scholarly journals Trend and Change-Point Analysis of Streamflow and Sediment Discharge of the Gongshui River in China during the Last 60 Years

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1273 ◽  
Author(s):  
Li-Ping Guo ◽  
Qiang Yu ◽  
Peng Gao ◽  
Xiao-Fei Nie ◽  
Kai-Tao Liao ◽  
...  

The Gongshui River basin exhibits one of the most serious soil erosion areas in southern China, and has always been the key control area of national soil and water conservation programs. This study used daily precipitation, streamflow, and sediment concentration data collected from 1957 to 2015 from the main hydrological stations of the Gongshui River to investigate streamflow and sediment discharge variations and their responses to precipitation and human activities. The Mann-Kendall and Pettitt’s test were used for trend and change-point detection. The double mass curve (DMC) method was employed to quantify the effects of precipitation change and human activities on hydrological regime shifts. The results showed insignificant trends of both annual precipitation and streamflow for all stations, while the sediment discharge of most stations exhibited significant decreasing trends. Change-point analyses revealed that all hydrologic stations except Mazhou had transition years. The estimation via DMC indicated that after the change point years, there was a rapid reduction in sediment discharge at Hanlinqiao, Fengkeng, Julongtan, Xiashan, and Chawu stations, but not at Mazhou, Ruijin, and Yangxinjian stations. Human activity provided a significantly greater contribution to sediment discharge than precipitation. The evidence clearly indicates that the degree and extension of conservation or destruction measures and the construction of large- and medium-sized reservoirs were the major factors significantly decreasing or increasing annual sediment discharge of the Gongshui River. This work could serve as the basis for decision making regarding river basin water resources management to estimate the effects of anthropogenic impacts on water and sediment discharge variations during the last few decades, thereby guiding adaptation and protection of the water resources of the Gongshui River flowing into the Poyang Lake.

2019 ◽  
Vol 11 (5) ◽  
pp. 560 ◽  
Author(s):  
Mingli Wang ◽  
Longjiang Du ◽  
Yinghai Ke ◽  
Maoyi Huang ◽  
Jing Zhang ◽  
...  

Yongding River is the largest river flowing through Beijing, the capital city of China. In recent years, Yongding River Basin (YDRB) has witnessed increasing human impacts on water resources, posing serious challenges in hydrological and ecological health. In this study, remote sensing techniques and statistical time series approaches for hydrological studies were combined to characterize the dynamics and driving factors of reservoir water extents in YDRB during 1985–2016. First, 107 Landsat 4, 5, 7 and 8 images were used to extract surface water extents in YDRB during 1985–2016 using a combination of water indices and Otsu threshold algorithm. Significant positive correlation was found between water extents and the annual inflow for the two biggest reservoirs, the downstream Guanting and upstream Cetian reservoirs, proving their representativeness of surface water availability in this basin. Then, statistical time series approaches including trend-free pre-whitening Mann-Kendall trend test, Pettit change-point test and double mass curve method, which are frequently used in hydrological studies, were adopted to quantify the trend of reservoir water extents dynamics and the relative contributions of climate variability and human activities. Results showed that the water extents in both reservoirs exhibited significant downward trend with change point occurring in 2001 and 2005 for Guanting and Cetian, respectively. About 74%~75% of the shrinkage during the post-change period can be attributed to human activities, among which GDP, population, electricity power production, raw coal production, steel and crude iron production, value of agriculture output, and urban area were the major human drivers. Hydrological connectivity between the upstream Cetian and downstream Guanting reservoirs declined during the post-change period. Since 2012, water extents in both reservoirs recovered as a result of various governmental water management policies including the South-to-North Water Diversion Project. The methodology presented in this study can be used for analyzing the dynamics and driving mechanism of surface water resources, especially for un-gauged or poorly-gauged watersheds.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1679 ◽  
Author(s):  
Guo ◽  
Mu ◽  
Hu ◽  
Gao ◽  
Zhang ◽  
...  

National large-scale soil and water conservation controls on the Gangjiang River basin have been documented, but the effect of governance on regional watershed hydrology and how the main driving factors act have not been systematically studied yet. To do this, this study evaluated changing trends and detected transition years for both streamflow and sediment discharge using long-term historical records at seven hydrological stations in the Ganjiang River basin over the past 50 years. The double mass curve (DMC) method was used to quantify the effects of both climate change and human activities on hydrological regime shifts. The results showed that the distributions of precipitation, streamflow, and sediment discharge within a year are extremely uneven and mainly concentrated in the flood season of Jiangxi Province. None of the stations showed significant trends over time for either annual precipitation or streamflow, while the annual sediment discharge at most stations decreased significantly over time. The estimation of sediment discharge via DMC indicated that after the transition years, there were rapid reductions in sediment discharge at all hydrological stations, and the average decline degree of midstream and downstream were much larger than that of upstream. Human activities, especially the increase of vegetation cover and construction of large and medium-sized reservoirs, provided a significantly greater contribution to the reduction of sediment discharge than did precipitation changes. As a case study of river evolution under global change environment, this study could provide scientific basis for the control of soil erosion and the management of water resources in Ganjiang River, as well as for the related research of Poyang Lake and the Yangtze River basin of China.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jinliang Zhang ◽  
Yizi Shang ◽  
Jinyong Liu ◽  
Jian Fu ◽  
Shitao Wei ◽  
...  

Abstract The Jinghe River remains the major sediment source of the Yellow River in China; however, sediment discharge in the Jinghe River has reduced significantly since the 1950s. The objective of this study is to identify the causes of sediment yield variations in the Jinghe River Basin based on soil and water conservation methods and rainfall analyses. The results revealed that soil and water conservation projects were responsible for half of the total sediment reduction; sediment retention due to reservoirs and water diversion projects was responsible for 1.3% of the total reduction. Moreover, the Jinghe River Basin has negligible opportunity to improve its vegetation cover (currently 55% of the basin is covered with lawns and trees), and silt-arrester dams play a smaller role in reducing sediment significantly before they are entirely full. Therefore, new large-scale sediment trapping projects must be implemented across the Jinghe River Basin, where heavy rainfall events are likely to substantially increase in the future, leading to higher sediment discharge.


2015 ◽  
Vol 46 (6) ◽  
pp. 1019-1036 ◽  
Author(s):  
Ye Zhu ◽  
Wen Wang ◽  
Yi Liu ◽  
Hongjie Wang

The impacts of climate variability and anthropogenic activities on hydrological processes have been of wide concern in the hydrology community during recent decades. In this study, specific investigations of individual impacts of climate variability and anthropogenic activities on runoff during 1964–2010 are conducted for the upper Huaihe River Basin at Huaibin (HB) and its five sub-catchments. The non-stationary relationship between precipitation and runoff was firstly analyzed, and according to change point detection results, long-term series for each catchment was divided into pre-change period and post-change period, respectively. Then, the climate variability and human activities that occurred in the whole HB catchment were analyzed. Finally, using two quantitative evaluation methods, the individual impacts of climate variability and human activities for each catchment were assessed. The results showed that for the whole HB catchment, runoff changes during the whole post-change period are mainly attributed to climate variability, as for its sub-catchments except the Xinxian catchment. As for decadal behaviors, runoff generally suffered more human-induced impacts in dry decades (1990s) than wet decades (1980s and 2000s). These results reflected the complex role of climate variability and human activities in influencing the runoff regime, which could be considered in local water resources management.


Author(s):  
Chenlu Huang ◽  
Qinke Yang ◽  
Weidong Huang ◽  
Junlong Zhang ◽  
Yuru Li

Precipitation and human activities are two essential forcing dynamics that influence hydrological processes. To investigate those impacts, the Zuli River Basin (ZRB, a typical tributary basin of the Yellow River in China) was chosen to identify the impact of precipitation and human activities on runoff and sediment discharge. A double mass curve (DMC) analysis and the test methods, including accumulated variance analysis, sequential cluster, Lee-Heghnian, and moving t-test methods was utilized to determine the abrupt change point based on data from 1956 to 2015. Correlation formulas and multiple regression methods were used to calculate the runoff and sediment discharge reduction effects of soil conservation measures and to estimate the contribution rate of precipitation and soil conservation measures to runoff and sediment discharge. Our results show that the runoff reduction effect of soil conservation measures (45%) is greater than the sediment discharge reduction effect (32%). Soil conservation measures were the main factor controlling the 74.5% and 75.0% decrease in runoff and sediment discharge, respectively. Additionally, the contribution rate of vegetation measures was higher than that of engineering measures. This study provides scientific strategies for water resource management and soil conservation planning at catchment scale to face future hydrological variability.


Author(s):  
Hang Li ◽  
Xiao-Ning Qu ◽  
Jie Tao ◽  
Chang-Hong Hu ◽  
Qi-Ting Zuo

Abstract China is actively exploring water resources management considering ecological priorities. The Shaying River Basin (Henan Section) serves as an important grain production base in China. However, conflicts for water between humans and the environment are becoming increasingly prominent. The present study analyzed the optimal allocation of water while considering ecological priorities in the Shaying River Basin (Henan Section). The ecological water demand was calculated by the Tennant and the representative station methods; then, based on the predicted water supply and demand in 2030, an optimal allocation model was established, giving priority to meeting ecological objectives while including social and comprehensive economic benefit objectives. After solving the model, the optimal results of three established schemes were obtained. This revealed that scheme 1 and scheme 2 failed to satisfy the water demand of the study area in 2030 by only the current conditions and strengthening water conservation, respectively. Scheme 3 was the best scheme, which could balance the water supply and demand by adding new water supply based on strengthening water conservation and maximizing the benefits. Therefore, the actual water allocation in 2030 is forecast to be 7.514 billion (7.514 × 109) m3. This study could help basin water management departments deal with water use and supply.


Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1720
Author(s):  
Pieter Van den Berghe ◽  
Maxim Gosseries ◽  
Joeri Gerlo ◽  
Matthieu Lenoir ◽  
Marc Leman ◽  
...  

A method is presented for detecting changes in the axial peak tibial acceleration while adapting to self-discovered lower-impact running. Ten runners with high peak tibial acceleration were equipped with a wearable auditory biofeedback system. They ran on an athletic track without and with real-time auditory biofeedback at the instructed speed of 3.2 m·s−1. Because inter-subject variation may underline the importance of individualized retraining, a change-point analysis was used for each subject. The tuned change-point application detected major and subtle changes in the time series. No changes were found in the no-biofeedback condition. In the biofeedback condition, a first change in the axial peak tibial acceleration occurred on average after 309 running gait cycles (3′40″). The major change was a mean reduction of 2.45 g which occurred after 699 running gait cycles (8′04″) in this group. The time needed to achieve the major reduction varied considerably between subjects. Because of the individualized approach to gait retraining and its relatively quick response due to a strong sensorimotor coupling, we want to highlight the potential of a stand-alone biofeedback system that provides real-time, continuous, and auditory feedback in response to the axial peak tibial acceleration for lower-impact running.


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