20 Future Perspectives
449
airplanes). This infonnation allows forecasting of expected Spring and early Summer flows in rivers. These forecasts lead to better hydropower scheduling providing more efficiency, reliability and higher economic benefits.
The use of RS data for water management includes the application of hydrological models, the parameters of which and the input into which is, at least partially,
based on remote sensing infonnation. One of the main advantages of RS for water
management lies, however, in the fact, that relevant data can be gathered over
large areas with high resolution in time and space at one spot, e.g. at the control
center of a water authority. Furthermore this infonnation, containing large quantities of spatial and temporal data can be acquired in real-time or almost real-time.
Figure 20.1 is a schematic illustrating all components of a remote sensing llllormation system for real time water management.
This allows the use of this high quality infonnation for management decisions in
real-time. This is of great value for decisions on e.g. releases from dams for water
supply purposes, for irrigation scheduling, but also for water quality control and
improvement. The benefits of such data are invaluable for real-time flood management in river systems as well as in urban drainage systems. Here the processes
are so highly dynamic that time intervals as short as 5 minutes are required for a
process lasting only a few hours or less (see e.g. Chap. 16).
One problem, which is not so relevant for hydrological applications of RS data
but is crucial in the field of real-time operation of water systems, is the question,
what shall be done, if there is a partial or complete failure of the infonnation system used. This problem also exists for the use of conventional data. If the decision
support system of a water authority were based on remote sensing data it has to be
clarified in advance, how the real-time operation should be carried out in case of a
failure of the RS data supply. As long as we have no answer to this problem the
reluctance of water managers to use RS data will continue to exist. It should be,
however, not pose too much difficulty, to solve this problem in the near future, be
it by combination of RS infosystems with conventional data acquisition systems or
by using RS data from different sources. Also, as usual, certain emergency rules
should be designed for these cases. It is hoped, that in the near future these problems will be overcome by appropriate research activities in order to enable water
managers to benefit from the significant advantages remote sensing data offer as
compared to conventional data.
20.4 Data Issues in Hydrology and Water Resources
Management
If we accept the arguments that the current stage of model development has not
given us better answers in spite of their complexity and that the new hydrological
sciences are demanding even more answers from very complex systems, what is it
that is needed most if we are to successfully answer the challenges of modem
hydrology? We believe the single most needed item is more, better and different
data. Not just numbers of measurements but the correct measurements with high
449
airplanes). This infonnation allows forecasting of expected Spring and early Summer flows in rivers. These forecasts lead to better hydropower scheduling providing more efficiency, reliability and higher economic benefits.
The use of RS data for water management includes the application of hydrological models, the parameters of which and the input into which is, at least partially,
based on remote sensing infonnation. One of the main advantages of RS for water
management lies, however, in the fact, that relevant data can be gathered over
large areas with high resolution in time and space at one spot, e.g. at the control
center of a water authority. Furthermore this infonnation, containing large quantities of spatial and temporal data can be acquired in real-time or almost real-time.
Figure 20.1 is a schematic illustrating all components of a remote sensing llllormation system for real time water management.
This allows the use of this high quality infonnation for management decisions in
real-time. This is of great value for decisions on e.g. releases from dams for water
supply purposes, for irrigation scheduling, but also for water quality control and
improvement. The benefits of such data are invaluable for real-time flood management in river systems as well as in urban drainage systems. Here the processes
are so highly dynamic that time intervals as short as 5 minutes are required for a
process lasting only a few hours or less (see e.g. Chap. 16).
One problem, which is not so relevant for hydrological applications of RS data
but is crucial in the field of real-time operation of water systems, is the question,
what shall be done, if there is a partial or complete failure of the infonnation system used. This problem also exists for the use of conventional data. If the decision
support system of a water authority were based on remote sensing data it has to be
clarified in advance, how the real-time operation should be carried out in case of a
failure of the RS data supply. As long as we have no answer to this problem the
reluctance of water managers to use RS data will continue to exist. It should be,
however, not pose too much difficulty, to solve this problem in the near future, be
it by combination of RS infosystems with conventional data acquisition systems or
by using RS data from different sources. Also, as usual, certain emergency rules
should be designed for these cases. It is hoped, that in the near future these problems will be overcome by appropriate research activities in order to enable water
managers to benefit from the significant advantages remote sensing data offer as
compared to conventional data.
20.4 Data Issues in Hydrology and Water Resources
Management
If we accept the arguments that the current stage of model development has not
given us better answers in spite of their complexity and that the new hydrological
sciences are demanding even more answers from very complex systems, what is it
that is needed most if we are to successfully answer the challenges of modem
hydrology? We believe the single most needed item is more, better and different
data. Not just numbers of measurements but the correct measurements with high