南京地区2001—2010年面源污染定量监测及时空变化分析

QUANTITATIVE MONITORING AND TEMPORAL AND SPATIAL VARIATION OF NON-POINT SOURCE POLLUTION IN NANJING AREA IN 2001—2010

基于2001—2010年气象资料和地理信息系统数据库,采用水土流失与土壤养分面源污染综合监测的模型方法,通过在南京全市范围土壤的布点采样和分析,对南京地区各区县10年期间水土流失与面源污染状况进行了定量监测和研究。结果表明:(1)全市各类土壤全氮、全磷、铵态氮和有效磷数据,能较好反映南京土壤养分现状和施肥情况。近年来全市大多数地区土壤具有全氮、有效磷显著增加、全磷明显减少的特点。(2)水土流失和面源污染具有年内和年度变化特征,其侵蚀与污染的月份多数发生在5～8月,侵蚀与污染最严重年度为2003年,最轻年度为2001年;(3)10年平均水土流失与面源污染的空间分布在各区县有显著差异,江宁区最严重,其次是六合区;(4)全市10年来水土保持和面源污染控制成效显著,植被覆盖率的增加和水土保持措施的加强,对减少水土流失与面源污染具有明显效果。

Based on meteorological data and the Geographic Information System （GIS） database of the Nanjing area during the period from 2001 to 2010, and by means of soil sampling and analyzing, non-point source pollution and soil erosion in various districts of the Nanjing area in the past 10 years were quantitatively analyzed with models for overall monitoring of erosion and non-point source pollution from soil erosion and nutrient loss. Results show the following, （ 1 ） the data of total nitrogen, total phosphorus, ammonium nitrogen and available phosphorus of the various types of soils in the area better reflected soil nutrient and fertilization status of the area. In recent years, soil total nitrogen and available phosphorus increased significantly and total phosphorus decrease significantly in most parts of the area; （2） The non-point source pollution and soil erosion were characterized by annual and inter-annual variations; which show that soil erosion and pollution occurred mostly from Apr. to Aug. and was the most serious in 2003 and the least in 2001 ; （3） Significant spatial variation of the 10-year averages of non-point source pollution and soil erosion existed among different districts; Jiangning was the most seriously polluted area and was followed by Luhe; （4） For the past 10 years, the effect of the efforts of Nanjing to control non-point source pollution and soil erosion was significant. Increasing vegetation coverage and enforcing soil erosion control measures are effective in controlling non-point source pollution and soil erosion.