太湖水体光学特征及其对水中初级生产力的影响  

Effect of underwater light spectrum on primary production of the Taihu Lake

作　　者：杨顶田[1] 陈伟民[1] 张运林[1] 季江[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所

出　　处：《农村生态环境》2003年第2期24-28,共5页Rural Eco-Environment

基　　金：中国科学院知识创新工程项目 (KZCX 2 -3 11)

摘　　要：对太湖梅梁湾水体实测结果表明 :在水体表面 ,UV -C的强度较小 ,只有 10 -5μE·m-2 ·s-1数量级 ;UV -B的强度随着波长的增加而呈现递增的趋势 ;UV -A的强度较强 ,达 10 -2 μE·m-2 ·s-1数量级 ,并且在水体中衰减较快 ,衰减系数 (Kd)可以达到 12 .5m-1。可见光在水体中Kd 可达 8.2m-1。在水下 0 .5m处 ,紫外线不足表面光强的 1% ,可见光是表面光强的 2 0 %左右。初级生产力在表面相对较小 ,在水下 0 .2m处最大 ,且随水深的增加而减少 ;在水体中直接测定发现 ,0 .2m处溶解氧值较高。初级生产力的这种分布是水体中紫外光与可见光共同作用的结果。Distribution of light spectrum and primary production in the waterbody of Meiliang Inlet of Taihu Lake was studied. The results show that on the water surface, the intensity of UV-C was low (10 -5 μE·m -2 ·s -1 ), that of UV-B increased with wavelength and that of UV-A was much higher (10 -2 μE·m -2 ·s -1 ) but attenuated rapidly with maximum vertical diffuse attenuation coefficient ( K d )value up to 12.5 m -1 . K d of visible light could reach as high as 8.2 m -1 . In comparison with the value on the surface, the intensity of ultraviolet at 0.5 m was less than 1%, and of visible light around 20%. The primary production was relatively low in the surface, reached peak at the depth of 0.2 m and then decreased with the increase in depth. Direct measurement revealed that dissolved oxygen in the water was high at the depth of 0.2 m. Concentration of chlorophyll-a varied with light intensity in the water. These results show that the distribution of primary production was the result of the joint effect of ultraviolet and visible light.

关 键 词：水体 紫外光谱 可见光谱 初级生产力 

分 类 号：P343.3[天文地球—水文科学]