The throughfall kinetic energy (TKE) is an essential indicator for the evaluation of rainfall erosivity. It is also a key factor for understanding the hydrological, biogeochemical and ecological cycles. 

The rubber plantations in Xishuangbanna have resulted in excessive water loss and soil erosion, and the TKE as a widely used indicator to express the potential of rainfall erosivity is an important parameter. 

Prof. LIU Wenjie and his team from Xishuangbanna Tropical Botanical Garden (XTBG) analyzed the spatial distribution of the TKE to obtain the spatial characteristics of splashing in a rubber plantation.  

They focused on individual rubber trees and concentrated on how the rainfall characteristics and canopy architecture affect the TKE on a small scale. The experiments used Tübingen splash cups with natural rainfall. 

They found that the leaf area index did not significantly affect the spatial distribution of the TKE, although it had significant monthly variations. The TKE was not correlated with distance from the trunk. The lateral translocation of the throughfall in the canopy significantly affected the spatial distribution of the TKE. 

The results also showed that the spatial distribution of the TKE under the rubber canopy is consistent with the spatial distribution of the throughfall. The coefficient of variation of the TKE became stable with increasing gross rainfall and rainfall intensity. 

The structure in the spatial variability demonstrated that the TKE exhibited a strong spatial autocorrelation within the range 1-2 m in the different rainfall and rainfall intensity classifications, but did not have a stable sill when the rainfall was large enough. 

The results confirm that the rainfall redistribution is important for the spatial distribution of the TKE in a rubber plantation. 

The study entitled "Effects of rainfall on the spatial distribution of the throughfall kinetic energy on a small scale in a rubber plantation" has been published in a paper in Hydrological Sciences Journal. 

Excessive soil erosion in mono-culture of rubber plantation in Xishuangbanna. (Image by LIU Jiaqing)