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The variation in particle size distribution for a sequence of sand samples, collected from the surface of a small barchanoid dune along a sampling line parallel to the windflow, is studied by means of the hyperbolic distribution. The modal (or typical) value of the log size increases linearly with distance from the windward foot to the crest of the dune, and falls off steeply on the lee side. The spread of the log‐size distribution, locally near the modal value, is roughly constant on the windward side but decreases significantly down the slip face. Two other parameters of the four‐parameter hyperbolic distribution can be considered largely constant. A comparison of the log size distributions for heavy and light mineral grains, based on a selected set of the samples, showed that heavy and light minerals follow different hyperbolic patterns. However, the difference in modal size of the distributions for the two types of minerals was virtually constant among the samples.

The effect of gauge height, exposure and screening on systematic errors in rainfall estimation is investigated. Adhesion losses are found to be more than 2% of the annual precipitation, but for summer periods alone it can amount to over 5%. A statistical model using the square root of observations (corrected for adhesion) is found to be adequate to describe differences due to the aerodynamic effects. A correction formula is proposed.