Analysis of the relation of hydrogen distribution and topographic roughness in the lunar south polar region

Appreciable amounts of hydrogen-bearing compounds have been detected within the lunar polar regions. Estimating the effect of the presence of water ice on surface topographic roughness is important for future exploration and activities in the vicinity of the lunar pole. To investigate this issue, we analyzed the correlations between water equivalent hydrogen in the top 1-m surface layer and topographic roughness of lunar south polar regions. The results show that water ice probably plays an important role in the surface roughness at the hectometer scale, and might has a suppressive effect on surface roughness. In the detailed analysis, most the surface roughness at the floor of Shoemaker, Faustini, Slater and Sverdrup shows a decreasing trend with increasing water equivalent hydrogen at different decreasing slopes; Haworth shows slightly increasing trend, contrary to the trend of other studied craters. These observations may be related to small-scale topographic features at the surface and/or subtle changes in surface and subsurface WEH, which in turn affect the roughness characteristics in detail.