Abstract: Surface waters can be contaminated by human activities in two ways:
(1) by point sources, such as sewage treatment discharge and storm-water
runoff; and (2) by non-point sources, such as runoff from urban and
agricultural areas. With point-source pollution effectively controlled,
non-point source pollution has become the most important environmental concern
in the world. The formation of non-point source pollution is related to both
the sources such as soil nutrient, the amount of fertilizer and pesticide
applied, the amount of refuse, and the spatial complex combination of land uses
within a heterogeneous landscape. Land-use change, dominated by human
activities, has a significant impact on water resources and quality. In this
study, fifteen surface water monitoring points in the Yuqiao Reservoir Basin,
Zunhua, Hebei Province, northern China, were chosen to study the seasonal
variation of nitrogen concentration in the surface water. Water samples were
collected in low-flow period (June), high-flow period (July) and mean-flow
period (October) from 1999 to 2000. The results indicated that the seasonal
variation of nitrogen concentration in the surface water among the fifteen
monitoring points in the rainfall-rich year is more complex than that in the
rainfall-deficit year. It was found that the land use, the characteristics of
the surface river system, rainfall, and human activities play an important role
in the seasonal variation of N-concentration in surface water.
Keywords: non-point source pollution, nitrogen concentration, seasonal variation, land use, Yuqiao Reservoir Basin, China
