『Abstract
A field study was conducted to determine the effect of landscape
spatial pattern and micro-topography on nutrient transfer via
runoff from two catchments into Yuqiao Reservoir in north China.
The surface runoff discharge was measured during rainfall events
and water samples were analyzed in 2004 and 2005. The mean annual
total nitrogen (TN) and total phosphorus (TP) exports per unit
area from Caogezhuang catchment (C catchment) were 1.048 and 0.561
kg ha-1 year-1, respectively, while the
TN and TP exports from Taohuasi catchment (T catchment) were 0.158
and 0.027 kg ha-1 year-1. In both catchments,
village and vineyard shared the highest nutrient export ability
due to the accumulated animal waste and heavy application of fertilizer
and manure. In T catchment, the distance of village and vineyard
was about 1,500 m away from the receiving water and in between
were woodland and cropland. In the hydrological pathway, there
were sink landscape structures of small stone dams, roadside swale,
vegetated filter strip and dry ponds, which could detain water
and nutrients. In C catchment, the distance between the village
and the receiving water was about 200 m, and the hydrological
pathway was compacted roads and ditches with no sink structures.
It is suggested that the distance between the pollution source
area and the receiving water and the micro-topographical features
were the main factors to control the great difference in nutrient
export rates.
Keywords: Agricultural catchment; Landscape spatial pattern; Micro-topography;
Nutrient transfer; Surface runoff』
Introduction
Materials and methods
Site description
Sample collection and analysis
Results
Rainfall and water output characteristics
Nutrient export distribution among different rainfall types
Nutrient mobile potential of various landscapes
Landscape spatial patterns and nutrient transport processes
Micro-topography within the two catchments
Discussion
Effects of landscape spatial patterns
Effect of micro-topography
Conclusion
Acknowledgments
References