亚热带小流域COD负荷及影响因子分析  

Analysis of the COD load and impact factor in subtropical watersheds

作　　者：刘梦霞[1,2] 周脚根[2] 黄新 谢可军 李冀 吕殿青[1] 李裕元[2] 

机构地区：[1]湖南师范大学资源与环境科学学院,湖南长沙410081 [2]中国科学院亚热带农业生态研究所业热带农亚生态过程重点实验室,湖南长沙410125 [3]湖南省农业资源与环境保护管理站,湖南长沙410005

出　　处：《农业现代化研究》2017年第1期168-175,共8页Research of Agricultural Modernization

基　　金：水利部公益性行业科研专项(201501055);湖南省科技计划项目(2015NK3055);湖南省教育厅重点项目(16A129)~~

摘　　要：化学需氧量(COD)是农业面源污染的重要方面。以湖南省长沙县9个典型小流域为研究对象,利用连续5 a(2011-2015)的定位观测资料,系统分析了亚热带典型小流域COD浓度与负荷的时空变化特征及其主要影响因素。结果表明:1)研究区近5 a来COD浓度的变化范围为0.31-42.63 mg/L,平均值为12.95 mg/L。不同类型小流域COD平均浓度的变化顺序为:种养>养殖>森林-种植>森林,从季节变化来看,COD浓度夏秋季节较高,而冬季与春季相对较低;从年际变化来看,从2011年到2015年COD浓度总体上呈波动上升趋势。2)COD月负荷的变化范围为3.15-1 086.6 kg/hm^2,研究区平均值为152.06 kg/hm2,不同类型小流域COD负荷时空变化规律与浓度基本一致。3)COD浓度主要与畜禽养殖密度及人口密度呈显著正相关关系,相关系数分别为0.86(P<0.05)和0.69(P<0.05);COD负荷则与养殖密度、种植比例、径流深等因子呈显著正相关,相关系数分别为0.87(P<0.05)、0.69(P<0.05)和0.54(P<0.05)。适当控制畜禽养殖密度、加强小流域生活污水治理以及促进养殖废弃物资源化利用是控制亚热带小流域COD排放的关键途径。Chemical oxygen demand （COD） is an important aspect of agricultural non-point source pollution. Nine subtropical typical small watersheds were selected in Changsha County of Hunan Province. The characteristics of COD concentration and its spatial-temporal variation and their main influencing factors were analyzed using the five-year＇s observation data （2011-2015）. The results showed that： 1） The COD concentrations in the study area varied in a range of 0.31-42.63 mg/L and the average was 12.95 mg/L in the past five years. For the different types of small watersheds, the averaged COD concentration sorted in the following order： cropping-livestock 〉 livestock 〉 forest-cropping 〉 forest. The COD concentrations were higher in summer and autumn than those in winter and spring, and generally increased from 2011 to 2015.2） The monthly COD loads ranged from 3.15 to 1,086.6 kg/hm^2, with average value of 152.06 kg/hm^2. The characteristics of spatial-temporal and variation of COD loads were similar to COD concentrations in different watersheds. 3） The COD concentrations were significantly correlated with the densities of livestock and poultry as well as the resident population, with the correlation coefficients of 0.86 （P〈0.05） and 0.69 （P〈0.05）, respectively. The COD loads were positively correlated with the livestock and poultry density, cropping area ratio, and runoff depth. The correlation coefficients were 0.87 （P〈0.05）, 0.69 （P〈0.05） and 0.54 （P〈0.05）, respectively. Appropriate controlling the scale of livestock and poultry breeding, strengthening the domestic sewage treatment in watersheds, and promoting the recycling use of livestock waste are the critical approaches in reducing discharge of COD in the small subtropical watersheds.

关 键 词：亚热带小流域 化学需氧量（COD） COD负荷 时空变化 影响因素 

分 类 号：X522[环境科学与工程—环境工程]