scholarly journals Attribution Analysis of Runoff Variation in the Yue River Watershed of the Qinling Mountains

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yiyi Hu ◽  
Yi He

In recent decades, global climate change, especially human activities, has led to profound changes in the hydrological cycle and hydrological processes in watersheds. Taking the Yue River watershed in the Qinling Mountains in China as the study area, the Mann–Kendall test and Pettitt mutation test method were used to analyze the various characteristics of hydrological and climatic elements from 1960 to 2018. Then, the elastic coefficient method based on the Budyko framework was used to estimate the elastic coefficient of runoff change on each influencing factor. The results showed that the annual runoff decreased at a rate of 0.038 × 108 m3/a ( P > 0.05 ), and a significant abrupt change occurred in 1990. The annual precipitation and potential evapotranspiration (ET0) increased and decreased, with change rates of 0.614 mm/a and −0.811 mm/a ( P > 0.05 ), respectively. The elasticity coefficients of precipitation, ET0, and the underlying surface were 1.95, −0.95, and −0.85, respectively, indicating that annual runoff was most sensitive to the change in precipitation, followed by the change in ET0, and had the lowest sensitivity to the change in the underlying surface. Underlying surface change is the main factor of runoff decrease; the contribution is 89.07%. The total contribution of climate change to runoff change is 10.93%, in which the contributions of precipitation and ET0 are 17.59% and −6.66%, respectively. The NDVI reflecting underlying surface change has been increasing since 1990, which is an important reason for the runoff decrease.

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2659
Author(s):  
Bao Shanshan ◽  
Yang Wei ◽  
Wang Xiaojun ◽  
Li Hongyan

In the past several decades, climate change and human activities have influenced hydrological processes, and potentially caused more frequent and extensive flood and drought risks. Therefore, identification and quantification of the driving factors of runoff variation have become a hot research area. This paper used the trend analysis method to show that runoff had a significant downward trend during the past 60 years in the Second Songhua River Basin (SSRB) of Northeast China. The upper, middle, and lower streams of five hydrological stations were selected to analyze the breakpoint of the annual runoff in the past 60 years, and the breakpoints were used to divide the entire study period into two sub-periods (1956–1974 and 1975–2015). Using the water–energy coupling balance method based on Choudhury–Yang equation, the climatic and catchment landscape elasticity coefficient of the annual runoff change was estimated, and attribution analysis of the runoff change was carried out for the Fengman Reservoir and Fuyu stations in SSRB. The change in potential evapotranspiration has a weak effect on the runoff, and change in precipitation and catchment landscape were the leading factors affecting runoff. Impacts of climate change and land cover change were accountable for the runoff decrease by 80% and 11% (Fengman), 17% and 206% (Fuyu) on average, respectively; runoff was more sensitive to climate change in Fengman, and was more sensitive to catchment landscape change in Fuyu. In Fengman, the population was small, owing to the comparatively inhospitable natural conditions, and so human activities were low. However, in Fuyu, human activities were more intensive, and so had more impact on runoff for the Lower Second Songhua River compared to the Upper Second Songhua River.


2011 ◽  
Vol 42 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Hailiang Xu ◽  
Bin Zhou ◽  
Yudong Song

The impacts of climate change on annual runoff were analyzed using hydrologic and meteorological data collected by 8 meteorological stations and 15 hydrological stations in the headstream of the Tarim River Watershed from 1957 to 2005. The long-term trend of climate change and hydrological variations were determined by parametric and non-parametric tests. The results show that the increasing scale of precipitation is less than the scale of rising temperature. The change and response of hydrological process have their own spatial characteristics in the tributaries of a headstream. Precipitation and temperature do not increase simultaneously in the hydro- and meteo-stations located in the headstream. The temperature and runoff displayed certain relations, and a relationship also existed between precipitation and runoff. The annual runoff of the Aksu and Kaidu rivers was consistent with an increasing trend in temperature and precipitation during the past 50 years; temperature increases have a greater effect on annual runoff. These results suggest that with the increase of temperature in the Tarim River Watershed, the glacier in the headstreams would melt gradually which results in runoff increase in several headstreams. However, glacier meltwater would be exhausted due to continual glacier shrinkage, and the increased trend of runoff in the headstreams would also slow or lessen. Thus, regional water resources shortage problems are still serious and have become a major feature in the Tarim River Watershed.


Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1028 ◽  
Author(s):  
Ting Zhang ◽  
Yixuan Wang ◽  
Bing Wang ◽  
Ping Feng

In the traditional point of view, if there is a significant decreasing trend for a runoff time series, while no significant trend for a precipitation series is present, then an unreliable conclusion will be made that the land surface change is the main contributor to the runoff change. To test it, we selected four sub-watersheds in the Luanhe river basin as the study areas where land use has changed severely. We first detected the long-term rainfall and runoff trend by the Mann–Kendall test, Sen’s slope, and the moving average method, and found that the runoff had a decreasing trend at the 0.05 significance level, while the rainfall had no significant trend in all sub-watersheds. Then an orderly cluster analysis and moving T test method were used to detect the change point of the runoff series. We quantified the contributions of the land surface change and climate variability based on Soil and Water Assessment Tool (SWAT), and the contribution of climate variability accounted for more than 50%, which implies that climate change is the main factor of runoff decrease in the study areas. To further test this, a trend analysis of a reconstructed annual runoff time series under undisturbed conditions has been done. The results showed that in some sub-watersheds, although rainfall series had no significant decreasing trend, the runoff series had significant downward trend. This can be explained by the nonlinear relationship between rainfall and runoff. This study came to a different conclusion from the common view, which observes that runoff decrease is mainly caused by land surface change if rainfall series lacks a significantly decreasing trend.


2015 ◽  
Vol 7 (2) ◽  
pp. 430-442 ◽  
Author(s):  
Jianzhu Li ◽  
Shuhan Zhou

Climate variability and human activities are two main factors influencing hydrological processes. For more reasonable water management, understanding and quantifying the contributions of the two factors to runoff change is a prerequisite. In this paper, the Budyko decomposition hypothesis and the geometric approach were employed to quantify climate change and human activities on mean annual runoff (MAR) in six sub-basins of Luanhe river basin. We split a long-term period (1956–2011) into two sub-periods (pre-change and post-change periods) to quantify the change over time. Observations show that annual runoff has had a decreasing trend during the past 56 years in the Luanhe river basin. Based on a geometric approach, the climate impacts in these six sub-basins were 7–49%, and the contributions of human activities were 51–93%, approximately. According to the Budyko decomposition method, impacts of climate variation accounted for 15–40% of the runoff decrease, and the contribution of human activities was 60–85%. Both methods were simple to understand, and it is feasible to separate the climatic- and human-induced impacts on MAR. This study could provide significant information for water resources managers.


Author(s):  
Yi He ◽  
Yiyi Hu ◽  
Jinxi Song ◽  
Xiaohui Jiang

Climate and underlying surface changes have a profound impact on runoff in the Qinling Mountains. This study attempts to identify the difference in runoff changes of two rivers in the south and north of China’s south-north transitional zone under climate change. The Pettit test and Mann-Kendall test were used to investigate the abrupt change and trend analysis on runoff in the Ba River watershed and Jinqian River watershed from 1960 to 2014. The coupled energy-water balance equation based on the Budyko hypothesis estimated the climate and landscape elasticity of runoff followed by attribution analysis of runoff in these two watersheds. The results showed that annual runoff in the Jinqian River (in the southern Qinling Mountains) and the Ba River (in the northern Qinling Mountains) exhibited a significant decreasing trend at P<0.05 and P<0.01, respectively. Abrupt runoff changes occurred in 1989 and 1992 in the Ba River and Jinqian River, respectively. The attribution analysis showed that the change in potential evapotranspiration had little impact on runoff in the southern and northern Qinling Mountains. In contrast, the dominant factors leading to runoff reduction were the change in precipitation and catchment landscape. The contributions of climate change and land surface alteration to runoff changes in the Ba River watershed and Jinqian watershed were 38.08% and 61.92%, and 23.95% and 76.05%, respectively. This study can provide a scientific reference for water resource protection in the south-north transitional zone.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 544
Author(s):  
Hang Ning ◽  
Ming Tang ◽  
Hui Chen

Dendroctonus armandi (Coleoptera: Curculionidae: Scolytidae) is a bark beetle native to China and is the most destructive forest pest in the Pinus armandii woodlands of central China. Due to ongoing climate warming, D. armandi outbreaks have become more frequent and severe. Here, we used Maxent to model its current and future potential distribution in China. Minimum temperature of the coldest month and precipitation seasonality are the two major factors constraining the current distribution of D. armandi. Currently, the suitable area of D. armandi falls within the Qinling Mountains and Daba Mountains. The total suitable area is 15.83 × 104 km2. Under future climate scenarios, the total suitable area is projected to increase slightly, while remaining within the Qinling Mountains and Daba Mountains. Among the climate scenarios, the distribution expanded the most under the maximum greenhouse gas emission scenario (representative concentration pathway (RCP) 8.5). Under all assumptions, the highly suitable area is expected to increase over time; the increase will occur in southern Shaanxi, northwest Hubei, and northeast Sichuan Provinces. By the 2050s, the highly suitable area is projected to increase by 0.82 × 104 km2. By the 2050s, the suitable climatic niche for D. armandi will increase along the Qinling Mountains and Daba Mountains, posing a major challenge for forest managers. Our findings provide information that can be used to monitor D. armandi populations, host health, and the impact of climate change, shedding light on the effectiveness of management responses.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1237 ◽  
Author(s):  
Caihong Hu ◽  
Li Zhang ◽  
Qiang Wu ◽  
Shan-e-hyder Soomro ◽  
Shengqi Jian

Runoff reduction in most river basins in China has become a hotpot in recent years. The Gushanchuan river, a primary tributary of the middle Yellow river, Northern China, showed a significant downward trend in the last century. Little is known regarding the relative contributions of changing environment to the observed hydrological trends and response on the runoff generation process in its watershed. On the basis of observed hydrological and meteorological data from 1965–2010, the Mann-Kendall trend test and climate elasticity method were used to distinguish the effects of climate change and human activities on runoff in the Gushanchuan basin. The results indicate that the runoff in the Gushanchuan Basin has experienced significant declines as large as 77% from 1965 to 2010, and a mutation point occurred around 1997; the contribution rate of climate change to runoff change is 12.9–15.1%, and the contribution rate of human activities to runoff change is 84.9–87.1%. Then we divided long-term data sequence into two stages around the mutation point, and analyzed runoff generation mechanisms based on land use and cover changes (LUCC). We found that the floods in the Gushanchuan Basin were still dominated by Excess-infiltration runoff, but the proportion in 1965–1997 and 1998–2010 decreased gradually (68.46% and 45.83% in turn). The proportion of Excess-storage runoff and Mixed runoff has increased, which means that the runoff is made up of more runoff components. The variation law of the LUCC indicates that the forest area increased by 49.61%, the confluence time increased by 50.42%, and the water storage capacity of the watershed increased by 30.35%.


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