A System Dynamics model for the water balance of Lake Bracciano (Lazio, Italy)

Abstract Lakes play a key role in both natural ecosystems and human activities, being rare hotspots of biodiversity and providing essential ecosystem services. In recent decades, lake systems around the world have been affected by multiple stressors related to climate and human activity. The environmental crisis makes the implementation of simple and low-cost, easily applicable and reliable methodologies for the sustainable management of water resources an urgent and necessary need. In this paper, a simulation model based on the System Dynamics method and supported by a GIS-based spatial analysis is presented. Using hydro-meteorological and socio-economic public data from 1970 to 2019 and following the multi-step path of trial, error and redoing, the study provides an application of the water balance of a significative lake-aquifer system. The water resource of Lake Bracciano (Lazio, Italy) is an emblematic example of the current critical issues, playing a strategic role both in the survival of a protected natural area and in the water supply system of the urban and extra-urban areas of the city of Rome. The aim of the study is to investigate the reliability of the System Dynamic approach in evaluating the main driving forces influencing the lake’s water balance and their interactions with the lake’s water level. The results evidence that System Dynamics may constitute a suitable quali-quantitative approach able to efficiently support land planning, environmental protection and optimization of the use of water resources.