Department of Zoology, B. N. Mandal University, Madhepura, Bihar, India
Received : 22nd December 2019 ; Revised : 21st February 2020
Abstract : The Koshi river is the major tributaries of the Ganges which originates from the snowy peaks of Tibetan plateau in the central Himalayas. A branch of Koshi River passing near Sonbarsa block, popularly known as Tilabay River. The physic-chemical parameters of Koshi River, Saharsa, Bihar have been studied monthly during August 2017 to July 2018 from two sites. This paper deals with the air temperature and physico-chemical parameters like temperature, transparency, pH, oxygen, carbon dioxide, alkalinity, hardness, chloride and biological oxygen demand of water of Sonbarsa River (Koshi area) of Saharsa district. The water temperature was recorded maximum in summer season but the
transparency, pH, dissolved oxygen, total alkalinity and total hardness were recorded maximum in winter season. Similarly, free carbon dioxide was higher in rainy season and chloride and biological oxygen demand were recorded maximum in summer season. The results revealed that there was significant seasonal variation in some physic-chemical parameters and most of the parameters are in the normal range indicating better quality water resources.