采集滇池以南双龙水库的沉积物柱状样，对不同层的沉积物使用²¹⁰Pb进行定年；分析了不同年代沉积物的粒度分布特征以及总有机碳(TOC)、总氮(TN)和总磷(TP)的含量；在此基础上，对环境指标与昆明市人口和经济发展数据关系进行了解析。结果表明：①双龙水库沉积物中值粒径的范围分布在4.07 ~ 6.90 μm，平均值为5.71 μm，沉积物中值粒径在1986年后突然减小；②沉积物中TOC、TN以及TP的含量的范围分别是8.78 ~ 26.15、1.59 ~ 3.26和0.23 ~ 0.47 g/kg，均值分别为11.30、2.01和0.33 g/kg。TOC、TN以及TP的含量在1998年之前相对稳定，而在1998年之后有较大程度增长；③利用有机指数和有机氮指标评价双龙水库沉积物污染的变化情况，结果发现两大指标有加速增长的趋势；④通过相关分析发现昆明市国内生产总值(GDP)与双龙水库沉积物有机指数和TOC含量存在较好的相关性。昆明市人口数量与双龙水库沉积物有机指数和TOC含量的相关性也较强。研究结果表明水体生态参数受到社会经济指标的显著影响，人类活动是近几十年影响双龙水库水质的主要因素。

Sediment core samples were collected in Shuanglong reservoir to the south of Dianchi Lake. Sedimentary history was analyzed by ²¹⁰Pb dating method; the distribution characteristics of granularity of sediment cores, total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) were investigated; the relationship between environmental parameters and socio-economic parameters of Kunming were established. The results showed that: 1) the granularity of sediment cores ranged from 4.07 μm to 6.90 μm, with an averaged value of 5.71 μm. The granularity of sediment cores decreased after 1986. 2) The averaged concentration of TOC, TN and TP were 11.30 g/kg (ranging from 8.78 to 26.15 g/kg), 2.01 g/kg(1.59 to 3.26 g/kg) and 0.33 g/kg(0.23 to 0.47 g/kg), respectively. The contents of TOC, TN and TP were relatively stable before 1998. However, the three indicators increased rapidly after 1998. 3) Organic index and organic nitrogen were employed to evaluate the water quality, the results showed that there are accelerate increase trends in both of the indicators. 4) Linear correlation was observed between TOC concentration versus gross domestic product(GDP), organic index versus GDP, and increasing TOC concentration had a significant correlation with population, as well as organic index versus population, respectively. The results indicated that water ecological parameters were significantly affected by socio-economic parameters, human activities are major factors influencing the water quality of Shuanglong reservoir in recent decades.

X144

国家自然科学基金项目(41273102, 41030751, 41273103)资助