Spatial And Temporal Variation Characteristics Of Soil Salinity In Weigan Oasis Of Xinjiang

Soil stalinization is a significant restriction for the sustainable development of oasis in aridareas. Along with the rising influence of human activity, Soil salinization extent of oasis and itsdistribution are directly affected by the variation characteristics of soil salinity.The agriculturalproduction activities in oasis area are concentrated and frequent, soil salinization status plays adecisive factor in agriculture development.The research of soil salinity features in arid oasis hasbecome a focus for the sustainable development of regional agriculture. Weigan river oasis ischoosed as the study aera. Based on the monitor data of soil salinity in1958,1985,1992,2012and statistical method combined with GIS technology, the quantitative research for soil salinitycharacteristics has proceeded. The study indicates that variation characteristics of soil salinity inoasis are under the influence of natural and artificial factors. The study discusses the reasonableratio about irrigation and drainage to balance soil salinity to provide basic information andscientific basis for the oasis.The results show that：（1）The soil salinization in Weigan river oasis types are mainly composed of chloride.Overall the soil salinization types in the study area belong to the salinization soil, moderate, mildsalinization soil salinization. The light salinization dominates. Distribution of the salt content inthe soil layer have similar characteristics in the study area, high salinity content areas are mainlyin the southeast, southwest and in the middle of the local area of the Weigan river oasis, with theincrease of soil depth soil salinity is gradually reduced, assume as “T” distribution.（2）The mean salt content on soil surface are46.02g·kg^-1,51.07g·kg^-1,13.86g·kg^-1,11.90g·kg^-1,6.22g·kg^-1respectively in1958,1985,1992,2006and2012year of the Weigan river oasis.During the period1958^-1985, a large number of saline-alkali land reclamation for arable land, Themain factors for increased soil salt content in basin irrigation area is unreasonable irrigation,combined with inadequate drainage system, the soil salinization of the new oasis and oasisperipheral localized was deteriorating trend.In1985-2012,the soil salinity on oasis surface decreased sharply. Due to the combined effect of natural and human factors, different periods ofsoil salt content showed the downstream>midstream>upstream.（3）Between1992and2012year, the moderate, severe and solonchak area were decreasedby422.7,818.19,422.7km2in the2012year, the salinization soil increased the area of1579.65km2, mild salinization soil increased the area of1150.61km2. Moderate salt mainly transformaesto the mild salinization soil and the salinization soil.Oasis within the soil salt to oasis periphery,soil salinization caused by internal to the external transfer of oasis, and performance as the studyarea in the upper to the lower.（4） The irrigation divered of Weigan river oasis for many years were25.59x108m3, themost appropriate irrigation and drainage ratio of oasis stood at10.48%～19.44%, the lower limitof displacement to keep irrigation water and salt balance were2.29x108m3in current situation.