A study on the "Trends and Regional Conditions in Irrigation and Drainage Canal Maintenance in Japan" reveals that:
- The declining functionality of farm households and agricultural disadvantages associated with farmland location were more important factors in deciding over the maintenance of the canals by the communities than the increase of non-farmers;
- More urbanized communities had less power to assign non-farmers to the maintenance of canals;
- Urbanized or depopulated communities were characterized by having difficulty in maintaining the canals whereas the communities in the middle elevated locations succeeded in keeping up their maintenance;
- There were regional differences between the influences of the substandard farmland location on the maintenance of the canals by communities.
http://www.arsa1996.org/pictures/pdf/ARSA_IV_PRCDGS_VOL1/SOCIAL%20CHANGE%20AND%20TRANSFORMATION/11_YASUKO%20HONDA_412-421.pdf