Abstract
Quantification of water quality (WQ) is an integral part of scientifically based water resources management. The main objective of this study was comparative analysis of two approaches applied for quantitative assessment of WQ: the trophic level index (TLI) and the Delphi method (DM). We analyzed the following features of these conceptually different approaches: A. similarity of estimates of lake WQ; B. sensitivity to indicating disturbances in the aquatic ecosystem structure and functioning; C. capacity to reflect the impact of major management measures on the quality of water resources. We compared the DM and TLI based on results from a series of lakes covering varying productivity levels, mixing regimes and climatic zones. We assumed that the conservation of aquatic ecosystem in some predefined, “reference”, state is a major objective of sustainable water resources management in the study lakes. The comparison between the two approaches was quantified as a relationship between the DM ranks and respective TLI values. We show that being a classification system, the TLI does not account for specific characteristics of aquatic ecosystems and the array of different potential uses of the water resource. It indirectly assumes that oligotrophication is identical to WQ improvement, and reduction of economic activity within the lake catchment area is the most effective way to improve WQ. WQ assessed with the TLI is more suitable for needs of natural water resources management if eutrophication is a major threat. The DM allows accounting for several water resource uses and therefore it may serve as a more robust and comprehensive tool for WQ quantification and thus for sustainable water resources management.
Highlights
The most challenging problem of modern theoretical and applied hydroecology is to understand the fundamental principles of ecology for its application in effective management of water resources for both hydrological availability and water quality [1]
We show that being a classification system, the trophic level index (TLI) does not account for specific characteristics of aquatic ecosystems and the array of different potential uses of the water resource
The ecological values of parameters such as S, chlorophyll a (Chl), total nitrogen (TN) and total phosphorus (TP) should be sustained within limits, (permissible ranges, (8)); excessive increase and decrease of the respective variables should be ranked as water quality (WQ) deterioration
Summary
The most challenging problem of modern theoretical and applied hydroecology is to understand the fundamental principles of ecology for its application in effective management of water resources for both hydrological availability and water quality [1]. Quality is not absolute; the terms “good” or “poor” water quality have meaning only in relation to the use of water and the assessment of the user. Quantification of water quality (WQ) aims at describing the condition of a water body with reference to human needs. Further progress in WQ assessment is associated with implementation of optimization approaches to establishment of the natural resource sustainable management policies contributing to conservation of aquatic ecosystems within some desired reference condition [1,7]. We analyze and compare two key approaches to WQ quantification in relation to the increasing need for natural water resources management. In the DM, the WQ ranking is completely defined by the needs of the water
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
