温度和降水对赣江流域土地利用方式与河流氮磷营养盐相关性的影响

针对赣江流域的10个子流域,研究温度和降水如何影响土地利用方式与河流氮磷营养盐浓度的相关性.土地利用类型划分为水田、旱地、林地、草地、水域和建设用地,氮磷指标为2014年每月对赣江7条支流测定的氨氮(NH⁺₄-N)、硝酸盐氮(NO^-₃-N)和总磷(TP)浓度,用相关分析得到土地利用方式与水体氮磷的相关性.结果表明:(i)不考虑温度和降水的影响,旱地与河流NH⁺₄-N具有显著相关性,建设用地与河流NO^-₃-N具有显著相关性;(ii)旱地、草地和林地在中温条件下与河流氮营养盐的相关性更高,在低温条件下与磷营养盐的相关性更高.水田和水域在高温条件下与河流氮营养盐的相关性更高,在中温条件下与磷营养盐的相关性更高;(iii)除林地外,其他土地利用方式在高降水量情况下与河流氮磷营养盐的相关性更高.

The Effect of Land Use Patterns on Stream Water Nitrogen and Phosphorus Nutrients underthe Variations of Temperature and Precipitation in Ganjiang River Basin

Ten sub-basins in the Ganjiang River Basin are used to study the effects of temperature and precipitation on the correlation between land use patterns and concentrations of nitrogen and phosphorus nutrients in river water.The land use patterns are categorized to paddy,dry land,forest,grassland,waters and construction land.Ammoniacal nitrogen(NH⁺₄-N),nitrate nitrogen(NO^-₃-N)and total phosphorus(TP)are tested monthly at seven tributaries of the Ganjiang River in 2014.Correlation analysis is used to identify the correlation between land use patterns and water nutrients in rivers.It is found that dry land is significantly related with concentration of NH⁺₄-N,and construction land is significantly related with concentration of NO^-₃-N,when the effect of temperature and precipitation is not considered.Dry land,grassland and forest have higher correlation with river nitrogen nutrition under moderate temperature conditions and higher correlation with phosphorus nutrient under low temperature conditions.Paddy and waters have higher correlation with nitrogen nutrition under high temperature conditions and higher correlation with phosphorus nutrient under moderate temperature conditions.Except forest,other land use patterns(including dry land,paddy,grassland,waters and construction land)have higher correlation with nitrogen and phosphorus nutrients under heavy precipitation conditions.