不同土地利用模式下洪泽湖流域非点源颗粒态磷负荷时空演变研究

综合星地协同技术手段,定量化表征1990年以来洪泽湖流域非点源颗粒态磷负荷的时空变化特征,并差别化地探讨其与流域土地利用变化的响应关系,厘清二者的作用机制,为实现非点源磷污染的有效管控提供科技支撑。主要结论包括:(1)近20年,颗粒态磷负荷呈现"下降-上升-下降"的波动状态,1990~1996年呈下降趋势,1998~2006年保持平稳增长状态,2008年后快速下降;(2)颗粒态磷单位负荷空间差异明显,高值区集中分布在淮河支流流域(3.88 t/km~2/a),低值区则主要分布在汴河流域(0.57 t/km~2/a);(3)不同土地利用模式下平均颗粒态磷负荷由高到低依次为:多种地类混合的淮河支流流域(681.84 t/a)、城镇化快速增长的高松河流域(317.65 t/a)、农用地主导的维桥河流域(185.73 t/a)、湿地保护区的汴河流域(121.09 t/a)。林地、湿地等用地类型能显著减少颗粒态磷污染物的流失量,农用地和建设用地则会加剧颗粒态面源磷污染。

RESEARCH ON SPATIO-TEMPORAL PATTERN EVOLUTION OF NPS PARTICULATE PHOSPHORUS LOAD IN HONGZE LAKE BASIN UNDER DIFFERENT LANDUSE PATTERNS

In this study,quantitative characterization of the spatial and temporal variation of non-point source (NPS) particulate phosphorus loads in the watershed area of the Hongze Lake since 1990 was carried out in order to find out the internal relation and the influence mechanism between non-point pollution and land use change Conclusions are as follows:1.during 1990-2012,the total loads of particulate phosphorus presented a trend of"fall-rise fall",with a gradual downward trend in 1990-1996,a stable growth state in 1996-2006,and a rapid downward trend after 2008.And the highest value was 2253.67 t/a in 2012,and the lowest value was 510.03 t/a in 1990;2.There was significant spatial differences in the intensity of Par-P.The high value area was distributed in a variety of mixing zone of the tributaries of the Huaihe River basin,with an average Par-P intensity of of 3.88 t/km2/a.The low value area was mainly distributed in the wetland protection area of the Bian River Basin,with an average Par-P intensity of of 0.57 t/km2/a;3.Average Par-P intensity of different land use patterns ranked as follows:Huaihe River Basin (681.84t/a),Gaosong River Basin (317.65t/a),Weiqiao River Basin (185.73t/a),Bian River Basin (121.09t/a).The corresponding land use pattern is a variety of mixed,urbanization rapid growth,the dominant land,wetland protection.The increase in the area of agricultural land and construction land will increase the phosphorus pollution,and the land types of forest land and wetland can significantly reduce the loss of particulate phosphorus.Rational land use planning has an important role in alleviating the non-point source pollution of particulate phosphorus.This study can extend the connotation of watershed NPS pollution research,and showed significant meaning for Integrated research of watershed scales,and also can provide the scientific basis for LUCC adjustment oriented to lake environment protection and management.