玛纳斯河流域农田土壤水盐空间分布特征及影响因素

Spatial distribution of soil moisture and salinity and their influence factors in the farmland of Manas River catchment,Northwest China

采用传统统计学和地统计学相结合的方法,通过野外实地分层采集土样,分析干旱区典型内陆河玛纳斯河流域农田土壤水盐的空间分布特征及其影响因素,并探讨了土壤水盐在空间分布上所体现的耦合作用关系.结果表明：研究区农田土壤整体上水分含量较低（14.2%-20.9%）,盐渍化程度较高（平均全盐量6.00-9.15 g·kg^-1）,土壤水盐的剖面分布均呈现出＂底聚＂现象;各层土壤水分均属于中等变异强度,土壤盐分变异强度较大;受结构性因素影响,各土层盐分和含水量均具有较强的空间相关性.各层土壤水盐的水平分布格局无规律,受地形、地貌等因素制约.在人类活动的干扰下,土壤水盐耦合作用的关系更趋复杂,但两者的空间分异呈现出一定程度的同步性.

Applying methods of statistics and geo-statistics,Manas River catchment was selected as the research area to study the spatial distribution of soil moisture and salinity in the soil profile as well as their influence factors. The coupling relationship between soil moisture and salinity presented in the spatial distribution was explored as well. The result showed that the soil moisture was overall at a low level（ varying from 14.2% to 20.9%）,while the salinity was relatively high（ about 6.00-9.15 g·kg^-1）. The soil profile distribution of water and salt contents both showed a trend of bottom accumulation. The variation of soil water moisture was moderate,while that of salt content was strong. Soil salinity and moisture of all layers showed strong spatial autocorrelation,which were mainly affected by structural factors. The horizontal distribution patterns of water and salt contents were irregular,and were constrained by factors like terrain and landforms,etc. Disturbed by human activities,the coupling relation of soil moisture and salinity became much more complex,but their spatial distribution variation was synchronized to some extent.