Soil moisture in Kazakhstan : in situ probes and satellite data

Wheat yield in Kazakhstan is strongly related to food security and international stability in Central Asia. In an effort to understand and monitor how soil moisture affects yields, probe data was used to detect fluctuations, which relates to variability in the satellite derived wetness values. The soil moisture observations provided by probe measurements serve as calibration points to the satellite measurements. The regression equations derived from these relationships identify the covariance between the quantities. Many of the relationships between the probe data and wetness index were meaningful and can be utilized to effectively identify how upper level moisture fluctuates in Northern Kazakhstan during the period of wheat production. The slope and intercepts of the equations determine the ratio between the two measurements, and the intercept identifies when the soil is effectively dry, relative to the satellite observation. Generally, there were two unique relationships: one for the summer season (June, July, and August) and one for May, when there was nominal vegetation covering the surface. Findings from this study were highly significant and can be applied in near real time in order to monitor the distribution of upper level soil moisture across the northern oblasts of Kazakhstan, where the production of wheat is critical to food security in Central Asia. (Author abstract)