Agricultural irrigation affects climate research and obtains new effective ways

[ China Agricultural Machinery Industry News ] In the past 200 years, the global irrigated farmland area has expanded rapidly, and the impact of irrigation on the climate has gradually attracted the attention of researchers all over the world. Agricultural irrigation mainly affects the regional climate by artificially changing the surface water process. There are many research work in China on the regional climate effects caused by changes in soil moisture.

Previous studies have not been accurate enough to describe irrigation in the model. Therefore, the development of agricultural irrigation parameterization schemes and the use of high-resolution regional climate models are effective ways to understand the regional climate water effects of agricultural irrigation.

Based on a certain land surface model design, Dr. Chen Liang of the Institute of Atmospheric Physics of the Chinese Academy of Sciences developed an agricultural irrigation parameterization scheme and coupled it into a weather forecast regional climate model, using this coupling model to carry out long-term treatment of the Yellow River Basin. (2001-2010) regional climate simulation.

This study has been published in the Journal of Atmospheric and Marine Science. The results show that when the agricultural irrigation parameterization scheme is introduced, the surface temperature of the agricultural irrigation area in the Yellow River Basin is reduced by about 0.1 to 0.4 degrees Celsius, and the sensible heat flux is correspondingly reduced. The latent heat flux increases correspondingly. In areas with a large proportion of irrigated area, the sensible heat (latent heat) flux can be reduced (increased) to more than 10Wm-2. The cooling effect caused by agricultural irrigation is consistent with changes in evaporation and energy flux. In addition, the rise of the condensation height and the height of the boundary layer lead to an increase in the amount of clouds, which causes changes in radiation, which in turn affects changes in surface flux and soil moisture, and ultimately affects the spatial distribution of surface air temperature and precipitation.