摘要
【目的】分析流域水质净化功能时空变化及其影响因素。【方法】基于InVEST模型生态服务水质净化模块,模拟北盘江流域2000、2010年和2020年TN、TP输出空间分布。【结果】北盘江流域2000、2010年和2020年TN、TP输出总量变化不大,但在空间分布上差异明显,TN输出总量均在8000 t/a以上,20 a以来总共减少了120.76 t;TP输出总量均在1200 t/a以上,20 a来总共减少了5.45 t,表明流域生态系统水质净化服务功能有逐渐变好趋势。TN、TP高输出区域主要集中在北盘江流域上游和中游以及城镇区周边,低输出区域主要在下游地势平坦的区域。【结论】耕地施肥过程中未被吸收转化的N、P营养物质以及城镇区的生活生产污水是造成流域水质净化功能恶化的主要因素,也是流域非点源污染的重要来源。
【Background and objective】Most catchments are able to decontaminate exogenous pollutants to some extent to maintain their ecological functions. This capability depends on many biotic and abiotic factors and varies spatiotemporally. Understanding this variation is important to improve catchment management but challenging. This paper proposes a new method to plug this gap.【Method】The model is based on simulating the dynamics of typical pollutants. By taking the Beipanjiang River basin as an example, we simulated the dynamics of total nitrogen(TN)and total phosphorus(TP) based on the measurement at the outlet of the basin in 2000, 2010 and 2020 using the InVEST model with the help of GIS, from which we analyzed their spatiotemporal variation and the underlying determinants. 【Result】The dynamics of TN and TP in 2000, 2010 and 2020 did not differ from each other noticeably, but a significant intra-year difference in spatial distribution of TN was found, where the minimum and maximum TN output per unit area in 2010 were 1.51 kg/hm;and 5.21 kg/hm;, respectively. The average total TN flow rate in the catchments was more than 8 000 T/years, reduced by 120.76 T in the 20 years. The average total TP flow rate in the catchment was more than 1 200/t year, reduced 5.45 T in the 20 years, indicating that the ability of the basin to attenuate nitrogen and phosphorus has been improving over the 20 years. The areas with high TN and TP were in the upper and middle reaches of the basin, as well as in the proximity of urban areas, while those with low TN and TP were the flatten areas at the downstream of the basin. Excessive application of N and P fertilizers in croplands as well as the sewage in urban areas were the source of the pollutants, which are too much for the basin to decontaminate. In addition, changes in climate and land use also alert the capacity of the basin to attenuate the contaminants.
作者
李威
赵祖伦
吕思思
赵卫权
LI Wei;ZHAO Zulun;Lü Sisi;ZHAO Weiquan(Institute of Mountain Resource,Guizhou Academy of Sciences,Guiyang 550001,China;Department of Karst Research Institute,Guizhou Normal University,Guiyang 550001,China)
出处
《灌溉排水学报》
CSCD
北大核心
2022年第3期105-113,共9页
Journal of Irrigation and Drainage
基金
贵州省自然科学基金项目(黔科合基础[2020]1Y410号,黔科合基础[2018]1418号)
贵州省科技支撑计划项目(黔科合支撑[2018]2806号)。
