摘要
土地利用类型变化是非点源污染呈现时空分布不均匀性和随机性的重要原因。以松涛水库上游为研究区构建SWAT模型,分析28年来流域内非点源污染氮负荷的时空分布以及不同土地利用类型与氮负荷的关系。结果表明:(1)构建的SWAT模型适用于松涛水库上游地区非点源污染氮负荷的估算;(2)1988—2002年流域全年总氮负荷增加了114.61%,1988—2016年增加了171.65%,湿季总氮负荷占全年输出约85%,干季占比约15%;(3)单位面积氮负荷量从高到低依次为:耕地>果园>橡胶林>浆纸林>天然林;(4)土地利用类型对全年总氮输出的贡献率由大到小依次为:天然林>橡胶林>浆纸林>耕地>果园,天然林的贡献率由58.4%降低为34.33%,而橡胶林的贡献率增加了5.43%,为28.95%。相关分析表明,天然林与氮负荷呈极显著相关,随着面积的减小,相关系数逐渐降低,由0.968变为0.658;而耕地、橡胶林、浆纸林对氮负荷的输出起到“源”的作用,天然林作为“汇”,可以滞缓非点源污染氮负荷发生。
Land use change is an important reason for the uneven and random distribution of non-point source pollution in time and space.This paper used the upstream of Songtao Reservoir as the study area to construct a SWAT model to analyze the spatial and temporal distribution of non-point source pollution nitrogen load in the basin over the past 28 years and the rela-tionship between different land use and nitrogen load.The results showed that:(1)The SWAT model is suitable for estimating the nitrogen load of non-point source pollution in the upstream area of Songtao Reservoir;(2)The annual total nitrogen load in the basin increased by 114.61%from 1988 to 2002,and 171.65%from 1988 to 2016.The total nitrogen load in the wet season accounted for about 85%of the annual output,and the dry season accounted for about 15%;(3)The order of nitrogen loading per unit area from high to low is:cultivated land>orchard>rubber>eucalyptus>natural forest;(4)The contribution rate of land use type to the annual total nitrogen output from high to small is:natural forest>rubber forest>eucalyptus>cultivated land>orchard,the contribution rate of natural forest decreased from 58.4%to 34.33%,while the contribution rate of rubber in-creased by 5.43%to 28.95%;Correlation analysis showed that the relationship between natural forest and nitrogen load is ex-tremely significant.As the area decreasing,the correlation coefficient gradually decreased,from 0.968 to 0.658;while culti-vated land,rubber,eucalyptus play a role in the output of nitrogen load.The role of natural forest as a“sink”can slow the occurrence of non-point source pollution nitrogen load.
作者
雷湘龄
叶长青
朱丽蓉
薛杨
LEI Xiangling;YE Changqing;ZHU Lirong;XUE Yang(Hainan Academy of Forestry,Haikou,Hainan 571100,China;School of Ecology and Environment,Hainan University,Haikou,Hainan 570228,China;Hainan Wenchang Forest Ecosystem National Orientation Observation and Research Station,Wenchang,Hainan 571300,China;School of Tourism,Hainan University,Haikou,Hainan 570228,China)
出处
《热带农业科学》
2022年第4期1-10,共10页
Chinese Journal of Tropical Agriculture
基金
国家自然科学基金(No.52069006)
海南省自然科学基金(No.419MS019)。
