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).