摘要
采用现场布点采样及室内分析方法,以位于巢湖流域的一个子流域——鲍家塘流域为例,研究了传统灌溉系统——多水塘系统对农业流域非点源污染TN,NO3--N和NH4+-N等的产生、运移过程的影响,以及流域不同土地利用类型在非点源污染物产生、运移过程中的生态功能。结果表明,流域输出的氮素主要以NO3--N,NH4+-N为主,在不同景观具有显著性差异;施肥水田是流域最主要的“源”景观,在降雨径流过程大量输出养分和悬浮物;水塘、荒地、没有施肥水田持留养分和悬浮物,是流域非点源污染物的“汇”景观;多水塘系统的沟渠是污染物的主要运移通道。鲍家塘子流域中农田-渠道-水塘系统影响非点源污染物的产生、运移过程,同时多水塘系统截留降雨径流,减少流域非点源污染物的输出。
With point pollution controlled effectively, agricultural non- point source pollution (ANPS) became a main source affecting lake eutrophication. Many methods, such as wetland buffer strips, land management, were used to control AGNPS, whereas the functions of landscape intercepting pollutants were often neglected. The special landscape of field- channel- pond, multi- pond system, distributed in the low and middle reaches of Yangtze River, intercepted most surface runoff via connecting ponds scatted over the watershed to influence mass flow within agricultural ecosystem. Multi- pond system in Baojiatang sub- watershed, Anhui province, located in Chaohu watershed, was used to study its effects on the production and transportation of agricultural pollutants. The index of TN, - N, - N was measured to investigate the spatial variability of soil nutrients in different rice fields, including wasteland, fertilized rice fields and seeding fields; while TN, - N, - N, and TSS in the runoff was used to investigate the pollutants variability. The results revealed that: (1) The spatial variability of soil nutrients in the watershed was the comprehensive result of artificially interference and heterogeneous landscape, and there were significant differences in - N and - N among different rice fields, fertilized rice fields and wasteland; (2) Fertilized rice fields was the most important pollution sources and discharged larger pollutants during rain- runoff as “ source” landscape; ponds, rice fields and wasteland retained pollutants as “ sink” landscape; the channel within the multi- pond system mainly transported pollutants.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2004年第3期530-535,共6页
Journal of Agro-Environment Science
基金
国家自然科学基金资助(50179040)
关键词
景观
多水塘系统
非点源污染
源
汇
landscape
multi- pond system
non- point source pollution
sources
sinks
