Yuji Hara

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.

Quantitative assessment of the Japanese "local production for local consumption" movement : a case study of growth of vegetables in the Osaka city region

This study aimed to assess Japan’s recent “local production for local consumption” (LPLC) movement, with a special focus on vegetables in the Osaka city region of central Japan. After collecting statistics and spatial data, we conducted a multi-scale analysis of vegetable production and consumption along with the associated energy consumption, using geographical information system software at three spatial scales along the vegetable flow paths: national, regional, and local. Vegetables consumed in the Osaka city region came from prefectures throughout Japan, and we mapped the foodshed within this region at 1-km spatial resolution, as well as the distribution of farmland, farmers’ and other markets. We also conducted a scenario analysis for reduced energy consumption through organic farming and the utilization of abandoned farmland near a city to replace food imports from distant areas. We found that the large majority of vegetables consumed in the Osaka city region currently come from remote prefectures, and that this is associated with a high level of energy consumption. Inside the Osaka city region, peri-urban vegetable farming contributes to regional vegetable provision, resulting in an approximately 70xa0% production/consumption ratio within an 80-km radius of the urban center; if all of the area of abandoned farmland were restored to production, this ratio would increase to approximately 75xa0%. Organic farming activities that bring together farmers and urbanites are emerging in many parts of the study area, contributing to increased LPLC. Scenario analysis suggested that a decrease of more than 1xa0×xa0106xa0GJ of energy inputs could be achieved through wider adoption of local organic farming for local consumption and complete utilization of abandoned farmland in the Osaka city region.

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.

Dynamic wetland mosaic environments and Asian openbill habitat creation in peri-urban Bangkok

This study examined the spatial relationships between various types of wetland and the distribution of Asian openbills (Anastomus oscitans) as an indicator species in a peri-urban industrial area of Bangkok. We (1) mapped the study area by using a time series of aerial photographs combined with field validations, (2) conducted a 2-year line census of Asian openbills in the field, (3) interviewed local farmers and residents about Asian openbill populations and spatial distributions, and (4) conducted an overlay analysis to statistically identify land-use factors related to spatiotemporal changes in the Asian openbill population and distribution. We found that the number of ponds increased from 1980 to 1999 and then decreased from 1999 to 2010, but the remaining ponds were relatively temporally stable in their numbers and volumes. Paddy fields were primarily replaced by aquaculture ponds, and excavated soil was used as fill in adjoining built-up areas. The number of coconut, banana, mango and other trees planted around the ponds increased during the period, providing Asian openbill habitat. The openbills fed in the remaining paddy fields, and the simultaneous existence of various rice cultivation stages in the area provided a stable year-round source of food. Overall, the results indicated that this expanding urban–rural mosaic landscape could include further spatial distribution of Asian openbills in the future. This study of Asian openbills reveals just one example of the ecosystem services provided by developments creating pond–fill landscapes, and the methods used may be applicable in other similar continental delta regions.

Assessing urban agriculture potential: a comparative study of Osaka, Japan and New York city, United States

In this study, we examined urban agricultural production potential in New York city (NYC) in the United States and Osaka in Japan in a comparative study not only due to their similarities in population and region size but also differences in historical geographies and urban formation processes. We utilized available high-resolution land-use- and land-cover data to map and empirically compare size, land use, and spatial patterns of sites of current urban agriculture as well as land areas with potential for expanding urban agriculture. By linking current vegetable production data, and potential future urban agriculture land with per capita vegetable consumption data, we were able to estimate the total potential population that could be supported by locally produced vegetables. Our results showed that by scaling up current vegetable production in existing NYC community gardens, potential agricultural productivity on other underutilized or vacant land was 0.26xa0kg/m2/year for NYC. For Osaka, existing rice and dry fields could produce in comparison 0.54 and 0.74xa0kg/m2/year, respectively. By combining potential urban and peri-urban vegetable production measures with estimated needed vegetable caloric intake per person per year, we show that the current vegetable production levels in Osaka can feed approximately 0.50xa0million people. However, if the region maximizes existing underused speculative dry fields, urban and peri-urban agriculture could feed approximately 3.4xa0million people per year. In NYC, current vegetable production in community gardens is estimated to feed only 1700 people per year. However, if NYC maximized all available urban vacant lots and other open spaces, potential vegetable production could provide food annually for 0.55xa0million people. We discuss how though both community gardens in NYC and remaining rice and dry fields in Osaka have been out of formal city planning with clear land-use definition in zoning, these agricultural practices have nonetheless emerged as important sources of local food production and nutrition on the one hand, and sites of social benefit on the other.

Establishing A Sustainable Community Through Urban and Rural Fusion

Urban and rural fusion has been a main subject of urban planning discussed for over 100 years. Recently it is drawing attention from the viewpoint of “sustainable cities” in particular. In Japan, along with consolidation of municipalities, local administrations including broad rural areas are emerging one after another. This should be regarded as a good opportunity to reestablish bioresource-circulating spheres through creating preferable landscapes and ecological networks as well as promoting the movement toward local production for local consumption. This concept of the urban and rural fusion might contribute to establishing sustainable urban communities in Asia.

Feeding Urban Regions: Estimating the Energy Consumption of Domestic Vegetable Supplies for Osaka, Japan

This study aimed to assess Japan’s recent local production for local consumption (LPLC) movement, with a special focus on vegetables in the Osaka city region of central Japan. After collecting statistics data from multiple sources, we determined the weights of the vegetables that flowed into the Osaka city region in 2003. To do so, we aggregated the 14 major vegetables into two categories according to their preservation properties: leaf and fruit vegetables, and root vegetables. We also calculated the energy consumption embodied in the vegetable flows into the Osaka city region in 2003. The results showed that vegetables consumed in the Osaka city region came from prefectures throughout Japan, the large majority of vegetables consumed in the Osaka city region currently come from remote prefectures, and this is associated with a high level of energy consumption. Scenario analysis suggested that a decrease of more than 3.7 × 105 GJ of energy inputs could be achieved through the promotion of LPLC activities in the Osaka city region.

Biowaste Reuse Through Composting: The Response of Barangay Holy Spirit in Quezon City, Philippines, to Solid-Waste Management

Biowaste is the large volume of solid waste generated daily by households, and it presents environmental and health hazards if not reused. Composting is one of the best options for such reuse. This study documents biowaste generation and collection from households and reuse through composting in Barangay Holy Spirit, Quezon City, Philippines. This barangay (the smallest administrative unit) has made pioneering efforts in composting, having developed it from a simple process to a mechanized process. The barangay’s composting has been integrated with its vegetable and flower urban garden, which serves as a demonstration and training center on how to provide livelihood opportunities and environmental benefits. However, to enhance the compost’s marketability, issues relating to quality, such as the high organic carbon, high carbon-to-nitrogen ratio, and low levels of nitrogen, phosphorus, and potassium, need to be addressed. The barangay intends to boost compost production and sales, thereby increasing income, which can further improve the solid-waste management and increase staff salaries. Barangay Holy Spirit is one of the most developed barangays in terms of solid-waste management, and it can serve as a model for other barangays.