农业现代化研究2017，Vol.38Issue(1)：168-175,8.DOI:10.13872/j.1000-0275.2016.0149
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
摘要
Abstract
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 inlfuencing factors were analyzed using the ifve-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 ifve 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/hm2, with average value of 152.06 kg/hm2. The characteristics of spatial-temporal and variation of COD loads were similar to COD concentrations in different watersheds. 3) The COD concentrations were signiifcantly correlated with the densities of livestock and poultry as well as the resident population, with the correlation coefifcients 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 coefifcients 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Key words
small watershed in subtropics/chemical oxygen demand (COD)/COD load/spatial-temporal change/inlfuencing factors分类
资源环境引用本文复制引用
刘梦霞,周脚根,黄新,谢可军,李冀,吕殿青,李裕元..亚热带小流域COD负荷及影响因子分析[J].农业现代化研究,2017,38(1):168-175,8.基金项目
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）。@@@@Special Scientiifc Research Fund of Public welfare Profession of the Ministry of Water Resources, China(201501055) （201501055）
Science and Technology Project of Hunan Province (2015NK3055), Key Projects of the Education Department of Hunan Province(16A129) （2015NK3055）
