Quantifying the Impacts of Climate Change, Coal Mining and Soil and Water Conservation on Streamflow in a Coal Mining Concentrated Watershed on the Loess Plateau, China

Qiaoling Guo,Yunsong Yang,Guobin Fu,Jianlin Li,Yaoyao Han

doi:10.3390/w11051054

Abstract

The streamflow has declined significantly in the coal mining concentrated watershed of the Loess Plateau, China, since the 1970s. Quantifying the impact of climate change, coal mining and soil and water conservation (SWC), which are mainly human activities, on streamflow is essential not only for understanding the mechanism of hydrological response, but also for water resource management in the catchment. In this study, the trend of annual streamflow series by Mann-Kendall test has been analyzed, and years showing abrupt changes have been detected using the cumulative anomaly curves and Pettitt test. The contribution of climate change, coal mining and SWC on streamflow has been separated with the monthly water-balance model (MWBM) and field investigation. The results showed: (1) The streamflow had an statistically significant downward trend during 1955–2013; (2) The two break points were in 1979 and 1996; (3) Relative to the baseline period, i.e., 1955–1978, the mean annual streamflow reduction in 1979–1996 was mainly affected by climate change, which was responsible for a decreased annual streamflow of 12.70 mm, for 70.95%, while coal mining and SWC resulted in a runoff reduction of 2.15 mm, 12.01% and 3.05mm, 17.04%, respectively; (4) In a recent period, i.e., 1997–2013, the impact of coal mining on streamflow reduction was dominant, reaching 29.88 mm, 54.24%. At the same time, the declining mean annual streamflow induced through climate change and SWC were 13.01 mm, 23.62% and 12.20 mm, 22.14%, respectively.

Highlights

Over the second half of the 20th century, the two factors which affected the change of catchment hydrology were climate change and human activities [1]
In northwest China, the streamflow reduction caused by climate change accounting for 14.3% [47]
In the first impact period (1979–1996), climate change was the main factor for annual streamflow decreasing

Summary

Introduction

Over the second half of the 20th century, the two factors which affected the change of catchment hydrology were climate change and human activities [1]. For example, the redistribution of precipitation and temperature change, has affected hydrological systems and water resources [4,5]. Human activities, such as agricultural irrigation, cultivation, dam construction, reservoir operation, soil and water. Water 2019, 11, 1054 conservation (SWC), urbanization construction and coal mining could affect hydrological processes, resulting in natural ecosystem and water resource problems [6,7]. The Loess Plateau, located in the middle reaches of the Yellow River, is the most severe soil and water loss region worldwide [8]. Intensive soil and water loss has resulted in water shortages, land productivity decline, and river ecosystem and environmental degradation

Results

Discussion

Conclusion