Rainfall runoff is the main factor affecting the formation of nonpoint pollution.

降雨径流是形成非点源污染的主要影响因素。

Endogenous effect mechanism of rural nonpoint pollution control are lack both in domestic and abroad.

国内外农村面源污染控制都缺乏内源的长效运行机制。

Sources of water pollution can be classified broadly into two categories: point sources and nonpoint sources.

水体环境污染源按其发生类型分为点源、非点源。

And among all sorts of nonpoint source pollutions, agricultural nonpoint source pollution is the biggest one.

而在各种非点源污染中，有很大一部分来源于农业非点源。