Science et changements planétaires / Sécheresse


Water ans soil management in arid northern Mexico Volume 12, issue 1, Mars 2001


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Route de la Ville-ès-Oiseaux, 22100 Léhon, Dinan.
  • Page(s) : 25-30
  • Published in: 2001

Arid and semi-arid parts of northern Mexico have large cultivable areas but water scarcity is limiting agricultural development. This is a problem in Hydrologic Region 36 where a sufficient supply of surface and underground water is needed to ensure development. Surface water resources in the western Sierra Madre region are dependent on rainfall. Surface runoff is stored in a 3.4 billion m3 reservoir located in the western part of the region from which water is distributed as far as 250 km for irrigation in the eastern arid plains (irrigation district). There is marked rainfall variability in the Sierra Madre region, so the mean annual surface water flow is highly irregular (1, 200 million m3). The irrigated area thus has to be reduced some years in order to maintain acceptable conveyance efficiency in canals. About 1, 300 million m3 of underground water is pumped yearly, leading to water table depletion of about 1.5 m/year. Depletion of the aquifer and progressive degradation of water quality are now priority concerns in Region 36. More efficient conveyance and water use is the only viable option to sustainably alleviate the problem. Research has proved that rational management of irrigation, which accounts for 82% of total availability, could ensure sufficient supplies, even in dry years.