Soil moisture plays an important role in agricultural monitoring, drought and flood prediction, forest fire prediction, water supply management, and other natural resource-related activities. Soil moisture observations can warn of imminent drought and flood conditions before other standard indicators are triggered. As defined in AMS Glossary of Meteorology, soil moisture is "the total amount of water vapor-containing water in unsaturated soil." Soil moisture (sometimes called soil water) refers to surface water in the pores of the soil, not rivers, lakes, or groundwater. Soil moisture levels are determined by a variety of factors other than weather conditions, such as soil type and associated vegetation. Second, soil moisture affects the various dynamics of soil and plants. Surface soil moisture is water located 10 cm above the soil, and root zone soil moisture is water available to plants-generally considered to be located 200 cm ab...