11:15 〜 11:30
[HTT16-03] Research about environment evaluation index focused on the fluctuation of carbon dioxide concentration in Ibaraki
キーワード：二酸化炭素濃度、環境評価指標、地理情報、緑被率
The Japan Meteorological Agency has reported that the atmospheric CO2 concentration has been on the increasing trend since the Industrial Revolution. The annual average carbon dioxide concentration in 2015 exceeded 400 ppm and it updated to the highest value. These data were obtained in isolated islands and mountains where there is little influence from human activity.
On the other hand, we have measured CO2 concentration in the living area of Ibaraki since 2007. It is thought that the carbon dioxide concentration obtained by measuring in the living zone can include the influence of geographical conditions (i.e. terrain, population, traffic, land cover, etc.) around the observation points. So far, increase and decrease, the fluctuation pattern of CO2 concentration is different for each region and is affected by the amount of vegetation around the measurement points. Then, our research group proposed the new environment evaluation index focusing on this feature. The index was suggested to quantify one day’s fluctuation of CO2 concentration and it is given as (Index) = (CO2_max - CO2_min) / CO2_max. Here, CO2_max is the maximum CO2 concentration of time mean, and CO2_min is the minimum CO2 concentration of time mean. However, in the past research, we did not fully verify the effectiveness of the index.
In this paper, we aimed to calculate the index from CO2 concentration for about three years and to investigate correlation with geographical information (e.g. land use, green coverage and population). The table shows that correlation between the information and environment evaluation index from 2014 to 2016. As a result, we found the high positive correlation with vegetation in summer and positive correlation with human activity in winter. Therefore, we conclude the nature of the index changes according to the season. Especially, analysis from the spring to autumn, we confirm that the index can express the CO2 absorption level and the activity of vegetation by season. In winter, few green spaces and the brisk areas of human activity, the index is increasing. From these results, they are shown the environment evaluation index derives from the fluctuation of CO2 concentration related to land cover near the observation points.
On the other hand, we have measured CO2 concentration in the living area of Ibaraki since 2007. It is thought that the carbon dioxide concentration obtained by measuring in the living zone can include the influence of geographical conditions (i.e. terrain, population, traffic, land cover, etc.) around the observation points. So far, increase and decrease, the fluctuation pattern of CO2 concentration is different for each region and is affected by the amount of vegetation around the measurement points. Then, our research group proposed the new environment evaluation index focusing on this feature. The index was suggested to quantify one day’s fluctuation of CO2 concentration and it is given as (Index) = (CO2_max - CO2_min) / CO2_max. Here, CO2_max is the maximum CO2 concentration of time mean, and CO2_min is the minimum CO2 concentration of time mean. However, in the past research, we did not fully verify the effectiveness of the index.
In this paper, we aimed to calculate the index from CO2 concentration for about three years and to investigate correlation with geographical information (e.g. land use, green coverage and population). The table shows that correlation between the information and environment evaluation index from 2014 to 2016. As a result, we found the high positive correlation with vegetation in summer and positive correlation with human activity in winter. Therefore, we conclude the nature of the index changes according to the season. Especially, analysis from the spring to autumn, we confirm that the index can express the CO2 absorption level and the activity of vegetation by season. In winter, few green spaces and the brisk areas of human activity, the index is increasing. From these results, they are shown the environment evaluation index derives from the fluctuation of CO2 concentration related to land cover near the observation points.