HYDROLOGICAL AND METEROLOGICAL DROUGHT ANALYSIS OF SOUTHEASTERN STREAMS

Due to the stochastic nature of drought, it is an extreme weather phenomenon known for causing significant anthropogenic impacts to local ecosystems, watersheds, and water sources. Improved understanding of drought is key to proper water resources planning and management especially through enhanced monitoring and forecasting strategies. Normalized indexes provide fundamental insight into drought effects by assimilating thousands of historical data records (temperature, rainfall, snowpack, soil moisture, streamflow, and other water supply indicators) into probability indices. Results from these indices are used decision making tools from determining the frequency and severity of droughts.

The Standardized Precipitation Index (SPI) uses only precipitation data to determine an index value, usually a single number with positive valves depicting wet periods and negative as dry periods to determine drought severity. This index only requires 30 years of respective data and can be used to define drought impacts over different temporal and spatial scales. SPI studies have shown correlations between drought index values and surface water levels. An SPI analysis was conducted with the 1, 3, 6, 9, 12, and 24 month timescales on Southeast streams to determine if there is a correlation between SPI values and streamflows.