Evaluation of the surface water system using statistical method (PCA, FA AND ANOVA): a case study of Binh Thuan province, Vietnam

This study aimed to assess the spatial and temporal variations in surface water quality in Binh Thuan Province and identify the underlying causes of pollution affecting regional water resources. The comprehensive assessment was based on surface water monitoring data systematically collected from 2016 to 2019, totaling 24 strategically positioned monitoring sites distributed across three distinct areas: 12 sites in upstream domestic water supply areas, 4 sites in downstream domestic water supply areas, and 8 sites in downstream non-domestic water supply areas. Water quality parameters were monitored quarterly throughout the study period, with sampling conducted twice during the rainy season and twice during the dry season to capture seasonal fluctuations. A total of 14 water quality parameters were collected at each monitoring event and rigorously compared against national water quality standards established by the Ministry of Natural Resources and Environment. The entire dataset was subjected to sophisticated statistical analysis employing multiple analytical approaches, including Principal Component Analysis and Factor Analysis (PCA/FA), two-way Analysis of Variance (ANOVA), and Water Quality Index (WQI) calculations. Statistical results from PCA/FA successfully identified five principal factors that significantly influence surface water quality conditions: domestic wastewater discharge, industrial activities, agricultural activities, saltwater intrusion, and meteorological conditions, collectively accounting for 54.52% of the total variance in the dataset. ANOVA analysis revealed that surface water quality in Binh Thuan Province exhibited distinct spatial and temporal variations throughout the monitoring period. WQI calculations demonstrated that water quality systematically declined from upstream to downstream areas and was consistently superior during the rainy season compared to the dry season. The comprehensive findings contribute significantly to elucidating the complex impacts and characteristics of socio-economic development activities on surface water quality in Binh Thuan Province, thereby providing valuable scientific evidence to assist provincial authorities in developing effective water resource protection strategies to support sustainable socio-economic development objectives.