Japan Geoscience Union Meeting 2022

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG45] Water and sediment dynamics from land to coastal zones

Thu. May 26, 2022 10:45 AM - 12:15 PM Exhibition Hall Special Setting (2) (Exhibition Hall 8, Makuhari Messe)

convener:Dai Yamazaki(Institute of Industrial Sciences, The University of Tokyo), convener:Shinichiro Kida(Research Institute for Applied Mechanics, Kyushu University), Yuko Asano(The University of Tokyo), convener:Keiko Udo(International Research Institute of Disaster Science, Tohoku University), Chairperson:Dai Yamazaki(Institute of Industrial Sciences, The University of Tokyo), Yuko Asano(The University of Tokyo)

11:15 AM - 11:30 AM

[ACG45-09] An efficient method to succinctly represent the explicit landcover heterogeneity formed by hillslope water dynamics

*Shuping Li1, Dai Yamazaki2 (1.Dept. Civil, UTokyo, 2.IIS, UTokyo)

Recent land surface models can explicitly represent the spatial heterogeneity of land surface process and focus more on terrestrial features at hillslope scale. However, discussions over the hillslope hydrology control on landcover are still lacking inside the land surface modeling community, and it remains unknown how this controlling effect can be effectively represented. Regarding this, we propose a spatial tessellation method that discretizes catchment into a predefined number of independent topographic columns along hillslope. By representing one dominant landcover type in each column, discretized columns are assumed to approximate the hillslope landcover heterogeneity effectively and efficiently. The proposed method can better represent land surface heterogeneity than the conventional grid-based method, in which 60-70% of the global terrestrial area denote a promising representing ability (> 70%). For areas in extremely arid/humid or in low latitude as well as low topographic relief regions such as Sahara and Amazonia, the average representing ability has reached 90%. We also found that the representing ability of columns shows an increasing trend from valley to hilltop. In addition, there is no significant decline in representing ability when reducing the number of discretized columns, indicating a remarkable improvement in efficiency by the method. Overall, the spatial tessellation method proposed in this study could effectively and efficiently represent the explicit landcover heterogeneity resulting from hillslope water dynamics. Based on the above results, in JpGU meeting we will make further discussions on scientific questions such as finding the locations where strong hillslope water control on the landscape can be observed.