建立内江水下光场分布预测模型,选择洪季、枯季两个典型全日潮,研究内江水下光场分布特征.结果表明:洪季内江水下光照条件明显优于枯季,枯季悬沙浓度较低,光强垂向衰减速度略慢于洪季;洪、枯两季水下0.3 m处光强分别比表面光强削减了89.1%和83.5%.受水量交换及水动力条件影响,洪季内江东部水域光照强度比西部水域平均增加59.2%;枯季内江南北两岸滩地水下光强平均约为主流区的2.63倍.洪季潮汐作用对内江水下光场分布影响较小;枯季潮差大于洪季,落潮期间,悬沙的落淤,水下光照强度平均较涨潮过程增加47.2%. The model of underwater light field distribution in the Neijiang River was established, and two typical all-tide floods in the flood season and dry season were selected to study the distribution characteristics of underwater light field in the Neijiang River.The results showed that the underwater lighting conditions in the Neijiang River were obviously better than those in the dry season and dry season The sand density was lower and the vertical decay rate of light intensity was slightly slower than that of flood season. The light intensity at 0.3 m in flood and dry season was 89.1% and 83.5% less than the surface light intensity, respectively. Under the influence of water exchange and hydrodynamic conditions , The light intensity in the eastern part of the Yangtze River was 59.2% higher than that in the western part in the flood season, and the average light intensity was 2.63 times of that in the mainstream in the dry season.The tidal effect in the flood season had less influence on the distribution of the underwater light field in the Neijiang River. The tidal range in the dry season is greater than that in the flood season. During the ebb tide, the suspended sediment deposition and the underwater light intensity increase by 47.2% on average.