Through bubble irrigation experiments conducted in ridge film mulching and furrow planting farmland,based on the observation of water advance process,the flow characteristic of field water and the influence of furrow width on the irrigation uniformity were analyzed in this paper.

Aiming these characteristics,the means of exterior gradual ditching and active drainage(EGD&AD), from part to whole,shallow to deep,and by stages to ditch,were used.

The waterproof construction of the roofing is composed of aluminum alloy board with vertical welt,covered gutter,main gutter,eaves gutter,overflow and siphon rainwater drainage system,solving the problem of low drainage capacity of previous public building roofing of similar large area.

construction details in roof drains such as gutter,eave gutter joint,flashing joint of parapet,joints of deformation joint,connection of drainage pipes and so on are introduced as well as corresponding treatment methods in order to ensure the waterproofing effects and appearance quality of buildings.