Jukka Alm, Tormød Schei, Yutaka Tateda & Jorge Machado Damazio INTERNATIONAL CONFERENCE AND EXHIBITION (29 to 31 October 2012 ~ Bilbao, Spain)

The Authors Jukka Alm Finnish Forest Research Institute, Finland Tormod Schei Statkraft, Norway Yutaka Tateda Environmental Science Research Laboratory CRIEPI, Japan Jorge Machado Damazio Centro de Pesquisas de Energia Elétrica, Brazil Collaborators in Annex XII, Task 1: Managing the Carbon Balance in Freshwater Reservoirs

Greenhouse gas emissions from a water body can be increased by Nutrient load, eutrophication Inflow of particulate or dissolved carbon Long water retention time Thermal stratification Ice cover Occurrence of hypoxia (CH4) Eutrophication and increased heterotrophic productivity, internal nutrient cycling

In reservoirs the factors include Catchment topography Thermal conditi0ns Geochemistry and amount of flooded organic matter Anthropogenic activities in the catchment Efflux from agriculture, forestry, dairy production, community sewage management/lack of it

Net emissions approach NET = POST – PRE impoundment emissions Makes the situation even more complicated But, are all emissions due to reservoir management? Other anthropogenic emissions should be accounted to the causing activity. Thus, NET = POST – PRE – UAS (Unrelated Anthropogenic Sources)

Help in determining the reservoir net ghg emissions A full-scale research programme is very expensive IEA proposes a set of decisions of how to identify the necessary workload The decision tree approach helps to Systematically assess the ghg balances in the PRE and POST impoundment situations Point out the key conditions when high ghg emissions can be expected Shows how possible UAS’s are be identified so that they can be accounted for the extra ghg emissions Is part of the IEA Guidelines for Quantitative Analysis of Net GHG Emissions from Reservoirs – Volume 1

Evaluate both the significant emissions and removals Depends of PRE land-use and landscape properties Possible adverse emissions or reduced C binding Facilitation of CH4 from flooded organic matter Cessation of forest CO2 sink Possible removals Carbon burial in sediment Reductions in landscape ghg emissions? Natural wetlands (CH4 emissions, but also CO2 sink) Neutral impacts? Natural watercourses are often net heterotrophic (net CO2 release)

Starting point

Reduce the workload? Part of normal practise!

… or take the hard way? Measure! We already know: From literature, or emission not feasible Can be zero

How to identify the key net flux components? Look for conditions enhancing the CH4 emissions When the reservoir is planned Hydrodynamical models may suggest the occurrence of hypoxia Inventory of the amount of soil organic matter in the flooded landscape Inventory of anthropogenic influence in the catchment In an existing reservoir Observed O2 deficiencies in the water body Increased eutrophy: Excess algae or macrophytes

No CH4

Other anthropogenic activity?

Examples of N load from Japan

But, The same population existed already in the PRE- impoundment landscape, causing N-load to the natural watercourses Can possible N2O emissions from the reservoir be consired as UAS? No, if the reservoir facilitates the emissions that did not occur in the PRE-impoundment watercourses Yes, because the polluter should be accounted for the emissions Probably already included in the National Greenhouse Gas Inventory reporting

Lack of emission indicators? Confirm insignificant emissions by making indicative, low intensity measurements of the unexpected gas species Reduced costs, but still qualitative information If no anthropogenic influence exists on the catchment, then UAS = zero for all gases Changes in landscape net emissions are due to the reservoir

Thank you!