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Xin'anjiang Nested Experimental watershed(XAJ-NEW)for Understanding Multiscale water Cycle:Scientific Objectives and Experimental Design

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Engineering 2022年第11期18卷 207-217页

作者： Ke Zhang Yunping Li Zhongbo Yu Tao Yang Junzeng Xu Lijun Chao Jin Ni Liutong Wang Yun Gao Yuzhong Hu Zuoding Lin State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai UniversityNanjing 210098China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210098China College of hydrology and water resources Hohai UniversityNanjing210098China bureau of hydrology(Information Center)of Taihu Basin Authority Shanghai 200434China bureau of hydrology of Anhui province Hefei 230022China Department of hydrology Chinese Ministry of Water ResourcesBeijing 100053China

This paper presents the background,scientific objectives,experimental design,and preliminary achievements of the Xin’anjiang nested experimental watershed(XAJ-NEW),implemented in 2017 in eastern China,which has a subtropical humid monsoon climate and a total area of 2674 *** scientific objectives of the XAJ-NEW include building a comprehensive,multiscale,and nested hydrometeorological monitoring and experimental program,strengthening the observation of the water cycle,discovering the spatiotemporal scaling effects of hydrological processes,and revealing the mechanisms controlling runoff generation and partitioning in a typical humid,hilly *** two years of operation,preliminary results indicated scale-dependent variability in key hydrometeorological processes and variables such as precipitation,runoff,groundwater,and soil *** effects of canopy interception and runoff partitioning between the surface and subsurface were also *** operation of this program can further reveal the mechanisms controlling runoff generation and partitioning,discover the spatiotemporal scaling effects of hydrological processes,and understand the impacts of climate change on hydrological *** findings provide new insights into understanding multi scale hydrological processes and their responses to meteorological forcings,improving model parameterization schemes,and enhancing weather and climate forecast skills.

关键词： water cycle Runoff generation Hydrological processes Hydrological scaling Soil moisture Groundwater Canopy interception

Flood risk control of dams and dykes in middle reach of Huaihe River

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water Science and Engineering 2014年第1期7卷 17-31页

作者： Zhen-kun MA Zi-wu FAN Ming ZHANG Yi-lu SU College of hydrology and water resources Hohai University State Key Laboratory of hydrology-water resources and Hydraulic Engineering Nanjing Hydraulic Research Institute Administration Office of Feilaixia water Conservancy Project of Guangdong province

Three stochastic mathematical models for calculation of the reservoir flood regulation process, river course flood release, and flood risk rate under flood control were established based on the theory of stochastic differential equations and features of flood control systems in the middle reach of the Huaihe River from Xixian to the Bengbu floodgate, comprehensively considering uncertain factors of hydrology, hydraulics, and engineering control. They were used to calculate the flood risk rate with flood regulation of five key reservoirs, including the Meishan, Xianghongdian, Nianyushan, Mozitan, and Foziling reservoirs in the middle reach of the Huaihe River under different flood frequencies, the flood risk rate with river course flood release under design and check floods for the trunk of the Huaihe River in conjunction with relevant flood storage areas, and the flood risk rate with operation of the Linhuaigang Project under design and check floods. The calculated results show that （l） the five reservoirs can withstand design floods, but the Xianghongdian and Foziling reservoirs will suffer overtopping accidents under check floods; （2） considering the service of flood storage areas under the design flood conditions of the Huaihe River, the mean flood risk rate with flood regulation of dykes and dams from Xixian to the Bengbu floodgate is about 0.2, and the trunk of the Huaihe River can generally withstand design floods; and （3） under a check flood with the flood return period of 1 000 years, the risk rate of overtopping accidents of the Linhuaigang Project is not larger than 0.15, indicating that it has a high flood regulation capacity. Through regulation and application of the flood control system of the Linhuigang Project, the Huaihe River Basin can withstand large floods, and the safety of the protected area can be ensured.

关键词： stochastic mathematical model reservoir flood regulation river course flood release risk factor risk rate middle reach of Huaihe River

Climate change characteristics of Amur River

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water Science and Engineering 2013年第2期6卷 131-144页

作者： Lan-lan YU Zi-qiang XIA Jing-ku LI Tao CAI River Basin Authority of Liaoning province State Key Laboratory of hydrology-water resources and Hydraulic Engineering Institute of International Rivers Research Academy Hohai University Hydrological bureau of Liaoning province

Unusually severe weather is occurring more frequently due to global climate change. Heat waves, rainstorms, snowstorms, and droughts are becoming increasingly common all over the world, threatening human lives and property. Both temperature and precipitation are representative variables usually used to directly reflect and forecast the influences of climate change. In this study, daily data （from 1953 to 1995） and monthly data （from 1950 to 2010） of temperature and precipitation in five regions of the Amur River were examined. The significance of changes in temperature and precipitation was tested using the Mann-Kendall test method. The amplitudes were computed using the linear least-squares regression model, and the extreme temperature and precipitation were analyzed using hydrological statistical methods. The results show the following： the mean annual temperature increased significantly from 1950 to 2010 in the five regions, mainly due to the warming in spring and winter; the annual precipitation changed significantly from 1950 to 2010 only in the lower mainstream of the Amur River; the frequency of extremely low temperature events decreased from 1953 to 1995 in the mainstream of the Amur River; the frequency of high temperature events increased from 1953 to 1995 in the mainstream of the Amur River; and the frequency of extreme precipitation events did not change significantly from 1953 to 1995 in the mainstream of the Amur River. This study provides a valuable theoretical basis for settling disputes between China and Russia on sustainable development and utilization of water resources of the Amur River.

关键词： climate change temperature precipitation extreme weather events Mann-Kendall test method," linear least-squares regression model," Amur River

A one-way coupled atmospheric-hydrological modeling system with combination of high-resolution and ensemble precipitation forecasting

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Frontiers of Earth Science 2016年第3期10卷 432-443页

作者： Zhiyong WU Juan WU Guihua LU College of hydrology and water resources Hohai University Nanjing 210098 China bureau of hydrology Information Center of Taihu Basin Authority Shanghai 200434 China

Coupled hydrological and atmospheric model- ing is an effective tool for providing advanced flood forecasting. However, the uncertainties in precipitation forecasts are still considerable. To address uncertainties, a one-way coupled atmospheric-hydrological modeling sys- tem, with a combination of high-resolution and ensemble precipitation forecasting, has been developed. It consists of three high-resolution single models and four sets of ensemble forecasts from the THORPEX Interactive Grande Global Ensemble database. The former provides higher forecasting accuracy, while the latter provides the range of forecasts. The combined precipitation forecasting was then implemented to drive the Chinese National Flood Forecasting System in the 2007 and 2008 Huai River flood hindcast analysis. The encouraging results demonstrated that the system can clearly give a set of forecasting hydrographs for a flood event and has a promising relative stability in discharge peaks and timing for warning purposes. It not only gives a deterministic prediction, but also generates probability forecasts. Even though the signal was not persistent until four days before the peak discharge was observed in the 2007 flood event, the visualization based on threshold exceedance provided clear and concise essential warning information at an early stage. Forecasters could better prepare for the possibility of a flood at an early stage, and then issue an actual warning if the signal strengthened. This process may provide decision support for civil protection authorities. In future studies, different weather forecasts will be assigned various weight coefficients to represent the covariance of predictors and the extremes of distributions.

关键词： one-way coupled hydrological and atmo- spheric modeling flood forecast high-resolution precipita-tion forecasting ensemble prediction

Evaluation of latest TMPA and CMORPH satellite precipitation products over Yellow River Basin

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water Science and Engineering 2016年第2期9卷 87-96页

作者： Shan-hu Jiang Meng Zhou Li-liang Ren Xue-rong Cheng Peng-ju Zhang State Key Laboratory of hydrology-water resources and Hydraulic Engineering Hohai University College of hydrology and water resources Hohai University

The main objective of this study was to evaluate four latest global high-resolution satellite precipitation products(TMPA 3B42 RT, CMORPH,TMPA 3B42V7, and CMORPH_adj) against gauge observations of the Yellow River Basin from March 2000 to December 2012. The assessment was conducted with several commonly used statistical indices at daily and monthly scales. Results indicate that 3B42V7 and CMORPH_adj perform better than the near real-time products(3B42RT and CMORPH), particularly the 3B42V7 product. The adjustment by gauge data significantly reduces the systematic biases in the research products. Regarding the near real-time datasets, 3B42 RT overestimates rainfall over the whole basin, while CMORPH presents a mixed pattern with negative and positive values of relative bias in low- and high-latitude regions,respectively, and CMORPH performs better than 3B42 RT on the whole. According to the spatial distribution of statistical indices, these values are optimized in the southeast and decrease toward the northwest, and the trend is similar for the spatial distribution of the mean annual precipitation during the period from 2000 to 2012. This study also reveals that all the four products can effectively detect rainfall events. This study provides useful information about four mainstream satellite products in the Yellow River Basin, and the findings can facilitate the use of global precipitation measurement(GPM) data in the future.

关键词： Satellite precipitation TMPA CMORPH Yellow River Basin

Inter-annual variation of streamflow,precipitation and evaporation in a small humid watershed(Chengcun Basin,China)

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Chinese Journal of Oceanology and Limnology 2014年第2期32卷 455-468页

作者： Mark AMO-BOATENG 李致家管仪庆 College of hydrology and water resources Hohai University

For sustainable water resource management,it is important to determine the relationship between streamfl ow and other variables that infl uence availability of water ***,many catchments do not have suffi cient data to allow for a more detailed study of these *** faced a similar challenge in the Chengcun Basin(limited historical data: from 1986–1999); and therefore we used a new approach to overcome *** found that,using nonparametric trend methods in conjunction with the climate elasticity analyses and the 2D visualization of hydrologic data,it is possible to assess the relationships between streamfl ow and other hydro-climatic *** the past,streamfl ow trends in the basin were more correlated with precipitation than with potential evapotranspiration(PET).In addition,there is a gradual shift in the hydrological regime of the catchment,which may affect the occurrence of available water resources and activities that depend on *** addition,based on our climate sensitivity analyses,the streamfl ow is dependent and more sensitive to variations in precipitation than to PET(δQ=0.79δP+0.42δE; precipitation elasticity,ε P=1.32; PET elasticity,ε E=-2.10).Therefore pending more detailed studies,the use of our approach will provide a rapid means to assess the variation of water resources(streamfl ow)in a *** the future,we hope to carry out related research in other watersheds and also perform a more detailed studies to improve upon the results of this study.

关键词： trend Mann-Kendall test climate elasticity Sen's slope streamflow 2D visualization hydrologic data

Impact of pond and fence aquaculture on reservoir environment

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water Science and Engineering 2011年第1期4卷 92-100页

作者： Huai-dong ZHOU Cui-ling JIANG Li-qin ZHU Xin-wei WANG Xiao-qin HU Jun-yu CHENG Ming-hua XIE College of hydrology and water resources Hohai University Nanjing 210098 P. R. China Shaoguan hydrology bureau of Guangdong province Shaoguan 512028 P. R. China

With the rapid development of aquaculture in lakes and reservoirs, its negative effects on water quality and aquatic organisms are clearly emerging. Toward a better understanding of these effects, chemical and biological monitoring was conducted in the Fangbian Reservoir to study the relationship between aquaculture and eutrophication. As a domestic water supply source, this reservoir has reached the mesotrophic level. The concentrations of total nitrogen （TN） and total phosphorus （TP） in the Fangbian Reservoir have frequently exceeded the prescriptive level according to the Environmental Quality Standardgfor SurJace water （GB3838-2002）. Pond and fence aquaculture feeding is the main cause of high levels of nitrogen and phosphorus, accounting for nearly half of the total pollution, and causing the reservoir environmental capacity to be exceeded. The amounts of nitrogen and phosphorus that went directly to the reservoir through the residual bait and fish droppings in fence aquaculture were 42 768 kg per year and 10 856 kg per year respectively, from 2007 to 2009. About 2 913 kg of nitrogen and 450 kg of phosphorus were imported to the reservoir through the exchange of water from the culturing ponds at the same time. Therefore, controlling the aquaculture scale and promoting eco-aquaculture are key measures for lessening the eutrophication degree and improving the water quality.

关键词： reservoir environment fence aquaculture pond aquaculture bait eutrophication nitrogen and phosphorus

Vegetation Index Reconstruction and Linkage with Drought for the Source Region of the Yangtze River Based on Tree-ring Data

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Chinese Geographical Science 2021年第4期31卷 684-695页

作者： LI Jinjian WANG Shu QIN Ningsheng LIU Xisheng JIN Liya School of Atmospheric Sciences Plateau Atmosphere and Environment Key Laboratory of Sichuan ProvinceChengdu University of Information TechnologyChengdu 610225China Institute of Plateau Meteorology China Meteorological AdministrationChengdu/Heavy Rain and Drought-Flood Disasters in Plateau and BasinKey Laboratory of Sichuan ProvinceChengdu 610072China hydrology and water resources bureau of qinghai province Xining 810000China

Variations in vegetation are closely related to climate change, but understanding of their characteristics and causes remains limited. As a typical semi-humid and semi-arid cold plateau region, it is important to understand the knowledge of long term Normalized Difference Vegetation Index(NDVI) variations and find the potential causes in the source region of the Yangtze River. Based on four tree-ring width chronologies, the regional mean NDVI for July and August spanning the period 1665–2013 was reconstructed using a regression model, and it explained 43.9% of the total variance during the period 1981–2013. In decadal, the reconstructed NDVI showed eight growth stages(1754–1764, 1766–1783, 1794–1811, 1828–1838, 1843–1855, 1862–1873, 1897–1909, and 1932–1945)and four degradation stages(1679–1698, 1726–1753, 1910–1923, and 1988–2000). And based on wavelet analysis, significant cycles of2–3 yr and 3–8 yr were identified. In additional, there was a significant positive correlation between the NDVI and the Palmer Drought Severity Index(PDSI) during the past 349 yr, and they were mainly in phase. However, according to the results of correlation analysis between different grades of drought/wet and NDVI, there was significant asymmetry in extreme drought years and extreme wet years. In extreme drought years, NDVI was positively correlated with PDSI, and in extreme wet years they were negatively correlated.

关键词： Normalized Difference Vegetation Index(NDVI) reconstruction dendrochronology tree ring Source Region of the Yangtze River

Vadose-zone moisture dynamics under radiation boundary conditions during a drying process

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Journal of Hydrodynamics 2014年第5期26卷 734-744页

作者：韩江波周志芳傅志敏王锦国 School of Earth Sciences and Engineering Hohai University State Key Laboratory of hydrology-water resources and Hydraulic Engineering Nanjing Hydraulic Research Institute College of hydrology and water resources Hohai University

In order to better understand the soil moisture dynamics during a drying process, a soil column experiment is conducted in the laboratory, followed by the numerical modeling with consideration of the coupled liquid water, water vapor and heat transport in the vadose zone. Results show that there are three distinct subzones above the water table according to the temporally dynamic variation of the water content profiles. Zone 1 sees a decrease in the water contents in the upper profiles （0 m-0.05 m） due to a negative net water flux in this zone where the upward isothermal water vapor flux becomes the main flow mechanism in the soils. Irl contrast, the water content within Zone 2 in the depth ranging from 0.05 m to 0.37 m sees an apparent increase over the, resulting from the positive net thermal water-vapor and isothermal liquid-water fluxes into this layer. Zone 3 （0.37 m-0.65 m） also sees an apparent decrease in the water content since the isothermal liquid water flux carries the liquid water either upward out of this region for vaporization or downward to the water table as a recharge to the groundwater.

关键词： moisture dynamics soil water flux vadose zone soil column experiment soil drying