西北灌区地下水矿化度变化及其对作物的影响

地下水矿化度的时空变化是影响地下水资源质量和作物生长的重要因素，尤其是对主要依靠抽取地下水用于灌溉的农业地区。该文以石羊河流域为例搜集了武威、昌宁、民勤共21个灌区1981－2003年间观测站点的地下水矿化度数据，选用反距离加权法（IDW）进行空间插值处理。并结合自然因素和人类活动的影响，分析其时空变化趋势，结果显示：流域内年平均矿化度（TDS）整体呈增加趋势，且从上游向下游逐渐增高，矿化度的年际波动也从上游向下游逐渐增大。该文还分析了矿化度变化对当地主要作物的安全生长影响，研究了当地两种典型作物春小麦和棉花的适合种植范围，得出：适合两种作物的种植面积略有缩小趋势。该研究表明在一些需要采用地下水进行灌溉的西北干旱灌区，应加强对地下水矿化度的监测与控制。

Variation of groundwater salinity and its influence on crops in irrigation area of Northwest China

Temporal and spatial variations of groundwater salinity in irrigation area are important factors affecting the quality of local groundwater resources and crop growth, especially in the irrigation area that relies on groundwater supply. In this study, the data of groundwater salinity was collected from 21 irrigation areas of the Shiyang River Basin from 1981 to 2003 and interpolated using inverse distance weighting (IDW) method. After considering the impact of natural and social activity in these 20 years, the variation of groundwater salinity was analyzed. The results showed that average annual groundwater salinity in the basin tended to increase generally, and it also increased gradually from upstream to downstream area, the same with its annual fluctuations. The influence of groundwater salinity change on the safety of crop growth and the suitable planting area of the two typical crops (spring wheat and cotton) were also analyzed. The suitable planting areas of both crops tended to decrease slightly. And this study implies the importance of monitoring and control of groundwater salinity in the arid irrigation area that depends on groundwater.