112
Chapter 12
5.
CONCLUSIONS
Ensuring sustainable and productive use of available water in many parts
of the semi-arid and arid zones presents critical challenges. Decisions on
water allocation, and the impacts of construction, reclamation and
rehabilitation projects on the productive use of land and water, while
maintaining environment sustainability, can only be addressed in a basin
context, but such evaluations are often impeded by incomplete field data.
Data availability, and hence the quality of analysis, can be improved by
incorporating satellite remotely sensed measurements at the scale of (sub-)
river basins and (sub-) continents. Careful validation of the information
based on remotely sensed data is necessary, but validation has been
demonstrated in the international literature for a number of key parameters.
Remote sensing data can further be used to improve the quality of public
domain databases for decision making with respect to water and
environment at scales ranging from tertiary irrigation units of a few hectares
up to heterogeneous river basins containing a variety of ecosystems. It is
expected, from the user’s side, that monitoring of irrigation processes can be
enhanced with Earth Observation data.
Knowledge on irrigated area, ecosystems, land cover, land use, crop
acreage, crop growing stages and crop water demands for optimal dry matter
production is often incomplete. The performance of water using sectors,
especially irrigation, and the productivity of water in terms of yield per unit
volume of water consumed needs to be known for making strategic decisions
related to the inter-sectoral competition for water. In the absence of adequate
spatio-temporal hydrological surveys, water resources management is
extremely difficult. Classification of crop types and delineation of
agronomic zones can help this process greatly, as can knowledge of crop
water stress and relative water availability, especially when monitored on a
frequent basis. Estimation of crop yields—measured with respect to both
land and water—provides the possibility to evaluate the productivity of land
and water and thus to assess allocation policies in relation to demand,
supply, and the impact of alternative strategies.
6.
REFERENCES
Ahmed, R.H. and C.M.U. Neale (1996) Mapping field crop evapotranspiration using airborne
multispectral imagery, IEEE, 2369–2371.
Allen, R.G., M. Smith, A. Perrier and L.S. Pereira (1994) An update for the definition of
reference evapotranspiration, ICID Bulletin, 43, 1–34.
Chapter 12
5.
CONCLUSIONS
Ensuring sustainable and productive use of available water in many parts
of the semi-arid and arid zones presents critical challenges. Decisions on
water allocation, and the impacts of construction, reclamation and
rehabilitation projects on the productive use of land and water, while
maintaining environment sustainability, can only be addressed in a basin
context, but such evaluations are often impeded by incomplete field data.
Data availability, and hence the quality of analysis, can be improved by
incorporating satellite remotely sensed measurements at the scale of (sub-)
river basins and (sub-) continents. Careful validation of the information
based on remotely sensed data is necessary, but validation has been
demonstrated in the international literature for a number of key parameters.
Remote sensing data can further be used to improve the quality of public
domain databases for decision making with respect to water and
environment at scales ranging from tertiary irrigation units of a few hectares
up to heterogeneous river basins containing a variety of ecosystems. It is
expected, from the user’s side, that monitoring of irrigation processes can be
enhanced with Earth Observation data.
Knowledge on irrigated area, ecosystems, land cover, land use, crop
acreage, crop growing stages and crop water demands for optimal dry matter
production is often incomplete. The performance of water using sectors,
especially irrigation, and the productivity of water in terms of yield per unit
volume of water consumed needs to be known for making strategic decisions
related to the inter-sectoral competition for water. In the absence of adequate
spatio-temporal hydrological surveys, water resources management is
extremely difficult. Classification of crop types and delineation of
agronomic zones can help this process greatly, as can knowledge of crop
water stress and relative water availability, especially when monitored on a
frequent basis. Estimation of crop yields—measured with respect to both
land and water—provides the possibility to evaluate the productivity of land
and water and thus to assess allocation policies in relation to demand,
supply, and the impact of alternative strategies.
6.
REFERENCES
Ahmed, R.H. and C.M.U. Neale (1996) Mapping field crop evapotranspiration using airborne
multispectral imagery, IEEE, 2369–2371.
Allen, R.G., M. Smith, A. Perrier and L.S. Pereira (1994) An update for the definition of
reference evapotranspiration, ICID Bulletin, 43, 1–34.