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abstract 584

Watershed based agricultural land use management for the future inter- regional sustainable development

Author(s): For a compatible management to improve water quality and regional economic gap
Author(s): Kiyama Shoichi
Author’s name: Kiyama Shoichi Position: Dr., Assistant Professor, Kyoto University Affiliation: Division of Environmental Science and Technology, Graduate School of Agriculture, Kyoto University Address: Kita-Shirakawa-Oiwake-Cho, Sakyo-Ku, Kyoto City

Keyword(s): Comprehensive watershed management, water quality impact assessment, regional economic gap, agricultural land use model, multi-regional input-output tables

Article:

Poster:

Session: Poster session 4

Abstract In Japan, there’s rising

concern that the rapid depression in rural community accelerates cultivation abandonment and delay environmentally

conscious farming. Definitely the past irrigation developments such as reclamation and chemical fertilizer applications

brought us a high elevation in agricultural production while reducing the labor hours drastically. In return for this,

there has been a shift in population from the rural regions to the urban regions and we also accelerated the water

pollution and regional economic gap. Furthermore, Japan has just run into an era of a decrease in its population.

These social issues would transform the land use in rural region, which invites the vulnerability of water environment

such as the water pollution and the flood not only in rural region but also in the watershed scale. However not much

has been done to clarify the way of comprehensive management to improve both the water quality and regional

economic gap.
That’s why we are being carried out to develop a methodology to elucidate mutual mechanism

between the productivity of goods and the environmental impact relevant to eutrophication by the aid of input-output

tables in the watershed scale. However, we have not yet considered the mechanism of cultivation abandonment and

incentive for environmentally conscious agriculture and therefore we lack the understanding the feasible

comprehensive management.
The first objective of this paper is therefore to develop two farmer’s behavioral

models on the cultivation abandonment and the environmentally conscious rice farming. Integrating these models with

multi-regional input-output tables and considering the prospective future population, we evaluated the future eco-

efficiency of the COD burden and regional economic gap. Furthermore, we examined the way of agricultural land

management to ensure goods production to have a lesser impact on the environment and improve regional economic

gap.
The watershed cultivation abandonment state was evaluated by a nested logistic model consisting of a series

of GIS polygon data, i.e. population composition, industrial employment rate, topographical information including the

proximity to a station. This proposed model was successfully verified compared with observed data.
The

cultivation method is classified into five categories depending on the amount of fertilizer and pesticide used on the rice

paddies. We rationally estimated the corresponding preference model using a series of census. The corresponding

utility function was defined as the Cob-Douglas function of farming labor hours, farmer population, crude production,

subsidy and eutrophication impact.
Reflecting the predicted future cultivation abandonment state and cultivation

method in sectoral import coefficients and input coefficients of input-output tables respectively, we performed

scenario analysis for sustainable management in the watershed scale. As a result, we observed that regional

economic gap would additionally widen by the strategy to minimize the watershed COD discharge. On the other

hand, there was a scenario to maximize the total watershed production promising current eco-efficiency levels and a

fair economic growth rate due to the proper inter-regional trading. It is shown that the proposed methodology is

significant to figure out the comprehensive watershed governance process in both environmental and socio-economic

aspects.

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Watershed based agricultural land use management for the future inter- regional sustainable development