Responses of runoff to historical and future climate variability over China

Chuanhao Wu,Guoru Huang,Peng Wang,Bill X. Hu,Kai Xu

doi:10.5194/hess-22-1971-2018

Abstract

Abstract. China has suffered some of the effects of global warming, and one of the potential implications of climate warming is the alteration of the temporal–spatial patterns of water resources. Based on the long-term (1960–2008) water budget data and climate projections from 28 global climate models (GCMs) of the Coupled Model Intercomparison Project Phase 5 (CMIP5), this study investigated the responses of runoff (R) to historical and future climate variability in China at both grid and catchment scales using the Budyko-based elasticity method. Results show that there is a large spatial variation in precipitation (P) elasticity (from 1.1 to 3.2) and potential evaporation (PET) elasticity (from −2.2 to −0.1) across China. The P elasticity is larger in north-eastern and western China than in southern China, while the opposite occurs for PET elasticity. The catchment properties' elasticity of R appears to have a strong non-linear relationship with the mean annual aridity index and tends to be more significant in more arid regions. For the period 1960–2008, the climate contribution to R ranges from −2.4 to 3.6 % yr−1 across China, with the negative contribution in north-eastern China and the positive contribution in western China and some parts of the south-west. The results of climate projections indicate that although there is large uncertainty involved in the 28 GCMs, most project a consistent change in P (or PET) in China at the annual scale. For the period 2071–2100, the mean annual P is projected to increase in most parts of China, especially the western regions, while the mean annual PET is projected to increase in all of China, particularly the southern regions. Furthermore, greater increases are projected for higher emission scenarios. Overall, due to climate change, the arid regions and humid regions of China are projected to become wetter and drier in the period 2071–2100, respectively (relative to the baseline 1971–2000).

Highlights

Climate change has become increasingly significant (IPCC, 2013), and numerous studies have reported that climate warming is likely leading to the alteration of the hydrological cycle (Oki and Kanae, 2006; Jung et al, 2010)
The results indicated that the P elasticity exhibits a large regional variation, with a small range in southern China, the Songhua River basin, and the northwest and a large range in the Hai River basin, the Yellow River basin, and the Liao River basin
Those results are close to our results for P elasticity ranging from 1.1 to 3.2 and for potential evaporation (PET) elasticity ranging from −2.2 to −0.1 in China

Summary

Introduction

Climate change has become increasingly significant (IPCC, 2013), and numerous studies have reported that climate warming is likely leading to the alteration of the hydrological cycle (Oki and Kanae, 2006; Jung et al, 2010). The potential consequences of anthropogenic climate change on the hydrological cycle have received significant attention over the last 2 decades (Wang et al, 2012; IPCC, 2013). There is a great deal of previous work exploring the impact of climate variations on R, with the motivation stemming from the region’s vast resources

Objectives

Results

Discussion

Conclusion