Estimation of green house gas emissions from Koteshwar hydropower reservoir, India

The emissions of greenhouse gas (GHG) from soils are of significant importance for global warming. The biological and physico-chemical characteristics of soil affect the GHG emissions from soils of different land use types. Methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) production rates from six forest and agricultural soil types in the Koteshwar hydropower reservoir catchments located in theUttarakhand, India, were estimated and their relations with physico-chemical characteristics of soils were examined. The samples of different land use types were flooded and incubated under anaerobic condition at 30 degrees C for 60 days. The cumulativeGHGproduction rates in reservoir catchment are found as 1.52 +/- 0.26, 0.13 + 0.02, and 0.0004 + 0.0001 mu g g soil(-1) day(-1) for CO2, CH4, and N2O, respectively, which is lower than global reservoirs located in the same eco-region. The significant positive correlation between CO2 productions and labile organic carbon (LOC), CH4 andC/Nratio, whileN(2)O and N/P ratio, while pH of soils is negatively correlated, conforms their key role in GHG emissions. Carbon available asLOCinthereservoir catchmentisfoundas3-14% of the total C'' available in soils and 0-23% is retained in the soil after the completion of incubation. The key objective of thisstudyto signify theC, N, andPratios, LOC, andpHwith GHGproduction rate by creating an incubation experiment (as inthecaseofbenthic soil/sediment) inthelabfor60days. In summary, the results suggest that carbon, as LOC were more sensitive indicators forCO(2) emissions and significant C, N, and P ratios, affects theGHGemissions. This study is useful for the hydropower industry to know the GHG production rates after the construction of reservoir so that its effect could be minimized by taking care of catchment area treatment plan.