Methodological foundations of the philosophical content of the system concepts “ecological state” and “ecological safety” in the use of water resourcesVladimir Bondarenko, Alla-Brerdi Ylyasov, Elena Semenova, Vitalii Bandurin and Maria ShtavdakerE3S Web Conf., 281 (2021) 09007DOI: https://doi.org/10.1051/e3sconf/202128109007