Establishment of physico-chemical variables and Chl a criteria based on land-use patterns and terrestrial ecosystem health

Developing numeric criteria is crucial for controlling cultural eutrophication and for protecting current and future water quality. Land-use changes in watersheds are the most important early warning indicators of lake eutrophication. In this study, the relationships between land-use patterns and physico-chemical variables and chlorophyll a (Chl a) concentrations were obtained through stepwise regression analysis to predict physico-chemical and Chl a criteria for the Eastern Plain Ecoregion. Ecological indicators (including landscape, function, and stressor aspects) related to land-use patterns and soil erosion was selected for the assessment of terrestrial ecosystem health using the analytic hierarchy process. The results indicated that the physico-chemical and Chl a criteria estimated from the relationships between anthropogenic land use and water quality variables were similar to the average values of the corresponding variables in the case of excellent terrestrial ecosystem health. The average values of water quality variables corresponding to excellent terrestrial ecosystem health can be used as criteria in the Eastern Plain Ecoregion. These findings are advantageous for understanding the health levels of the terrestrial ecosystems of the shallow lakes in this region and the degree of interference from human activities, as well as for providing a theoretical basis for the determination of criteria.