This paper introduces the basic concept of soil and water loss and agricultural non-point source pollution,and then points out that soil and water loss is the important form and transportation carrier of agricultural non-point source pollution.

Based on the principle of system engineering and the method of system dynamics,this paper divides the big highway overloading transportation system into three subsystems,such as overloading transportation,overloading management and economy.

It is concluded that overloading transportation is the main problem to China s traffic safety at present and in the future.

The paper analyzes the benefit of heavy-load transportation capacity expansion of Daqin railway,considers that the benefit analysis should aim at economic benefit and social benefit and uses a practical example to prove that heavy-load transportation is an important way to get obvious benefits.

so as to providing the base for heavy-load transportation plan on Daqin line.

Railway heavy haul transportation is used to transport large amount fr.

Four grades of priority are defined in the goal programming model according to the practices of heavy haul transportation in China railways.

Effect of overloaded transportation on fatigue performanceof existing reinforced concrete arch bridges;

Dalian-Qinhuangdao line is a heavy-haul transportation line in China.

The present and problems of Datong-Qinghuangdao railway are introduced in the article as the railway opened to traffic in 1988 and promise of heavy-haul transportation is described.

The heavy-haul transportation mode has been applied in China railway,and it will deveolp rapidly,it affect the shunting operation of marshalling yard directly,so we will research the new speed control design system and new speed control equipment to fill the new requirement of the development of the heavy-haul transportation.