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

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.

Assessment of Soil and Water Conservation Practices in the Loess Hilly Region Using a Coupled Rainfall-Runoff-Erosion Model

“…In this study, only monthly rainfall was used as climatic input to the model. Rainfall intensity and rainfall duration greatly influenced the amount of runoff, but they were not included in this SCS-CN model [68]. The rainfall erosivity calculated using the Wischmeier model based on monthly rainfall was higher than that calculated using a half-month model based on daily rainfall.…”

“…Therefore, more heavy rainfall and runoff events in the rainy season will result in more soil and water erosion. However, climate change may contribute to 14.3-31% of streamflow change in north China [74,75], while human activities, such as land-use change and SWCPs, would also be an important factor influencing runoff and soil erosion [68,76]. The reduction rates of surface runoff and soil erosion varied among experimental plots with different SWCPs (Figure 2).…”

“…These SWCPs could reduce surface runoff and soil erosion because the topography of the watershed could be changed to greatly delay surface runoff, improve rainfall infiltration, and reduce the runoff discharge. A large proportion of rainfall can be retained by vegetation and evaporate into the atmosphere, causing a significant decrease in the effective rainfall for runoff generation [68]. Under the same rainfall conditions, plot A (shrub/Seabuckthorn + horizontal terracing), B (grass + horizontal terracing), and H (forest/Chinese Pine + horizontal terracing) showed high reduction rates of soil erosion (about 54, 68, and 67%, respectively), which were due to the high vegetation cover (50.5-71.0%).…”

Modeling Future Streamflow for Adaptive Water Allocation under Climate Change for the Tanjung Karang Rice Irrigation Scheme Malaysia

“…Several research works were carried out to understand the variability of streamflows due to climate change [10][11][12][13][14][15] with mixed results in the streamflow variability, depending on the region and season. For instance, a decrease in annual streamflow was observed [5,16].…”

Climate Variability and Climate Change Impacts on Land Surface, Hydrological Processes and Water Management

“…Their results suggest an increasing trend in streamflow without the effect of dams, while the inclusion of a few major dams resulted in decreased river streamflow of 6% to 15%, possibly due to irrigation diversions and climate change. Guo et al [2] quantified 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. They found that 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 (70.95%).…”