区域土壤盐渍化预报模型的初步研究

THE PRELIMINARY STUDY ON MODEL FOR PREDICTING SOIL SALINITY

本文根据1987年春、夏季黄淮海平原曲周县北部247.4km^2面积上,60个点的土壤盐分观测结果,结合前人的研究,详细分析了影响土壤盐分变化的各种因素,如土壤质地剖面(主要是粘土层厚度),地下水埋深及矿化度,降雨、灌溉和土壤初始含盐量,并以此为自变量,运用逐步回归分析方法,建立了春、夏季0—100和0—40cm土体盐分储量统计预报模型。逐步回归拟合的效果较好,主要影响因素都被选入预报方程,不同季节、不同深度土体选入方程的自变量各有侧重。初步检验证明,这种模型至少可满足农业生产中等级预报的精度要求。但预报模型只适用于与1987年相似年型及自然条件下。

In the light of the data on soil salt regime in 60 points in the northern part of Quzhou County (247.4 km^2), Huang-Huai-Hai plain, observed in spring and summer, 1987, and the study results of some predecessors, all kinds of factors influencing the salt regime in soils, such as the texture of soil profile (mainly the thickness of clay layer), the depth and saly content of groundwater, precipitation, irrigation and the initial saly content in soils are used as independent variables in the statistical models for predicting soil salt content in spring and summer developed with the method of stepwise regression. The dependent variables are contents of total dissolved saly in 0—100 and 0—40cm deep soils at next time interval. The factors seriously affecting the salt regime are all selected into the predicting equations. The independent variables that are selected into the equations are different with the season and soil depth. There is a good agreement between the predicted results and observed data. Preliminary test demonstrates that the models can at least be used for the prediction of soil salinity in agricuhure production. The predicting models can only be used in such situations that the year type of predicting ime is the same as 1987 and the natural conditions are similar to Quzhou County's.