于桥水库流域地表水非点源N时空变化特征

Temporal and Spatial Characteristics of Non-point Source N in Surface Water of Yuqiao Reservior Watershed

在野外水样监测 (1999年 5月～ 2 0 0 0年 10月 )和土地利用调查的基础上 ,利用遥感影像和数字化地形图 ,运用GIS的空间分析和图形叠置功能 ,研究于桥水库流域地表水非点源N的时空变化特征。结果表明 ,在时间上 ,NH+ 4 -N的峰值出现在枯水期 ,而NO-3 -N的峰值出现在丰水期 ;在空间上 ,NH+ 4 -N含量在中部平原区最高 ,南部丘陵和北部山区居其次 ,NO-3 -N含量的变化则不具有明显的规律性。NH+ 4 -N和NO-3 -N不同的时空分布特征与它们的化学性质及流域内土地利用格局有关。

Water samples were taken from May 1999 to Oct.2000 and land use investigation was carried out in Aug.2000 in Yuqiao Reservior watershed. Using the functions of space overlapping and graph computing of GIS, related data was collected to analyze temporal and spatial characteristics of non point source N in surface water of the study area. The results indicate that the peak value of NH + 4-N appears in the low water period while the peak value of NO - 3-N displays in the high water period; On spatial, peak value of NH + 4-N appears in the central plain area followed by the southern rolling area and northern mountain area, but the diversification of the content of NO - 3-N in the surface water of the watersheds does not have regular rules. Topography, land use, land cover, human activities and the influencing factors of nitrifcation and denitrification were considered in each region (northern mountain area, central plain area and southern rolling area) of the study area to explain the variance of NH + 4-N and NO - 3-N, and proposal about sustainable watershed development was brought forward as well.