Artificial Intelligence Technique in Hydrological Forecasts Supporting for Water Resources Management of a Large River Basin in Vietnam

Hydrological forecasting plays an important role in water resource management, supporting socio-economic development and managing water-related risks in river basins. There are many flow forecasting techniques that have been developed several centuries ago, ranging from physical models, physics-based models, conceptual models, and data-driven models. Recently, Artificial Intelligence (AI) has become an advanced technique applied as an effective data-driven model in hydrological forecasting. The main advantage of these models is that they give results with compatible accuracy, and require short computation time, thus increasing forecasting time and reducing human and financial effort. This study evaluates the applicability of machine learning and deep learning in Hanoi water level forecasting where it is controlled for flood management and water supply in the Red River Delta, Vietnam. Accordingly, SANN (machine learning algorithm) and LSTM (deep learning algorithm) were tested and compared with a Physics-Based Model (PBM) for the Red River Delta. The results show that SANN and LSTM give high accuracy. The R-squared coefficient is greater than 0.8, the mean squared error (MSE) is less than 20 cm, the correlation coefficient of the forecast hydrology is greater than 0.9 and the level of assurance of the forecast plan ranges from 80% to 90% in both cases. In addition, the calculation time is much reduced compared to the requirement of PBM, which is its limitation in hydrological forecasting for large river basins such as the Red River in Vietnam. Therefore, SANN and LSTM are expected to help increase lead time, thereby supporting water resource management for sustainable development and management of water-related risks in the Red River Delta.

Complementary system-theoretic modelling approach for enhancing hydrological forecasting

Hydrologic models generally represent the most dominant processes since they are mere simplifications of physical reality and thus are subject to many significant uncertainties. As such, a coupling strategy is proposed. To this end, the coupling of the artificial neural network （ANN） with the Xin＇anjiang conceptual model with a view to enhance the quality of its flow forecast is presented. The approach uses the latest observations and residuals in runoff/discharge forecasts from the Xin＇anjiang model. The two complementary models （Xin＇anjiang ＆ ANN） are used in such a way that residuals of the Xin＇anjiang model are forecasted by a neural network model so that flow forecasts can be improved as new observations come in. For the complementary neural network, the input data were presented in a patterned format to conform to the calibration regime of the Xin＇anjiang conceptual model, using differing variants of the neural network scheme. The results show that there is a substantial improvement in the accuracy of the forecasts when the complementary model was operated on top of the Xin＇anjiang conceptual model as compared with the results of the Xin＇anjiang model alone.

TIME SERIES NEURAL NETWORK MODEL FOR HYDROLOGIC FORECASTING

Time series analysis plays an important role in hydrologic forecasting,while the key to this analysis is to establish a proper model.This paper presents a time series neural network model with back propagation procedure for hydrologic forecasting.Free from the disadvantages of previous models,the model can be parallel to operate information flexibly and rapidly.It excels in the ability of nonlinear mapping and can learn and adjust by itself,which gives the model a possibility to describe the complex nonlinear hydrologic process.By using directly a training process based on a set of previous data, the model can forecast the time series of stream flow.Moreover,two practical examples were used to test the performance of the time series neural network model.Results confirm that the model is efficient and feasible.

Flood Forecasting and Warning System: A Survey of Models and Their Applications in West Africa

Flood events occurrences and frequencies in the world are of immense worry for the stability of the economy and life safety. Africa continent is the third continent the most negatively affected by the flood events after Asia and Europe. Eastern Africa is the most hit in Africa. However, Africa continent is at the early stage in term of flood forecasting models development and implementation. Very few hydrological models for flood forecasting are available and implemented in Africa for the flood mitigation. And for the majority of the cases, they need to be improved because of the time evolution. Flash flood in Bamako (Mali) has been putting both human life and the economy in jeopardy. Studying this phenomenon, as to propose applicable solutions for its alleviation in Bamako is a great concern. Therefore, it is of upmost importance to know the existing scientific works related to this situation in Mali and elsewhere. The main aim was to point out the various solutions implemented by various local and international institutions, in order to fight against the flood events. Two types of methods are used for the flood events adaptation: the structural and non-structural methods. The structural methods are essentially based on the implementation of the structures like the dams, dykes, levees, etc. The problem of these methods is that they may reduce the volume of water that will inundate the area but are not efficient for the prediction of the coming floods and cannot alert the population with any lead time in advance. The non-structural methods are the one allowing to perform the prediction with acceptable lead time. They used the hydrological rainfall-runoff models and are the widely methods used for the flood adaptation. This review is more accentuated on the various types non-structural methods and their application in African countries in general and West African countries in particular with their strengths and weaknesses. Hydrologiska Byråns Vattenbalansavdelning (HBV), Hydrologic Engineer Center Hydrologic Model System (HEC-HMS) and Soil and Water Assessment Tool (SWAT) are the hydrological models that are the most widely used in West Africa for the purpose of flood forecasting. The easily way of calibration and the weak number of input data make these models appropriate for the West Africa region where the data are scarce and often with bad quality. These models when implemented and applied, can predict the coming floods, allow the population to adapt and mitigate the flood events and reduce considerably the impacts of floods especially in terms of loss of life.

Application of GIS in Hydrologic Information Forecasting

In recent years, China has attached great importance to the research in the field of hydrology, and hydrological work has also made great progress. Hydrological information forecasting is the focus of hydrological work, and it has close relationship with social development and people’s life. After long-term development. More and more advanced information technology has gradually been applied in hydrological information forecasting, among which GIS has effectively improved the level of hydrological information forecasting.This paper analyzes the application of GIS in hydrological information forecasting to provide an in-depth understanding of this technology.

Real-time flood forecasting of Huai River with flood diversion and retarding areas

A combination of the rainfall-runoff module of the Xin’anjiang model, the Muskingum routing method, the water stage simulating hydrologic method, the diffusion wave nonlinear water stage method, and the real-time error correction method is applied to the real-time flood forecasting and regulation of the Huai River with flood diversion and retarding areas. The Xin’anjiang model is used to forecast the flood discharge hydrograph of the upstream and tributary. The flood routing of the main channel and flood diversion areas is based on the Muskingum method. The water stage of the downstream boundary condition is calculated with the water stage simulating hydrologic method and the water stages of each cross section are calculated from downstream to upstream with the diffusion wave nonlinear water stage method. The input flood discharge hydrograph from the main channel to the flood diversion area is estimated with the fixed split ratio of the main channel discharge. The flood flow inside the flood retarding area is calculated as a reservoir with the water balance method. The faded-memory forgetting factor least square of error series is used as the real-time error correction method for forecasting discharge and water stage. As an example, the combined models were applied to flood forecasting and regulation of the upper reaches of the Huai River above Lutaizi during the 2007 flood season. The forecast achieves a high accuracy and the results show that the combined models provide a scientific way of flood forecasting and regulation for a complex watershed with flood diversion and retarding areas.

A Hybrid Model for the Mid-Long Term Runoff Forecasting by Evolutionary Computation Techniques

The mid-long term hydrology forecasting is one of most challenging problems in hydrological studies. This paper proposes an efficient dynamical system prediction model using evolutionary computation techniques. The new model overcomes some disadvantages of conventional hydrology forecasting ones. The observed data is divided into two parts; the slow 'smooth and steady' data, and the fast 'coarse and fluctuation' data. Under the divide and conquer strategy, the behavior of smooth data is modeled by ordinary differential equations based on evolutionary modeling, and that of the coarse data is modeled using gray correlative forecasting method. Our model is verified on the test data of the mid-long term hydrology forecast in the northeast region of China. The experimental results show that the model is superior to gray system prediction model (GSPM).

FORECASTING OF A NONLINEAR CASCADE FOR WATERSHED RUNOFF

Forecasting of a nonlinear cascade was developed for modeling watershed runoff, and was tested by computing the direct runoff hydrograph for two rainfall- runoff events on a small watershed in China . The forecasting model was superior to Ding s variable unit hydrograph method and the method of limited differences for these two events.

Monthly and seasonal streamflow forecasting of large dryland catchments in Brazil

Streamflow forecasting in drylands is challenging.Data are scarce,catchments are highly humanmodified and streamflow exhibits strong nonlinear responses to rainfall.The goal of this study was to evaluate the monthly and seasonal streamflow forecasting in two large catchments in the Jaguaribe River Basin in the Brazilian semi-arid area.We adopted four different lead times:one month ahead for monthly scale and two,three and four months ahead for seasonal scale.The gaps of the historic streamflow series were filled up by using rainfall-runoff modelling.Then,time series model techniques were applied,i.e.,the locally constant,the locally averaged,the k-nearest-neighbours algorithm(k-NN)and the autoregressive(AR)model.The criterion of reliability of the validation results is that the forecast is more skillful than streamflow climatology.Our approach outperformed the streamflow climatology for all monthly streamflows.On average,the former was 25%better than the latter.The seasonal streamflow forecasting(SSF)was also reliable(on average,20%better than the climatology),failing slightly only for the high flow season of one catchment(6%worse than the climatology).Considering an uncertainty envelope(probabilistic forecasting),which was considerably narrower than the data standard deviation,the streamflow forecasting performance increased by about 50%at both scales.The forecast errors were mainly driven by the streamflow intra-seasonality at monthly scale,while they were by the forecast lead time at seasonal scale.The best-fit and worst-fit time series model were the k-NN approach and the AR model,respectively.The rainfall-runoff modelling outputs played an important role in improving streamflow forecasting for one streamgauge that showed 35%of data gaps.The developed data-driven approach is mathematical and computationally very simple,demands few resources to accomplish its operational implementation and is applicable to other dryland watersheds.Our findings may be part of drought forecasting systems and potentially help allocating water months in advance.Moreover,the developed strategy can serve as a baseline for more complex streamflow forecast systems.

An Operational Hydro-Meteorological Chain to Evaluate the Uncertainty in Runoff Forecasting over the Verbano Basin

The development and implementation of a real-time flood forecasting system with a hydro-meteorological operational alert procedure during the MAP-D-PHASE Project is described in this paper. This chain includes both probabilistic and deterministic forecasts. The hydrological model used to generate the runoff simulations is the rainfall-runoff distributed FEST-WB model, developed at Politecnico di Milano. The observed data to run the control simulations were supplied by ARPA-Piemonte. The analysis is focused on Maggiore Lake basin, an Alpine basin between North-West of Italy and Southern Switzerland. Two hindcasts during the D-PHASE period are discussed in order to evaluate certain effects regarding discharge forecasts due to hydro-meteorological sources of uncertainties. In particular, in the June convective event it is analysed how the effect of meteorological model spatial resolution can influence the discharge forecasts over mountain basins, while in the November stratiform event how the effect of the initial conditions of soil moisture can modify meteorological warnings. The study shows how the introduction of alert codes appears to be useful for decision makers to give them a spread of forecasted QDFs with the probability of event occurrence, but also how alert warnings issued on the basis of forecasted precipitation only are not always reliable.

推动长江经济带高质量发展的水文实践与思考

长江流域经济社会高质量发展离不开水文的强有力支撑。近年来,长江流域水文站网布局与功能日趋完善,水文监测自动化水平不断提高,水文预报能力进一步提升,水文信息处理智慧化水平逐步提高,对水旱灾害防御、水资源配置调度、水生态保护修复等支撑作用更加凸显,水文现代化发展成效较为显著。当前,推动长江经济带高质量发展对水文提出新的更高要求,通过分析研判当前面临的新形势新要求,提出了下一步工作重点。

基于知识图谱的“水文预报”课程教学改革实践

知识图谱以图形化、结构化的方式呈现复杂的学科知识体系,帮助学生更好地理解和掌握知识,提高学习效率和质量。文章主要介绍了水文预报课程知识图谱建设,阐述了知识图谱在水文预报课程中的应用优势,包括构建完整的知识体系、提供个性化的学习支持等,探讨了知识图谱建设在水文预报课程教学实践改革中的成效。实践表明,水文预报课程知识图谱建设是提高课程教学质量的有效途径之一。

基于集合卡尔曼滤波的水文模型状态变量反馈校正方法

集合卡尔曼滤波已应用于水文模型初始状态误差校正。如何选择校正变量、是否同步校正模型参数、如何优选滤波超参数是其应用难点。为此,以綦江流域GR5J模型为原型,同化实测流量反馈校正模型状态,通过合成实验和滚动预报实验,分析状态变量选择、模型参数扰动、滤波超参数对预报精度的影响。结果表明:准确识别有偏初始状态,集合卡尔曼滤波能提高预报精度;若难以识别,建议同步校正产流汇流状态变量,减少过校正。模型参数有偏时,应先识别模型参数,再校正模型状态。增加集合数和预热时长能提高校正精度,模型和观测噪声的影响具有非单调性;滤波校正效果随预见期延长而衰减,但要优于模型预热技术。该发现可作为作业预报应用状态校正法的参考。

多源融合降水和智能网格预报在渭河一次洪水预报中的应用

选取2018年6月28日至7月15日渭河干流魏家堡水文站洪水过程为研究对象,开展多源融合降水和智能网格预报在洪水模拟中的应用试验。结果表明,以多源融合和站点实况降水为输入均能较好地模拟洪水过程,因此在无降水观测资料的流域,采用多源融合降水产品代替站点实况降水进行洪水模拟分析和计算是可行的,但多源融合降水模拟的径流深和洪峰流量较小。在魏家堡水文站两次洪水过程洪峰出现前48 h的面雨量相差不大的情况下,产流量相差显著,说明前期土壤湿度对渭河流域的产流影响很大,防汛时特别要关注持续性降水的影响。以落地雨进行洪水预报的预见期为12 h,以智能网格预报产品作为降水输入,能够提前84 h预报出超保证流量的洪峰流量,将洪水预见期由12 h延长至84 h。但以智能网格降水预报计算的面雨量与实况面雨量相比有一定的高估,造成了模拟的洪峰流量和径流深相对误差较大。建议针对不同的天气背景开展面雨量订正方法研究,以提高面雨量预报准确率,在延长洪水预见期的同时,进一步提高洪水预报精度。

海河“23·7”流域性特大洪水复盘模拟

为支撑海河流域特大洪水的决策及预报预警工作,基于实测降水与流量资料,采用新安江-海河模型对海河流域2023年7月发生特大洪水的大清河2个典型小流域——紫荆关流域和漫水河流域进行了洪水模拟,并选取紫荆关流域1996—2020年5场洪水、漫水河流域1953—2016年8场洪水进行了参数率定,选取海河“23·7”流域性特大洪水进行了验证。结果表明:新安江-海河模型对“23·7”流域性特大洪水的模拟精度较高,可反映实际洪水过程,两个小流域洪峰、洪量模拟的相对误差均在20%以内,峰现时间误差均为0 h;相较于受人类活动影响小的紫荆关流域,在受人类活动影响更大的漫水河流域,新安江-海河模型的模拟效果较新安江模型的模拟效果提升更为明显。

全球气象预报驱动流域水文预报研究进展与展望

全球气象模型及新兴人工智能模型为流域水文预报提供了日、次季节、季节等不同时间尺度的海量气象预报数据。与此同时,基于气象预报开展水文预报,涉及到数据获取、模型构建、评估检验等技术问题。本文以全球气象预报相关的研究计划为切入点,调研现有的1 d至2周小时尺度中短期天气预报、1~60 d次季节尺度气象预报、1~12个月季节尺度气象预报以及新兴的人工智能气象预报;梳理气象预报驱动下流域水文预报模型方法,阐述气象预报订正、水文模型设置和预报评估检验等技术环节。基于全球气象预报生成实时和回顾性流域水文预报,定量检验不同预见期下预报精度以评估相关模型方法的预报性能,为水利工程预报-调度实践应用打下坚实的基础。

河网地区洪水预报模型开发及在长江下游地区的应用

平原水网地区的洪水预报一直是水文学科的难点问题,尤其受人类活动影响剧烈。为了更好地模拟流域水文循环过程,解决工程实际应用中的挑战,提出了一种新颖的分布式架构水文模型。该模型具有分布式特征,能够根据流域特征和需求灵活选择最合适的水文特征单元进行组合,从而支持对不同水文特征单元精确化、理论化的研究。为了实现实时预报功能,还研发了数据库耦合技术、大型河网实时校正技术及水利工程调度技术。在此基础上,应用分布式架构思想建立了太湖流域模型,对其进行了概化处理,并选取2016年实况数据对模型参数进行了率定。通过对太湖水位1 d、2 d、3 d预见期的实时预报,计算成果基本能够反映平原水网地区太湖流域的水流运动实际状况。综合而言,该分布式架构水文模型方法不仅在科学性上得到验证,而且在实现技术上具有可行性,成功地解决了从理念到现实的应用实践问题,为平原水网地区洪水预报提供了新的思路和方法。

考虑融雪及土壤冻融的新安江模型及其应用——以雅砻江上游径流模拟为例

寒区为中国大江大河的主要产流区,其径流预报精度直接影响下游水利工程调度和水资源科学管理。针对传统概念性水文模型较少考虑积雪融雪及土壤冻融过程对径流的叠加影响这一问题,以新安江模型为基础,以降水量和气温为驱动数据,提出了基于“等效土壤温度”和“土壤冻融特征曲线”的概念性土壤冻融模块来刻画积雪融雪及土壤冻融共同影响下的流域产流过程,构建了考虑融雪产流和土壤冻融的新安江模型。以雅砻江甘孜水文站以上流域为典型研究区,开展了流域2017—2022年冰雪消融期逐小时的径流模拟分析。结果表明,相比于HBV模型,考虑融雪产流和土壤冻融的模型可以显著提升流域冰雪消融期的水文模拟精度,各年份消融期径流的纳什效率系数中位数由0.69提升至0.83,相关系数中位数由0.88上升至0.92。本研究所提出的考虑融雪及土壤冻融的新安江模型可以为寒区的水文业务预报提供科学支撑。

五强溪流域相似性研究及参数移植分析

在PUB计划的引领下,流域相似性研究得到了进一步发展。为探究相似流域参数移植的可行性,结合DEM及土地利用等数据,选取多个表征水文特征的相似性指标,通过相对均方根误差法和层次聚类法判别五强溪内10个流域相似关系,将相似的流域参数移植并进行洪水预报。结果表明,陶伊和五强溪近坝区流域坡度分布相对均方根误差值为0.44、地形指数相对均方根误差为0.25,且层次聚类法计算的两个流域距离系数为0.11,水文特征最为相似。将陶伊流域部分参数移植到五强溪近坝区流域,通过新安江模型进行洪水预报,取得了较好的洪水模拟结果。

滨湖城市防洪智能调度与“四预”业务系统开发--以江苏无锡市运东大包围为例

信息化技术的革新为水利行业发展提供了重要的机遇,但受限于历史实测资料不足,人工智能算法在滨湖平原河网地区洪涝预报中的应用存在一定困难。以江苏无锡市运东大包围为研究区域,详细阐述了城市洪涝智能预报调度的实现路径,利用水文水动力模型生成调度预案集,分别采用长短期记忆网络模型与卷积网络模型构建城市河网关注点水位智能预报方法与城市内涝风险阈值快速计算方法;以服务“四预”(预报、预警、预演、预案)业务为导向设计防洪智能预报调度系统,开发系统功能,集成专业模型与智能模型服务于业务场景应用,以实践探索为太湖滨湖城市洪涝预报调度一体化、智能化、业务化提供参考。