A model for ecosystem state and water quality management in the Dnieper River delta

An ecologically sound management methodology for maintaining ecosystem stat e and water quality in regulated rivers downstream of hydropower stations i s presented. The main components of this methodology are applied to the Dni eper River mouth zone as an example. The relationship between production-de struction (respiration) balance and releases through the Kakhovka hydropowe r dam has been determined for the channel network, floodplain lakes, the fl oodplain proper, and the Dnieper River mouth zone combined. Production-dest ruction processes are predicted as the change in organic matter content, as measured by BODtot. We have developed calculation methods for ecosystem fu nctioning and water quality management in the Dnieper River mouth zone chan nel network as a result of releases through the Kakhovka dam. The concept o f ecosystem, ecological and extremal (target) releases and sanitary additio n to ecosystem release for liquidation of anthropogenic pollution was formu lated and the volumes of all these releases for the Dnieper River mouth zon e were estimated. This methodology and calculation methods can be used for ecosystem state and water quality management in regulated rivers. (C) 2000 Elsevier Science B.V. All rights reserved.