风浪作用下的底泥悬浮沉降及内源释放量研究  

Suspension-sedimentation of Sediment and Release Amount of Internal Load in Lake Taihu Affected by Wind

作　　者：逄勇[1] 颜润润[1] 余钟波 李一平[1] 李瑞玲[1] 

机构地区：[1]河海大学环境学院教育部浅水湖泊综合治理与资源开发重点实验室,南京210098 [2]Department of Geoscience University of Nevada Las Vegas,Las Vegas,NV 89154-4010,USA

出　　处：《环境科学》2008年第9期2456-2464,共9页Environmental Science

基　　金：国家自然科学基金项目(50579015);江苏省科技厅太湖专项(BK2007742);高等学校博士学科点专项科研基金项目(20070294019);河海大学自然科学基金项目(2007416611)

摘　　要：分别于春夏秋冬4个季节对太湖梅梁湾水体开展了5次野外实验,利用沉积物捕获器收集沉积物,采用Gansith公式法计算了沉积物的再悬浮通量,并建立了其与风速的关系;对代表不同风浪作用下的太湖悬浮物进行了7次静沉降实验,计算了悬浮物的静沉降通量,并建立了其与悬浮物浓度关系.以3.7 m/s为界对低泥悬浮沉降过程进行分解和概化,计算了2005年每日的悬浮沉降量,并利用近10年的风速资料估算了太湖年均内源释放量.结果表明,太湖每日的内源释放量受风速影响显著,和风速变化趋势较为接近,然而不同营养盐的释放状况却各不相同.太湖内源年均进入水体的净底泥量有19.03万t,冬季最大,夏季次之;就营养物质释放量而言,COD约4.96万t、总氮约7 773.0 t、总磷约275.5 t,其中秋季营养物质释放量最小,夏季最大.The water quality in Meiliang Bay of the Taihu Lake was totally tested five times in the four seasons. The suspension samples were obtained by using a sediment trap. The sediment settling flux and resuspended flux were calculated according to the observation data by using Gansith formula, and the relationships between these fluxes and wind speeds were established. Seven experiments were conducted in Laboratory for hydrostatic settling behavior of suspended matter affected by different wind speeds in Lake Taihu. The hydrostatic settling fluxes of suspended matter were calculated and the relationships between the fluxes and suspended matter concentrations were established. Base on these works, the suspension-sedimentation process was decomposed and generalized according to the critical wind speed of 3.7m/s. Daily sediment resuspended amount and settling amount of the year 2005 was calculated and annual average release amount of internal load in Lake Taihu was estimated using the wind data of nearly 10 years. The results indicate that daily release amount of internal load in Lake Taihu significantly influenced by wind and have the same trend of change with wind, while the release amount of different nutrients in the same condition are different. The Lake Taihu has an annual average release amount of internal load with COD 49 600 t, TN 7 773.0 t and TP 275.5 t, of which summer has the markedly highest release amount than other seasons.

关 键 词：内源释放 再悬浮 静沉降 风浪 沉积物 太湖 

分 类 号：X143[环境科学与工程—环境科学]