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Estimating the annual runoff frequency distribution based on climatic conditions and catchment characteristics:A case study across China

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International Soil and Water Conservation Research 2023年第3期11卷 470-481页

作者： Ziwei Liu Hanbo yang Taihua Wang dawen yang State Key Laboratory of Hydro-Science and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing100084China

Estimation of the annual runoff frequency distribution is an essential basis for water resource *** study proposes a framework for estimating the annual runoff frequency distribution across252 catchments in China based on climatic conditions and catchment characteristics from 1956 to *** Budyko land-specific parameter n,which intergrates influences other than the mean climate conditions,is firstly estimated based on easily ascertainable catchment characteristics without the requirementsof having long-term runoff ***,the annual runoff statistical parameters,namely,the mean value and standard deviation(STD),are derived based on the Budyko rainfall-runoffmodel with the central moment ***,the annual runoff on any recurrence interval is obtainedby the Pearson-Ill frequency *** show that the parameter n can be estimated fromthe catchment average slope,longitude,and climatic seasonality *** estimated statistical parametersof annual runoff have acceptable agreement with observed values(mean value:R^(2)-0.94,STD:R^(2)-0.91,and both relative errors<10%).In addition,estimated annual runoff at each catchment fortypical wet and dry years(25%and 75%ranked percentiles)coincides well with observed values,with R^(2) of 0.92-0.93 and relative erors less than 10%.This result indicates the robustness of this framework forestimating the annual runoff frequency distribution,which provides a simple and effective tool forungauged orpoorlygauged catchments.

关键词： runoff distribution climatic

Accuracy and spatio-temporal variation of high resolution satellite rainfall estimate over the Ganjiang River Basin

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Science China(Technological Sciences) 2013年第4期56卷 853-865页

作者： HU QingFang yang dawen WANG YinTang yang HanBo Department of Hydraulic Engineering Tsinghua University State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research Institute

Based on spatial interpolation rainfall of the ground gauge measurement,we proposed a method to comprehensively evaluate and compare the accuracy of satellite rainfall estimates (SREs) at three spatial scales:0.25°×0.25° grid scale,sub-catchment scale and the whole basin *** this method,we evaluated the accuracy of six high-resolution monthly SREs (TRMM 3B42 V6,3B42RT V6,CMORPH,GSMaP MWR+,GSMaP MVK+ and PERSIANN) and revealed the spatio-temporal variation of the SRE accuracy based on spatial interpolated rainfall from a dense network of 325 gauges during 2003-2009 over the Ganjiang River Basin in the Southeast *** results showed that ground gauge-calibrated 3B42 had the highest accuracy with slight overestimation,whereas the other five uncalibrated SREs had severe *** accuracy of the six SREs in wet seasons was remarkably higher than that in the dry *** the time scale was expanded,the accuracy of SRE,particularly 3B42,***,the accuracy of SREs was relatively low in the western mountains and northern piedmont areas,while it was relatively high in the central and southeastern hills and basins of the Ganjiang River *** the space scale was expanded,the accuracy of the six SREs gradually *** study provided an example for of SRE accuracy validation in other regions,and a direct basis for further study of SRE-based hydrological process.

关键词： satellite rainfall estimate accuracy evaluation spatio-temporal variations TRMM CMORPH GSMaP PERSIANN Ganjiang River Basin

Spatio-temporal variation of net anthropogenic nitrogen inputs in the upper yangtze River basin from 1990 to 2012

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Science China Earth Sciences 2016年第11期59卷 2189-2201页

作者： WANG Ai TANG LiHua yang dawen LEI HuiMin State Key Laboratory of Hydroscience and Engineering Department of Hydraulic Engineering Tsinghua University

The net anthropogenic nitrogen input(NANI) is an important nutrient source that causes eutrophication in water bodies. Understanding the spatio-temporal variation of NANI is important for regional environment assessment and *** paper calculated NANI in the upper yangtze River basin(YRB), upstream of the Three Gorges Dam(TGD), from1990 to 2012, and analyzed its spatio-temporal characteristics. Over the past 23 years of the study, the average annual NANI increased from 3200 kg N km^(-2) to 4931 kg N km^(-2). The major components were fertilizer N application, atmospheric N deposition,and net food and feed N import. In the northwest high mountainous region with a sparse population, the main component was atmospheric N deposition. Fertilizer N application and net food and feed N import were concentrated in the Chengdu Plain because of the high population density and large areas of farmland. This research found that NANI increased with rapid urbanization and increasing population. The Pearson correlation results illustrated that the spatial distributions of NANI and its major components were affected by land cover/use, agricultural GDP and total population. Increasing NANI has been the major cause of the degrading stream water quality over the past 20 years and is becoming a major threat to the water quality of the TGD reservoir.

关键词： Net anthropogenic nitrogen input yangtze River basin Land use Urbanization Water quality

A distributed scheme developed for eco-hydrological modeling in the upper Heihe River

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Science China Earth Sciences 2015年第1期58卷 36-45页

作者： yang dawen GAO Bing JIAO yang LEI Hui Min ZHANG YanLin yang HanBo CONG ZhenTao State Key Laboratory of Hydro-science and Engineering Department of Hydraulic EngineeringTsinghua University School of Water Resources and Environment China University of Geosciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Modeling the hydrological processes at catchment scale requires a flexible distributed scheme to represent the catchment to- pography, river network and vegetation pattern. This study has developed a distributed scheme for eco-hydrological simulation in the upper Heihe River. Based on a 1 km x 1 km grid system, the study catchment is divided into 461 sub-catchments, whose main streams form the streamflow pathway. Furthermore, a 1 km grid is represented by a number of topographically similar ＂hillslope-valley＂ systems, and the hillslope is the basic unit of the eco-hydrological simulation. This model is tested with a simplified hydrological simulation focusing on soil-water dynamics and streamflow routing. Based on a 12-year simulation from 2001 to 2012, it is found that variability in hydrological behavior is closely associated with climatic and landscape condi- tions especially vegetation types. The subsurface and groundwater flows dominate the total river runoff. This implies that the soil freezing and thawing process would significantly influence the runoff generation in the upper Heihe basin. Furthermore, the runoff components and water balance characteristics vary among different vegetation types, showing the importance of coupling the vegetation pattern into catchment hydrological simulation. This paper also discusses the model improvement to be done in future study.

关键词： distributed scheme catchment discretization streamflow pathway hillslope parameterization the upper Heihe River

Variability of complementary relationship and its mechanism on different time scales

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Science China(Technological Sciences) 2009年第4期52卷 1059-1067页

作者： yang HanBo yang dawen LEI ZhiDong SUN FuBao CONG ZhenTao State Key Laboratory of Hydro-Science and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China

In the complementary relationship (CR) between actual and potential evapotranspiration, wet envi- ronment evapotranspiration (Ew) is usually calculated using the Priestley-Taylor (P-T) equation. Based on the data obtained from 38 catchments of the Haihe River basin and the Weishan experiment site in Shandong Province of China, this study has found variations in the Priestley-Taylor parameter α (e.g. increase in values with increase in the amount of precipitation on annual scale, seasonal fluctuation noted to be at a maximum during winter and at a minimum during summer, and increased values in the forenoon and decreased values in the afternoon on an hourly scale). This paper explains that the in- ter-annual variation in α is due to the negative feedback of atmosphere in response to changes in ac- tual increase in evapotranspiration, which is weakened because the atmosphere system is open. The parameter α undergoes a seasonal fluctuation brought about by seasonal changes in advection be- tween continent and ocean; α likewise undergoes a daily variation as a result of atmospheric hysteresis in response to the changes in land surface energy.

关键词： complementary relationship temporal scales wet environment evapotranspiration Priestley-Taylor equation state space

Long-term variability of the carbon balance in a large irrigated area along the lower Yellow River from 1984 to 2006

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Science China Earth Sciences 2013年第4期56卷 671-683页

作者： LEI HuiMin yang dawen CAI JianFeng WANG FengJiao State Key Laboratory of Hydroscience and Engineering Department of Hydraulic Engineering Tsinghua University Management Office of the Weishan Irrigation District Binzhou Bureau of Meteorology

The irrigated areas in the northern region of China are important food production areas. Therefore, studies on the variability of the carbon balance in these agro-ecosystems are fundamental for the management of carbon sequestration. This paper simulated the long-term variability of the carbon balance in a typical irrigated area along the lower Yellow River from 1984 to 2006, using a process-based ecosystem model called the Simple Biosphere Model, version 2. The mean annual gross primary production (GPP), mean annual net assimilation rate (NAR), mean annual soil respiration (Rs ), and mean annual net ecosystem exchange (NEE) were 1733, 1642, 1304, and 338g C m-2 a-1 , respectively. A significant increasing trend in the seasonal total NAR during the wheat growing season, and a significant decreasing trend in the seasonal total NAR during the maize growing season were detected. However, no significant trend was found in the annual NAR, R s , and NEE. The average carbon sequestration was 1.93 Tg C a-1 when the grain harvest was not taken into account, and the carbon sequestration amount during the maize season was higher than that during the wheat season. However, the agro-ecosystem was a weak carbon source with a value of 0.23 Tg C a-1 , when the carbon in the grain was assumed emitted into the atmosphere.

关键词： carbon balance winter wheat summer maize process-based ecosystem model irrigated area

Analysis of catchment evapotranspiration at different scales using bottom-up and top-down approaches

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Frontiers of Structural and Civil Engineering 2010年第1期4卷 65-77页

作者： Xiangyu XU dawen yang State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China

Physically-based hydrological models are used to predict catchment water balance through detailed simulation of hydrological processes at small temporal and spatial ***,annual catchment water balance can also be easily and simply predicted using lumped conceptual *** between physically-based hydrological models and lumped conceptual models can help us understand the dominant factors on catchment water balance at different *** this paper,a distributed physically-based hydrological model(i.e.,bottom-up approach)and a simple water-energy balance model(i.e.,top-down approach)are used to predict actual evapotranspiration in nine sub-catchments,and the whole basin of the Luan River in northern *** simulations give very close values of annual evapotranspiration and show the same complementary relationship between actual and potential evapotranspiration at annual time *** the analysis at different time scales through comparison of the top-down and the bottom-up methods,it is shown that the annual catchment evapotranspiration is controlled mainly by annual precipitation and potential evapotranspiration,and the variability of soil water and vegetation becomes more important at a smaller time scale in the study *** is also known that the relationship between potential and actual evapotranspiration shows a highly nonlinear relationship at the annual and catchment scale but can be simplified to a linear relationship at hourly temporal and hillslope scales,which is commonly used in the physicallybased hydrological models.

关键词： catchment evapotranspiration distributed hydrological model water-energy balance model topdown and bottom-up approaches

Response of water-use efficiency to phenology in the natural forest and grassland of the Loess Plateau in China

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Science China Earth Sciences 2023年第9期66卷 2081-2096页

作者： Xingyan TAN yangwen JIA Cunwen NIU dawen yang Wen LU Chunfeng HAO State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Simulation and Regulation of River Basin Water Cycle(SKL-WAC) China Institute of Water Resources and Hydropower Research(IWHR)Beijing 100038China

Ecosystem water use efficiency(WUE)is an integrated physiological metric for the coupling cycle between terrestrial carbon,water,and *** WUE responds to vegetation phenology(e.g.,SOS,EOS-start,end of growing season,and GSL-growing season length)shifting in temperate semi-arid regions is a hot spot in relative research *** on remotesensing products and in-situ measured climate data,this study discussed how gross primary productivity(GPP),evapotranspiration(ET),and WUE(quantified by GPP/ET)would change with the altering vegetation phenology and climate in the untouched semi-arid forests and grasslands of the Chinese Loess Plateau during 2001–*** results show that vegetation tended to green-up earlier and brown-down later from 2001 to 2020,causing an extended *** forests had an earlier SOS,later EOS,and longer GSL than the grasslands,but the latter had a bigger variation *** WUE in the study area decreased significantly during spring and summer,while the grassland WUE increased in autumn;the annual mean reduction rate in grassland WUE was approximately twice that of *** SOS could increase forest WUE but reduce grassland WUE in spring,mainly because leaf unfolding has a more pronounced limitation on soil evaporation beneath the forest *** had less impact on WUE,and no apparent difference existed between these two *** change could affect WUE directly by changing GPP and ET and indirectly by regulating vegetation *** can increase GPP and ET,causing an earlier SOS,further promoting GPP and ET(except forest ET).Precipitation significantly affected forest GPP and ET in spring,grassland GPP and ET in summer,and grassland ET in autumn;precipitation affects spring grassland WUE mainly via regulating *** solar radiation could suppress grassland GPP in spring,promote forest ET in autumn,and regulate grassland WUE by affecting *** study is meaningful for improving the process-ba

关键词： Water use efficiency Vegetation phenology Climate change Remote sensing The Loess Plateau

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Hydrological cycle and water resources in a changing world:A review

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Geography and Sustainability 2021年第2期2卷 115-122页

作者： dawen yang Yuting yang Jun Xia State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Hubei Provincial Key Lab of Water System Science for Sponge City Construction Wuhan UniversityWuhan 430072China

Water is the fundamental natural resource that supports life,ecosystems and human *** studying the water cycle is important for sustainable *** the context of global climate change,a better under-standing of the water cycle is *** study summarises current research and highlights future directions of water science from four perspectives:(i)the water cycle;(ii)hydrologic processes;(iii)coupled natural-social water systems;and(iv)integrated watershed *** should be placed on understanding the joint impacts of climate change and human activities on hydrological processes and water resources across temporal and spatial *** the interactions between land and atmosphere are keys to addressing this *** systematic approaches should be developed for large basin *** for focused research include:variations of cryosphere hydrological processes in upper alpine zones;and human activities on the wa-ter cycle and relevant biogeochemical processes in middle-lower *** the water cycle is naturally coupled with social characteristics across multiple scales,multi-process and multi-scale models are ***-drological studies should use this new paradigm as part of water-food-energy frontier *** will help to promote interdisciplinary study across natural and social sciences in accordance with the United Nation’s sustainable development goals.

关键词： scales cycle watershed