China Water Resources

Attenuation mechanisms and attribution analysis of estuarine geomorphic response to floods under human modification

Extreme floods are critical natural drivers of estuarine geomorphic evolution. However, how longterm human modifications quantitatively regulate this process remains poorly understood. Although the 2020 flood in the Yangtze Estuary exhibited peak discharge and water levels comparable to the 1998 event, the resulting geomorphic adjustment was significantly reduced. High-resolution bathymetric surveys indicate a 39.5% reduction in deep-channel scouring and a 37% decline in shoal deposition during the 2020 flood. Attribution analysis, integrating hydrological data, long-term tidal records, and numerical modeling, reveals that this dampened response stems not only from shortened flood duration, reduced cumulative flood volume, and weakened tidal dynamics(associated with the 18.6-year nodal cycle), but more critically from reduced sediment supply driven by upstream reservoir operations and over two decades of estuarine engineering. While reduced sediment supply has shifted the estuary's baseline state from net accretion to erosion, estuarine engineering has stabilized the river regime by confining flows to the main channel and inhibiting overbank flow. This promotes a “shoal accretion and channel scouring” pattern, thus optimizing the river regime, stabilizing the shoal-channel configuration, and significantly reducing geomorphic changes during extreme floods. This study clarified how human activities altered the morphodynamic mechanisms of the Yangtze Estuary, significantly weakening the bed adjustment induced by extreme floods. These findings provide a general framework for attributing flood impacts in estuaries worldwide and offer a scientific basis for engineering strategies to enhance resilience to hydrological extremes.

Ecological water demand pattern and regulation strategy under national water network in Yellow River's “Ji-shaped” bend region

The Yellow River's “Ji-shaped” bend region, rich in energy resources and home to diverse ethnic groups, faces ecological vulnerability and frequent natural disasters. As a central area in the Yellow River basin, its ecological and socio-economic development is severely constrained by water scarcity. This study collected the historical meteorological data, leaf area index, soil composition, and soil moisture data from 1982 to 2019, as well as future climate projections under different carbon emission scenarios, using a comprehensive calculation method that considers potential evapotranspiration, vegetation coefficient, and soil moisture coefficient to assess the spatiotemporal variation of ecological water demand in the region. The results show that ecological water demand exhibits an increasing trend over 97.16% of the area in the Yellow River's “Jishaped” bend region. Under medium and high carbon emission scenarios, future ecological water demand will increase further. Vegetation type significantly influences the spatial distribution of ecological water demand, with areas such as southern forests exhibiting higher leaf area indices and greater water requirements. In the context of constructing the national water network, graded planning of water supply and demand should be implemented to improve the operational efficiency of the water network. Coordinated regulation of ecological protection and water resources should be carried out to enhance the resilience and recovery capacity of ecosystems. Additionally, the promotion of water-saving technologies and green development will improve water use efficiency. It is also necessary to combine large-scale terraced fields, Yudiba dams, cellars, and water resources management in the local area to construct a “water, energy, food, and ecosystem” integrated development model and improve the efficiency of water and soil resource utilization, while strengthening drought tolerance in vegetation and ecological restoration to reduce ecological water consumption.

Flood retrospective simulation and risk analysis of “7·20” extreme rainstorm flood in Zhengzhou City

After the “7·20” extreme rainstorm flood in Zhengzhou City in 2021, a series of engineering and nonengineering measures were implemented in Zhengzhou City, and the flood control capacity was systematically improved. In order to test the actual effect of the current working conditions to deal with extreme rainstorm floods, this study was based on the hourly rainfall, topography, and current working conditions data of rainstorm, relying on the “five pre”(forecasting, pre-assessment, early-warning, rehearsal and contingency planning) system of flood control in Zhengzhou City, using the coupling technology of three-source Xin'anjiang model, water engineering dispatching model, and one-dimensional river hydrodynamic model to carry out flood retrospective simulation and risk analysis. The whole process was integrated into the pre-judgment function to realize the advanced research and judgment of flood risk and the optimization of engineering joint dispatching. The applicability of the model method and the reliability of the simulation results were verified by comparing with the actual situation of the “7·20” disaster. The results show that the operation of 15 reservoirs under the current operating conditions can give full play to the role of flood storage and regulation. The highest water level adjusted according to the “7·20” actual water level does not exceed the design water level, and the highest water level adjusted according to the current flood limit water level does not exceed the check water level. The river channel in the main urban area has been significantly improved through comprehensive management and drainage capacity. The Jialu River(from Science Avenue to Beijing-Hong Kong-Macao Expressway section) and the whole section of the Jinshui River have reached the flood control standard of 100-year return period, and only the local sections of the Chaohe River and Qilihe River have overflow danger. The risk of flood overflowing into the channel of the two cross-buildings of the middle line of the South-to-North Water Diversion Project in Jiayu River and Jialu River is greatly reduced, which can effectively guarantee the water conveyance safety of the middle line of the South-to-North Water Diversion Project. The research results can provide technical support for extreme precipitation defense, unconventional rainstorm flood forecasting and early warning, and flood control system optimization and improvement in Zhengzhou City.

Research and application on a flood control scheduling model integrating physical constraints with deep learning

In response to the highly nonlinear and sudden characteristics of flood processes of the section from the Xiaolangdi Reservoir to the Huayuankou Hydrological Stationin the middle reaches of the Yellow River, as well as the computational complexity and lack of timeliness associated with traditional optimization scheduling models, this paper proposed a flood control scheduling model(CNN-BiLSTM-SA) that integrated physical constraints with deep learning. The model employed a one-dimensional convolutional neural network(1D-CNN) to extract local correlation features from hydrological time series, utilized a bidirectional long shortterm memory(BiLSTM) network to model global temporal dependencies, and incorporated a self-attention mechanism(SA) to dynamically capture flood lag characteristics. To enhance the model's physical consistency, the principle of water balance was formulated as a physical constraint and incorporated into the loss function. Application results indicate that the model's simulation accuracy on the test set outperforms the baseline model: the Nash-Sutcliffe Efficiency(NSE) for outflow from Xiaolangdi Reservoir and flow at Huayuankou Station reaches 0.9171 and 0.9691, respectively, while the root mean square error(RMSE), mean absolute error(MAE), and mean absolute percentage error(MAPE) are all significantly reduced. It demonstrates the superiority of the hybrid network architecture in handling complex scheduling logic. This study leverages the bidirectional information propagation mechanism of BiLSTM and the dynamic weighting modeling of the self-attention mechanism to more accurately characterize the nonlinearity, long-term delay, and hysteresis of flood wave propagation on long-distance river channels. The proposed approach provides a modeling method for flood control scheduling simulation in basins that balances computational efficiency with physical consistency.

A deep learning flood forecasting model based on dual-source water balance constraints

Global climate change, coupled with anthropogenic impacts, has led to frequent flood disasters, making high-accuracy and long-lead-time hydrological forecasting a critical support for enhancing disaster prevention and mitigation capabilities and ensuring water resource security. Existing artificial intelligencebased flood forecasting methods predominantly rely on extrapolation from single historical discharge series, failing to adequately consider the dynamic interaction mechanism of dual water sources from local precipitation and upstream inflow, as well as the water balance constraint. Consequently, these models exhibit weak representation of the physical mechanisms governing runoff generation and confluence, resulting in limited prediction accuracy during flash flood events. This paper proposed HydroFormer-TS, a deep learning flood forecasting model based on dual-source water balance constraints. By designing a network architecture that integrates dual-source information and embeds physics-guided features, the model was forced to satisfy the water balance principle, thereby enhancing the physical plausibility and interpretability of the simulation process. This approach advanced the modeling paradigm from purely “data-driven” to “data-physics fusiondriven”. By taking the Beijiang River basin, a typical humid watershed in southern China, as the study area, multiple typical flood events and sudden extreme floods were selected for validation. The model demonstrates outstanding performance across all lead times, achieving a maximum Nash Sutcliffe efficiency coefficient of 0.94. It shows an improvement of 85.4% over the LSTM model and 38.2% over the iTransformer at the 72-hour lead time, while reducing the mean absolute percentage error to 23.05% for sudden flood events. This work provides a novel modeling perspective and technical pathway for high-precision hydrological forecasting.

Pilot studies and reflections on deep groundwater recharge and restoration in North China

Overdraft of confined deep groundwater remains a serious issue in North China, where natural recovery is difficult due to limited recharge and slow renewal of deep aquifers. This has led to the long-term existence of groundwater depression cones, further triggering a series of ecological damages and geological hazards such as ground subsidence and seawater intrusion, exerting ongoing impacts on regional production, livelihoods, and ecological security. To address the groundwater depletion caused by long-term overdraft, a coordinated “point-line-area” approach and a comprehensive governance and restoration model integrating “suppression, recharge, and reinjection” have been proposed. This paper introduces the conditions and progress of recharge experiments conducted at four established pilot sites, and summarizes the findings and outcomes of a series of thematic studies carried out in conjunction with these recharge trials. Existing challenges of the pilot projects are identified, including short experimental durations,insufficient research, unoptimized water sources, and the need for improved test site conditions. In response, several targeted recommendations are proposed: extending the duration and depth of experimental studies, optimizing recharge areas and water sources, advancing research on anti-blocking and permeability-enhancement technologies,strengthening scientific and technical support, evaluating recharge effectiveness, improving research platform infrastructure, and increasing dedicated financial support, aiming to provide experiences for systematic recharge and restoration of deep groundwater and ensure sustainable utilization of groundwater resources.

Safety of river courses of middle and lower mainstreams of the Yangtze River and measure study

Safety of the middle and lower reaches of the Yangtze River relates directly to flood control, water supply, navigation and ecology of the basin. After years of practices, great achievements have been made in improving river regime, flood control safety, ecology and navigation. Key issues were examined including failure to ciontrol high flood peak due to insufficient storage and discharge capacity, unstable conditions of local rivers and mainstreams caused by erosion and sedimentation, water level drops during dry seasons, and degradation of water environment that fail to meet the water quality requirements specified for water function zones. New situations in the new stage and under new water-sediment condition are examined. First, highquality development of the Yangtze River Economic Belt makes new and higher requirements for the safety of the river. Second, erosion and sedimentation of the middle and lower reaches and the relationship between river and lake have undergone changes and will continue to be adjusted in the long term in the future. Further analysis was conducted on the characteristics of water and sediment change since the operation of the Three Gorges Dam and the evolution pattern and impact of different river type. Future trend of water and sediment and changes of river lake relationship were analyzed. In response to the existing problems, fully considering the trend of strategic adjustments in the new period, and focusing on the multi-objective synergy needs, a series of main measures have been implemented to ensure river safety, including formulating relevant laws and plans, upgrading river and canal regulation and dredging projects, improving the river lake administration and supervision system, strengthening the coordinated operation of reservoir groups, and promoting the construction of digital twin Yangtze River.

Speech at the Symposium on Ecological Protection and High-quality Development of the Yellow River Basin

Water Rights and Water Markets: Discussing Economic Means for Achieving Optimal Allocation of Water Resources

This article serves as a speech outline prepared for the 2000 annual conference of the China Institute of Water Resources. On March 30, 1999, during the Seventh National Congress of the China Institute of Water Resources, I presented the viewpoint of "transitioning from engineering water resources to resource-based water resources." That speech cannot be considered a purely academic theoretical article; rather, it was a set of requirements for water resources work based on the practical development of water resources. It aimed to initiate a major discussion on "how China's water resources should face the 21st century" and fulfilled my responsibilities as a leader. Similarly, "Water Rights and Water Markets", although discussing issues of water economics, does not make me an expert in this field. Instead, the urgent demand for the reform and development of water resources in China requires us to research and address such topics. I have merely laid the groundwork to draw attention to this issue.

The Outline of the 14th Five-Year Plan(2021—2025) for National Economic and Social Development and the Long-Range Objectives Through the Year 2035 of P. R. China

Analysis of Water Supply and Demand in 21st Century China: Ecological Water Conservancy Research

Facing the resource and environmental challenges in 21st-century China, the issue of water is particularly severe. Scarcity and wastage coexist; abundance and ecological imbalance coexist; contamination and poor management coexist. In fact, there are interconnected and transformative relationships among water resources, water disasters, and water environments. Water, as a core element of ecology and the environment, has positive effects when utilized efficiently as a water resource. However, fluctuations in its abundance and scarcity can lead to water-related disasters, while its quality evolution is closely related to water management and environmental protection efforts...

River health connotation

River health, as one of the river assessment tools, rather than a strictly scientific concept performs a well function in setting up relative bench mark and evaluable criterion, Based on it , river ecosystem states , which varies under double actions of nature force and human activity, could be dynamically monitored and evaluated in order to predict its revolution trend through research and prompt its well development through management. The river health assessment should exhibit the balance between development and protection, the benefit coordinating among correlatively interested individuals and groups. Since water pollution becomes the severest threat to river health in our country, so at present stage of our ecologic environmental construction , its control and treatment should be put in the first place.

A preliminary discussion of the engineering ethics and advanced cultural in Dujiang Weir

The Chinese people has thousands years of history for water governance.The practices of water governance,utilization and management of successive dynasties have left us with rich material,institutional and spiritual wealth.In order to explore the multiple values of this world cultural heritage,discussions are made on the contribution of those outstanding water projects represented by Dujiang Weir,so that Chinese wisdom and China's plan can be developed to address issues of imbalance between water supply and demand and other water crisis.Eco-friendly water project construction in the new age should be led by advanced water culture,with learning from good practices of Dujiang Weir from conservation and cultural prospective,so as to build a society with harmony of man and water and water structures in a modernized and eco-friendly ways.

Human activity and the global climate change and its impact on water resources

In understanding the effect of human activity on the global climate change for recent 100 years, IPCC (Intergovernmental Panel on Climate Change) has played a key role. During 17 years from 1990, IPCC has continuously gained insight into better understanding on the global climate change during the recent 100 years mainly caused by human activity, with its four assessment reports. This achievement has been made with provision of three aspects of evidences: (1) rapid increase in greenhouse gases since preindustrial era (after 1750); (2) temperature rise or warning of surface, tropospospere and oceans; (3) 100-yr climate simulations since 1900 for detection and attribution of the past climate change. These results have shown that recent 100-yr warming is jointly caused by natural climate fluctuation and anthropogenic activity, but most of recent 50-yr climate change is caused by the authropogenic activity. The present paper has first reviewed this issue. Then, the debates and uncenrtainties of global climate change issue have been discussed. The global climate change has had a significant impact on global water resources and management. This issue is further discussed based on changes in temperature, precipitation, sea level rise and evapotranspiration, which may be a necessary scientific basis for adaptation.

Discussions on key issues of water ecological civilization construction

How to understand water ecological civilization construction? On the basis of the interpretation of the spirit of the 18th National Congress of the Communist Party of China,this paper analyses and discusses several key issues of water ecological civilization as follows.First,the definition and connotation of water ecological civilization are given and the links between water ecological civilization construction and ecological civilization construction proposed by the state are elaborated.In addition,this paper analyses the crucial issues which should be paid attention to during the process of advancing water ecological civilization,and proposes specific recommendations to help to make the 5 goals of water ecological civilization come to be realized.

Speech at the Symposium on Ecological Protection and High-quality Development of the Yellow River Basin

The Outline of the 14th Five-Year Plan(2021—2025) for National Economic and Social Development and the Long-Range Objectives Through the Year 2035 of P. R. China