Impacts of Climate Change and Human Activities on the Surface Runoff in the Wuhua River Basin

Abstract

The impacts of climate change and human activities on the surface runoff in the Wuhua River Basin (hereinafter referred to as the river basin) are explored using the Mann–Kendall trend test, wavelet analysis, and double-mass curve. In this study, all the temperature and precipitation data from two meteorological stations, namely, Wuhua and Longchuan, the measured monthly runoff data in Hezikou Hydrological Station from 1961 to 2013, and the land-cover type data in 1990 and 2013 are used. This study yields valuable results. First, over the past 53 years, the temperature in the river basin rose substantially, without obvious changes in the average annual precipitation. From 1981 to 2013, the annual runoff fluctuated and declined, and this result is essentially in agreement with the time-series characteristics of precipitation. Second, both temperature and precipitation had evidently regular changes on the 28a scale, and the annual runoff changed on the 19a scale. Third, forestland was the predominant land use type in the Wuhua river basin, followed by cultivated land. Major transitions mainly occurred in both land-use types, which were partially transformed into grassland and construction land. From 1990 to 2013, cultivated land was the most active land-use type in the transitions, and construction land was the most stable type. Finally, human activities had always been a decisive factor on the runoff reduction in the river basin, accounting for 85.8%. The runoff in the river basin suffered most heavily from human activities in the 1980s and 1990s, but thereafter, the impact of these activities diminished to a certain extent. This may be because of the implementation of water loss and soil erosion control policies.

Seasonal and Inter-Annual Variability of Groundwater and Their Responses to Climate Change and Human Activities in Arid and Desert Areas: A Case Study in Yaoba Oasis, Northwest China

“…The positive value of the contour is represented by a solid line corresponding to the rise phase of the time series. By contrast, the negative value in the isogram is enclosed by a dashed line indicating the reduction phase [50]. As shown in Figure 8 The wavelet variance change in time scales was calculated using Equation (2) ( Figure 9).…”

Response of runoff and suspended load to climate change and reservoir construction in the Lancang River

“…Merriam first used this method to analyze the consistency of precipitation data in the Susquehanna watershed of the United States (Merriam 1937), and Searcy then explained it theoretically (Searcy & Hardison 1960). This method can be used to make an estimation about the impact of climate change and human activities on the variation of runoff and suspended load (Zhang et al 2018). It is a plot of the cumulative relationship between one variable versus another, which is high linearly related in a concurrent time (Walling 2006;Gao et al 2017;Zhao et al 2018;Zhou et al 2020).…”

Characteristics of Land-Use Carbon Emissions and Carbon Balance Zoning in the Economic Belt on the Northern Slope of Tianshan

“…Previous articles also revealed that the main sources of CEs from land use were mainly the activities of mankind on the land, as well as the maintenance of and changes in the land itself [11] Meanwhile, land is a field and vital effecting factor for CEs from energy consumption Thus, it was suggested that human activities on the land were the greatest factor for [12] Most of the human activities were carried by land, and the land-use structures of differen countries and areas are different to some extent, and accordingly, the mechanism of land use CE was complex and contains several uncertain factors [13]. Comprehensive studies on land-use CE and its characteristics were beneficial for improving the calculation accu racy of CEs, by which the affecting factors would be further clarified [14][15][16]. In addition the concrete analysis on specific issues could be implemented via focalized studies on sec tional land-use CEs, which is greatly conductive with the adjustment of land-use structure and further formulation of relevant policies on CE reduction [17].…”