Nutrient Dynamics During Flood Events in Tropical Catchments: A Case Study in Southern Vietnam

Abstract

Assessing surface water quality variation as well as chasing water pollution sources is essential for water quality management. However, for existing conditions in developing countries, this assessment may not be done properly in many affected catchments due to limited data and lacking of tools. In particular, pollutant transport from the catchment to its river system during flood events needs quantification and is the aim of the study. For this, a combined water quality monitoring and modeling approach is proposed. The study was exemplarily performed for a typical ungauged medium scale catchment located in the southern area of Vietnam. The available budget allowed at least a limited monitoring of nutrients and driven parameters (e.g., flow, sediment). These data were used to, in total, successfully calibrate the complex Hydrological Simulation ProgramFortran (HSPF) model. The results lead to three main conclusions: (1) the contributions of point and diffuse sources to nutrient loadings could clearly be identified with the help of monitoring; (2) water quality sampling during flood events is critical to assess pollution sources, especially, diffuse ones. However, just a monitoring of data alone is not adequate to interpret the observed concentrations; modeling is required. (3) Despite of the limited amount of data, which could be recorded and processed during the study, a representative catchment modeling during floods could be performed. It delivered essential information for linking pollution sources with water quality data. Furthermore, the limits of an application of the complex HSPF model under given conditions were shown.

Dynamic Multivariate Analysis for Pollution Profiling and Abatement Recommendation in La Buong Watershed of Vietnam

“…This also suggested that TSS and Fe pollutions of La Buong river is rather a natural phenomenon which are intensi ed in wet season by surface run-off. This phenomenon was also observed in another study in Dong Nai river basin (Quan and Meon 2015). Therefore, a proper abatement scheme for TSS and Fe pollution should consider controlling of pollution sources by land-use practices in wet season combined with water treatment solutions before using.…”

Development of an Event-Based Water Quality Model for Sparsely Gauged Catchments

“…The only identified point source of wastewater comes from a factory which produces tapioca starch from cassava (tapioca) roots. The company produces on average 30 tons of tapioca starch per day, which generates about 360-600 m 3 of wastewater per day [50]. An analysis of the water quality data of the main Tay Ninh river can be found in Nguyen and Meon [3].…”

“…Eutrophication can be seen as a consequence of excessive nutrients, which can lead to serious environmental problems such as limited water supply, severe hypoxia, and polluted aquatic ecosystems. Through the food chain, water pollution can cause serious waterborne diseases to human [1][2][3].…”

A Multidisciplinary Approach for Evaluating Spatial and Temporal Variations in Water Quality

“…Though located in the tropical region with potential water resources, Vietnam has been suffering from a water shortage in both quantity and quality [5]. Water is mostly being polluted by untreated wastewater from point and diffuse sources [6,7]. The study area Binh Thuan is one of those central arid provinces of Vietnam with low rainfall intensities, of which the total volume is unevenly distributed across the landscape [8].…”