土壤质量变化对地表径流水质量的影响

Effect of Change in Soil Quality on Water Quality of Surface Runoff

为了解喀斯特山区小流域不同农作行为下的地表径流水质量变化,采用相关分析、逐步回归、通径分析和聚类分析等方法,对贵州中部喀斯特山区普定县猫洞小流域(低复种旱作区、高复种旱作区和高复种复合农作区)的径流水进行了采样分析。结果表明:在长期不同农作行为的影响下,3类农作生态区地表径流水中的化学组分有明显不同,从低复种指数旱作区、高复种指数旱作区到高复种指数复合农作区,地表径流中的NO3-、NH4+、PO43-、SO42-的含量和高锰酸钾指数依次增大,均呈显著上升趋势;经相关分析、逐步回归及通径分析,农用地地表径流中NO3-、PO43-、NH4+含量和高锰酸钾指数一定程度上受土壤有机质、氮磷含量和植被变化的影响;主成分聚类分析,第1类型即低复种旱作区,指标达Ⅰ类水体的标准,水质量良好;第2类型以高复种旱作区为主,兼有高复种复合农作区,NH4+、PO43-含量部分达Ⅱ～Ⅲ类水体的标准,高锰酸钾指数达Ⅰ～Ⅱ类水体的标准,水体质量受到一定程度的影响;第3类型即高复种复合农作区为主,NH4+、NO3-部分超地表Ⅲ类水体标准,PO43-含量部分达Ⅱ～Ⅲ类水体的标准,高锰酸钾指数达Ⅰ～Ⅱ类水体的标准,地表径流水质在Ⅱ～Ⅲ类水体标准,部分指标超Ⅲ类水体标准,水体已受到污染。

The water quality of surface runoff samples from three areas with different farming pattern in Maodong basin of Puding county was analyzed by using correlation analysis,stepwise regression,path analysis and clustering analysis to study the effect of different farming patterns on water quality of surface runoff.The results show that there is obvious difference in chemical components of surface runoff among three farming biological areas under the long-term farming pattern,the NO-3、NH＋4、PO3-4、SO2-4content and potassium permanganate index in surface runoff is the complex farming area with high multiple crop index the dry-farming area with high multiple crop index the dry-farming area with low multiple crop index,the NO-3,PO3-4 and NH＋4content and potassium permanganate index in surface runoff were affected by the organic matter,N and P content in soil and vegetation change,the water quality of the dry-farming area with low multiple crop index meets I water standard,the NH＋4 and PO3-4 content and potassium permanganate index of the dry-farming area with high multiple crop index and the complex farming area with high multiple crop index meetⅡ～Ⅲ water standard andⅠ～Ⅱ water standard respectively,the NH＋4 and NO-3content,PO3-4 content and potassium permanganate index of the dry-farming area with high multiple crop index meet Ⅲ water standard,Ⅱ～Ⅲ water standard andⅠ～Ⅱ water standard separately and its water quality of surface runoff meetsⅡ～Ⅲ water standard,which indicates that water quality of surface runoff from the complex farming area with high multiple crop index is polluted.