Potentialities Evaluation of Rainwater Utilization in Xianing Port of Changsha

The Mann-Keddall formula was used for precipitation distribution and variation in Xianing Port of Changsha. The results shown that most rain fell between March and August,the rainfall in these month was about 70% of the annual rainfall. Monthly precipitation between March and July was greater than annual precipitation. Annual precipitation was 1413.5mm, and had the characteristics of uneven distribution and large fluctuation. The potential volume of rainwater for utilization was 1.82×1012m3.