Across China: China initiates microwave remote sensing experiments for vegetation, soil moisture

SHIJIAZHUANG, Aug. 7 (Xinhua) — Chinese researchers have recently initiated remote sensing experiments for vegetation and soil moisture in north China’s Hebei Province, according to the Aerospace Information Research Institute (AIR) under the Chinese Academy of Sciences.
“Vegetation plays a crucial role in the transfer of water between the land and the atmosphere, acting not only as a reservoir for terrestrial water resources but also as a natural water pump,” said Husi Letu, a researcher from the AIR.
“Traditional studies on water transfer have been limited to the microscale, which restricts our understanding of the water balance of entire ecosystems. There is an urgent need to develop modern technological methods capable of observation on a larger spatial scale,” he added.
The experiments, based on an aviation platform, primarily utilized microwave technology for precise observation of forests, farmlands, and grasslands in the Saihanba mechanized forest farm and the Yudaokou ranch.
Microwaves possess strong penetration capabilities, enabling them to pass through clouds and vegetation, and function normally even at night and in rainy weather.
“Through multichannel microwave synergistic observation, researchers can delve into the internal moisture status and distribution of plants, and meticulously analyze the entire moisture transfer process from the soil to the plant stems, through the canopy and into the atmosphere,” said Zhao Tianjie, a researcher from the AIR.
The data obtained from the experiment will be used to develop and verify intelligent remote sensing methods for key parameters of the terrestrial water cycle at various spatiotemporal scales, such as soil moisture, plant moisture, plant water potential, atmospheric water vapor and evapotranspiration.
Researchers can further capture the internal moisture changes of plants through aerospace technology, and understand the complex interactions between the soil moisture supply and the atmospheric water demand.
The experiment result will provide technical support for the processing and innovative applications of new payload observation data for domestic satellites such as the terrestrial water resources satellites and the ocean salinity detection satellites.
It will offer a scientific basis for further enhancing the soil water storage capacity and water productivity of forests, and increasing the capacity for conservation and regulation of water resources. ■