梯级筑坝会改变河流水文特征与物质迁移转化特征，对水环境质量产生影响。探究梯级筑坝下黑河上游水体氮磷营养盐时空分布及富营养化风险问题对黑河流域生态修复及梯级水资源管理具有一定参考意义。对黑河上游16个主要控制断面10项水体理化指标多年数据进行统计分析。结果表明：黑河上游水体理化性质时空差异显著，水体整体呈弱碱性，自净能力较好，总氮（TN）、总磷（TP）的浓度符合Ⅲ、Ⅱ类水质标准。从时间分布来看，黑河上游水体TN、氨氮（NH₃-N）和亚硝酸盐氮（NO{}_{\mathrm{2}}^{-}-N）浓度表现为枯水期>丰水期，TP浓度为丰水期>枯水期。从空间分布来看，单个水库水体营养盐分布具有潜在的累积效应，但梯级水库作用下整体营养盐的分布呈下降趋势，说明梯级筑坝使沿程累积作用在逐渐削弱； NH₃-N和NO{}_{\mathrm{2}}^{-}-N主要分布在水库中层，TN、TP下层浓度高于上层，分层现象表明有大量的氮磷蓄积在下层沉积物中。富营养化风险分析表明，梯级筑坝在一定条件下降低了水体富营养化风险，丰水期大部分水体断面处于氮限制，枯水期主要为氮磷共同限制；结合氮磷比特征的分析，本研究认为控制外源氮磷输入是黑河梯级水库富营养化防控的有效途径。

Cascade dams alter the hydrological characteristics along with material transport and transformation patterns of rivers， thereby influencing water environment quality. Therefore， exploring the spatio-temporal distribution impact of nitrogen （N） and phosphorus （P） nutrients in the upper reaches of Heihe River under cascade dams and analyzing eutrophication risks is of certain reference significance for ecological restoration and cascade water resources management in Heihe River Basin. This study conducted statistical analysis on multi-year data of 10 water physicochemical indicators at 16 major monitoring sections in the upper reaches of Heihe River. The results demonstrate that there were significant spatio-temporal differences in the physicochemical properties of the water in the upper reaches of Heihe River. The overall water quality is weakly alkaline with good self-purification capacity， and the concentrations of total nitrogen （TN） and total phosphorus （TP） comply with Class III and Class II water quality standards. For temporal distribution， the concentrations of TN， ammonia nitrogen （NH₃-N）， and nitrite nitrogen （NO{}_{\mathrm{2}}^{-}-N） in the upper reaches of Heihe River are higher during the dry season than the flood season， while TP concentration is higher during the flood season than the dry season. In terms of spatial distribution， the distribution of nutrient salts in individual reservoirs exhibits potential cumulative effects， but under the action of cascade reservoirs， the overall distribution of nutrient salts shows a decreasing trend， indicating that the cumulative effect along the river is gradually weakening. Furthermore， NH₃-N and NO{}_{\mathrm{2}}^{-}-N are primarily distributed in the middle layer of the reservoir， while TN and TP have higher concentrations in the lower layer than the upper layer， indicating a stratification phenomenon with a large amount of N and P accumulating in the lower layer sediment. This study highlights the necessity for the implementation of management strategies aimed at mitigating eutrophication risks.