土地利用驱动下洪泽湖支流流域非点源颗粒态磷流失时空变化特征

选取洪泽湖支流流域,根据1990、2000、2005、2010年Landsat TM/ETM遥感影像,应用泥沙输移分布模型,计算出研究区非点源颗粒态磷流失负荷,研究土地利用变化对非点源颗粒态磷流失负荷的影响。结果表明,土地利用与非点源颗粒态磷流失负荷息息相关:在2、3号子流域,建设用地、林地和颗粒态磷流失负荷呈正相关,主要因为2号和3号子流域在盱眙及周边城市需求驱动下,耕地由原来种植水稻转型为蔬菜等高附值经济作物,种植强度较高,磷肥施肥量增加,造成颗粒态磷的流失负荷与当地建设用地和林地面积变化趋势相近;4号子流域由于土地类型转变,造成旱地与颗粒态磷流失负荷呈负相关;其他子流域大多为水田、旱地与颗粒态磷流失负荷呈正相关,建设用地、林地和颗粒态磷流失负荷呈负相关。

Temporal and spatial distribution characteristics of NPS particulate phosphorus driven by land use in Hongze Lake tributary basin

Land use changes greatly influence non-point source particulate phosphorus pollution. Here,the effect of land types changes non-point source particulate phosphorus pollution was studied based on remote sensing image(Landsat TM/ETM) in 1990, 2000, 2005 and 2010 using the method of sediment delivery-distribution model. The results showed:There was a close relationship between land use types and non-point source(NPS) particulate phosphorus load. In the region of NO.2 and NO.3 sub-basins,constructed land and forest had significant positive correlation with particulate phosphorus load. Driven by the demand of Xuyi and surrounding cities. The arable land which in NO.2 and NO.3 sub-basins were conversed from the original cultivation of rice to vegetables and other high added value crops. For increasing application rate of phosphorus fertilizer,particulate phosphorus load increased which is close to the change trend of constructed land and forest.Dry land had negative correlation with particulate phosphorus load in NO.4 sub-basin,which is resulting of changing crop types. In the other sub-basins,mostly appearing that paddy field and dry land had significant positive correlation with particulate phosphorus load,but forest and constructed land reversed.