{'fraction_non_alphanumeric': 0.013196480938416423, 'fraction_numerical': 0.009530791788856305, 'mean_word_length': 5.319444444444445, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Assessment of Water Quality of the Atrak River Based on Watershed Attributes and Water Quality Index

3 Abstract: Anthropogenic activities along the river have severe impact on the water quality parameters. The present study was carried out to test effect of topographic variables on predicting of changes of physicochemical water parameters in the Atrak River (in the southeast of the Caspian Sea). For this goal, 12 water quality parameters were measured from 10 points along the Atrak River during July 2007 to June 2008, monthly. Also, catchment-scale attributes were derived by geographical information system. Results showed that watershed attributes are affected on chemical water characteristics. Principal Component Analysis indicated that total solids and total nitrogen are the main parameters in this ecosystem. Moreover, there is a positive relationship between drainage density and slope with total nitrogen and turbidity and negative one between elevation and these parameters. Results of the water quality index in the Atrak River revealed that the water quality ranges from being bad to medium conditions along the river. Regard to limited information available on Atrak River watershed and nutrient load values related to water quality issues in the Caspian Sea and natural wetlands, this study will help decision makers for effective management.