北盘江支流打帮河溶解氧分布特征及影响因素分析

摘要

打帮河为北盘江一级支流,大坝建成蓄水后,打帮河流域的鱼类种群数急剧减少.本文通过对打帮河流域的现场水质监测,分析了打帮河流域溶解氧的季节变化及空间分布特征,探讨了流域内溶解氧与其他水质因子的相关性.结果显示:全年(春、夏、秋、冬)最大平均溶解氧浓度分别为9.87 mg/L、11.58 mg/L、12.63 mg/L、7.80 mg/L.冬春两季上下层平均浓度差分别为2.71 mg/L、3.35 mg/L;夏秋两季在水面以下10 m和5 m 左右出现明显跃层,上下层平均浓度差分别为5.03 mg/L、4.49 mg/L.整个研究河段全年溶解氧浓度分布呈现出"两端高,中间低"的现象.受水温影响的大气复氧能力直接影响溶解氧的垂向分布,随着水深增大,浮游植物光合作用降低,水中溶解氧含量供需不足.同时上游泄水也是影响溶解氧时空变化的主要原因之一.研究结果有效反映出流域的水质状况,可对河流水质状况改善及流域生态环境保护提供参考.%Dabang River,the tributary of Beipanjiang River,the dam was built and then impounding,The ba-sin fish population in Dabang River decreased dramatically.In this paper,the seasonal variation and spatial distribution of dissolved oxygen in Dabang River basin are analyzed by monitoring the water quality of Dabang River basin;and the correlation between dissolved oxygen and other water quality factors in the river basin is discussed.The results show that the maximum dissolved oxygen concentrations are 9.87mg/L,11.58mg/L, 12.63mg/L and 7.80mg/L respectively in the whole year (spring,summer,autumn and winter).The average concentration differences of the upper and lower layers in spring and winter are 2.71mg/L and 3.35mg/L re-spectively.The average concentration differences of the upper and lower layers in the summer and autumn are 5.03mg/L,4.49mg/L.The distribution of dissolved oxygen concentration in the whole study shows a"high at both ends and low in the middle".At the same time,the upstream discharge is also one of the main reasons for the change of dissolved oxygen.The study results can effectively reflect the water quality of the river ba-sin,so as to provide reference for the improvement of river water quality and the protection of river basin eco-logical environment.