Spatial Distribution and Temporal Trends of Monthly Precipitation Concentration in Poyang Lake Basin

The study on monthly distribution of annual precipitation is of great significance to drought or flood and water resources management. The 14-station monthly rainfall data in the Poyang Lake basin from 1957 to 2012 was collected. To analyze the distribution of monthly precipitation, the Precipitation Concentration Degree (PCD) and Precipitation Concentration Period (PCP) were adopted. Moreover, the modified Mann-Kendall (MMK) was applied to find the trend of precipitation concentration indices. It shows that these indices are applicable in this basin. The precipitation concentration detected by the PCD gradually increased from southwest to northeast in this basin. The variation range of precipitation concentration period is from early April to mid-June, with a downward trend from the west part to the east part. The precipitation concentration index shows an insignificant decrease trend in most of parts in this basin. Additionally, the result of the PCP shows an insignificant delay trend.