都市化の進展とともに都市の生物多様性の重要性が認知され，都市活動と生態系との関連性から都市計画を見直すことの必要性が指摘されている．そこで本研究は森林に関する生態系サービスへの依存度を生態系面積単位で評価するエコロジカル・フットプリントを基にしたフレームワーク(Ecosystem Service Use: ESU)を用いて，大阪府の市区町村レベルで都市活動の主な活動形態である民生業務部門活動の生態系サービス依存度を評価・分析した．その結果，対象とした9業種によってFESU(Forest Ecosystem Service Use)の合計値は大きく異なったが，ほぼ全ての業種で森林生態系のCO2吸収サービスへの依存度は高かった．また，市区町村別での生態系サービス依存度の分析では大阪市中央区と北区の2区の生態系サービス依存度が非常に大きい値を示した．各市区町村の民生業務部門の業種構成割合，民生業務部門の従業員数あたりのFESU，森林生態系サービスへの域外依存度を変数としてクラスタ分類を行ったところ，それぞれ特徴を持つ5つの地域に分類することが出来た．
Sedimentation occupies the storage capacity of reservoirs and reduces the amount of available surface water resource. The countermeasure to the sedimentation is required especially in arid land where the land erosion is very severe due to low vegetation in the catchment area, and even fine particles are deposited because of the low water rotation of the reservoirs under the climatic condition of clear difference between rainy season and drought season. However, it has not been carried out because the conventional technologies against the sedimentation, such as dredging or bypass for sediment inflow, are quite costly. The authors proposed the exploitation idea which can valorize the sediment and will financially assist the cost of dredging or other countermeasures to the sedimentation. One of the exploitation ways is producing construction bricks. Sediment in Tunisian reservoirs is fine and sticky clay or silt, so there is a potential of the material for producing ceramics. In this study, the current situation of the production of the construction bricks in Tunisia was surveyed; price of raw material, a wholesale price, market price, processing cost and material flow. This information defines the market of construction bricks and the possibility of reservoir sediment for the production of construction bricks can be evaluated. Physical feasibility of the sediment for construction bricks was also investigated by the trial production of small pieces of slate and carrying out the flexure test with them. The slate samples made from the sediment gave almost same strength as the slate made from clay which is used in a brick factory in Tunisia.
This paper assessed the solid waste management (SWM) service cost estimate system for major Indonesian cities and develop standards for major SWM service costs, which consist of: collection, transfer and treatment, transportation, landfill management costs. This paper also presents the results of economic assessments that compare the options available for SWM in major Indonesian cities. The options compared are: collection and transport efficiency (CTE), communal waste treatment (CWT), and a centralized composting and recycling facility (CRF). An expenses-benefit calculation is used for the economic assessment. The results of our study show that composting at a centralized plant is the most economically feasible option under the current conditions prevailing in Indonesia.
In order to find out the potential causes that affect CO2 emission and their changes in freight transport sector, this paper examines the relationship between carbon dioxide emission and transportation activities in the sector. First, CO2 emission from the freight transport sector from 2001 to 2010 is calculated based on presented methods. Second, LMDI (logarithmic mean Divisia index) method is employed to analyze the influencing factors of CO2 emission in freight transport sector. As a result, we find: (1) from 2001 to 2010, CO2 emission of freight transport in Beijing increased by 69%, i.e., from 3.50 million tons to 5.91 million-tons, while that in Shanghai rose by 242%, i.e., from 4.23 million tons to 14.5 million tons; (2) based on the result obtained by using LMDI method, population effect, per capita GDP effect, energy source effect and mode shift effect have positive effects on CO2 emission in both cities; while the factors of transport intensity and the emission coefficient effect show negative impacts on CO2 emission; (3) the reason why the decrease in transport intensity appears is that transported products are becoming more and more valuable and more value added. Therefore, policy makers should make corresponding policies to encourage rail transport and shorter travel distance in the freight transport sector to reduce CO2 emission.
本研究では，送配水ポンプの電力使用量を最小にすることを目的とした最適水運用計画について検討する．都市における送配水システムの概要について述べ，省エネルギー化を図るためにはどのような水運用が必要かを明らかにした．需要水量を満たしながら，送配水システム全体の電力使用量を最小化するルート・流量決定問題としてモデル化を試み，混合整数線形計画（MILP: Mixed Integer Linear Programming）法によって定式化した．提案したMILPモデルの有効性を検証するためのケーススタディを試みたところ，各施設からの送配水量の配分比をMILPモデルに基づく水運用方法に変更することで，従来の電力使用量に比べて一日当たり約8％削減できることが明らかになった．
Reliable data are necessary to evaluate the current status of municipal solid waste (MSW) management and improve current treatment systems. Many developing countries, however, lack reliable data on MSW. The objectives of this study were to accumulate data on MSW in urban areas of Vietnam in 2008 in order to confirm whether the fundamental data existed at the local level, and to evaluate the reliability of the data obtained from waste treatment facilities. Questionnaires about MSW management were distributed to 90 "urban environment companies" (waste management companies) that are in charge of managing MSW in urban areas of Vietnam. A top-down approach was used in the survey, which may have contributed to the high response rate (92%). The MSW collection amounts per person per day were compared with maximum and minimum values in published data; any values above or below these values were corrected if errors were identified in data collection or entry. The total reported population with MSW collection service was 19.1 million, which is about 22% of the total population of Vietnam. The total amount of MSW collected was about 5,335,000 t, 96% of which was transported to landfill sites and 4% to composting sites. The proportion of organic waste in terms of physical composition was 65% on average. Data on the population with MSW collection service and MSW collection amounts in Vietnam were more variable (less reliable) than those in Japan, and the results of our reliability analysis suggest that installation of weighbridges at treatment and disposal facilities would improve the reliability of MSW collection data in Vietnam.