Assessing the Specific Impacts of Climate Variability and Human Activities on Annual Runoff Dynamics in a Southeast China Coastal Watershed
Ervinia A, Huang J*, Zhang Z
Coastal and Ocean Management Institute, Xiamen University, China 361005;
*Correspondence to: Jinliang Huang (jlhuang@xmu.edu.cn)
Keywords: climate change, human activities, hydrological sensitivity analysis, runoff, Jiulong River Watershed
Received: March 16, 2017; Revised: October 16, 2017; Accepted: November 6, 2017; Published: January 30, 2018; Available Online: January 30, 2018
Abstract
Understanding how climate variability and human activities interact to affect watershed hydrology is needed for adaptive watershed management. The Mann-Kendall test and hydrological sensitivity analysis were coupled in this study to evaluate the specific impacts of climate variability and human activities on the change in mean annual runoff for the Jiulong River Watershed using a long-term hydro-climatic data during 1961-2013. Based on the results of MK test, the study period was divided into two periods, the baseline period (1961-1974) and the altered period (1975-2013). The mean annual runoff during the altered period increased by 31 mm (3.5%) and 93 mm (11.6%) for the North and West Rivers, respectively, compared with that of baseline period. Climate variability was identified as the dominant factor controlling the increased annual runoff, accounted for 58 mm (193%) and 90 mm (97%) of the changes in the North and West Rivers, respectively. Human activities (e.g. increasing water withdrawal, cascade dams, and reforestation) played a more important role in the reduction of annual runoff, particularly in the North River of about 27 mm. The present study suggests that human activities may buffer the severity of hydrological changes associated with climate changes, particularly in Southeast China region where more intense and extreme weather events have been experienced.