新疆三工河流域尾闾绿洲地下水变化与土壤积盐的响应

研究地下水动态和土壤积盐过程有助于了解地下水抬升对土壤积盐的作用规律,合理利用水资源,防止土壤盐渍化。根据1985年、2000年和2005年的地下水等值线图资料,结合研究区1983~2005年水资源利用和0~20cm土壤层总盐数据以及土地利用数据,利用GIS技术和地统计学方法,分析了近23a来地下水动态,以及地下水抬升与地表积盐的关系。结果表明:区域输水灌溉是地下水水位抬升的直接动因。年均地下水水位抬升0.09m,地下水位每抬升1m,造成区域地表积盐区增加144.45hm2,地下水位的抬升对区域灌溉景观的积盐面积的扩张作用要强于非灌溉景观,在灌溉景观中耕地积盐速率最快,达0.43t.hm-.2a-1,23a间,单位面积的积盐量增加了40.04%,在非灌溉景观中,盐碱地的积盐作用较强,积盐速率达0.68.thm-.2a-1。

Response of salt accumulation in soil to groundwater changes at the oasis in the lower reaches of Sangong River, Xinjiang

The current study is focused on the relationship between groundwater and the soil salt accumulation in inland river basins, which is important in understanding the interaction between the rising groundwater table and soil salt accumulation, preserving water resources and preventing soil salinization. Based on the groundwater table charts of 1985, 2000 and 2005, the water resources data from 1983 to 2005, as well as data of total soil salt at 0-20cm and the data of land use for the same period, with geo-statistics and GIS methods, analysis was done on the temporal-spatial changes in regional landscape and soil salt accumulation, as well as the relationship between the level of groundwater table and salt accumulation in the soil. The results revealed that importing of water to this region for irrigation was the main cause that resulted in the rising of groundwater table. Groundwater table rose at 0.09m per year for the last 23 years. And with 1m increase in groundwater table, the area of soil salt accumulation expanded 144.45hm2. In the irrigated landscape, the groundwater table had more significant effect on the expansion of soil salt accumulation area than that in non-irrigated landscapes. The rate of soil salt accumulation in the cropland was 0.43t•hm^-2 per year from 1983 to 2005; with salt content increased 40.04% during this period, which was the fastest among irrigated landscapes. While among the non-irrigated landscape, the most significant salt accumulation in soil occurred in Saline alkali land, with a rate of 0.68t•hm² per year.