Water is the primary resource required for the exploitation of lunar resources. Investigating the distribution of water on the surface of the moon has become a focal point in the lunar exploration plans of several nations.

This study aims to quantify the presence of hydrogen and analyze its spatial distribution on the lunar surface using data from the Chang'E-2 gamma-ray spectrometer (CE2-GRS).

Firstly, an analytical method combining branch specific stripping with the nonlinear least-square fitting Gaussian function was proposed to subtract the characteristic γ rays of interfering nuclides (²¹⁴Bi@2.204 MeV, ²⁷Al@2.210 MeV, ⁴⁹Ca@2.371 MeV) ranging from 2.1 MeV to 2.5 MeV. Then, a characteristic function between the abundance and counts of aluminum γ rays around the moon was established to subtract the counts of aluminum in the mixed peak. Finally, the spatial distribution of hydrogen γ rays for counts per 3 s on the whole lunar surface was obtained.

The analysis results show that high-value characteristics exhibited in some areas, including the Aiken basin, Mare Ingenii, Mare Imbrium, and Oceanus Procellarum, are approximately 2.6 times the average value of hydrogen counts among the 14 major maria. Comparison between the distribution characteristics of hydrogen elements on the lunar surface and the data of epithermal neutrons from Lunar Prospector (LP) reveals a highly negative correlation between the distribution characteristics of the two in these regions.

The distribution characteristics of hydrogen elements on the lunar surface further predict that there may be a large amount of structural water in the Mare Ingenii, Mare Imbrium, and Oceanus Procellarum, formed by the combination of hydroxyl groups or molecular hydrogen (H₂), achieving a better understanding of the orbit γ deep mining and scientific application of energy spectrum data.