Relationship among Nutrients, Chlorophyll- a, Physical and Chemical Properties of Water in Srinadharin Reservoir, Kanchanaburi Province

Abstract

On the relationships of nutrients determination, chlorophyll-a, physical and chemical properties of water in Srinadharin reservoir, Kanchanaburi province in order to access ecological status and changeability, and to correlate between them, field data collection was done at all 15 selected sampling stations representing upstream, midstream and downstream areas during April 2008 to March 2009. Chlorophyll-a, physical and chemical properties of water were collected at every 2- month intervals. Determinations were both made at in situ and in the chemical laboratory. The results revealed that Srinadharin reservoir was of oligotrophic status, containing an average of 4.099 mg/m3 of chlorophyll-a and its water quality was appropriated for aquatic animals’living. The distribution of nutrients and chlorophyll-a were varied, depending on periods and collection areas. Nutrients and chlorophyll-a concentration in the upstream were higher than those in the middle and downstream sections. The average concentrations of nutrients were the highest in the rainy season, average in summer and lowest in winter, whereas the average chlorophyll-a concentrations were the highest in summer (5.307 mg/m3), average in the rainy season and winter (4.591 and 2.399 mg/m3), respectively. Chlorophyll-a concentration has positive correlation to total nitrogen, organic nitrogen, inorganic nitrogen, total phosphorus, ammonia nitrogen, water temperature and dissolved oxygen, while it has negative correlation to transparency, electrical conductivity and alkalinity. The results obtained from the study can be used as a guide equation to estimate fish yield and manage Srinadharin reservoir for future getting sustainable yield as well.