摘要
Soil salinity is the most important factor affecting vegetation distribution,and the secondary salinization has affected the development of oasis agriculture.In arid areas the spatial variation of soil moisture and sa lt content is marked-ly affected by groundwater,irratio nal irrigation in artificial oasis.By analyzing the soil moisture,salt content and groundwa-ter table in different areas of old oasis,new oasis and desert in Fukang Oa sis,it is shown that topography and l and use are main factors affecting the change of groundwater table,the redistribution of soil moisture and salt cont ent.When undis-turbed by human,the groundwater tab le rises from mountain to belt of grou nd water spillage,the groundwater t able rises mightily in plain because of the artificial irrigation,and the secondary salinization of soil is very seriou s.In oasis the ground-water table raises compared with that in the natural desert at the same latitude.In old oasis of upper reaches o f river salt has not been concentrated too much in rhizosphere because this area is the belt of groundwater drainage,soil t exture is coarse,the groundwater table is very low,and the salt in soil is drained i nto the groundwater.The new oasis has been the areas of salt accumulation becau se of the artificial irrigation,the salt content in soil is higher than th at in old oasis,so some cultivated fields here had to be thrown out because of the serious s econdary salinization.
Soil salinity is the most important factor affecting vegetation distribution,and the secondary salinization has affected the development of oasis agriculture. In arid areas thespatial variation of soil moisture and salt content is markedly affected by groundwater, irrationalirrigation in artificial oasis. By analyzing the soil moisture, salt content and groundwa-ter tablein different areas of old oasis, new oasis and desert in Fukang Oasis, it is shown that topographyand land use are main factors affecting the change of groundwater table, the redistribution of soilmoisture and salt content. When undisturbed by human, the groundwater table rises from mountain tobelt of ground water spillage, the groundwater table rises mightily in plain because of theartificial irrigation, and the secondary salinization of soil is very serious. In oasis theground-water table raises compared with that in the natural desert at the same latitude. In oldoasis of upper reaches of river salt has not been concentrated too much in rhizosphere because thisarea is the belt of groundwater drainage, soil texture is coarse, the groundwater table is very low,and the salt in soil is drained into the groundwater. The new oasis has been the areas of saltaccumulation because of the artificial irrigation, the salt content in soil is higher than that inold oasis, so some cultivated fields here had to be thrown out because of the serious secondarysalinization.
基金
UndertheauspicesoftheNationalKeyProjectofBasicResearch(G1999043503).
