Comparative rain measurements and rain‐gage performances on a steep slope adjacent to a pine stand

In this study, measurements from two rows of rain gages, extending outward along contours from the edge of a pine plantation on a steep slope, showed that the 45 foot‐high trees influenced the amount of rain reaching the ground for a distance not exceeding 34 ft from the edge of the plantation. Seven types of rain‐gaging installations were tested for accuracy on a windy, 40 per cent slope, including three types of shielding, gages exposed with the orifice horizontal and with orifice tilted parallel to the slope. Best results were obtained with tilted, shielded gages, but tilted, unshielded gages were only slightly less accurate for the conditions encountered. Shielding of untilted gages proved much less effective than tilting unshielded gages, although superior to a conventionally exposed gage, unshielded and with orifice horizontal. It was demonstrated again that the conventional installation is unsuitable for accurate rain gaging on windy slopes.