中文摘要：

嘉陵江是重庆的重要饮用水源，其水质与城市居民的生活和生态环境息息相关。为研究其水质及其变化，在重庆主城区嘉陵江段平水期3～5月，采用三维荧光技术对7个取样点的水体样品进行分析，得到了溶解性有机质（DOM）含量变化引起的三维荧光光谱变化数据，水体样品存在两个荧光峰分布，荧光峰激发波长λex=330～350nm，发射波长λem=400～450nm；荧光峰Ⅱ激发波长Eex=270-300nm，发射波长λem=320～350nm。结果表明，取样江段水样三维荧光谱中的荧光峰主要由类腐殖质和类蛋白质形成；同时，由于受到气温、降雨、地理环境等因素的影响，3—5月各河段水样的荧光指数（f450／50）分别在1．41～1．57、1．30～1．47和1．42～1．68之间，由此可以判断，采样时间段内水质污染主要是陆源性输入形成。

英文摘要：

During the level season of Jialing fiver （from March to May）, samples of seven representative sites of Chongqing urban areas are analyzed and compared by three-dimensional （3-D） fluorescence spectra. The differences of 3-D fluorescence spectra are obtained from measurements in the same condition and related to the variations of dissolved organic matter （DOM） contents so that they indicate the chan- ges of water quality of Jialing River. Then the change regulations of three-dimensional fluorescence spectra are discussed in details. At last, the results show that the fluorescence peaks of samplings are mainly humic-like and protein-like peaks. Moreover, the average fluorescence indexes of samplings from March to May are 1.41-1.57,1.30-1.47 and 1.42-1.68,respectively. And according to the fluorescence in- dex （f450/500）, water pollutions mainly come from terrestrial sources during the sampling period. In addition, the difference of fluorescence index results from the influence of temperature, rain, geography and other factors.