非点源污染影响因素及区域差异

随着点源污染控制加强，非点源问题更加突出。污染时间、方式、总量的三不确定给农业环境管理带来困难，控制措施难以有效实施，特别是农业非点源污染日益加剧，水环境质量不断恶化。从污染产生过程，结合污染特征，分析了非点源污染汇污的各种影响因素，包括污染物现存总量及变化趋势和环境净化能力、农业生产活动及管理水平、气候和水文条件；特别提出社会经济活动对污染影响显著；指出主导影响因子的时空变化，并存在地域差异。强调了在三峡库区开展基础调查工作和建立污染数据库的必要性，以期为库区农业环境质量现状评价和总体控制措施的筛选提供科学依据。

ANALYSIS OF NON POINT SOURCE POLLUTION INFLUENCE FACTORS AND THEIR DISCREPANCY

With the effective control of source pollution,non-point source pollution becomes more outstanding. Indeterminacy of time,way and quantity brought much difficulty to the management of agricultural environment and crippled availability of control measures. The carried-out research was most focused on calculating pollutant load and selecting controlling measures. But the influence factors were devoid of thorough understanding. According to the process of engendering pollution and pollution characteristic,all kinds of factors affecting non-point source pollution are analyzed in this paper. These factors include the pollutant gross at present and its changing direction,environmental purification competency,farm activity,climate and hydrological condition,and especially socio-economy function. Dominants influence factors changing space with and time and the discrepancy among different terrains are pointed out. And the necessity of basic pollution investigation and database is emphasized,which will contribute to further study in the Three-Gorge Area.