摘要
根据2009年6月巢湖32个样点的实测数据以及归一化PAR强度数据,探讨巢湖水体的水下光场结构,并计算该水域的真光层深度,在此基础上结合叶绿素a浓度评价其初级生产力.结果表明,巢湖水体水下光强随着深度的增加呈现出指数衰减趋势,水深1 m处光强只有表层光强的0.07%～15.17%;且不同水深处的光场分布总体呈现出西部湖区、东北部湖区较高,西北湖区、中东部湖区较低的趋势;同时发现真光层深度的变化范围为0.64～2.33 m,平均值为1.2 m,其中最大值出现在西南湖区,西北湖区以及中东部湖区的真光层深度则相对较小.采用VGPM模型得到的巢湖水体的初级生产力在1 363.77～7 349.37 mg/(m2.d)范围内变动,将巢湖初级生产力划分为3个等级,其中1级[0～2 500 mg/(m2.d)]主要分布于巢湖东部水域以及零星分布在西部湖区,面积大约为312.66 km2;2级[2 500～5 000 mg/(m2.d)]主要分布在巢湖西部以及东北部,占了巢湖水体面积的47.12%,大约为353.42 km2;3级[5 000～7 500 mg/(m2.d)]的面积则只有83.92 km2,分布在巢湖西北湖区以及少量分布在中部偏北湖区.
According to the in situ measured data on 32 sampling sites in Chaohu Lake in June 2009,underwater light distribution was explored,as well as,the euphotic depth was calculated in these waters.Furthermore,primary productivity was evaluated with chlorophyll-a concentration.The results indicate that： the underwater light intensity power decayed with the depth,and at the depth of 1m it decreased to only 0.07%-15.17% compared with that at water surface.In general,underwater light intensity was higher in the west and northeast lake at different water depth,on the contrary,it presented lower in northwest and east-central waters.At the same time,the euphotic depths ranged from 0.64 m to 2.33 m（mean 1.2 m） in Chaohu Lake.The maximum value was presented in the southwest lake;however,the euphotic depth was relatively lower in the northwest and east-central parts.Primary production values which were calculated by VGPM model were divided into three levels from 1 363.77 mg/（m2.d） to 7 349.37 mg/（m2.d）.Among these,Level 1[0-2 500 mg/（m2.d）]was mainly distributed in eastern waters and scattered in western region,and the total area was 312.66km2;Level 2 [2 500-5 000 mg/（m2.d）]located in the west and northeast and occupied 47.12% of the area（353.42 km2）;simultaneously,Level 3 [5 000-7 500 mg/（m2.d）]with area of 83.92 km2 was distributed in the northwest and a small area in the central north.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2011年第5期1257-1265,共9页
Environmental Science
基金
国家水体污染控制与治理科技重大专项(2009ZX07527-006)
国家自然科学基金项目(40971215)
南京师范大学优秀硕士论文培育计划项目(2010ss0012)
关键词
初级生产力
水下光场
漫衰减特性
真光层
巢湖
primary productivity
underwater light climate
diffuse attenuation characteristic
euphotic depth
Chaohu Lake
