Within the three countries, two provinces (or group of provinces
for Thailand) each (one upland and one lowland) were selected for
study (Table 1). The upland provinces consistently were characterized
by a smaller area of perennial water bodies, and a lower occurrence
of regular flooding than the lowland provinces in the same countries.
Rice farming in the Cambodian and Thai study sites was predominantly
rainfed (sometimes with small-scale supplementary
irrigation), while farming in the Vietnamese sites was mostly