In the integrated observation field, there is a large-scale lysimeter, which was built in 1990 and is the earliest independently developed large evapotranspiration meter in China, with a soil surface area of 3.14m² and a depth of 5.0m. The weighing system bears a weight of about 35 tons and has a sensitivity of less than 60g, which is equivalent to the ability to measure the change of 0.02mm water depth with an absolute accuracy of 1/500000. The new multi-functional evapotranspiration instrument is the No.1 in China and has reached the international advanced level in terms of design scheme, measurement accuracy and stability. The successful development of this instrument provides an advanced tool for the research of evaporation and SPAC system in agricultural fields. It has played a leading role in China for the study of farmland evapotranspiration process with the help of high precision measurement system, and the set of facilities has been promoted in 10 stations of CERN, which has comprehensively improved the research level of the same field in China. So far, it has been operating for more than 30 years with stable operation and accurate data, providing standard validation data for a large number of farmland evapotranspiration dispersion and water consumption calculation methods, parameters and models, and revealing the characteristics and patterns of water consumption changes in farmland in the region.

Large-scale Lysimeter (top: surface layer, bottom: barrel and base)