Impact of natural climate variability on runoff based on Monte Carlo method

Guoxin Xu,Jianxia Chang,Jie Yang,Jun Yao,Qiang Huang,Yimin Wang

doi:10.2166/wcc.2017.177

Guoxin Xu, Jianxia Chang + Show 4 more

Open Access

https://doi.org/10.2166/wcc.2017.177

Copy DOI

Abstract

Abstract Studying the impact of climate variability is important for the rational utilization of water resources, especially in the case of intensified global climate variability. Climate variability can be caused by natural climate variability or human-caused climate variability. The analysis of Jinghe River Basin (JRB) may not be comprehensive because few studies have concentrated on natural climate variability. Therefore, the primary goal is to explore the impact of natural climate variability on runoff. A modified Mann–Kendall test method was adopted to analyze the aberrance point to determine the natural condition period during which runoff was only influenced by natural climate variability. Then, the Monte Carlo method was employed to extract segments of monthly runoff in the natural condition period and combine them to construct a long series to reduce the instability. Results indicate that the percentage of runoff variability affected by natural climate variability is 30.52% at a confidence level of 95%. Next, a topography-based hydrological model and climate elasticity method were used to simulate runoff after the aberrance point without considering the impact caused by local interference. Through a comparison of the measured and simulated runoff, we discovered that local interference has the greatest impact on runoff in the JRB.

Highlights

Over the past century, the global climate has changed dramatically, which has affected hydrologic circulation (Christensen et al ; Graham et al ; Xu et al ; Croitoru & Minea )
It can be concluded that the aberrance point occurred in 1996, and that runoff from 1960 to 1995 was in the natural condition. This means that during this period, runoff was in a natural state of fluctuation and the variability of runoff was only affected by climate variability without local interference
Zhan et al ( ) used an improved climate elasticity method to assess the impact on runoff in the Weihe River Basin and found that local interference made a greater contribution to the decrease in runoff than climate variability

Summary

Introduction

The global climate has changed dramatically, which has affected hydrologic circulation (Christensen et al ; Graham et al ; Xu et al ; Croitoru & Minea ). Local interference (such as the variability of land use, large number of reservoirs and dams, water and soil conservation engineering, and urbanization) has changed hydrologic circulation (White & Greer ; Astaraie-Imani et al ; Zhou et al ). Climate variability includes natural climate variability and human-caused climate variability. Human-caused climate variability refers to climate affected by local interference, such as increasing greenhouse gas emission, land use change, and deforestation. After the third assessment report of the IPCC, an increased emphasis on the impact of climate variability on runoff was proposed for future study regarding the attribution of natural climate variability.

Objectives

Results

Discussion

Conclusion