研究雅砻江天然径流特征对流域内已建梯级水电站群工程运行、管理及水能开发规划具有重要参考意义。本文选取雅砻江流域特枯、偏丰、特丰三个典型年份，利用水量平衡方法还原河川天然径流量，综合运用基尼系数和径流贡献率两项指标．分析其天然径流量时空分布特征。结果表明：(1）特枯年份，各个站点基尼系数均介于0. 30～ o. 39之间，天然径流年内分配相对均匀；偏丰和特丰年份，各个站点基尼系数均介于0.40～0.59之间，天然径流年内分配不均匀；特丰、偏丰和特枯年份，流域基尼系数均值分别为 o.419、0.43和0. 35，各站点天然径流年内分配不均匀程度与径流量正相关。（2）枯季，特枯、偏丰水年流域上、中、下游径流贡献率比例接近1 : 1 : 1，而特丰水年流 域径流贡献率为上游＞下游＞中游；汛季和全年，特枯、特丰水年流域径流贡献率为上游＞下游〉中游，而偏丰水年流域径流贡献率比例接近1 : 1 : 1，总体呈现左岸径流量大于有岸径流量的分布格局。（3）雅碧江流域天然径流时间分布特征主要受降雨因素影响，而空间分布特征由降雨、地形和集水面积等多种因素共同决定。

The study on the natural runoff characteristics of Yalong River Basin has important significance for the operation and management of cascade hydropower stations and the planning of hydropower development and utilization in the future. This paper selected three typical years of extremely high，above-average and extremely low annual runoff. The water balance method was used to restore the natural numff of the river. The Gini coefficient and the runoff contribution rate were used to analvze the temporal and spatial distribution characteristics of natural runoff. The results showed that Gini coefficients of each station were between 0.30 and 0.3 9, respectively, and the distribution of natural runoff was relatively unifom1 in extremely dry years. Gini coefficient of each station was between 0. 40 and 0.59，and the distribution of natural runoff was relatively uneven in above-aver age and extremely high annual runoff years. Gini coefficient of special abundance, partial abundance and special dry years were 0.49,0.43 and 0.35，respectively, and the distribution inhomogeneity of natural runoff was positively correlated with lotal runoff. In the dry season, the proportion of contribution rate of runoff in the upper, middle and lower reaches of the basin was close to 1 : l : l in extremely low and above-average annual runoff years, while the runoff contribution rate was followed by upstream,dowmstream and midstream in the Year of extremely high annual runoff. The spatial distribution characteristics of runoff in the flood season and the whole year were the same. The runoff contribution rate of the basin was followed upstream, down stream and midstream in the years of extremely high and extremely low annual runoff, while the proportion of the runoff contribution rate of the basin was close to 1 : 1 : 1 in the Year of above-average annual runoff. Overall, the spatial distribution pattern of left bank runoff was larger than the right bank runoff. The distribution of natural runoff time in the Yalong River Basin was mainly affected by rainfall factors, while the spatial distribution characteristics were detemiined by various factors such as rain fall, topography and catchment area.

国家重点研发计划（2017YFC0404605）；国家自然科学基金〔51709178)