Studies on changes in extreme flood peaks resulting from land-use changes need to consider roughness variations

ABSTRACT

The impacts of changes in forest coverage on extreme floods have drawn much attention globally. This study quantifies the sensitivity of flood peaks to forest coverage and roughness changes. With this objective, a framework is first introduced that includes a variance-based sensitivity analysis approach and a water and energy budget-based distributed hydrological model with a vegetation module. The influence of forest coverage changes is simulated by altering land-use types that are based on physical parameters. A variance decomposition approach is used to quantify the contribution of influential factors, i.e. event size, forest coverage and roughness changes, to extreme flood peak variations. The results in a medium-sized river basin show forest coverage changes have little influence: variations in canopy interception, ground surface water retention, soil moisture and groundwater table resulting from changing forest coverage did not alter flood peaks considerably. In contrast, it is found that flood peaks are more sensitive to roughness variations.

KEYWORDS:

• floods
• forest coverage
• roughness
• WEB-DHM

Editor A. Castellarin; Associate Editor M. Borga

Editor A. Castellarin; Associate Editor M. Borga

Acknowledgements

The data of the Biliu basin was collected from the Biliu reservoir administration.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

¹ https://edcftp.cr.usgs.gov/project/glcc/globdoc2_0.html.

Additional information

Funding

This study was supported by the Young Scientists Fund of the National Natural Science Foundation of China (51809136), the Strategic Priority Research Program of Chinese Academy of Sciences (XDA20060402), and China Postdoctoral Science Foundation (2017M622516). Additional support was provided by Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control (2017B030301012), and State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control.