SHORT TERM ASSESSMENT OF INFLUENCE OF HYDROGEOCHEMISTRY ON METHANE EMISSION FROM TWO CONTRASTING TROPICAL WETLANDS OF CENTRAL GUJARAT, INDIA

摘要

Methane emission from two wetlands namely Khodiyar and Pariyej of Central Gujarat. India was measured during pre-summer season. Along with the methane emission, hydro and geo chemistry of these two contrasting wetlands (SO_4~(2-) PO_4~(-2)~2 and organic carbon) were determined. The methane emission ranged from 1219.51 mg/m~2/h to 7274.47 mg/m~2/h, having greater emission at noon period (11 am to 1 pm) of the day in the Khodiyar wetland. Besides, the methane emission ranged between 80.84 mg/m~2/h and 495 mg/m~2/h, having higher emission at same time of the day at Pariyej wetland. The methane release was declined from first trip followed by second, third and fourth trips. The results of the current investigation confirm that methane emission vary substantially between the two study wetlands, and suggest that hydrochemistry and geochemistry might control methane emission in both the wetlands. Correlation analysis revealed that the methane emission from both the sites has positive correlation with organic carbon of the sediment and negative correlations with phosphate and sulphate content of water and sediment. The details of the reasons have been discussed in this paper.