| Analysis of characteristics of water-salt balance in Weigan—Kuqa River irrigation district |
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| DOI：10.7606/j.issn.1000-7601.2009.06.39 |
| Key Words: Weigan—Kuqa River irrigation district water balance salt balance change feature |
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| Abstract: |
| Based on the field work data this paper analyses the water balance salt balance the variability of diversion and discharge water mineralization degree desalt capacity and the main drainage salt ions in the Weigan—Kuqa River irrigation district．The results show that （1） Affected by the storage of large-scale reservoir upstream in the irrigation areas the diversion of surface water has little annual change in the irrigation district and it appears a split-blip． The ratio of irrigation and drainage is 8．79％～18．65％．The use of water introduction is 22．53×108m3～30．05×108m3 and it was mainly used for agricultural irrigation water and 75．26％ of the consumption is used for farmland and garden．（2） With the improvement of irrigation and drainage system the Weigan—Kuqa River irrigation district is being in a desalting process．The average annual desalination capacity is86．64×104t．The area of non—salinized land is expanded while the salinized area reduced and the salinity in the cultivated soil is reduced in the irrigation．（3） Because of the storage of the large reservoir the amplitude of the diversion surface-water salinity is also getting smaller in the irrigation district．It has an average of 0．38g／L from1993to1996 while the average is 0．42g／L from 1997 to 2001．During the flood period the water is abundant and the mineralization degree is smaller．The average annual amount of drainage salt is 99．77×104t～275．40×104t and the drainage salt and water displacement are overall in a micro-rising trend．The main anion of the salt ions is Cl- in the drainage and followed by SO2-4．The cation is mainly Na+ while Mg2＋ has a smaller chance to appear．To maintain the necessary balance of water-salt in the irrigation district the ratio of discharge and diversion water is 0．09∶1． |