پراکنش مکانی پارامترهای نفوذ آب به خاک در مقیاس ناحیه ای

Spatial variability of infiltration parameters were investigated in about ۴۰۰۰ ha of Kavar plain, east of Shiraz, Iran. For this purpose, infiltration was measured on a systematic squared grid pattern with ۵۰۰ by ۵۰۰ m in ۱۶۱ sites using double ring infiltrometer. Soil bulk density (BD), initial soil water content, soil texture, organic carbon content (OC), saturation percentage (SP), pH, and EC were also measured. The interpolation of infiltration parameters in non-sampled areas were predicted using kriging, inverse distance weighted, and co-kriging methods. The experimental semi-variograms were fitted to linear, exponential, gaussian, and spherical models. Cross validation method using statistical parameters of MBE, MAE, MSE, and RMSE was used to choose the most accurate interpolation method. The spatial distribution map of parameters was obtained using the best interpolation method. Estimating the coefficientof a in Kostiakov model using co-kriging method (spherical model) and co-factor of BD with R۲=۰.۹۹, nugget effect of -۰.۰۰۲, and range of ۳۳۸۰ m was superior to kriging method. The power b of  Kosiakov was estimated by exponential mode and kriging method with R۲= ۰.۹۷, nugget effect of ۰.۰۰۵ and range of ۱۴۴۱۰ m. To estimate sorptivity parameter (S) of Philip model, the co-kriging method with spherical model and co-factor of BD with R۲=۰.۹۹ and range of ۲۹۷۳ m was preferred to kriging method. Likewise, estimation of transmissivity parameter of Philip model using co-kriging method (Gaussian model) with R۲=۰.۹۹۶, nugget effect of ۰.۰۰۰۳, and range of ۳۸۶۲ m showed high accuracy. Using soil moisture content, BD, texture, SP, and organic carbon as co-factors of co-kriging method, resulted in relatively better estimation of infiltration model parameters.

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توزیع مکانی ، زمین آمار ، کریجینگ ، کوکریجینگ ، نفوذ آب به خاک