scholarly journals Spatial Variability and Periodicity of Precipitation in the Middle Reaches of the Yellow River, China

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yi He ◽  
Xingmin Mu ◽  
Peng Gao ◽  
Guangju Zhao ◽  
Fei Wang ◽  
...  
Keyword(s):  
Hurst Exponent ◽  
Large Scale ◽  
Yellow River ◽  
Ensemble Empirical Mode Decomposition ◽  
The Yellow River ◽  
Study Region ◽  
Flood Season ◽  
Current Trends ◽  
Mode Decomposition ◽  
Circulation Patterns

Rainfall is one of the most important reasons causing the soil erosion in the Loess Plateau. The precipitation across the most severely eroded areas in middle reaches of the Yellow River (MRYR), China, was investigated by analyzing the precipitation of flood season(Pf)and precipitation of main flood season(Pmf)from 26 meteorological stations during the period from 1958 to 2013. The empirical orthogonal function (EOF), ensemble empirical mode decomposition, and Hurst exponent are used to detect spatial, multiscale characteristics of periodicity and trend for precipitation. The results show that there exist quasi-3- and quasi-6-year interannual periods and quasi-11- and quasi-28-year interdecadal scale periods forPfandPmf. However, periodical features in most of the study area are not statistically noticeable. Moreover, first EOFs indicated precipitation was affected by the large-scale circulation patterns, and the spatial patterns of the second EOFs indicated an obviously north-south gradient in the MRYR, whereas the third EOFs displayed east-west patterns. Hurst exponent analysis indicates that precipitation inPfandPmfwill continue the current trends in the future. These findings can provide important implications for ecological restoration and farming operations across the study region.

scholarly journals Evaluation of Environmental and Ecological Impacts of the Leading Large-Scale Reservoir on the Upper Reaches of the Yellow River

2019 ◽  
Vol 11 (14) ◽  
pp. 3818
Author(s):  
Jun Qiu ◽  
Tie-Jian Li ◽  
Fang-Fang Li
Keyword(s):  
Flood Control ◽  
Large Scale ◽  
Yellow River ◽  
Yellow River Basin ◽  
Water Area ◽  
Economic Benefits ◽  
Control Area ◽  
Ecological Impacts ◽  
The Yellow River ◽  
Water Demands

Large-scale reservoirs have played a significant role in meeting various water demands and socio-economic development, while they also lead to undeniable impacts on the environment and ecology. The Longyangxia reservoir located on the Yellow River is the first large-scale reservoir on the upper Yellow River with a control area of 18% of the entire Yellow River Basin. Since it was put into operation in 1987, it has made great contributions to the national economy for over 30 years. In this study, the socio-economic benefits of the Longyangxia reservoir in power generation, water supply, flood control, and ice prevention are investigated. More importantly, its impacts on the ecology and environment are also presented and analyzed, such as the impacts on river morphology, flow regimes, peak flow, fish, phytoplankton, and zooplankton. It can be concluded that the construction of the Longyangxia reservoir contributes greatly to socio-economic benefits, the water area nearby has formed a new ecological environment, and the trophic level of the aquatic environment has probably increased.

scholarly journals Magnitude and Frequency of Temperature and Precipitation Extremes and the Associated Atmospheric Circulation Patterns in the Yellow River Basin (1960–2017), China

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2334 ◽  
Author(s):  
Xiaogang Dong ◽  
Shiting Zhang ◽  
Junju Zhou ◽  
Jianjun Cao ◽  
Liang Jiao ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
River Basin ◽  
Yellow River ◽  
Yellow River Basin ◽  
The Yellow River ◽  
Temperature Extremes ◽  
Precipitation Temperature ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
The Yellow River Basin

Since there are many destructive effects caused by extreme climate events in the Yellow River, it is of great theoretical and practical significance to explore the variations of climatic extremes in this key basin. We used a meteorological dataset from 66 stations within the Yellow River basin (YRB) for the period 1960–2017 to calculate magnitude and frequency of precipitation/temperature extremes. We also analyzed the relationships between the main large-scale atmospheric circulation patterns (ACPs) and precipitation/temperature extremes. The trends in precipitation extremes were nonsignificant, only a few stations were characterized by significantly increasing or decreasing anomalies; this indicates the precipitation intensity may have been strengthened, and the extreme rainfall duration appears to have been reduced during 1960–2017. The trends of magnitudes for “cold” extremes were larger than those for “warm” extremes, changes of trends in frost days were higher than those for summer days, and the trends in increasing warm nights were higher than those of warm days. The influence of the El Niño–Southern Oscillation (ENSO) and Arctic Oscillation (AO) on temperature extremes outweighed the influence of the North Atlantic Oscillation (NAO), Indian Ocean Dipole (IOD), and Pacific Decadal Oscillation (PDO) for the other extreme climate indices. The YRB might be at risk of increased extreme high temperature events, and more attention should be paid to this higher risk of extreme climatic events.

Application of MEEMD-ARIMA combining model for annual runoff prediction in the Lower Yellow River

2019 ◽  
Vol 11 (3) ◽  
pp. 865-876 ◽  
Author(s):  
Xianqi Zhang ◽  
Wei Tuo ◽  
Chao Song
Keyword(s):  
Time Series ◽  
Empirical Mode Decomposition ◽  
Yellow River ◽  
Arima Model ◽  
Ensemble Empirical Mode Decomposition ◽  
Annual Runoff ◽  
Lower Yellow River ◽  
The Lower Yellow River ◽  
Mode Decomposition ◽  
Runoff Prediction

Abstract The prediction of annual runoff in the Lower Yellow River can provide an important theoretical basis for effective reservoir management, flood control and disaster reduction, river and beach management, rational utilization of regional water and sediment resources. To solve this problem and improve the prediction accuracy, permutation entropy (PE) was used to extract the pseudo-components of modified ensemble empirical mode decomposition (MEEMD) to decompose time series to reduce the non-stationarity of time series. However, the pseudo-component was disordered and difficult to predict, therefore, the pseudo-component was decomposed by ensemble empirical mode decomposition (EEMD). Then, intrinsic mode functions (IMFs) and trend were predicted by autoregressive integrated moving average (ARIMA) which has strong ability of approximation to stationary series. A new coupling model based on MEEMD-ARIMA was constructed and applied to runoff prediction in the Lower Yellow River. The results showed that the model had higher accuracy and was superior to the CEEMD-ARIMA model or EEMD-ARIMA model. Therefore, it can provide a new idea and method for annual runoff prediction.

scholarly journals Shield Equipment Optimization and Construction Control Technology in Water-Rich and Sandy Cobble Stratum: A Case Study of the First Yellow River Metro Tunnel Undercrossing

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fei Ye ◽  
Nan Qin ◽  
Xiang Gao ◽  
Xue-yong Quan ◽  
Xian-zhuo Qin ◽  
...  
Keyword(s):  
Large Scale ◽  
Yellow River ◽  
Shield Tunnel ◽  
The Yellow River ◽  
Protective Device ◽  
Aperture Ratio ◽  
Metro Tunnel ◽  
Sand Pits ◽  
Cutter Head

The Lanzhou Yellow River Tunnel is the first metro shield tunnel that undercrosses the Yellow River in China. It was completed after successfully overcoming several construction challenges, including strata with a high proportion of large-sized sandy cobble stratum being saturated, large-scale sand pits along the bank of the Yellow River, and a combination of boulders and erratic blocks of rock. Given the difficulties in constructing the tunnel, this paper summarizes the scheme employed to transform the cutter and cutter head design to be applicable to sandy cobble stratum and the key technology used to form the slurry film to facilitate crossing the sand pits in a systematic way. The transformation scheme primarily involved the addition of an adjusting device to control the aperture ratio of the shield on the cutter head, a protective device for the hob hub, and a protective device for the piston rod in the oil cylinder of the crusher. The implementation of measures mentioned above guarantees the safe completion of the tunnel, which can provide a reference for similar projects.

scholarly journals Changes in Vegetation Greenness in the Upper and Middle Reaches of the Yellow River Basin over 2000–2015

2019 ◽  
Vol 11 (7) ◽  
pp. 2176 ◽  
Author(s):  
Wei Wang ◽  
Lin Sun ◽  
Yi Luo
Keyword(s):  
Land Use ◽  
Ecological Restoration ◽  
Yellow River ◽  
The Yellow River ◽  
Fluctuation Analysis ◽  
Vegetation Development ◽  
Vegetation Dynamic ◽  
Study Region ◽  
Entire Study ◽  
Land Use Types

The Grain to Green Project (GTGP), a large ecological restoration project aiming to control soil erosion and improve the ecological environment, has been implemented since 1999 and has led to great land use changes with decreased farmland and increased forest and grass, and significant vegetation variations. Understanding vegetation variations for different land use types is important for accessing the present vegetation development and providing scientific guidance for future ecological restoration design and regional sustainable development. With two land use maps and MODIS LAI data, trend analysis, fluctuation analysis, and R/S methods were applied to analyze the vegetation dynamic changes and sustainability for converted land use types from cropland and unconverted types over 2000–2015 in the upper and middle reaches of the Yellow River. The results obtained were as follows: (1) Vegetation greening was remarkable in the entire study region (0.036 yr−1). The increasing rate was higher in wetter conditions with AI < 3 (0.036–0.053 yr−1) than arid regions with AI > 3 (0.012–0.024 yr−1). (2) Vegetation improved faster for converted forestland, shrubland, and grassland than unconverted types under similar drying conditions. Converted shrubland and grassland had a larger relative change than converted forestland. (3) Converted land use types generally exhibited stronger fluctuation than unconverted types with small differences among types. (4) Vegetation exhibited a sustainable increasing trend in the future, which accounted for more than 73.1% of the region, mainly distributed in the middle reach of the Yellow River. Vegetation restoration exerted important influences on vegetation greening and the effect was stronger for converted types than unconverted types.

scholarly journals Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yunzhao Li ◽  
Junbao Yu ◽  
Kai Ning ◽  
Siyao Du ◽  
Guangxuan Han ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Coastal Wetland ◽  
Yellow River ◽  
Yellow River Delta ◽  
Common Species ◽  
River Delta ◽  
The Yellow River ◽  
Study Region ◽  
The Yellow River Delta ◽  
Road Verge

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice ofβTand Jaccard’s coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparingβ-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion.

scholarly journals Drought Evaluation with CMORPH Satellite Precipitation Data in the Yellow River Basin by Using Gridded Standardized Precipitation Evapotranspiration Index

2019 ◽  
Vol 11 (5) ◽  
pp. 485 ◽  
Author(s):  
Fei Wang ◽  
Haibo Yang ◽  
Zongmin Wang ◽  
Zezhong Zhang ◽  
Zhenhong Li
Keyword(s):  
Remote Sensing ◽  
Spatial Distribution ◽  
Large Scale ◽  
Drought Index ◽  
Yellow River ◽  
Yellow River Basin ◽  
The Yellow River ◽  
Precipitation Data ◽  
Standardized Precipitation Evapotranspiration Index ◽  
The Yellow River Basin

The traditional station-based drought index is vulnerable because of the inadequate spatial distribution of the station, and also, it does not fully reflect large-scale, dynamic drought information. Thus, large-scale drought monitoring has been widely implemented by using remote sensing precipitation products. Compared with station data, remote sensing precipitation products have the advantages of wide coverage and dynamic, continuous data, which can effectively compensate for the deficiency in the spatial distribution of the ground stations and provide a new data source for the calculation of a drought index. In this study, the Gridded Standardized Precipitation Evapotranspiration Index (GSPEI) was proposed based on a remote sensing dataset produced by the Climate Prediction Center morphing technique (CMORPH), in order to evaluate the gridded drought characteristics in the Yellow River basin (YRB) from 1998 to 2016. The optimal Ordinary Kriging interpolation method was selected to interpolate meteorological station data to the same spatial resolution as CMORPH data (8 km), in order to compare the ground-based meteorological parameters to remote sensing-based data. Additionally, the gridded drought trends were identified based on the Modified Mann–Kendall (MMK) trend test method. The results indicated that: (1) the GSPEI was suitable for drought evaluation in the YRB using CMORPH precipitation data, which were consistent with ground-based meteorological data; (2) the positive correlation between GSPEI and SPEI was high, and all the correlation coefficients (CCs) passed the significance test of α = 0.05, which indicated that the GSPEI could better reflect the gridded drought characteristics of the YRB; (3) the drought severity in each season of the YRB was highest in summer, followed by spring, autumn, and winter, with an average GSPEI of −1.51, −0.09, 0.30, and 1.33, respectively; and (4) the drought showed an increasing trend on the monthly scale in March, May, August, and October, and a decreasing trend on the seasonal and annual scale.

scholarly journals Evaluation of Water Quality and Heavy Metals in Wetlands along the Yellow River in Henan Province

2020 ◽  
Vol 12 (4) ◽  
pp. 1300 ◽  
Author(s):  
Hong ◽  
Zhao ◽  
Chang ◽  
Peng ◽  
Wang ◽  
...  
Keyword(s):  
Water Pollution ◽  
Heavy Metals ◽  
Water Quality ◽  
Heavy Metal ◽  
Yellow River ◽  
Spatiotemporal Variation ◽  
The Yellow River ◽  
Lower Yellow River ◽  
Heavy Metal Concentrations ◽  
Flood Season

Assessing spatiotemporal variation in water quality and heavy metals concentrations in wetlands and identifying metal contamination source are crucial steps for the protection and sustainable utilization of water resources. Using the water quality identification index (Iwq), heavy metal pollution index (HPI), hierarchical cluster analysis (HCA) and redundancy analysis (RDA), we evaluated spatiotemporal variation in water quality and heavy metals concentrations, and their interrelation in wetlands along the middle and lower Yellow River. The average Iwq was highest during flood season but the average HPI was lowest in the same season. Meanwhile, the trend in mean HPI across three hydrological seasons was the opposite to that of mean Iwq. There was significant variation in wetlands water pollution status across seasons. During the flood season, the wetlands in the affected area with hanging river were seriously polluted. In other seasons, pollution in the artificial wetlands was even more severe. Moreover, serious pollution of wetlands in belt transect #03 (Yuanyang-Zhongmu) was more frequent. Dissolved oxygen and chemical oxygen demand strongly influenced heavy metal concentrations, while other water quality parameters had different influences on heavy metal concentrations in different hydrological seasons. The causes of water pollution were divided into natural factors and human disturbance (with potential relationships between them). The polluted wetlands were greatly affected by the Yellow River during the flood season while they were more impacted by agricultural and domestic sewage discharge in other seasons. However, heavy metal deposition and leaching into riparian wetlands were still affected by diverse channel conditions. If this trend is allowed to continue unabated, wetlands along the middle and lower Yellow River are likely to lose their vital ecological and social functions.

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