Specifications

Beijing, 100026, China
Abstract: Using statistical methods for a study on the spatial variations of soil properties has
become one of hot topics in the study of soil science. Due to the deep research on the spatial
variation of soil hydraulic parameters, and the lack of research on the dynamic characteristics of
soil air and heat transfer, we cannot compare the spatial variation characteristics of soil, water, air,
and heat transfer kinetic parameters. As the interaction between the soil and the environment as
well as the precise regulation of farmland soil moisture, air and heat condition problem is
receiving more and more attention, the numerical model used to study the soil moisture, air and
heat transport process, effectiveness and its impact on crop growth and ecological environment
has gradually become a reality. But model accuracy depends largely on the accuracy of soil, water,
air, and heat transfer kinetic parameters. Thus, seeking a simple and feasible method of
determining the thermal dynamic parameters of soil moisture is the focus of research around the
world. In order to define the dynamiccharacteristics of water conductivity, air permeability and
heat conductivity's spatial variability, this paper examines the spatial variation of the above
parameters in Linze County, an agricultural area in the middle reaches of the Heihe River Basin.
PL-300 soil air permeability measurement and soil heat pulse meter were applied to measured
soil air permeability and thermal conductivity. In this paper, we designed an experiment of four
levels of moisture content and took the average of three replications. Hydraulic conductivity is
measured by qdisc infiltration instrument, each measuring point design four suction head, based
on a spatial analysis function of GIS, The results showed as follows: 1) simulate the spatial
structure and variability of the water, air, and heat parameters using land statistics of a wheat
field. The optimal fitting model for saturated hydraulic conductivity, air permeability, thermal
conductivity are an exponential model, the sum of squared residuals are small, nearly zero, and
the determination coefficient R2 reached more than 80%. The results show that the statistical
method can better simulate the spatial structure and variation characteristics of soil moisture air
and thermal parameters. Fractal dimension (D) was close to 2, illustrating that soil water
conductivity, air permeability and heat conductivity have strong spatial variation characteristics in
this region. 2) Saturated hydraulic conductivity, air permeability and heat conductivity's C / (C
+C0)>75%, had a strong degree of spatial autocorrelation in the study scale. Recommend
sampling distances of hydraulic conductivity, air permeability and heat conductivity both are 10m.
And sampling distances of the other soil physical parameters are recommend to be 4m. 3)
Kringing interpolation results show that soil water and gas parameters change was having a
certain degree of consistency, Thermal conductivity has certain regional characteristics in the
study area. The higher the moisture content, bulk density and the greater the sand content are,
the greater the thermal conductivity is, and the thermal conductivity has certain regional
characteristics. Among the soil, thermal conductivity is high, the north and south were on both
sides of the lower tendency in the saddle. The research will be for the local soil moisture, air and
thermal parameters field scale space mutation research to provide a certain reference basis.
Number of references: 31
Main heading: Geologic models
Controlled terms: Agriculture - Air permeability - Fractal dimension - Heat transfer
- Hydraulic conductivity - Kinetic parameters - Moisture - Moisture determination
- Research - Soil moisture - Soils - Space applications - Spatial variables
measurement - Statistical methods - Thermal conductivity - Thermal conductivity of