基于空间插值的区域尺度土壤全盐量时空变异规律研究

为准确获取区域尺度的土壤全盐量空间分布特征以及其年际动态变化规律。以甘肃景泰川电力提灌灌区为研究区,以2015年的16个监测点测得的土壤全盐量数据为基础,采用ArcGIS软件中的空间插值模块分别运用反距离权重法、样条函数法、趋势面法以及普通克里金法对区域内土壤全盐量数据进行空间插值。分析表明,反距离权重法插值精度最高、与实际监测的结果吻合度高,能准确反映土壤全盐量时空变异规律及分布特征。运用反距离权重法对研究区1994、2001、2008和2015年的土壤全盐量观测数据进行空间插值,结果表明:研究区内的土壤全盐量最大值逐年增大,由1994年的2.2648%增大到2015年的3.2294%,土壤全盐量最小值除个别年份有所降低外,总体亦呈现增大趋势,全盐量平均值持续增高在2015年达到了1.1228%,较1994年总体增长了0.1167%;研究区土壤盐分总体呈现西南低东北高的分布状况,且西南区域土壤全盐量呈现降低趋势而东北区域则呈现增加趋势,该结果可为研究区土壤盐渍化的水盐调控及盐渍化治理提供借鉴。

Spatial and Temporal Variation of Total Salt Content of Soil at Regional Scale Based on Spatial Interpolation

In order to accurately obtain the spatial distribution characteristics of soil total salt at the regional scale and its interannual dynamics.In this paper,the Jingtaichuan Electric Power Irrigation Area in Gansu Province is taken as the research area.Based on soil total salt data measured at 16 monitoring sites in 2015,the spatial interpolation module in ArcGIS software is used to interpolate the soil total salt data in the region by using the inverse distance weight method,the spline function method,the trend surface method and the ordinary kriging method.The analysis shows that the inverse distance weighting method has the highest precision and is consistent with the actual monitoring results,which can accurately reflect the temporal and spatial variation and distribution characteristics of soil total salt content.The spatial interpolation results of the soil total salt observation data in the study area in 1994,2001,2008 and 2015 using the inverse distance weighting method showed that the maximum soil salt content in the study area increased year by year,from 2.2648%in 1994 to 3.2294%in 2015.The minimum total salt content of the soil decreased in addition to the individual years,and the overall increase also showed an increasing trend. The average salt content continued to increase in 2015, reaching 1.228%, an increase of 0.116 7% over 1994. The soil salt distribution in the study area is low in the southwest and high in the northeast. And the total salt content of the soil in the southwest region showed a decreasing trend while the northeast region showed an increasing trend. The results serve as a reference for water salt regulation and salinization control of soil salinization in the study area.