Impact of Climate Change and Human Activities on Streamflow Variations Based on the Budyko Framework

Lee Lee,Yeh Yeh

doi:10.3390/w11102001

Abstract

In recent years, the influence of climate change and human activity on the global environment have become a concern. It is essential to better understand the hydrologic environment to evaluate water availability and related issues. In this study, we perform a trend and breakpoint analysis on streamflow time series in the Lanyang, Keelung, Dahan, Fengshan, Youluo and Shangping River Basins in northern Taiwan. Furthermore, we apply the Budyko–Fu equation and the Budyko–Mezentsev–Choudhury–Yang equation to evaluate the elasticity of streamflow with respect to climate factors and the catchment characteristics parameter. We discuss the sensitivity of streamflow to climate factors (precipitation and potential evapotranspiration), as well as sensitivity to human activities such as land use changes. We detected breakpoints in the streamflow time series for the Lanyang and Keelung rivers in in 1993 and 1990, respectively. The streamflow of Lanyang River increased by 32.50% during the variation period (1993–2017), with 109.00% of the variation caused by non-climate factors. The Keelung River’s streamflow was reduced by 18.11% during the variation period (1990–2017), and the dominant factor was climate change, accounting for 71.53% of the reduction. Sensitivity analysis showed that precipitation changes were the most sensitive factor of streamflow variation. For every 1% increase in precipitation, the streamflow would increase by 1.05% to 1.37%. These results could serve as a reference for the sustainable development of water resources and territorial policies in northern Taiwan.

Highlights

Water resources are essential assets for the development of human society
This study conducted trend analyses based on hydrological data of the major river basins in northern Taiwan, including the precipitation, streamflow, and potential evapotranspiration of Lanyang, Keelung, Dahan, Fengshan, Youluo and Shangping river basins
We looked at the Normalized Difference Vegetation Index (NDVI) to evaluate the changes of vegetation cover in the Lanyang River Basin before and after the implementation of the program

Summary

Introduction

Water resources are essential assets for the development of human society. In recent years, changes in the hydrologic environment due to the combination of climate change and other human activities have triggered water resource difficulties in many regions. Events associated with extreme weather and environmental disasters such as heavy rainfall, floods and droughts are being reported more frequently [1,2,3,4]. Assessing hydrological responses under the influences of human activities and climate change has become an important issue for policy makers. Human activities, including land use change, water diversion, dam construction, and soil and water conservation policies [5,6,7], cause variation of the environment. The change of streamflow is one of the key factors in understanding the pattern of the hydrological cycle in a watershed [8]

Methods

Results

Conclusion