Available online at www.worldscientificnews.com ( Received 10 February 2020; Accepted 28 February 2020; Date of Publication 29 February 2020 ) WSN 143 (2020) 79-102 EISSN 2392-2192 Elucidation of tidal spatial-temporal variation of physico-chemical and nutrient parameters of estuarine water at South Gujarat Nisheeth C. Desai 1, *, Nipul B. Kukadiya 1 , Jignasu P. Mehta 1 , Dinesh R. Godhani 1 , Jayendra Lakhmapurkar 2 and Bharti P. Dave 3 1 Department of Chemistry, (DSTFIST sponsored Department) Mahatma Gandhi Campus, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar 364 002, Gujarat, India 2 Gujarat Ecology Society (GES) Subhanpura, Vadodara - 390002, India 3 School of Sciences, Indrashil University, Kadi, Gujarat, India *E-mail address: dnisheeth@gmail.com ABSTRACT In the present study, the four estuaries were selected from the South Gujarat region to appraise the impact of industrial pollution in the estuarine water samples. The study focused on the tidal variation of nutrients, which disclosed that concentrations of NO2–N, NO3–N, NH4–N, TN, and reactive silicates were higher in low-tide whereas pH, salinity, and dissolved oxygen were higher in high-tide water samples. The results of high BOD and low DO expose the anthropogenic inputs in these estuaries during the low-tide. The results of physico-chemical and nutrients parameters of water showed that the pollution level is strongly influenced by tidal and seasonal changes. Pearson’s correlation matrix and principal component analysis (PCA) are applied to a hydrological and hydrographical dataset for finding the spatial-temporal variation during the tidal difference. This study suggested that there is an impact of industrial pollution and anthropogenic inputs on the estuarine water of the study area. Keywords: Estuary water, Physico-chemical parameters, Nutrients, Tidal variation, Principal component analysis