Scale effect of spatial variability of soil water-salt

Scale problems in hydrology and soil science have become one of focuses in the field of water and soil science at present. Using spatial information science — geostatistics, the article preliminarily studied some laws of spatial variability of one-and two-dimensional soil water and salt on moderate-or small-measuring-scale grid at Chang Sheng experimental demonstraion in He Tao Plain of Yellow River. The results showed selection and classification of measuring scale were related closely to spatial variability of soil water and salt. Studies on scale effect could guide design of field sampling systems and reduce field workload and was significant in calculating and evaluating results of prediction or simulation in agricultural research, and disclosing regionalized natural laws in the field of agricultural engineering.