Study On The Monitoring Points' Layout And Spatial Variability Of Soil Moisture In Typical Farmland

In the process of monitoring soil moisture, there has a great influence to determine the number of reasonable monitoring sites and the optimal coordinates. Due to the factor of spatial variability, under the condition of a certain monitoring accuracy, there are crucial through scientific and reasonable method to determine the number of reasonable monitoring sites and the optimal coordinates.With the help of Spss19.0, Arcgis10.2, Surfer 12.0 software and the theory of classical statistics and geostatistics, analyze the typical spatial variability regular of experimental area; explores the number of reasonable monitoring sites and the optimal coordinates in the China Water Resources and Hydropower Research Institute of DaXing experimental base. The main conclusions are as follows:(1)Through the analysis of the characteristic curve and soil texture in experimental area, learned that the sandy loam are mainly soil texture in winter wheat farmland of experiment site, in which have loamy sand, silty loam, and loam in different depth soil; Also learned that in the larger plot soil texture changes range, the variability of soil moisture content is stronger, within the scope of relatively uniform soil texture, that the variability is weaker.(2) The soil moisture content data conforms to normal distribution in different depth of farmland, with the deepness of soil deepen, the spatial variability of soil moisture content all show a trend of first increases and then decreases. And in 0-10cm?10-20cm?60-70cm?70-80cm 90-100cm depth spatial variability of soil moisture content is the weak variation; And 30-40cm,40-50cm,50-60cm depth is medium variability, but 20 to 30cm depth spatial variability of soil moisture content is the complex variation.(3) Making use of statistical methods to analysis the Experimental zone soil moisture content trend, learned that in two direction along the north-south and east-west trend is not obvious. For the interpolation analysis according to different depth of soil moisture content, including 0 to 60 cm depth of variability of soil moisture content is more complex, the space structural general,0-30 cm and 60-100cm depth of variability is small, space structural significantly. Overall, with the deepness of soil deepen, the spatial variation of soil moisture show a trend of first increases and then decreases in experimental zone.(4) At the same confidence level, the number of reasonable monitoring point decreases with the increases of sampling error. At the same sampling error, the number of reasonable monitoring point decreases with the lower of confidence level. At 90% confidence level,5% ?sampling error conditions, the number of reasonable monitoring experimental area is three;(5) The spatial correlation of soil moisture content is 21m in experimental zone. At 90% confidence level,5% ? sampling error conditions, the exact location of the three monitoring point respectively is (5,17)?(26,11)?(47,14).