Ai Hiramatsu

Municipal solid waste flow and waste generation characteristics in an urban--rural fringe area in Thailand.

In the urban—rural fringe of the Bangkok Metropolitan Region, rapid urbanization is creating a land-use mixture of agricultural fields and residential areas. To develop appropriate policies to enhance recycling of municipal solid waste (MSW), current MSW management was investigated in the oboto (local administrative district) of Bang Maenang in Nonthaburi Province, adjoining Bangkok. The authors conducted a structural interview survey with waste-related organizations and local residents, analysed household waste generation, and performed global positioning system (GPS) tracking of municipal garbage trucks. It was found that MSW was collected and treated by local government, private-sector entities, and the local community separately. Lack of integrated management of these entities complicated waste flow in the study area, and some residences were not served by MSW collection. Organic waste, such as kitchen garbage and yard waste, accounted for a large proportion of waste generation but was underutilized. Through GPS/GIS analysis, the waste collection rate of the generated waste amount was estimated to be 45.5— 51.1% of total generation.

Estimation of heat discharges by residential buildings in Tokyo

Residential buildings are one of the important parts of the urban system. They are dense in the mega-cities such as Tokyo. This paper has analyzed the residential buildings and floor area distribution for Tokyo 23 wards. Methodology was formulated, based on the DOE-2.1E building energy simulation model, to estimate the heat discharges from residential buildings to the outside environment for a representative detached house and an apartment building by accounting for the heat storage within the building structures.

Impacts of housing development on nutrients flow along canals in a peri-urban area of Bangkok, Thailand

Change of nutrients load and flow according to land-use change induced by housing development was investigated in Bang Yai, Nonthaburi, Thailand, which located in the peri-urban area of Bangkok. Each house in the newly developed residential community was regulated to be equipped with a septic tank to collect night soil. However, greywater and leachate from the septic tank was collected by a community sewage system and discharged into the canals with insufficient treatment, while the canals still function as infrastructure for irrigation and transportation. In the study area, built-up area became 1.4 times and agricultural fields decreased by 13% from 2003 until 2007. Total nutrients load to the canals was increased by 25% as nitrogen and 14% as phosphorus according to the increase of built-up area. Net nutrients load from agricultural fields was largely set off when we evaluated nutrients inflow from the canals to the agricultural field through irrigation. Consequently, nutrients load from domestic wastewater accounted most of net nutrients load into the canal.

Supply-Demand Balance of Compost between Urban and Agricultural Sectors According to Peri-Urban Development in an Urban-Rural Fringe Area in Asia: A Case Study in Nonthaburi, Thailand

We investigated the current situation of supply and demand potential of compost and illustrated the shift of supply-demand balance of compost between urban and agricultural sectors according to peri-urban development in an urban-rural fringe area of Bangkok. In the study area in Bang Maenang, Nonthaburi, Thailand,42% of the supply potential is estimated to exceed the demand balance in 2007. The population density where supply and demand potential balance was estimated as approximately 1,300–1,400 persons/km2. Since the nitrogen supply potential in the study area exceeded the estimated demand potential, proper collection and treatment of surplus nitrogen was required to protect the canal water environment.