A study of soil moisture across the Delmarva Peninsula from 2005-2008
Date
2010
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Publisher
University of Delaware
Abstract
The annual cycle and persistence of soil moisture is influenced by a multitude of factors including such variables as soil type, vegetation cover, weather patterns, and seasonal variability. Utilizing data derived the Delaware Environmental Observing System (DEOS), a network of ground stations located throughout most of the Delmarva Peninsula, as well as remotely sensed observations using the NASA MODIS and AMSR-E satellite sensors, the spatial and temporal variability of soil moisture across the Delmarva Peninsula is determined. The vegetation indices and land surface temperatures provided by the MODIS satellite sensor provide an indication of soil moisture conditions at the land surface, and the AMSR-E satellite sensor gives a quantitative measure of soil moisture conditions at the top 1cm of soil. The remotely sensed data, used in conjunction with the DEOS ground-level observations of daily rainfall, maximum daily volumetric water content (30cm depth), and average daily air temperature provide insight into the conditions responsible for fluctuations in soil moisture conditions. The average soil moisture conditions at each ground station site were compared to one another in terms of soil texture and estimated field capacity. In general, it was found that soils with a higher percentage of sand show greater variability than those with a higher composition of silt and clay. In addition to soil texture, it was found that influences from topography, vegetation cover, and weather can also have a major impact on soil moisture conditions, particularly at the land surface. Using a statistical autocorrelation, soil moisture tends to persist no more than 1-2 weeks across the Delmarva Peninsula.