北洛河流域水质空间异质性及其对土地利用结构的响应

Spatial variation of water quality and its response to landuse in the Beiluo River Basin

根据2011年10月和2012年10月的北洛河流域水体采样数据,利用GIS技术和地统计学方法,分析了北洛河流域水质指标TP、TN、NO-3-N、NH+4-N和高锰酸盐指数(CODMn)的空间变异特征,并探讨了子流域尺度上不同土地利用结构对河流水质的影响.结果表明,北洛河流域水质指标TN和NO-3-N受结构性因素影响显著,表现出较强的空间变异性,而TP、NH+4-N和CODMn受到结构性因素和随机性因素共同作用,表现出较弱的空间变异特征.TN与农业用地面积百分比呈显著正相关关系,与林地面积百分比呈显著负相关关系,NO-3-N与农业用地面积百分比存在显著正相关关系.可以初步推测,控制TN空间异质性分布的结构性因素是农业用地和林地,而控制NO-3-N空间分布的结构性因素为农业用地.

Spatial variation characteristics of water quality factors,including TP,TN,NO-3-N,NH＋4-N and CODMn,were analyzed by using GIS technique and geo-statistics method based on water sampling data collected in the Beiluo River basin in October 2011 and 2012. Responses of water quality to landuse were investigated in a sub-basin scale. Results showed that the distributions of TN and NO-3-N had a high level of variation,which were significantly affected by some structural factors. TP,NH＋4-N and CODMnshowed a weak spatial variation jointly affected by structural and random factors.Positive relationships were found between TN and agriculture lands,NO-3-N and agriculture lands,respectively. TN was negatively related to forest lands.Therefore,structural factors affecting TN were most likely agriculture and forest lands,and agriculture lands was the dominant structural factor for NO-3-N.