Drought Trend Analysis in DMAP V2.1
Learn how to perform and interpret drought trend analysis in DMAP V2.1 using Mann–Kendall, Sen’s slope, Modified Mann–Kendall, Spearman’s Rho, linear regression, and Innovative Trend Analysis (ITA).
What this tutorial covers
Calculating a moving 12-month SPI for Ames and Minneapolis, opening the Trend Analysis window, comparing 1% and 5% significance levels, accounting for serial correlation, interpreting slope and p-value results across complementary methods, reading the ITA chart, and exporting chart data, statistics, and graphs to Excel.
Why compare several trend methods?
The example demonstrates that ordinary Mann–Kendall and Spearman’s Rho can indicate a weak trend while Modified Mann–Kendall, regression, or ITA may not classify it as significant. Comparing methods helps reveal the influence of significance level, serial correlation, and the assumptions behind each test.
Related pages
- How do you analyze the trend of a drought index?
- DMAP V2.1 tutorial
- DMAP formulas and methodology
- DMAP V2.1 product page
Browse the full DMAP tutorial playlist on YouTube.