GR4J模型在赣江流域日径流模拟中的应用

GR4J是一个简单实用的概念性水文模型,在模型原理和结构上具有鲜明特色,目前在国内应用还较少.本文将该模型应用于赣江流域19个集水区域2003 ～2009年日径流模拟中.结果显示,在各集水区域,GR4J在检验期和率定期的确定性系数均达到0.85以上,径流总量相对误差在10％以内.因此,GR4J模型在赣江流域的日径流模拟中具有较高精度,具有较好的推广应用前景.

基于GR4J-LSTM混合模型的洪水预报研究

为提高洪水过程预报的准确性,将概念性水文模型GR4J (modèle du Génie Ruralà4 paramètres Journalier)的预报流量耦合到长短时记忆神经网络(Long Short-Term Memory Neural Network, LSTM)中,构建了GR4J-LSTM混合模型,并与GR4J、LSTM模型进行对比。基于2012~2019年陆水水库汛期与洪水事件相关的数据集,并结合欧洲中期天气预报中心的3 h预报降水产品,驱动GR4J-LSTM混合模型,预报陆水水库3~12 h预见期的入库流量。最后采用平均影响值(Mean Impact Value, MIV)算法评估输入变量的相对重要性。结果表明:GR4J、LSTM和GR4J-LSTM模型均具有较好的模拟预报能力,但GR4J-LSTM混合模型的预报性能最优,既可以学习GR4J模型的产汇流过程,又提高了洪水预报的精度。研究成果可为洪水预报方案制定提供参考。

GR4J模型在钱塘江流域的适用性研究

以钱塘江流域的子流域兰江流域为研究区域,利用24个水文气象站点1980年~1990年的逐日数据,采用GR4J水文模型对6个水文站点的逐日径流进行模拟,对模型的适用性进行分析评价。结果表明,6个站点率定期和验证期Nash-Sutcliffe系数均达到0.7以上,其中衢州、金华和兰溪3个站点的Nash-Sutcliffe系数均达到0.9以上,模型模拟效果总体较好;模拟径流总量的相对误差总体控制在±10%以内(除金华站验证期为-11.26%);密赛站参数X_3(GR4J模型的一个参数)的率定结果在推荐范围的下限,需进一步探究扩大参数范围的可能性。

基于多种水文模型结构改进新安江模型

【目的】针对水文模型结构的不足提出改进方法。【方法】选择新安江模型、GR4J(mode′le du Ge′nie Rural a′4parame′tres Journalier)模型以及HYMOD模型在淮河流域进行应用对比分析,并基于GR4J模型与HYMOD模型的汇流结构对新安江模型进行改进,提出2种改进模型方法。【结果】(1)3种概念性水文模型在淮河王家坝流域均具有较好的适用性,其中新安江模型效果最好,但该模型在大流量模拟时存在低估现象;(2)M2模型(HYMOD模型汇流结构下的新安江模型)与新安江模型的模拟结果相近,大流量的模拟同样偏小,改进效果不明显;(3)M1模型(GR4J模型汇流结构下的新安江模型)模拟效果最佳,可以有效改善新安江模型对大流量的模拟效果,改进效果显著。【结论】M1模型可以有效改善新安江模型模拟径流时出现流量以及洪峰流量的低估现象,在研究流域内具有一定的应用价值。

时变增益模型在辽宁干旱半干旱流域的适用性研究

自然流域属于典型复杂开放的系统,水文要素的时空变化具有高度非线性的特点,干旱半干旱流域尤其显著。因此,针对干旱半干旱流域降雨径流非线性问题,运用水文非线性时变增益模型(TVGM)、GR4J模型、总径流线性响应模型及线性扰动模型对辽宁省干旱半干旱流域日径流过程进行模拟分析,从2个精度衡量指标对4个模型的应用效果进行较为深入的对比分析,探究这4个模型在干旱半干旱流域降雨径流模拟中的适用性。结果表明:在辽宁省干旱半干旱流域的水文模拟中,TVGM模型适用性最好、GR4J模型次之,两种线性模型适用性较差。TVGM模型引入时变增益因子,综合考虑了土壤湿度、降雨强度等产流的关键要素,其模拟和验证效果都比较理想,体现了该模型的特色和应用价值。

Rain-Flow Modelling Using the GR4J Model for Flood Risk Management in the Oti Watershed (Togo)

In recent years, West Africa has been confronted with hydro-climatic disasters causing crises in both urban and rural areas. The tragedy in the occurrence of such events lies in the recurrent aspect of high water and associated floods. The devastating floods observed in Africa’s major rivers have revealed the need to understand the causes of these phenomena and to predict their behavior in order to improve the safety of exposed people and property. The aim of this study is to reproduce flood flows using the GR4J (Rural Engineering Four Daily Parameters) model to analyze flood risk in the Oti watershed in Togo. Daily data on flows (m3/s), potential evapotranspiration (mm/day) and average precipitation (mm) over the basin from 1961-2022 collected at the National Meteorological Agency of Togo (ANAMET) and the Department of Water Resources in Lome, were used with the R software package airGR. The Data from the West African Cordex program from 1961-2100 were used to analyze projected flows. The results obtained show the GR4J model’s effectiveness in reproducing flood flows, indicating that observed flows are well simulated during the calibration and validation periods, with KGE values ranging from 0.73 to 0.85 at calibration and 0.62 to 0.81 at validation. These KGE values reflect the good performance of the GR4J model in simulating flood flows in the watershed. However, a deterioration in the KGE value was observed over the second validation period. Under these conditions, there may be false or missed alerts for flood prediction, and the use of this model should be treated with the utmost caution for decision-support purposes.

基于Hadgem2_ES的气候变化对金华江流域枯水变化的影响评估

气候变化引发降雨径流等水文要素的变化已经成为学界的共识,浙江省内近年来频发的气候极端事件更是引起众多学者的重视。枯水水文作为水文学的一部分,分析其变化有其积极的实际意义。选取了金华江流域1975-2004年的日降水、温度和径流资料,使用多站统计降尺度方法,基于最新CMIP5中的Hadgem2_ES模型,利用GR4J水文模型模拟了未来(2071-2100年)的径流,重点分析了几个重要枯水指数7Q10和30Q10的变化。结果表明,未来这两个指数都有明显的上升趋势,即气候变化可能缓和金华江流域未来的枯水情况。

黄河流域典型流域水文气象变化与径流过程模拟

典型流域水文气象分析及水文过程模拟是合理评价黄河流域水资源变化的重要基础。利用Mann-Kendall秩次相关检验法和均值差异T检验法分析了黄河流域7个典型流域的年降水量、年径流量和年均气温序列的变化特征,并采用VIC模型、新安江模型、WBM模型和GR4J模型模拟站点的径流过程。结果表明:各典型流域年均气温显著升高;年降水量变化趋势和突变情况均不明显;而年径流量呈显著下降趋势,且突变多发生在1980s。模型模拟结果表明4种水文模型在黄河流域应用效果较好。就Nash效率系数而言,VIC和新安江模型因为考虑产汇流过程较为详细,模拟径流过程与实测过程更贴近;就径流相对误差而言,WBM模型在水量模拟计算中表现较优,其结构简单,适用于流域水资源的模拟与评价。

Integrated Water Resource Assessment of Irrigation System of Haryana

Agriculture is the major activity in the state of Haryana and large volume of water is required to meet the irrigation demands of the crops grown. But, there is limited water availability in the state. Haryana receives water from Yamuna River and Bhakra system. Sowmelt, rainfall and groundwater are main sources of water in the catchment. It is essential to integrate the manmade canal system with hydrological system. This paper focuses on integrated hydrological modeling framework to conceptualize the system and to assess the Water Resources of the state. Snowmelt and Rainfall runoff modeling using GR4JSG model were combined to model the inflows to the irrigation system of Haryana. Irrigator canal model of eWater Source has been used to generate water demands from crops grown. The water balance and water use efficiency have been worked out for each district of Haryana. The hydro climate input data, stream flows, crop data and soil data have been used in the study. The flows modeled at Tuini (P), Yashwant Nagar, Bausan, Haripur, Poanta and HKB sites were compared with the observed flows. The objective function of NSE Daily and log Flow duration was used for model calibration and validation at various locations up to Mathura, the outlet of the study area. The value of the objective function at Mathura was 0.54, a fairly good value. The results of the Irrigator canal model have shown that all the Inflows, Outflows and the Utilizations of water have been properly balanced for each district. The water use efficiency of districts varies from 27% to 59%. The overall water use efficiency for Haryana canal system has been calculated as 39%. This is low value indicating excess water is being extracted to meet the water demands.