in the prior research two environmental factors
defined the water use behavior, and in the level of the
whole basins, the WUAs devised their way to adapt
to environmental changes. In our study, social and
environmental factors were mainly influential to
water use behavior, and adaptation methods were
developed only among the downstream WUAs.
Although exploring customary laws can reveal
factors of current conditions, it does not always let us
find solutions for problems or predict future
conditions. To examine customary laws on water use
we applied game theory. We supposed three values;
α, β and γ (0≥α>β>γ) showing negative impacts
and made a payoff table (Table 6). For Subak B
through Subak E, coordinating with other Subaks
took efforts and time to arrange water use, but the
restrained decline in rice production. On the contrary,
disarranging water use saved efforts and time but
caused a decline in rice production. From submissive
laws, we can see that for farmers decline in rice
production (=γ) is more serious damage than taking
efforts and time ( =β). In the case of Subak A,
coordinating with other Subaks did not benefit Subak
A nor increased rice production, but only took efforts
and time. However, uncoordinated water use with the
other Subaks yielded the same rice production as it
coordinated with the others and took none of the
efforts and time, too (=α). As Table 6 presents when
Subak A is uncooperative and Subak B through
Subak E are cooperative, they achieve Nash
equilibrium and Pareto optimality. It suggests that
with the current customary laws their water allocation
system not be changed and uncooperative water use
behavior of Subak A not change. This reveals that
focusing on one case study will not be enough to find
solutions. We can also see that predicting future
conditions should be difficult because future changes
of externalities cause changes in factors. Therefore, to
enhance sustainable resource management, we need
to understand what factors and their rules and/or laws
are useful to enhance the resilience and adaptability
of institutions. However, as prior researchers pointed,
although case studies have similarities, to employ
rules and/or laws found in other areas to solve
problems, we need to carefully tailor them to fit into
the target condition (
Mukherji et al., 2010). At this
point, digital technologies have the potential to
facilitate analysis.
Field research results suggested that labor force
also influences changes in cropping schedules. Hence,
considering rainfall and Saba intake weir inflow is
unlikely enough to conduct time series analysis at the
current stage of the model development. With further
development of digital technologies such as ABM,
Table 6: Payoff table between Subak A and Subak B
through Subak E.
Subak B through Subak E
Uncooperative Cooperative
Subak A
Uncooperative
(α, γ) (α, β)
Cooperative
(β, γ) (β, β)
analysis of time series and massive information in
resource management could be conducted. In our
study, we found that water resources were the main
factor of water users’ behavior, but other natural,
social and institutional factors also govern their
behavior. So far, factors could be divided into three
categories; irrigation facilities, cropping systems, and
institutions. Irrigation facilities are designed to
convey water supply using gravity so that they are
influenced by topographical features of an irrigated
area. For example, paddy field engineering in Japan
has been developed for more than 500 years, and
paddy field expansion reached physical limits (The
Japanese Society of Irrigation, Drainage and Rural
Engineering, 2010
). Cropping systems and cropping
patterns reflect preferences and strategies of farmers
to fit in natural conditions (Corselius et al., 2002 and
Dury et al., 2013). Institutions define rules for
collective resource use (Ostrom, 2005). This study
mainly focused on factors of institutions. To
understand and find out robust WUAs, factors in all
three categories are needed to consider together. If we
accumulate and analyze factors and their rules and/or
laws related to resource use in areas of both
developing and developed countries, we will be able
to grasp the nexus of factors. It will also help us
understand how a factor activates another factor(s)
and induce rules and/or laws. Understanding resource
use behavior in a factor level will enable us to
improve resource management by changing some
behavior in a more tailored manner. Applying the
method of this study to other agricultural resource
management needs further research. For instance,
agricultural land change may be more influenced by
economic change such as land price and market. In
such a case, economic models may need to be
incorporated into our method.
6 CONCLUSIONS
Recently, to improve food and water security, the
agriculture sector has attempted to systematize
agricultural management which currently mainly
relies on farmers’ experience. In addition to the
challenge, climate change and population growth