scholarly journals Study on the influence of vegetation change on runoff generation mechanism in the Loess Plateau, China

2020 ◽  
Author(s):  
Xueli Zhang ◽  
Yue Yu ◽  
CaiHong Hu ◽  
Jianhua Ping
Keyword(s):  
Loess Plateau ◽  
Vegetation Change ◽  
Overland Flow ◽  
Yellow River ◽  
Generation Mechanism ◽  
Underlying Surface ◽  
The Yellow River ◽  
Runoff Generation ◽  
The Loess Plateau ◽  
Related Factors

Abstract In recent years, the amount of water and sediment in the Yellow River Basin has dropped drastically. This paper selected 125 rainfall and flood data points from 1965 to 2015, combined hydrological methods and mathematical statistics to analyze the hydrological factors and runoff generation mechanism, and combined the underlying surface conditions of the Gushanchuan Basin. The characteristics of change revealed the temporal and spatial variation characteristics and related factors of the runoff generation mechanism in the basin. The results showed that the Gushanchuan Basin is still dominated by HOF runoff, but the runoff generation mechanism also has changed with changes in the underlying surface, which are reflected in increased runoff components, the reduced proportion of HOF runoff, and the increased proportion of saturation-excess overland flow (SOF) runoff and mixed runoff. We analyzed the variation law of underlying surface in the basin, which indicated that the increase in the forest grass area was the main factor affecting changes in the watershed runoff generation mechanism. This research will enable a deeper understanding of the runoff generation mechanism of the main soil erosion areas in the Loess Plateau, reveal variations in the runoff generation mechanism in the Yellow River.

scholarly journals Rainfall-runoff processes in the Loess Plateau, China: Temporal dynamics of event rainfall-runoff characteristics and diagnostic analysis of runoff generation patterns

2020 ◽  
Author(s):  
Qiang Wu ◽  
Zhaoxi Zhang ◽  
Guodong Zhang ◽  
Shengqi Jian ◽  
Li Zhang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Time Scale ◽  
Overland Flow ◽  
Yellow River ◽  
Separation Procedure ◽  
Runoff Coefficient ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
The Loess Plateau

Abstract. The Loess Plateau is the most erosion-prone area in China, while under large-scale ecological restoration runoff and sediments continue to decrease. This study examined the runoff generation mechanism at the catchment scale to understand the change in runoff generation. Six baseflow used to separation method were tested and the nonparametric simple smoothing method was seperating base flow. With the event runoff separation procedure, 340 rainfall–runoff events are selected in five typical catchments affected by significant human intervention in the Loess Plateau. Runoff characteristics, such as the event runoff coefficient, time scale, rise time, and peak discharge are studied on monthly and long-term scales. In catchments of Jialuhe, Chabagou and Gushanchuan with poor vegetation runoff response is strongly decided by rainfall intensity and is produced by Horton overland flow (HOF). While the mountainous catchments of Jingle and Zulihe runoff response is controlled by rainfall volume. The relation between runoff event characteristics and rainfall is complicated in Loess Plateau, where rainfall and underlying surface is significantly changing. The monthly of event characteristics is mostly controlled by rainfall characteristics. Long-term runoff coefficient experiences decreasing trend, while time scale trend is increasing. Land use changes lead to increasing catchment wetness display mostly strong reason in event characteristic response. According to our proposed framework for classifying dominant runoff generation patterns considering of hydrograph response time, discharge source, and flow paths, HOF runoff is still the dominant mechanism, but gradually shifts to Dunne overland flow (DOF) and combination runoff. We speculate that the reduction in runoff in the Yellow River is likely to be the dominant runoff mechanism changing.

scholarly journals Response of the parameters of excess infiltration and excess storage model to land use cover change

2020 ◽  
Vol 68 (2) ◽  
pp. 99-110 ◽  
Author(s):  
Yuexiu Wen ◽  
Caihong Hu ◽  
Guodong Zhang ◽  
Shengqi Jian
Keyword(s):  
Land Use ◽  
Overland Flow ◽  
Yellow River ◽  
The Yellow River ◽  
Model Parameters ◽  
Runoff Generation ◽  
The Loess Plateau ◽  
Infiltration Capacity ◽  
Infiltration Excess ◽  
Generation Mechanisms

AbstractThe Loess Plateau is the main source of water in Yellow River, China. After 1980s, the Yellow river water presented a significant reduction, what caused the decrease of the Yellow river discharge had been debated in academic circles. We proceeded with runoff generation mechanisms to explain this phenomenon. We built saturation excess runoff and infiltration excess runoff generation mechanisms for rainfall–runoff simulation in Jingle sub-basin of Fen River basin on the Loess Plateau, to reveal the influence of land use change on flood processes and studied the changes of model parameters under different underlying conditions. The results showed that the runoff generation mechanism was mainly infiltration-excess overland flow, but the flood events of saturation-excess overland flow had an increasing trend because of land use cover change (the increase of forestland and grassland areas and the reduction of cultivated land). Some of the model parameters had physical significances，such as water storage capacity (WM), infiltration capacity (f), evapotranspiration (CKE), soil permeability coefficient (k) and index of storage capacity distribution curve (n) showed increasing trends, and index of infiltration capacity distribution curve (m) showed a decreasing trend. The above results proved the changes of runoff generation mechanism from the perspective of model parameters in Jingle sub-basin, which can provide a new perspective for understanding the discharge reduction in the Yellow River basin.

Soil conservation on the Loess Plateau and the regional effect: impact of the ‘Grain for Green' Project

2018 ◽  
Vol 109 (3-4) ◽  
pp. 461-471
Author(s):  
Xiaofeng WANG ◽  
Feiyan XIAO ◽  
Xiaoming FENG ◽  
Bojie FU ◽  
Zixiang ZHOU ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Land Cover ◽  
Loess Plateau ◽  
Soil Conservation ◽  
Yellow River ◽  
Vegetation Coverage ◽  
The Yellow River ◽  
The Loess Plateau ◽  
Regional Effect ◽  
Grain For Green

ABSTRACTSoil conservation on the Loess Plateau is important not only for local residents but also for reducing sediment downstream in the Yellow River. In this paper, we report a decrease in soil erosion from 2000 to 2010 as a result of the ‘Grain for Green' (GFG) Project. By using the Revised Universal Soil Loss Equation and data on land cover, climate and sediment yield, we found that soil erosion decreased from 6579.55tkm–2yr–1 in 2000 to 1986.66tkm–2yr–1 in 2010. During this period, there was a major land cover change from farmland to grassland in response to the GFG. The area of low vegetation coverage with severe erosion decreased dramatically, whereas the area of high vegetation coverage with slight erosion increased. Our study demonstrates that the reduction in soil erosion on the Loess Plateau contributed to the decrease in the sediment concentration in the Yellow River.

scholarly journals Prediction of Sediment Yield in the Middle Reaches of the Yellow River Basin Under Extreme Precipitation

2020 ◽  
Vol 8 ◽  
Author(s):  
Suzhen Dang ◽  
Xiaoyan Liu ◽  
Huijuan Yin ◽  
Xinwei Guo
Keyword(s):  
River Basin ◽  
Loess Plateau ◽  
Sediment Yield ◽  
Extreme Precipitation ◽  
Land Surface ◽  
Yellow River ◽  
Yellow River Basin ◽  
The Yellow River ◽  
The Loess Plateau ◽  
The Yellow River Basin

The Yellow River is one of the rivers with the largest amount of sediment in the world. The amount of incoming sediment has an important impact on water resources management, sediment regulation schemes, and the construction of water conservancy projects. The Loess Plateau is the main source of sediment in the Yellow River Basin. Floods caused by extreme precipitation are the primary driving forces of soil erosion in the Loess Plateau. In this study, we constructed the extreme precipitation scenarios based on historical extreme precipitation records in the main sediment-yielding area in the middle reaches of the Yellow River. The amount of sediment yield under current land surface conditions was estimated according to the relationship between extreme precipitation and sediment yield observations in the historical period. The results showed that the extreme rainfall scenario of the study area reaches to 159.9 mm, corresponding to a recurrence period of 460 years. The corresponding annual sediment yield under the current land surface condition was range from 0.821 billion tons to 1.899 billion tons, and the median annual sediment yield is 1.355 billion tons, of which more than 91.9% of sediment yields come from the Hekouzhen to Longmen sectionand the Jinghe River basin. Therefore, even though the vegetation of the Loess Plateau has been greatly improved, and a large number of terraces and check dams have been built, the flood control and key project operation of the Yellow River still need to be prepared to deal with the large amount of sediment transport.

The role of run-on for overland flow and the characteristics of runoff generation in the Loess Plateau, China

2012 ◽  
Vol 57 (6) ◽  
pp. 1107-1117 ◽  
Author(s):  
Dengfeng Liu ◽  
Fuqiang Tian ◽  
Hongchang Hu ◽  
Heping Hu
Keyword(s):  
Loess Plateau ◽  
Overland Flow ◽  
Runoff Generation ◽  
The Loess Plateau

scholarly journals Trends of streamflow, sediment load and their dynamic relation for the catchments in the middle reaches of the Yellow River over the past five decades

2012 ◽  
Vol 16 (9) ◽  
pp. 3219-3231 ◽  
Author(s):  
Z. L. Gao ◽  
Y. L. Fu ◽  
Y. H. Li ◽  
J. X. Liu ◽  
N. Chen ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Large Scale ◽  
Sediment Load ◽  
Yellow River ◽  
Kendall Test ◽  
The Yellow River ◽  
Catchment Management ◽  
The Loess Plateau ◽  
Dynamic Relation ◽  
Monthly Streamflow

Abstract. To control severe soil erosion on the Loess Plateau, China, a great number of soil conservation measures have been implemented since 1950s and subsequently, the "Grain for Green" project was implemented in 1999. The measures and the project resulted in a large scale land use/cover change (LUCC). Understanding the impacts of the measures and the project on streamflow, sediment load and their dynamic relation is essential because the three elements are closely related to the sustainable catchment management strategy on the Loess Plateau. The data for seven selected catchments in the middle reaches of the Yellow River were used and standardized with the precipitation and the controlling area for analysis. The nonparametric Mann-Kendall test and the Pettitt test were employed to detect trends and change points of the annual streamflow and annual sediment load. Simple linear regressions for the monthly streamflow and sediment load from May to October were made to express their relationship. Based on the change point identification and the time when the project began to be implemented on the Loess Plateau, the complete time for the data records was divided into three periods to compare the change degrees of streamflow, sediment load and their relation for the catchments. Results show that there are three types of responses in streamflow, sediment load, and their dynamic relations for the seven catchments. The effects of the LUCC on streamflow, sediment load, and their relationships are greatest in the three transition zone catchments followed by the two rocky mountain catchments. The effects are much weaker in the two loess hilly-gully catchments. In general, the change degrees for sediment load are much greater than those for streamflow, which results from the decreased streamflow and weakening trend of their dynamic relation period by period in catchments.

scholarly journals Analysis of baseflow index based hydrological model in Upper Wei River basin on the Loess Plateau in China

2015 ◽  
Vol 368 ◽  
pp. 403-408 ◽  
Author(s):  
D. Liu ◽  
J. Chang ◽  
F. Tian ◽  
Q. Huang ◽  
X. Meng
Keyword(s):  
River Basin ◽  
Loess Plateau ◽  
Hydrological Model ◽  
Yellow River ◽  
Dry Season ◽  
Separation Method ◽  
The Yellow River ◽  
The Loess Plateau ◽  
Wei River Basin ◽  
Wei River

Abstract. The baseflow is the drainage from the groundwater and soil water to the streamflow. As one important source of the streamflow, the baseflow could be the main source of the streamflow in the dry season. The Wei River, located in the semi-arid region of the Loess Plateau which is overlain by deep and loose soil, is the largest tributary of the Yellow River. According to former research, most of the streamflow in the dry season in the headwater of the Yellow River is baseflow. For the whole Yellow River basin, the baseflow is an important component of the streamflow, and accounts for about 44% of the annual runoff. Physically-based distributed hydrological models can simulate the runoff components separately, and are important tools to analyse the runoff components. Given the importance of the baseflow in the dry season for drought relief to support the ecological water requirement and irrigation, especially in the Wei River, the baseflow is analysed in this study. To investigate the baseflow in the Upper Wei River basin, a semi-distributed hydrological model based on a Representative Elementary Watershed approach (THREW) is employed to investigate the runoff generation process. To compare the results, an automatic baseflow separation method proposed by Arnold is used to separate the baseflow from the daily streamflow at Beidao hydrological station in Upper Wei River basin from 2001 to 2004. Based on the hydrological modelling and the Arnold separation method, the average annual baseflow index, i.e. the ratio of baseflow to the total runoff, is estimated as in the range of 0.30–0.36. The average intra-annual monthly baseflow index represents the seasonality of the baseflow due to the seasonality of the precipitation and evapotranspiration, and is also analysed.

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