通过对华东某水库进行现场水样采样, 并结合沉积物氨氮释放试验, 分析水库典型区域表层沉积物、上覆水和间隙水中总氮、氨氮含量, 揭示氮素组成的时空分布特征和表层沉积物对上覆水氨氮的影响. 结果表明: 库内氨氮和总氮呈现明显的季节变化, 且冬季明显高于夏季; 表层沉积物中总氮的质量浓度高于上覆水, 沉积物氨氮扩散通量为 0.18$\sim$0.53 mg/(m$^{2}\cdot $d), 低于污染严重水库一个数量级; 底泥-间隙水-上覆水的氨氮热力学分配过程中, 表层沉积物对氨氮具有吸附作用, 可一定程度上缓冲突发氨氮污染问题, 但水流强扰动也能短时促进底泥中氨氮向水体扩散.

To determine the contribution of ammonia nitrogen release from the surface sediments of reservoirs, the total nitrogen and ammonia nitrogen contents in surface sediments ($<$10 cm), overlying water, and interstitial water in typical areas of a reservoir were analyzed via on-site sampling of a reservoir in East China combined with an ammonia nitrogen release test, which revealed the temporal and spatial distribution characteristics of nitrogen in the reservoir sediments. The results showed that the ammonia nitrogen and total nitrogen contents in the reservoir showed clear seasonal changes, and the total nitrogen concentration in the surface sediment was higher than that in the summer. The total nitrogen concentration in the surface sediment was higher than that in the overlying water, and the ammonia nitrogen diffusion flux in the sediment was 0.18$\sim$0.53 mg/(m$^{2}\cdot $d), which was one order of magnitude lower than that of a heavily polluted reservoir. During the thermodynamic distribution of ammonia nitrogen in the sediment-interstitial water-overlying water, the surface sediment had an adsorption effect on ammonia nitrogen, which could buffer the sudden ammonia nitrogen pollution problem to a certain extent; however, the strong disturbance of the water flow could also promote the diffusion of ammonia nitrogen in the sediment to the water body in a short time.