Quantifying the hydrological responses to climate change in an intact forested small watershed in Southern China

Abstract

Responses of hydrological processes to climate change are key components in the Intergovernmental Panel for Climate Change (IPCC) assessment. Understanding these responses is critical for developing appropriate mitigation and adaptation strategies for sustainable water resources management and protection of public safety. However, these responses are not well understood and little long-term evidence exists. Herein, we show how climate change, specifically increased air temperature and storm intensity, can affect soil moisture dynamics and hydrological variables based on both long-term observation and model simulations using the Soil and Water Assessment Tool (SWAT) in an intact forested watershed (the Dinghushan Biosphere Reserve) in Southern China. Our results show that, although total annual precipitation changed little from 1950 to 2009, soil moisture decreased significantly. A significant decline was also found in the monthly 7-day low flow from 2000 to 2009. However, the maximum daily streamflow in the wet season and unconfined groundwater tables have significantly increased during the same 10-year period. The significant decreasing trends on soil moisture and low flow variables suggest that the study watershed is moving towards drought-like condition. Our analysis indicates that the intensification of rainfall storms and the increasing number of annual no-rain days were responsible for the increasing chance of both droughts and floods. We conclude that climate change has indeed induced more extreme hydrological events (e.g. droughts and floods) in this watershed and perhaps other areas of Southern China. This study also demonstrated usefulness of our research methodology and its possible applications on quantifying the impacts of climate change on hydrology in any other watersheds where longterm data are available and human disturbance is negligible.

Application of SWAT Model with CMADS Data to Estimate Hydrological Elements and Parameter Uncertainty Based on SUFI-2 Algorithm in the Lijiang River Basin, China

“…In recent years, SWAT has been successfully applied in the study of hydrological elements in various watersheds. For example, the SWAT model was applied to study changes in the water budget caused by climate change [20][21][22][23]. The SWAT model was used to study hydrological elements in ice-and snow-covered mountainous area [24][25][26].…”

Climate change impacts and adaptation in forest management: a review

“…However, most of these have been undertaken at small catchment scale (Mahat and Anderson 2013;Neukum and Azzam 2012;Zhou et al 2011) with few basin-scale assessments (van Dijk and Keenan 2007). However, the effects of climate and forest cover change on hydrology are complicated.…”

Uncertainties of isoprene emissions in the MEGAN model estimated for a coniferous and broad-leaved mixed forest in Southern China

“…Most of them were measured in DBR. These emission factors were extrapolated to be canopy scale emission factors using the MEGAN canopy environment model, which considered the canopy radiation reduction, the leaf mass (Zhou et al, 2011;Yan et al, 2006) and the LAI for the MEGAN standard condition. The contributions of specific tree species to total tree cover in the Dinghushan forest were used to weight and group the species emission factors for each PFT (Wang et al, 2011).…”