28
STANLEY N . DAVIS
(a)
(c)
Fig. 14. Destruction of desert land through the development of irrigation using
groundwater of marginal chemical quality, (a) Natural condition of the desert.
(b) Irrigation with groundwater. Perched water develops owing to lack of drainage.
(c) Perched water plus salinity kills orchards. Water supply is almost exhausted,
and land is left almost sterile owing to high salinity of soil.
potential changes should then be called to the attention of all those involved with final decisions concerning the projects. It is possible that some
small projects as well as a few large projects will actually produce aesthetic
as well as economic damage which will exceed the expected benefits of
the project.
REFERENCES
Blanc, P., and Conrad, G. (1968). Evolution géochimique des eaux de l'oued
Saovra (Sahara nord-occidental). Rev. Geogr. Phys. 10, 415-428.
STANLEY N . DAVIS
(a)
(c)
Fig. 14. Destruction of desert land through the development of irrigation using
groundwater of marginal chemical quality, (a) Natural condition of the desert.
(b) Irrigation with groundwater. Perched water develops owing to lack of drainage.
(c) Perched water plus salinity kills orchards. Water supply is almost exhausted,
and land is left almost sterile owing to high salinity of soil.
potential changes should then be called to the attention of all those involved with final decisions concerning the projects. It is possible that some
small projects as well as a few large projects will actually produce aesthetic
as well as economic damage which will exceed the expected benefits of
the project.
REFERENCES
Blanc, P., and Conrad, G. (1968). Evolution géochimique des eaux de l'oued
Saovra (Sahara nord-occidental). Rev. Geogr. Phys. 10, 415-428.