Evaluation of CO 2 emissions reductions by timber check dams and their economic effectiveness

We calculated the life cycle CO2 emissions and direct installation costs for two types of timber check dams (all-wood timber and hybrid timber) developed in Akita Prefecture and non-timber check dams (concrete and steel). Additionally, we evaluated the effect of timber check dams in reducing CO2 emissions and their economic efficiency compared with non-timber check dams. We found that switching from concrete to all-wood timber and hybrid timber check dams reduced CO2 emissions by 54 and 43 %, respectively. Switching from steel to all-wood timber and hybrid timber check dams reduced CO2 emissions by 28 and 11 %, respectively. In terms of direct installation costs, all-wood timber check dams were 241 % that of concrete check dams and 179 % that of steel check dams, but hybrid timber check dams were only 132 and 98 %, confirming that they could be competitive in terms of price. From the perspective of reducing CO2 emissions costs, we found that a policy for switching from concrete to all-wood or hybrid timber check dams did not constitute a low-cost means of reducing CO2 emissions, compared with other policies for reducing CO2 emissions.