TREND is designed to facilitate statistical testing for trend, change and randomness in hydrological and other time series data. TREND has 12 statistical tests, based on the WMO/UNESCO Expert Workshop on Trend/Change Detection and on the CRC for Catchment Hydrology publication 'Hydrological Recipes: Estimation Techniques in Australian Hydrology' by Grayson et al. (available online at http://www.catchment.crc.org.au/pdfs/hydrorecipes.pdf).

TREND is designed for hydrologists, environmental scientists, consultants and researchers to facilitate statistical testing for trend, change and randomness in time series data.

TREND is easy to use and is based on statistical tests that are relatively robust and easy to understand.

Users can gain a good appreciation of the tests by following the descriptions in Section 4.2 of the TREND User Guide and the examples in the Excel spreadsheet TrendTests.xls (both can be downloaded from 'Documentation').

TREND can be used to test for changes in hydrological data caused by climate change, land use change, change in management practices, etc...

TREND has 12 statistical tests, based on the WMO/UNESCO Expert Workshop on Trend/Change Detection and on the CRC for Catchment Hydrology publication 'Hydrological Recipes: Estimation Techniques in Australian Hydrology' by Grayson et al.:

• Mann-Kendall (non-parametric test for trend)
• Spearman's Rho (non-parametric test for trend)
• Linear Regression (parametric test for trend)
• Distribution-Free CUSUM (non-parametric test for step jump in mean)
• Cumulative Deviation (parametric test for step jump in mean)
• Worsley Likelihood Ratio (parametric test for step jump in mean)
• Rank-Sum (non-parametric test for difference in median from two data periods)
• Student's t (parametric test for difference in mean from two data periods)
• Median Crossing (non-parametric test for randomness)
• Turning Points (non-parametric test for randomness)
• Rank Difference (non-parametric test for randomness)
• Autocorrelation (parametric test for randomness).

Features of TREND include:

• Allows easy statistical testing using different tests
• Supports various time series data input formats
• Provides simple statement of test result
• Displays test statistic and critical values for various statistical significance levels
• Performs resampling analysis to determine critical test statistic values
• Allows easy retrieval of test results.