Temporal Analysis of Interannual Soil Moisture Variability in Iowa

El Niño-Southern Oscillation (ENSO) plays an important part in the ever changing global climate causing droughts and floods. The main objective of this research is to identify the temporal patterns of soil moisture in Iowa and examine the driving forces behind these patterns. This study uses soil moisture data provided by the Iowa State University Extension from 60 sites in Iowa that took monthly measurements from 1954-1983. This extensive data set allows us to examine long-term trends in volumetric water content (VWC) which is dominated by a five to seven year cycle. This study will examine the causes of interannual variability by examining the relationship between ENSO and other teleconnetions. Coupled with statewide annual precipitation records, it is hypothesized that the relationship between ENSO and soil moisture will have a weak to moderate positive correlation since there are other, more immediate, influences that affect soil moisture such as land cover, topography and soil type.