Quantifying the effects of climate change and human activities on runoff in the water source area of Beijing, China

Abstract

Quantitative assessment of the effects of climate change and human activities on runoff is very important for regional sustainable water resources adaptive management. In this study, the non-parametric Mann-Kendall test is used to identify the trends in and change points of the annual runoff with the aim of analysing the changing characteristics of the hydrological cycle. The study presents the analytical derivation of a method which combines six Budyko hypothesis-based water-energy balance equations with the PenmanMonteith equation to separate the effects of climate change and human activities. The method takes several climate variables into consideration. Results based on data from the Yongding River basin, China, show that climate change is estimated to account for 10.5-12.6% of the reduction in annual runoff and human activities contribute to 87.4-89.5% of the runoff decline. The results indicate that human activities are the main driving factors for the reduction in runoff.Key words climate change; human activities; runoff; Yongding River basin, China Quantification des effets du changement climatique et des activités humaines sur l'écoulement dans la zone d'alimentation en eau de Pékin, Chine Résumé L'évaluation quantitative des effets du changement climatique et des activités humaines sur l'écoulement est très important pour une gestion durable et adaptative des ressources en eau régionales. Dans cette étude, le test non paramétrique de Mann-Kendall a été utilisé pour identifier les tendances et les sauts de l'écoulement annuel afin d'analyser l'évolution des caractéristiques du cycle hydrologique. L'étude présente l'établissement une méthode analytique qui combine six équations de bilan eau-énergie basées sur l'hypothèse de Budiko avec l'équation de Penman-Monteith, pour séparer les effets du changement climatique et ceux des activités humaines. La méthode prend plusieurs variables climatiques en considération. Les résultats basés sur les données du bassin de la rivière Yongding, en Chine, montrent que l'on peut estimer que la réduction de l'écoulement annuel prévu serait due pour 10,5 à 12,6% au changement climatique et pour 87,4 à 89,5% aux activités humaines. Ces résultats indiquent que les activités humaines sont le principal facteur responsable de la réduction de l'écoulement.

Impact of Climate Variabilities and Human Activities on Surface Water Extents in Reservoirs of Yongding River Basin, China, from 1985 to 2016 Based on Landsat Observations and Time Series Analysis

“…Wang et al (2013) [44] evaluated four catchments in HRB, and reported that human activities contributed to 63.1% of runoff reduction. Xia et al (2014) [45] studied the runoff variations in YDRB from 1960 to 2010, and reported that the contributions from human activities to runoff declination accounted for 71.0%~92.7%. Although our study focused on the reservoir water extents instead of runoff, we have shown that the reservoir water extents correlated significantly with runoff, and the relative contributions of climate variability and human activities to water extents were similar.…”

Recent water quality trends in a typical semi-arid river with a sharp decrease in streamflow and construction of sewage treatment plants

“…However, human activities were the main reason for streamflow decline over the longer period of time. Previous studies showed that the streamflow in the Guanting Reservoir basin decreased significantly with no significant change in precipitation from the 1950s to the 2000s, with an abrupt change occurring in about 1980 (Liu et al 2013, Xia et al 2014, Yang and Tian 2009). The decreasing streamflow had been thought to be due to the increasing demand for water for human use, especially for irrigation, since 1978 when China implemented the reform and opening-up policy (Yang and Tian 2009).…”

“…Studies in northern China showed that streamflow in a large number of basins had a significantly decreasing trend during the past decades (1950s-2000s), and abrupt changes in streamflow mostly occurred between 1978 and 1985 (Bao et al 2012, Wang et al 2013, Xu et al 2014. This period corresponded to the beginning of China's reform and opening up, when agricultural and industrial water use dramatically increased; this was considered to be the main reason for the decline in streamflow (Liu and Xia 2004, Xia et al 2014, Yang and Tian 2009). Similar conclusions were drawn for many basins located in the Mediterranean region.…”

Impacts of Climate Change and Human Activities on Streamflow in the upper basin of the Yongding River, North China

“…The water scarcity in the study area has become increasingly severe (Wang, 2004;Wang et al, 2010), the increase in the amount of water withdrawal from the river course is the direct cause why observed runoff decreases in the northern part of China (Ren et al, 2002). Xia et al (2014) presents the analytical derivation method based on Budyko hypothesis to separate the effects of climate change and human activities in Upper Yongding River Basin (UYRB). Results show that climate change is estimated to account for 10.5-12.6% of the reduction in annual runoff and human activities contribute to 87.4-89.5% of the runoff decline, indicating that human activities are the main driving factors for the reduction in runoff.…”