Figure 11: Spatio-temporal distribution of PDSI drought conditions
in Iowa.
Discussions
The spatio-temporal analysis of these indices demonstrates their
complementary roles in assessing drought impacts on crop yields. SPI-3
captures immediate precipitation anomalies, SPEI-3 incorporates
temperature-driven evaporative demand, and PDSI reflects cumulative
moisture conditions. The indices collectively highlight the temporal and
spatial variability of drought impacts, with 2012 emerging as a critical
year for agricultural productivity loss. The year was marked by
prolonged precipitation deficits, elevated temperatures, and heightened
evapotranspiration, which collectively exacerbated soil moisture
depletion and hindered crop growth during critical developmental phases.
This underscores the need for region-specific agricultural planning that
considers the dual risks of drought and flooding.
These findings emphasize the importance of integrating multiple drought
indices to develop resilient farming strategies. Future work should
explore how these indices perform under changing climate scenarios,
particularly with increasing temperatures and variability in
precipitation patterns.