土地利用变化下的水文响应及其可检测性分析

以涪江桥流域为研究区域,采用SWAT模型模拟流域水文过程,将相同水文气象条件下1985和1995年2个时期土地利用情景的SWAT模型模拟结果与土地利用空间转化图相结合,分析土地利用变化引起的水文要素变化及其可检测性问题。结果表明:1985—1995年间涪江桥流域发生较为剧烈的土地利用变化,但并未检测到足够显著的水文要素变化;不同土地利用类型水文效应的相似性、不同土地利用类型水文效应差异性以及统计中和效应和统计均化效应是导致土地利用变化引起的水文要素变化难以检测的主要原因。在此基础上,提出了水文动态响应度指标,来消除统计中和效应。该指标可以在一定程度上帮助研究者了解研究区特定水文要素变化的相对剧烈程度。研究结果可为土地利用总体规划和流域水资源保护与合理配置提供参考。     

基于FLUS模型的流域土地利用变化预测及水文响应评估

模拟未来不同发展情景下流域土地利用变化,评估其对流域水文的影响,对流域的土地利用优化和水安全起着重要的指导作用.通过分析2000—2018年汨罗江流域土地利用变化趋势,基于流域土地利用变化特点,运用FLUS模型从不划定发展控制区域的基准情景和划定限制发展区域的限制情景2个方面出发,进行2035年汨罗江流域土地利用预测,...     

南小河沟土地利用变化对水文过程的影响

为了解决黄土高原水资源短缺、水土流失等生态环境问题,当地实施的退耕还林(草)、坡改梯等措施使土地利用发生了很大的变化,从而对水文过程产生了深刻的影响。选取南小河沟流域内的杨家沟和董庄沟两条小流域作为研究对象,基于西峰水土保持科学试验站在南小河沟的实测资料,分析研究区1954—2010年的土地利用变化及其水文过程响应。结果表明:南小河沟及杨家沟的土地利用有很大的变化,草地及耕地产流较少,道路及庭院等产流较多,坡面产流<沟谷产流<塬面产流;治理后的杨家沟与未经治理的董庄沟相比,对暴雨最大洪峰流量的削减效益最大,对单次降雨洪水的拦蓄效益次之;相对于草地,林地径流量减少明显,保水削峰效益较高。     

Hydrological Simulation by SWAT Model with Fixed and Varied Parameterization Approaches Under Land Use Change

Land use and land cover (LULC) change within a watershed is recognized as an important factor affecting hydrological processes and water resources. Modeling the hydrological effects of land-use change is important not only for after-the-fact analyses, but also for understanding and predicting the potential hydrological consequences of existing land-use practices. The main aim of the study is to understand and quantify the hydrological processes in a rapid urbanization region. The SWAT model and the Qinhuai River basin, one of the most rapidly urbanizing regions in China were selected to perform the study. In the study, a varied parameterization strategy was developed by establishing regression equations with selected SWAT parameters as dependent variables and catchment impermeable area as independent variable. The performance of the newly developed varied parameterization approach was compared with the conventional fixed parameterization approach in simulating the hydrological processes under LULC changes. The results showed that the model simulation with varied parameterization approach has a large improvement over the conventional fixed parameterization approach in terms of both long-term water balance and flood events simulations. The proposed modeling approach could provide an essential reference for the study of assessing the impact of LULC changes on hydrology in other regions.     

SWAT-Based Hydrological Modelling Using Model Selection Criteria

Calibration is an important step for the applicability of hydrological models as different parameter sets could produce similar results, calling for the use of appropriate performance criteria differentiating different parameter sets. This study focuses on the evaluation and comparison of SWAT-based hydrological modeling using both classical Nash Sutcliffe (NS) and the so called model selection criteria (MSC). Twelve SWAT models of the Sirwan River Basin in Iran are built based on different combinations of observed data, number of parameters and strategies used for calibration. The models are then evaluated against NS and eight MSC including AIC, AICc, AICu, CAIC, SIC, SICc, HIC and HICc, to rank the models and discriminate the most promising calibration setting from the aforementioned twelve candidate settings. Results show outperformance of MSC in terms of the robustness of the ranking outcomes both in calibration and validation phases as well as their discriminating power.     

水文模型模拟水文极值的不确定性分析

以黄河源区为研究区,运用GLUE法分析了HBV模型和新安江模型模拟水文极值的不确定性。目标似然函数阈值分别选用0.7、0.6、0.5,将得到的洪水和枯水水文极值以及选出的模拟结果按丰水年、平水年和枯水年过程分别进行分析。结果表明:两个模型均擅长于模拟洪水,而且对洪水模拟的不确定性较对枯水模拟的不确定性低;从两个水文模型模拟日过程估计区间的差别看,HBV模型估计区间与实测相比,洪水年总体偏低,枯水年总体偏高,平水年不存在明显趋势,新安江模型则不存在这个特点;在相同的参数采样方法和策略下,HBV模型的不确定性比新安江模型更显著;两个水文模型对枯水指标Q_(90)和Q_(75)模拟的不确定性都较大;新安江模型对洪水指标Q_(25)和Q_(10)的估计区间小于HBV模型的,不确定性水平较低。     

A Note to the Variable Sorptivity Infiltration Equation

A simplification for the variable sorptivity infiltration equation of Poulovassilis et al. (1989) is proposed. The resulting equation has three parameters S _x, c and K ₀. From these, S _x and c are considered as fitting parameters and K ₀ as a physical one. The new empirical infiltration equation is tested for precision, parameter time-dependence and applicability for soil surveys. The test was carried out by comparison with reference solutions i.e. infiltration data obtainedexperimentally, analytically or numerically for two different head conditionsat the infiltration surface. A good agreement is observed for all examinedcases. The dependence of the fitting parameters S _x and c on the initialand boundary conditions, as well as the error that arises by taking intoaccount different values of them, are examined. In fine textured soilsparameter c seems to be very small, so that one can easily suppose that the proposed equation reduces to the well-known Philip's infiltration equation (Philip, 1957).     

Multi-Criteria Process-Based Calibration Using Functional Data Analysis to Improve Hydrological Model Realism

It has been argued that rainfall-runoff model calibration based solely on streamflow is not sufficient to evaluate the realism of a hydrological model to represent the internal fluxes. Therefore, model calibration has evolved to evaluating model performance using a number of hydrological signatures that link the model to the underlying processes. However, this approach uses goodness-of-fit measures, unable to describe the entire dynamic of time series, to evaluate model consistency and to simulate hydrological signatures. The present paper develops a stepwise multicriteria calibration using hydrograph partitioning and calibration criteria defined on the basis of Functional Data Analysis (FDA), a statistical tool that conserves all important features of the hydrograph by approximating times series as a single function. The aim of this approach is to improve model realism by scrutinizing model components and by evaluating its ability to reproduce the entire flow dynamic. The proposed approach is compared to a calibration against daily streamflow only. The stepwise calibration improved the estimation of the flood curve, the annual peak volume as well as the performance of the model at sites other than the calibration station.     

Hydrological Prediction in a Tropical Watershed Dominated by Oxisols Using a Distributed Hydrological Model

Hydrological models have been used in many places of the world in order to support practitioners with respect to watershed management actions. The goal of this research was to apply the Lavras Simulation of Hydrology (LASH model) to a Brazilian tropical watershed dominated by Oxisols, to estimate maximum, minimum and mean stream flows for both current land-use (“scenario 1”) and other regional trend land-use scenarios (“scenario 2”—pasture into eucalyptus; and “scenario 3”—eucalyptus into pasture). This model is a continuous, distributed and semi-conceptual model for simulation of different hydrological components on a daily basis. The model had a good performance with respect to the “scenario 1”, resulting in Nash-Sutcliffe coefficients equal to 0.81, 0.82 and 0.98 for minimum, maximum and mean discharges, respectively. When “scenario 2” was simulated, it was found that minimum, mean and maximum stream flows had their values reduced in average by 7.39 %, 13.84 % and 20.38 %, respectively. On the contrary, it was observed in “scenario 3” an increase in average by 0.23 %, 0.44 % and 1.19 % for minimum, mean and maximum stream flows, respectively. With respect to water yield, scenario 2 resulted in a mean reduction of 119 mm, whereas for scenario 3 the difference was not so pronounced in relation to the current land use. Results obtained in scenario 2 are troublesome since this watershed drains into an important regional Hydroelectric Power Plant Reservoir and this approach needs to be considered by the Minas Gerais State electric energy company for its planning strategies for the future.     

结合G1法与变权理论的杞麓湖流域生态用地分析

杞麓湖流域作为典型高原湖泊流域之一,生态极易遭到破坏.选取高程、坡度、人口密度、道路缓冲区、居民点缓冲区、水域缓冲区来构建生态敏感性评价的指标体系,并结合G1法、变权栅格理论确定各指标权重,进行杞麓湖流域生态敏感性评价和流域生态用地分析.结果表明:①引入变权栅格理论可有效避免因子之间的相关干扰;②高、中、低度敏感区分别...     

基于VIC模型和Palmer干旱指数的区域干旱化评价研究

基于VIC(可变下渗容量)模型的流域网格划分及其对径流、蒸散发和土壤含水量变化的模拟，对Palmer干旱指数各水量平衡分量的计算进行了优化，并采用分级修正的方式，改进了Palmer干旱指数中气候特征系数K的确定方法。在此基础上，建立了基于VIC模型和Palmer干旱指数的区域气候干湿变化评价系统，并将该系统在黄土高原进行了应用。结果表明，近40 a黄土高原气候正向暖干化趋势发展，1990年以后暖干化趋势尤为明显。研究区干旱发生频率在空间上呈由西北向东南递减趋势，不同季节干旱发生频率空间分布存在一定差异。该评价系统物理机制清晰，地区适应性较强，在实时监测和评估气候干湿变化及其时空分布上存在较大应用潜力。     

基于可变下渗容量模型和Palmer 干旱指数的区域干旱化评价研究

基于可变下渗容量(Variable Infiltration Capacity,VIC)模型的流域网格划分及其对径流、蒸散发和土壤含水量变化的模拟,对Palmer干旱指数各水量平衡分量的计算进行了优化,并采用分级修正的方式,改进了Palmer干旱指数中气候特征系数K的确定方法。在此基础上,建立了基于VIC模型和Palmer干旱指数的区域气候干湿变化评价系统,并采用该系统对黄土高原进行了研究。结果表明,近40年黄土高原气候正向暖干化趋势发展,1990年以后暖干化趋势尤为明显。研究区干旱发生频率在空间上呈由西北向东南递减趋势,不同季节干旱发生频率空间分布存在一定差异。该评价系统物理机制清晰,地区适应性较强,在实时监测和评估气候干湿变化及其时空分布上存在较大应用潜力。     

农业用水水价承受能力分析

在分析国内外研究成果的基础上,提出适宜于本地区的确定农业用水户对水价承受能力的方法,并在对农业生产成本、效益进行调研分析的基础上,确定了农业用水的水价承受能力,提出提高农户对水价承受能力的对策.     

拉萨河流域径流对土地利用和气候变化的响应分析

拉萨河流域处青藏高原中南部,因其独特的地理位置是对气候变化较为敏感的区域之一,同时也是青藏高原人口和耕地较为密集区域.在建立SWAT模型对拉萨河流域水循环过程进行模拟的基础上,通过设置不同气候情景与土地利用状况,分析近30 a来拉萨河流域径流变化的成因,并研究径流对气候因子变化的敏感性.结果表明:①气候变化与土地利用对...     

亚热带山区红壤可蚀性对土地利用变化的响应

为探究土地利用方式变化对表层土壤可蚀性的影响,分别在湖南省湘东大围山和湘西小溪国家级自然保护区选取现有4种典型土地利用方式(天然林及由其转变而来且紧邻的杉木林、果园和坡改梯耕地),分析土地利用方式发生转变后表层土壤理化性质差异,选择Torri.D模型计算土壤可蚀性K值,利用系统聚类法对本研究采样点和江西鹰潭中国科学院红...     

分布式水文模型EasyDHM在海河阜平流域的应用

目前很多分布式水文模型还主要应用在科研领域,缺乏在实际的水管理业务中的应用。分布式水文模型EasyDHM的开发则以实用为目的,着重关注模拟效果及建模效率。模型具有友好的操作界面,适用于各种时空尺度的流域水文模拟,并且模型易于扩展,可进行水资源评价。以海河流域阜平水文站以上流域为研究对象,应用EasyDHM模型进行流域水文模拟,通过对模型参数进行敏感性分析及率定,使阜平流域率定期及验证期Nash效率系数达到0．96。分析表明,EasyDHM模型在阜平流域具有很好的适用性。     

Hourly Analyses of Hydrological and Water Quality Simulations Using the ESWAT Model

Detailed analyses of hydrological and water quality variables are very important to study the dynamic processes in a river basin. In this study, we have further modified the Enhanced Soil and Water Assessment Tool (ESWAT) model by incorporating hourly evapotranspiration and overland flow routing modules. Results from comparison of the performances by two ESWAT versions indicate that the modified version performed better than the original model. The modified ESWAT model has reasonably reproduced observed time series runoff and most commonly collected water quality data. In addition, input data availability at required spatial and temporal resolutions is the major bottleneck in implementing many detailed hydrological models. In this paper, we have also developed a robust methodology to successfully disaggregate daily rainfall data into hourly datasets. Furthermore, we have assessed the implications of such daily rainfall disaggregation schemes on subsequent simulation of hydrological and water quality variables at river basin level. The outcomes suggest that the multivariate rainfall disaggregation scheme better reproduced observed rainfall and runoff data.     

Hydrological Modeling of Zarqa River Basin – Jordan Using the Hydrological Simulation Program – FORTRAN (HSPF) Model

Jordan is an arid country with limited water resources, so there is a chronic need to study and understand its hydrology at the watershed scale which will eventually help in achieving good management for the existing scarce water resources. The studied watershed was the Zarqa River Basin which is considered as the largest watershed in Jordan. The objective of this study was to calibrate the hydrological component of the Hydrological Simulation Program – FORTRAN (HSPF) model for the Zarqa River Basin. The calibrated model could be used in a later stage to examine the impact of different management practices and climate change scenarios on the water resources in the basin. The calibration of the HSPF water quantity parameters was aided by GIS and by the automatic calibration model (PEST). The automatic calibration was done for the years 1988–1991 and the validation was done for the years 1996–1998. The coefficient of determination, R ² for the calibration and verification years of the monthly flows was 0.81 and 0.76, respectively.     

基于SWAT和GIS的洱海流域土地利用变化对径流影响的研究

利用DEM、土地利用、土壤、气象等时空数据并结合GIS和RS技术,建立洱海流域SWAT模型,分析了2000年和2010年不同土地利用情景对径流的影响,其结果为洱海流域土地利用变化引起径流的变化率为2.46%。以《云南省土地利用总体规划大纲(2006—2020)》为依据,结合洱海流域土地利用分布的实际情况,设置3种土地利用情景,研究不同土地利用情景对径流的影响。结果表明情景1中,66.06 km²的耕地转林地和89.16 km²的耕地转草地,模拟的年均径流值增加75.73 mm;情景2中,100.13 km²的裸地和105.74 km²的草地转为耕地,年均径流增加39.89 mm;情景3中,138.72 km²的草地和292.86 km²林地转耕地,年均径流减少20.36 mm。模拟表明在坡度15°以上,洱海流域森林和草地面积的增加将会增加径流量;在坡度15°以下,耕地的增加会一定程度上减少径流量。研究成果为洱海流域水资源空间合理调配提供参考依据。     

基于可变模糊识别模型的大连市水资源承载能力研究

在总结众多研究成果的基础上,阐述了水资源承载能力的内涵,提出了具体的水资源承载能力综合评价指标体系和量化计算模型。将可变模糊识别模型应用到大连市1996年-2007年水资源承载能力综合评价研究当中,结果表明,大连市水资源整体上处于可承载状态但已接近极限。提出了提高大连市水资源承载能力的途径,并计算大连市2020年及2030年三种不同供水条件下的水资源承载能力。