Rainfall stats

I read your recent article on “Bottled Water: A Drink Against Nature” [September 5] with interest. Regarding your listed eight points against bottled water in Hawaii, I would like to reinforce the first point of “Dry Facts.” The HRI (Hawaii Rainfall Index, Chu and Chen, 2005, Journal of Climate, 18, 4796-4812) [has declined] over the last 30 years or so. We experienced a long-term drought condition since the late 1980s. The HRI is derived from nine stations from each of three islands (Kauai, Oahu, and Hawaii). On each island, three stations are located on the windward [side] three on the leeward, three in between [with] stations arranged from low to high elevations. These 27 stations are representative of varying locations with respect to the prevailing winds.i.

Pao-Shin Chu, Ph.D. Honolulu, HI