The runoff variation characteristics of Dongting Lake, China

Abstract

Mao, D., Feng, C., Zhou, H., Hu, G., Li, Z., & Guo, R. (MarchApril, 2017). The runoff variation characteristics of Dongting Lake, China. Water Technology and Sciences (in Spanish), 8(2), 77-91. The runoff variation characteristics of Dongting Lake were analyzed by applying the methods of concentration degree, concentration period, Mann-Kendall trend test, and variation coefficient. The analysis showed that: 1) The runoff concentration period of Dongting Lake occurs mainly between June and July of each year, with the peak time in late June–early July, and the composite vector directions in concentration period range from 103.2° to 190.2°; 2) The runoff variation coefficient ranges from 0.194 to 0.761, which indicates the instability of runoff. Extreme ratios of inflow and outflow are over 0.6 with an obvious attenuation; 3) The alternating pattern between wet years and dry years showed that the water distribution of the four rivers is relatively equal, while Ouchikou from three bayous is more violent, accounting for 32.79% of wet years and 57.38% of dry years respectively. The drastic change of annual water allocation is adverse to rational utilization of water resources.

Keywords

• runoff variation characteristics, annual variation, concentration degree and period, interannual variation, trend analysis, dongting lake