Improvement and Impacts of Forest Canopy Parameters on Noah-MP Land Surface Model from UAV-Based Photogrammetry

Ming Chang,Xuemei Wang,Jiachen Cao,Bingyin Chen,Qi Zhang,Shengjie Zhu,Weihua Chen,Shiguo Jia,Padmaja Krishnan

doi:10.3390/rs12244120

Abstract

Taking a typical forest’s underlying surface as our research area, in this study, we employed unmanned aerial vehicle (UAV) photogrammetry to explore more accurate canopy parameters including the tree height and canopy radius, which were used to improve the Noah-MP land surface model, which was conducted in the Dinghushan Forest Ecosystem Research Station (CN-Din). While the canopy radius was fitted as a Burr distribution, the canopy height of the CN-Din forest followed a Weibull distribution. Then, the canopy parameter distribution was obtained, and we improved the look-up table values of the Noah-MP land surface model. It was found that the influence on the simulation of the energy fluxes could not be negligible, and the main influence of these canopy parameters was on the latent heat flux, which could decrease up to −11% in the midday while increasing up to 15% in the nighttime. Additionally, this work indicated that the description of the canopy characteristics for the land surface model should be improved to accurately represent the heterogeneity of the underlying surface.

Highlights

The land surface process is the lower boundary condition of atmospheric movement, and the different types of underlying surface have multiple weather and climate effects [1]
A typical subtropical forest’s underlying surface was taken as the research area; we mainly focused on the establishment of the connection between forest canopy parameters including the tree heights and crown radius of this forest by unmanned aerial vehicle (UAV) photogrammetry and obtained these accurate canopy parameters for land surface model improvement
This shows that the distribution of the Dinghushan forest appeared to present two stages, which could indicate the characteristics of a successional subtropical forest

Summary

Introduction

The land surface process is the lower boundary condition of atmospheric movement, and the different types of underlying surface have multiple weather and climate effects [1]. The development of land surface models provides a way to help us understand the complex processes and interactions between the land surface and the atmosphere across micro to global scales. Some 3D computer simulation models are suitable for studying smaller-scale scenes with fine structures, the demands of extreme computational resources have still made it difficult for them to be applied at a large scale [8]. In this case, the range of typical parameter values in forests remains a large source of uncertainty [4]

Methods

Results

Discussion

Conclusion