岸边带正广泛应用于世界各地的面源污染治理项目,遥感也逐渐成为面源污染研究的重要手段,但如何将遥感技术与岸边带结合使截污效果更佳仍然是一个挑战。该文以云南省星云湖流域为例,耦合遥感建立土壤水分评估模型(soil and water assess...岸边带正广泛应用于世界各地的面源污染治理项目,遥感也逐渐成为面源污染研究的重要手段,但如何将遥感技术与岸边带结合使截污效果更佳仍然是一个挑战。该文以云南省星云湖流域为例,耦合遥感建立土壤水分评估模型(soil and water assessment tool,SWAT),通过改变土地利用类型的方式建立岸边带进行情景模拟,研究不同宽度和植被类型对污染物消减效果的差异。结果发现,设置岸边带对氮元素的截留效果好于磷元素;当岸边带植被类型不同时,林地的截污效果明显好于草地,并随着岸边带宽度的增加污染物消减率逐渐变大。设置30 m林地加30 m草地的岸边带可减少5.20%的总氮产量和6.03%的总磷产量,且可截留19.83%的有机氮入湖量和21.30%有机磷入湖量,在所有岸边带中截污效果最好。展开更多
针对高寒脆弱河流水环境容量受水文-生物地球化学耦合过程制约,缺乏量化研究的问题,以洮河部分河段为研究对象,基于SWAT(Soil and Water Assessment Tool)模型模拟流域径流特征,结合WASP(Water Analysis Simulation Program)模型分析河...针对高寒脆弱河流水环境容量受水文-生物地球化学耦合过程制约,缺乏量化研究的问题,以洮河部分河段为研究对象,基于SWAT(Soil and Water Assessment Tool)模型模拟流域径流特征,结合WASP(Water Analysis Simulation Program)模型分析河流水环境指标构建SWAT-WASP耦合水质模型,建立水环境容量定量计算框架,定量评估青藏高原东北缘高寒流域水环境容量时空分布特征.模型模拟结果与实测数据具有良好的一致性,在水流量、径流深等方面相关系数均达到0.6以上;Ⅰ类水质标准下BOD、TP和DO的年水环境容量分别为157.6、2.067和221.8t,而TN需放宽至Ⅳ类标准,年水环境容量为50.38t;对于BOD、TP和DO的水环境容量,空间维度显示上游为下游的9.9%~10.3%,时间维度显示1月(枯水期)为7月(丰水期)的10.1%~34.2%,分别凸显了高寒脆弱流域水动力条件和季节性水文驱动的主导作用,明确高寒脆弱流域可持续发展阈值;以TN为优先管控限制因子,提出时空协同分配策略,为高寒脆弱型水源区适应性水质管理提供科学依据.展开更多
径流模拟一直是水文科学的研究热点,对水资源研究具有重要指导意义。基于极限梯度提升算法(XGBoost)和SWAT(Soil and Water Assessment Tool)模型,采用赣江流域外洲水文站的观测水文数据,构建径流模拟模型,对比及分析两个模型的模拟效...径流模拟一直是水文科学的研究热点,对水资源研究具有重要指导意义。基于极限梯度提升算法(XGBoost)和SWAT(Soil and Water Assessment Tool)模型,采用赣江流域外洲水文站的观测水文数据,构建径流模拟模型,对比及分析两个模型的模拟效果。同时,基于XGBoost模型,采用残差校正方法对SWAT模型径流模拟结果进行校正,结果表明:①XGBoost模型的模拟效果较好,XGBoost模型日径流模拟的纳什效率系数(NSE)比SWAT模型高15.66%;②SWAT模型在高流量处存在低估的情况,而XGBoost模型模拟值与观测值变化基本一致,模拟过程线拟合度较高,表现出良好的相关性;③经XGBoost校正后的SWAT模型模拟精度明显提高,可有效改善径流模拟效果。当采用残差误差校正后,径流模拟的NSE值可达0.96,增加了15.66%。展开更多
Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle ...Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle in the Wadi Mina upstream watershed(northwest Algeria)by applying the Soil and Water Assessment Tool(SWAT)hydrological model.SWAT modelling integrates spatial data such as the Digital Elevation Model(DEM),land use,soil types and various meteorological parameters including precipitation,maximum and minimum temperatures,relative humidity,solar radiation and wind speed.The SWAT model was calibrated and validated using data from January 2012 to December 2014,with a calibra-tion period from January 2012 to August 2013 and a validation period from September 2013 to December 2014.Sensitivity and parameter calibration were conducted using the SWAT-SA program,and model performance evaluation relied on comparing the observed discharge at the outlet of the basin with model-simulated discharge,assessed through statistical coefficients including Nash-Sutcliffe Efficiency(NSE),coefficient of determination(R2)and Percent Bias(PBAIS).Calibration results indicated favourable objec-tive function values(NSE=0.79,R2=0.93,PBAIS=-8.53%),although a slight decrease was observed during validation(NSE=0.69,R2=0.86,and PBAIS=-11.41%).The application of the SWAT model to the Wadi Mina upstream watershed highlighted its utility in simulating the spatial distribution of different components of the hydrological balance in this basin.The SWAT model revealed that approximately 71%of the precipitation in the basin evaporates,while only 29%contributes to surface runoff or infiltration into the soil.展开更多
高寒地区(如青藏高原地区)水循环过程复杂,蒸散发是决定水资源平衡的关键环节,但传统SWAT (Soil and Water Assessment Tool)模型在蒸散发模拟过程中,受植被冠层导度参数化精度限制,导致水循环过程模拟存在较大不确定性,影响流域水资源...高寒地区(如青藏高原地区)水循环过程复杂,蒸散发是决定水资源平衡的关键环节,但传统SWAT (Soil and Water Assessment Tool)模型在蒸散发模拟过程中,受植被冠层导度参数化精度限制,导致水循环过程模拟存在较大不确定性,影响流域水资源评估与管理的可靠性。针对该问题,本研究耦合冠层导度模型——Irmak模型至SWAT模型,构建改进的SWAT-I模型,并在拉萨河流域开展模拟及验证。结果表明:1) SWAT-I模型显著提升了水文过程模拟性能,率定期与验证期的径流Nash-Sutcliffe效率系数较传统SWAT模型分别提高8.11%和4.23%;2) SWAT-I模型中Irmak模型的冠层导度的多因子协同参数化方案改善了蒸散发的模拟,R2提升57.14%,PBIAS改善28.71%;3) SWAT-I模型表明拉萨河流域蒸散发表现出明显的空间异质性,2000~2017年间年均蒸散发量以9.94 mm/a的速率显著上升,其中下游低海拔地区蒸散发量显著高于上游高海拔地区;4) 降水–水文要素关系呈现海拔梯度特征:流域上游受冰川融雪影响,降水与流域径流的相关性较弱(相关系数约为0.50),而中下游降水主导区相关系数达0.70以上,符合水源分割理论。本研究提出的耦合Irmak冠层导度模型的SWAT-I模型可有效提升流域蒸散发、径流等水循环过程的模拟精度,为气候变化下拉萨河流域水资源精准管理提供了模型支撑。展开更多
文摘岸边带正广泛应用于世界各地的面源污染治理项目,遥感也逐渐成为面源污染研究的重要手段,但如何将遥感技术与岸边带结合使截污效果更佳仍然是一个挑战。该文以云南省星云湖流域为例,耦合遥感建立土壤水分评估模型(soil and water assessment tool,SWAT),通过改变土地利用类型的方式建立岸边带进行情景模拟,研究不同宽度和植被类型对污染物消减效果的差异。结果发现,设置岸边带对氮元素的截留效果好于磷元素;当岸边带植被类型不同时,林地的截污效果明显好于草地,并随着岸边带宽度的增加污染物消减率逐渐变大。设置30 m林地加30 m草地的岸边带可减少5.20%的总氮产量和6.03%的总磷产量,且可截留19.83%的有机氮入湖量和21.30%有机磷入湖量,在所有岸边带中截污效果最好。
文摘针对高寒脆弱河流水环境容量受水文-生物地球化学耦合过程制约,缺乏量化研究的问题,以洮河部分河段为研究对象,基于SWAT(Soil and Water Assessment Tool)模型模拟流域径流特征,结合WASP(Water Analysis Simulation Program)模型分析河流水环境指标构建SWAT-WASP耦合水质模型,建立水环境容量定量计算框架,定量评估青藏高原东北缘高寒流域水环境容量时空分布特征.模型模拟结果与实测数据具有良好的一致性,在水流量、径流深等方面相关系数均达到0.6以上;Ⅰ类水质标准下BOD、TP和DO的年水环境容量分别为157.6、2.067和221.8t,而TN需放宽至Ⅳ类标准,年水环境容量为50.38t;对于BOD、TP和DO的水环境容量,空间维度显示上游为下游的9.9%~10.3%,时间维度显示1月(枯水期)为7月(丰水期)的10.1%~34.2%,分别凸显了高寒脆弱流域水动力条件和季节性水文驱动的主导作用,明确高寒脆弱流域可持续发展阈值;以TN为优先管控限制因子,提出时空协同分配策略,为高寒脆弱型水源区适应性水质管理提供科学依据.
文摘径流模拟一直是水文科学的研究热点,对水资源研究具有重要指导意义。基于极限梯度提升算法(XGBoost)和SWAT(Soil and Water Assessment Tool)模型,采用赣江流域外洲水文站的观测水文数据,构建径流模拟模型,对比及分析两个模型的模拟效果。同时,基于XGBoost模型,采用残差校正方法对SWAT模型径流模拟结果进行校正,结果表明:①XGBoost模型的模拟效果较好,XGBoost模型日径流模拟的纳什效率系数(NSE)比SWAT模型高15.66%;②SWAT模型在高流量处存在低估的情况,而XGBoost模型模拟值与观测值变化基本一致,模拟过程线拟合度较高,表现出良好的相关性;③经XGBoost校正后的SWAT模型模拟精度明显提高,可有效改善径流模拟效果。当采用残差误差校正后,径流模拟的NSE值可达0.96,增加了15.66%。
文摘Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle in the Wadi Mina upstream watershed(northwest Algeria)by applying the Soil and Water Assessment Tool(SWAT)hydrological model.SWAT modelling integrates spatial data such as the Digital Elevation Model(DEM),land use,soil types and various meteorological parameters including precipitation,maximum and minimum temperatures,relative humidity,solar radiation and wind speed.The SWAT model was calibrated and validated using data from January 2012 to December 2014,with a calibra-tion period from January 2012 to August 2013 and a validation period from September 2013 to December 2014.Sensitivity and parameter calibration were conducted using the SWAT-SA program,and model performance evaluation relied on comparing the observed discharge at the outlet of the basin with model-simulated discharge,assessed through statistical coefficients including Nash-Sutcliffe Efficiency(NSE),coefficient of determination(R2)and Percent Bias(PBAIS).Calibration results indicated favourable objec-tive function values(NSE=0.79,R2=0.93,PBAIS=-8.53%),although a slight decrease was observed during validation(NSE=0.69,R2=0.86,and PBAIS=-11.41%).The application of the SWAT model to the Wadi Mina upstream watershed highlighted its utility in simulating the spatial distribution of different components of the hydrological balance in this basin.The SWAT model revealed that approximately 71%of the precipitation in the basin evaporates,while only 29%contributes to surface runoff or infiltration into the soil.
