STUDY ON KOKKALA CANAL WATER IN KOLE LANDS NEAR THRISSUR CORPORATION AND ITS EFFECTS ON PADDY FIELDS

The Thrissur kole wet land is a unique natural wet land system lying in Thrissur district. It is used for paddy cultivation and it covers more than 10,000 Ha. In fact kole in Malayalam means bumper yield, bumper prize, Jackpot etc. As the wet land all over the world are depleted and affected by development, the importance of natural wet land in water shed system becomes increasingly apparent effort to restore and maintain wet land have been crucial to water quality in many areas. This kole land provides natural fresh water resources for groundwater recharge, provide a sink for the large surface runoff from eastern height land in every monsoon and keep Thrissur city free from flood. The act as natural draining system through a network of canals and ponds and finally to the Arabian sea through back waters. But for the past decades the kole land which lies adjacent to Thrissur city re facing severe pressure due to urbanisation. The entire storm water drainage network of Thrissur city carries the urban waste with its flow and passes through the Kole lands. The municipal waste water it’s made up of domestic waste water, Industrial waste water, Storm water, Groundwater seepage. Due to this Kole land adjacent to Thrissur city becomes highly polluted and is severe in a stream named Kokkala stream leading to Kole lands from the thrissur railway station. So in this project it has been studied the pollution level of the Kokkala stream and its effect on Kole lands. The collected water sample had been tested for different physical, chemical and biological parameters during the pre monsoon and post monsoon. From this result It is found that all the parameters tested in rainy season are well within the irrigation standard. But from the result of summer samples it is found that the parameters like Turbidity, BOD, suspended matters, oil and grease and COD are high and above the irrigation standard.