Yongqiang Zhang

Institute of Geographic Sciences and Natural Resources Research, CAS · Key Laboratory of Water Cycle and Related Processes

The Penman-Monteith-Leuning version 2 (PML-V2) evapotranspiration (ET) model, an advanced iteration of the classic Penman-Monteith (PM) model, is available globally via Google Earth Engine with a spatio-temporal resolution of 500 m and 8 days. PML-V2 improves canopy conductance estimation and incorporates carbon dioxide effects on transpiration via...

This study examined the factors that influence the groundwater quality (GWQ) of the Miandoab aquifer, located in the northwest of Iran. The study investigated the impact of climate change, anthropogenic activities, teleconnection, total water storage (TWS), and the area and level of the Urmia Lake on GWQ. To identify the relationship between TWS fl...

Prediction of surface freshwater flux (precipitation or evaporation) in a CO2‐enriched climate is highly uncertain, primarily depending on the hydrological responses to physiological and radiative forcings of CO2 increase. Using the 1pctCO2 (a 1% per year CO2 increase scenario) experiments of 12 CMIP6 models, we first decouple and quantify the magn...

Global surface soil moisture (SSM) mapping at a 9-km intermediate resolution from microwave remote sensing could play a pivotal role in advancing detailed global hydrological investigations. Despite the wide recognition of the Soil Moisture Active Passive (SMAP) mission’s 9-km SSM products based on oversampling of the L-band radiometry, concerns pe...

Global streamflow, crucial for ecology, agriculture, and human activities, can be influenced by elevated atmospheric CO2 (eCO2) though direct regulation of vegetation physiology and structure, which can either decrease or increase streamflow. Despite a 21.8% rise in CO2 over 40 years, its impact on streamflow is not obvious and remains highly debat...

In the North China Plain (NCP), the assessment of water surplus or deficit (WSD), which is calculated as precipitation minus reference evapotranspiration (ET0), holds significant implications for water resource management and agricultural irrigation decision‐making, given the region's long‐standing severe shortage of water resources. However, the m...

Evaporation rates and land surface temperatures can be modified by planned water availability as well as land use and land cover changes. In general, a higher evaporation rate via its associated latent heat flux yields a cooler surface. Here we demonstrate that increasing energy at the land surface necessitates more intense latent heat fluxes for t...

Study area: The headwater catchment of the Yellow River (HCYR) (95 • 90′-103 • 42′E, 32 • 16′-36 • 13′N) is located on the northeast of the Tibetan Plateau, a presentative high-cold region catchment, China. Study focus: HCYR serves as the primary water supply during the dry season in downstream of the Yellow River Basin. Herein, we applied linear r...

Accurate prediction of global sea surface temperature at sub-seasonal to seasonal (S2S) timescale is critical for drought and flood forecasting, as well as for improving disaster preparedness in human society. Government departments or academic studies normally use physics-based numerical models to predict S2S sea surface temperature and correspond...

This study aimed to assess the coherence between groundwater levels and various factors during two distinct periods, 2002-2020 and 2025-2050, in Miandoab aquifer in northwestern of the Iran. Partial wavelet coherence and multi-wavelet coherence analyses were employed to assess the coherence between individual parameters and their simultaneous coher...

Groundwater level declines are largely associated with natural processes and human activities. In particular, the drivers of groundwater change can be more complex during meteorological drought owing to human activities. However, disentangling their specific contribution remains poorly understood. By focusing on semiarid ecosystems in the northern...

Phenology is a critical mirror reflecting vegetation growth and has a major impact on terrestrial ecosystems. The Loess Plateau (LP) is a paramount ecological zone in China that has experienced considerable vegetation changes. However, understanding the dynamics of vegetation phenology is limited by ambiguous vegetation interpretation and anthropog...

Predicting flood event classes aids in the comprehensive investigation of flood behavior dynamics and supports flood early warning and emergency plan development. Existing studies have mainly focused on historical flood event classification and the prediction of flood hydrographs or certain metrics (e.g., magnitude and timing) but have not focused...

The adverse impacts of Australia’s Millennium Drought on both surface and groundwater hydrological systems are extensively documented. During the Millennium Drought, the Murray Basin experienced a severe rainfall deficit. Our study revisited groundwater table trends in 451 wells within the Murray Basin during the drought from 1997 to 2009. These tr...

Surface soil moisture estimates (SSM) from microwave sensors onboard the polar-orbit satellites are important data sources for investigating hydrological signatures of the global terrestrial area. However, daily SSM products from any single satellite platform have significant inter-swath gaps and thus incomplete spatial coverage in low latitudes. T...

Classification is beneficial for understanding flood variabilities and their formation mechanisms from massive flood event samples for both flood scientific research and management purposes. Our study investigates spatial and temporal variabilities of 1446 unregulated flood events in 68 headstream catchments in China at class scale using hierarchic...

A reliable understanding of linkages between meteorological, hydrological and agricultural droughts (MD, HD, and AD respectively) is crucial to building resilience and planning for future climate changes. Despite Australia being prone to severe droughts, lagtimes of propagation (and recovery), from meteorological to hydrological and agricultural dr...

Meteorological drought, especially when influenced by human activities, significantly impacts agriculture. We assessed the Yangtze River Basin (YRB)’s crop ecosystem resilience during the 2022 southern China drought. Using the elasticity framework, we quantified crop Leaf Area Index (LAI) changes with meteorological factors and human activities (ir...

Soil moisture (SM) is a critical parameter influencing hydrological cycles, evaporation, and plant transpiration, connecting land surface and atmospheric interactions. However, traditional SM inversion methods mainly offer daily resolution data, potentially overlooking diurnal fluctuations due to factors such as precipitation and human activities....

As extreme climate events become more common with global warming, groundwater is increasingly vital for combating long-term drought and ensuring socio-economic and ecological stability. Currently, the mechanism of meteorological drought propagation to groundwater drought is still not fully understood. This study focuses on the North China Plain (NC...

Direct streamflow outputs from CMIP6 models are important for studying future water supply under climate change. However, the hydrological community generally ignores such data as its ability to predict streamflow change is largely unquantified and presumably considered biased. Here, we examined the ability of the 15 CMIP6 models to directly reprod...

Subsurface water storage is a key component in the water cycle, and China is facing severe issues with water resource shortage. This study estimates the terrestrial water storage (TWS) changes from 2003 to 2017 using a water balance approach over seven large basins in China. The estimated inter‐annual variations and trends in TWS correspond well wi...

Since the variables involved in changing evaporation rate interact with each other, the result of first-order Sensitivity Analysis (SA1) is imperfect to reveal the dynamics of this phenomenon. The main goal of this study was to reveal coupling patterns of climatic agents in forming evaporation. The Partial Deviations (PaD) method, based on Back-Pro...

Global land water underpins livelihoods, socioeconomic development, and ecosystems. It remains unclear how water availability has changed in recent decades. Using an ensemble of observations, we quantified global land water availability over the past two decades. We show that the Southern Hemisphere has dominated the declining trend in global water...

Baseflow is pivotal in maintaining catchment ecological health and improving sustainable economic development. The Yellow River Basin (YRB) is northern China's most important water supplier. However, it faces water shortage due to synergistic effects between natural conditions and anthropogenic activities. Investigating baseflow characteristics qua...

A reliable understanding of linkages between meteorological, hydrological and agricultural droughts (MD, HD and AD respectively) is crucial to building resilience and planning for future climate changes. Despite Australia being prone to severe droughts, lagtimes of propagation (and recovery) from meteorological to hydrological and agricultural drou...

Satellite passive microwave (PMW) observations are important data sources for obtaining land surface temperature (LST) especially for cloudy conditions. Considering the generally poorer spatial representativeness of PMW observations, fusion of PMW-based and thermal infrared-(TIR-) based observations have been considered as an important approach to...

Root zone soil moisture (RZSM) is a critical parameter for drought monitoring, agriculture, and vegetation growth. In situ measurements of RZSM are scarce, and therefore, RZSM products are derived mainly through modeling approaches. This study evaluated seven RZSM products, including ERA5, MERRA2, CFSR, SMAP level 4, GLDAS-NOAH2.1, GLDAS-Catchment2...

Plain Language Summary Water is essential to agricultural production. Increasing water consumption in water supply limited areas may result in a water crisis and threaten sustainable food security, especially in China, the most populated agricultural country in the world. There are continuous arguments regarding the matches between agricultural wat...

本文选取黄土高原为研究区，基于GEE（Google Earth Engine）平台，应用PML_V2（2002―2017 年）和NDVI（1990―2020 年）数据集，利用线性回归、Mann-Kendall 非参数检验，对黄土高原长时间尺度植被变化影响下的蒸散发分量变化过程进行定量分析。结果表明：① 1990―2020 年黄土高原植被呈显著增加趋势（P<0.05），植被变 化总体以基本不变（31.2%）和轻微改善（59.4%）趋势为主，空间上由东南向西北逐渐减小；② 2002―2017 年黄土高原地区植被蒸腾、冠层截留蒸发呈显著上升趋势）（P<0.05），土壤蒸发呈不显著下降趋势（P>0.05）；③ NDVI 的增加导致了土壤蒸发的降低（P<0.05），增加了植被蒸腾和冠层截留蒸发（P<0...

Over the last two decades, the significant vegetation increase caused by the execution of several ecological restoration programs has modified the integrated carbon and water cycles. However, the underlying mechanisms of ecosystem water-use efficiency (EWUE) change remain unclear. The current study estimates the annual and seasonal variations in th...

Extreme riverine floods and hydrodynamic response of downstream lakes are the main focus of catchment flood control, especially under climate change. In this study, future changes in the extreme floods and their hydrodynamic responses are projected by driving the external coupling of the hydrological and hydrodynamic models using the precipitation...

Recent forest fires potentially intensify flood hazards. However, forest fire amplification of floods is not well understood at a large scale due to the complex compound impacts of forest fires and climate variability, while available small‐scale cases may not represent regional changes. Here, we show that the 2019–2020 mega forest fires in southea...

[目的]探究气候因素驱动下沂河流域暴雨径流的变化规律，阐释流域暴雨径流的影响因素，为深入理解流域水文响应过程和水资源管理提供科学参考。[方法]利用改进后的Lyne-Hollick数字滤波法估算了沂河流域的暴雨径流量，通过水文信号方法与皮尔逊相关系数法，定量分析沂河流域暴雨径流的变化特征及影响因素。[结果](1) 1975—2000年，流域年均暴雨径流指数SFI呈缓慢下降趋势(R2=0.37,p<0.01),年际SFI下降率0.048/10 a,暴雨径流占河川径流比重下降；(2)年均暴雨径流量呈波动增加趋势(R2=0.04,p=0.35),于1998年达到研究时段峰值；(3)暴雨径流量年内季节分配差异显著，年内暴雨径流量峰值出现在7—9月，夏季暴雨径流Q(s(sf))与冬季暴雨径流Q(w(sf...

Heatwaves have increased significantly in recent decades, seriously affecting the biosphere. The vegetation canopy is altered by heatwaves through high temperatures and water deficit, adversely affecting the ecosystem's health. However, how the canopy resilience of different ecosystems responding to heatwaves behaves remains less understood. Canopy...

Estimation of evapotranspiration (ET) and yield over cropland is essential for water resources management and food security. Particularly the estimation at long-term and regional scales still needs to be investigated. In this study, a remotely sensed and water-carbon coupled model was combined with a process-based crop growth simulation method to s...

Coupling patterns of climatic variables in the formation of evaporation from open water bodies still are not clear due to the uncertainty involved in the process. The main goal of this study was the detection of such patterns via second-order sensitivity analysis. The Partial Deviations method, based on the Artificial Neural Network, was utilized t...

Climate change and increasing water use associated with socio-economic growth have exacerbated the water crisis in many parts of the world. Many regional studies rely on Earth System Models that, however, do not fully exploit streamflow observations. Here we offer an observation-based approach to predicting streamflow change on the basis of the ela...

以滦河山区流域为研究对象，运用趋势检验、经验正交、Budyko敏感性系数等方法，对流域气象和水文要素及土地利用数据进行分析，探讨了变化环境下滦河山区流域水文响应过程。结果表明：（1）1961-2018年滦河山区流域降水呈不显著下降趋势（-3.4mm/10a），潜在蒸散发呈显著下降趋势（-7.5mm/10a），且二者空间变化方向具有一致性；径流呈显著下降趋势（-4.1亿立方米/10a），并呈现出干湿交替的周期变化特征；（2）在人类活动影响下，整个变化期（1980-2018年）径流量减少11.8亿立方米；（3）归因分析表明，气候在径流变化的贡献中占比27.2%，人类活动的贡献度达69.6%，是引起滦河山区径流量减少的主要因素。 Trend Test, Empirical orthogonal...

Projections of future climate change for given CO2 and other greenhouse gas emission scenarios depend on the response of global climate-carbon cycle feedback, which consists of carbon-concentration feedback (e.g., CO2 physiology effect on land carbon sink) and carbon-climate feedback (e.g., CO2 radiative effect on land carbon sink). Previous studie...

Understanding the runoff response to climate change in the Tibetan Plateau (TP) is critical to water resources management since TP is the “Water Tower of Asia” and is sensitive to climate change. However, previous studies have paid more attention to the changes in annual and monthly runoff. Therefore, the changes in the characteristics of floods an...

Accurate high-resolution actual evapotranspiration (ET) and gross primary production (GPP) information is essential for understanding the large-scale water and carbon dynamics. However, substantial uncertainties exist in the current ET and GPP datasets in China because of insufficient local ground measurements used for model constraint. This study...

Vegetation greening profoundly impacts the water cycle, and recent concerns about greening impacts have focused on various hydrological cycle components. However, the impacts of greening on catchment runoff signatures reflecting magnitude, low/high flow frequency, low/high flow duration and flow dynamics remain poorly understood. To properly simula...

Understanding and exploring hydrological (H) or soil moisture (SM) drought due to meteorological (M) drought under changing climate is crucial for drought early warning. Previously, different methods were used to calculate drought propagation from one state (M to another [H or SM]). However, each method has its pros and cons and thus cannot describ...