scholarly journals Secondary production and its trophic basis of five dominant chironomids in Heizhuchong Stream, Hanjiang River Basin

2006 ◽  
Vol 18 (2) ◽  
pp. 163-171 ◽  
Author(s):  
YAN Yunjun ◽  
◽  
LI Xiaoyu
Keyword(s):  
River Basin ◽  
Secondary Production ◽  
Hanjiang River ◽  
Heizhuchong Stream

Runoff Forecast and Analysis of the Probability of Dry and Wet Transition in the Hanjiang River Basin

2021 ◽  
Author(s):  
Haoyu Jin ◽  
Xiaohong Chen ◽  
Ruida Zhong
Keyword(s):  
Water Resources ◽  
River Basin ◽  
Transition Probability ◽  
Conversion Model ◽  
Drought And Flood ◽  
Runoff Prediction ◽  
Runoff Forecast ◽  
Hanjiang River ◽  
Basin Area ◽  
Regional Water

Abstract Runoff prediction has an important guiding role in the planning and management of regional water resources, flood prevention and drought resistance, and can effectively predict the risk of changes in regional water resources. This study used 12 runoff prediction methods to predict the runoff of four hydrological stations in the Hanjiang River Basin (HRB). Through the MCMC method, the HRB runoff probability conversion model from low to high (high to low) is constructed. The study found that the runoff of the HRB had a decreasing trend. In the mid-1980s, the runoff had a significant decreasing trend. The smoother the runoff changes, the easier it is to make accurate prediction. On the whole, the QS-MFM, MFM, MA-MFM, CES and DNN methods have strong generalization ability and can more accurately predict the runoff of the HRB. The Logistic model can accurately simulate the change of runoff status in the HRB. Among them, the HLT station has the fastest conversion rate of drought and flood, and the flow that generates floods is 6 times that of drought. The smaller the basin area, the larger the gap between drought and flood discharge. Overall, this research provides important technical support for the prediction of change in water resources and the transition probability from drought to flood in the HRB.

Small Valley Urban Spatial Form in Hanjiang River Basin

2018 ◽  
Vol 43 (1) ◽  
pp. 11-15
Author(s):  
Yu Xiaohui ◽  
Yang Ruhui ◽  
Liu Bo
Keyword(s):  
River Basin ◽  
Spatial Form ◽  
Narrow Valley ◽  
The Social ◽  
Ecological Development ◽  
Southern Shaanxi ◽  
Hanjiang River ◽  
The City ◽  
Small Valley

Urban spatial form influences the social, economic, and ecological development modes of the city. The spatial form during the urbanization of Hanjiang River Basin in Southern Shaanxi needs to be studied. In this study, research methodologies on urban spatial form in China and abroad were summarized. The concept of ecology background was applied, and the research framework for urban spatial form, which integrated the background, framework, core, axis, cluster, and skin, was established. Valley cities in the Hanjiang River Basin in Southern Shaanxi were classified into wide valley, narrow valley, and canyon cities. The spatial form characteristics of these three types of valley cities were discussed. A case study based on a typical city-Yang County-was conducted to discuss the characteristics of the aforementioned six elements of urban spatial form. Finally, spatial form characteristics were summarized. These characteristics provide a basis for the study of the small valley urban spatial form in the Hanjiang River Basin in Southern Shaanxi.

scholarly journals The Long-term Projection of Surface Runoff in the Regions above Danjiangkou in Hanjiang River Basin based on Water-energy Balance

2018 ◽  
Vol 246 ◽  
pp. 01099
Author(s):  
Jun Yin ◽  
Zhe Yuan ◽  
Run Wang
Keyword(s):  
Climate Change ◽  
Energy Balance ◽  
River Basin ◽  
Surface Runoff ◽  
Hydrological Model ◽  
Climatic Factors ◽  
Climate Change Impacts ◽  
Basin Scale ◽  
Hanjiang River ◽  
Distributed Hydrological Models

The projection of surface runoff in the context of climate change is important to the rational utilization and distribution of water resources. This study did a case study in regions above Danjiangkou in Hanjiang River Basin. A basin scale hydrological model was built based on macroscale processes of surface runoff and water-energy balance. This model can describe the quantity relationship among climatic factors, underlying surface and surface runoff. Driven by hypothetical climatic scenarios and climate change dataset coming from CMIP5, the climate change impacts on surface runoff in the regions above Danjiangkou in Hanjiang River Basin can be addressed. The results showed that: (1) Compared with other distributed hydrological models, the hydrological model in this study has fewer parameters and simpler calculation methods. The model was good at simulating annual surface runoff. (2) The surface runoff was less sensitivity to climate change in the regions above Danjiangkou in Hanjiang River Basin. A 1°C increase in temperature might results in a surface runoff decrease of 2~5% and a 10% precipitation increase might result in a streamflow increase of 14~17%. (3) The temperature across the Fu River Basin were projected to increase by 1.4~2.3°C in 1961 to 1990 compared with that in 1961 to 1990. But the uncertainty existed among the projection results of precipitation. The surface runoff was excepted to decrease by 1.3~23.9% without considering the climate change projected by NorESM1-M and MIROC-ESM-CHEM, which was much different from other GCMs.

Potential natural vegetation dynamics driven by future long-term climate change and its hydrological impacts in the Hanjiang River basin, China

2012 ◽  
Vol 43 (1-2) ◽  
pp. 73-90 ◽  
Author(s):  
Fei Yuan ◽  
Liliang Ren ◽  
Zhongbo Yu ◽  
Yonghua Zhu ◽  
Jing Xu ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
21St Century ◽  
Land Surface ◽  
Natural Vegetation ◽  
Potential Natural Vegetation ◽  
Area Index ◽  
Hanjiang River ◽  
Ipcc Sres

Vegetation and land-surface hydrology are intrinsically linked under long-term climate change. This paper aims to evaluate the dynamics of potential natural vegetation arising from 21st century climate change and its possible impact on the water budget of the Hanjiang River basin in China. Based on predictions of the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC-SRES) A1 scenario from the PRECIS (Providing Regional Climates for Impact Studies) regional climate model, changes in plant functional types (PFTs) and leaf area index (LAI) were simulated via the Lund-Potsdam-Jena dynamic global vegetation model. Subsequently, predicted PFTs and LAIs were employed in the Xinanjiang vegetation-hydrology model for rainfall–runoff simulations. Results reveal that future long-term changes in precipitation, air temperature and atmospheric CO2 concentration would remarkably affect the spatiotemporal distribution of PFTs and LAIs. These climate-driven vegetation changes would further influence regional water balance. With the decrease in forest cover in the 21st century, plant transpiration and evaporative loss of intercepted canopy water will tend to fall while soil evaporation may rise considerably. As a result, total evapotranspiration may increase moderately with a slight increase in annual runoff depth. This indicates that, for long-term hydrological prediction, climate-induced changes in terrestrial vegetation cannot be neglected as the terrestrial biosphere plays an important role in land-surface hydrological responses.

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