Method for establishing water balance field for observing water and soil loss in shallow mountainous area of Qilian Mountain

The invention relates to a method for establishing a water balance field for observing the water and soil loss in a shallow mountainous area of the Qilian Mountain. The method comprises the following steps: (1) according to demands of observation, confirming the specification and the range of the water balance field by an ordinary method, and drawing a boundary line of the shallow mountainous area, of which the radial flow is to be measured, in the Qilian Mountain by a tool; (2) digging a deep groove which is 1cm wide and 20cm-150cm deep in the boundary line, and subsequently, longitudinally inserting a plurality of Bayer solar plates, which are 500cm long and 30cm wide, into the deep groove; (3) fully filling connecting parts of the plurality of Bayer solar plates with a glass sealant so as to tightly connect the Bayer solar plates; (4) refilling the deep groove with refined soil, and tamping and fixing so as to obtain the water balance field; and (5) forming a hole in the middle of a Bayer solar plate at th