Characteristic is and evolution of soil nitrogen in dam land and terrace in Loess Hilly Region;

But flood occurs frequently, and dam land often be waterlogging in this region.

Through analyzing soil samples and using statistical analytical method,characteristics on contents,correlations and vertical and temporal distributions of soil potassium for artificial farmland——dam land and terrace in loess hilly region were studied systematically.

On the basis of investigated data of Wangmaogou watershed check dams system,the benefits of flood trapping and sediment blocking,increasing land productivity,eco-environment,society are analyzed.

Study on the potential and approach to increase the country economics in small watershed by check dam in loess plateau;

Test of overflow spillway with geomembrane liner built on an earth check dam;

Effect of check dam on retaining and reducing coarse grain sediment in middle reaches of Yellow River;