中文摘要：

为了研究抚仙湖紫外辐射（LVR)和光合有效辐射（PAR)衰减的时空特征及其与有色可溶性有机物（CDOM)、悬浮物（^)、浮游植物（叶绿素a表征）等因子的关系，于2014年10月（秋季）、2015年1月（冬季）开展现场调查,结果显示:秋季不同波长（段）的漫射衰减系数心（305)、&(340)和&(PAR)分别为1.27±0.12、0.68±0.11和0.32±0.13m—1,冬季分别为1.13±0.10、0.63±0.07和0.36±0.07m_l;秋季⑶OM的不同波长吸收系数ay(254)、ay(305)和ay(340)分别为4.09±0.26、1.18±0.09和0.57±0.05m—l,冬季分别为2.95±0.24、0.61±0.11和0.11±0.07m—l,秋季ay(254)、ay(305)和ay(340)显著高于冬季;秋季&(305)显著大于冬季，这与秋季（雨季）较高的CDOM丰度、浮游植物生物量（及SS浓度）有关.秋季“^305)/^(305)…^口彳。)/^。“。）均显著高于冬季;秋季及秋冬季整体而言，ay(254)与&(305)、^(340)呈显著正相关，各多元逐步回归方程中均包含ay(254),说明CDOM吸收对LVR的衰减有重要贡献.空间差异方面,秋季北部的ay(254)、&(305)和&(340)显著高于南部，冬季南北部无明显差异,或与雨旱季北岸河流输入的CDOM和SS的情况有关.此外，浮游植物对LV-B衰减的影响和SS(与CDOM的交互作用）对LV-A衰减的影响更在于季节变化方面，而影响LVR、PAR衰减的各因子的相对贡献有待进一步量化.

英文摘要：

To understand the temporal-spatial characteristics of the diffuse attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) and its relationship with chromophoric dissolved organic matter (CDOM), suspended solids (SS), chlorophyll-a (Chl.a) and other factors in Lake Fuxian, an oligotrophic deep lake in Yunnan Plateau, we carried out an investigation based on field work in October 2014 (autumn) and January 2015 (winter). The results showed that the values of diffuse attenuation coefficient that Kd(305), Kd(340) and Kd(PAR) were 1.27±0.12 m-1, 0.68±0.11 m-1and 0.32±0.13 m-1, respectively in autumn, which were 1.13±0.10 m-1, 0.63±0.07 m-1and 0.36±0.07 m-1, respectively in winter. Meanwhile, the values of absorption coefficient of CDOM that ag(254), ag(305) and ag(340) were 4.09±0.26 m-1, 1.18±0.09 m-1, 0.57±0.05 m-1, respectively in autumn, which were 2.95±0.24 m-1, 0.61±0.11 m-1, 0.11±0.07 m-1, respectively in winter. The values of of ag(254), ag(305) and ag(340)in autumn were significantly higher than in winter. The values of of Kd(305) in autumn were significantly higher than in winter, which was related with higher CDOM abundance, phytoplankton biomass (and SS concentration) in autumn (rainy season). Furthermore, the values of ag(305)/Kd(305) and ag(340)/Kd(340) in autumn were significantly higher than which in winter; there were significant positive correlations between ag(254) and Kd(305), Kd(340), and the ag(254) included in all stepwise regression equations both in autumn and autumn-winter, indicated that the absorption of CDOM was an important factor affecting on the diffuse attenuation of UVR. Moreover, there were obvious differences depend on spatial distribution of ag(254), Kd(305) and Kd(340) in autumn, the values of ag(254), Kd(305) and Kd(340) in the north region of the lake was significantly higher than in the south region, whereas there were no significant differences between the north and south regions of ag(254), Kd(305) and Kd(340) in winter, which might