an optimal sustainable complex structure of the floodplain territory. The algorithm and the results of its numerical implementation will be presented in part II of the study.