Florinsky, Igor
al., 1999). The irrigation sector is often criticised for insufficient use of water resources. By
comparing water diversions to consumptive use, estimates of water losses can be made.
Irrigation water supply in Pakistan is based on equal access to all farmers. Without doubt, such novel
aspiration is difficult to achieve, in any irrigation scheme in the world. Farmer communities often
claim that they are not receiving the volume of water they are entitled to. The same discussion on
water volumes occurs between fellow states sharing an international water course. Fig. 4 shows that
the head end villages in the South-eastern Punjab receive systematically more water — the actual
evapotranspiration is 3 to 4 mm d' at the end of the winter season - than the tail end farmers with an
evapotranspiration of 2 mm d' (Alexandridris et al, 1999). Not only on one moment during a satellite
flyover, but this trend was observed to hold for the entire irrigation season. The communities settling
in the tail end can make a strong case now to their government if the images are given to them; they
are right to complain. It is sour though, that academists working from advanced centers can see that
they are shortened, and farmer communities don't know that this information is readily available.
Actual Evapotranspiration
Feb. 17, 1994
Actual Evapatranspiration
April 29, 1994
Fig. 4: Consumptive use along distributaries in South eastern Punjab showing inequity access to
diverted water volumes
Case 4: Agricultural productivity in the Ganges Basin, India
River basins with fertile alluvial soils are suitable for crop production and nations have to eat from
basins. For reasons of food security, State and Federal governments need to be timely informed on the
crop growth status. This is essential for food distribution, storage arrangement and in case of shortage,
for timely purchasing food on the world market before prices rise up. A significant international food
trade is expected to emerge in the 21* century. A crop growth monitoring system can help policy
makers estimating the yields and understand whether trade with basin counterparts is necessary. It
also provides interesting insights in yield gaps arising in the same agro-ecological production zone.
The yield gap tells the possibilities of increased food production, provided the water is available.
The wheat yield in part of the Ganges river basin in Nortwestern India was discussed. The yields in
the state of Haryana and Uttar Pradesh were different, in favour of Haryana The explanatory factors :
have to be explored, and factors such as different water duties, geology, soil types and farm
management are likely to play a role. Systematically, the highest yields occur close to the source of
water at the foothills of the Himalya. But yields are also systematically higher at the left and right
bank of the Yamuna river North of New Delhi.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 447