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81.
Hydrological modelling uncertainty analysis for different flow quantiles: a case study in two hydro-geographically different watersheds 总被引:2,自引:2,他引:0
This study focuses on analysis of hydrological model parameter uncertainty at varying sub-basin spatial scales. It was found that the variation in sub-basin spatial scale had little influence on the entire flow simulations. However, the different sub-basin spatial scales had a significant impact on the reproduction of the flow quantiles. The coarser sub-basin spatial scale provided a better coverage of most prediction uncertainty in observations. However, the finer sub-basin spatial scale produced the best single simulation output closer to the observations. In general, the optimal sub-basin spatial scales (ratio to the entire watershed size) in the two test watersheds were found to be in the ranges 14–19% and 2–4% for good simulation of high and low flows, respectively. It is therefore worthwhile to put more effort into reproducing different flow quantiles by investigating an appropriate sub-basin spatial scale. 相似文献
82.
Attribution of changes in the water balance of a tropical catchment to land use change using the SWAT model 总被引:1,自引:0,他引:1 下载免费PDF全文
Changes in the water balance of the Samin catchment (277.9 km2) on Java, Indonesia, can be attributed to land use change using the Soil Water Assessment Tool model. A baseline‐altered method was used in which the simulation period 1990–2013 was divided into 4 equal periods to represent baseline conditions (1990–1995) and altered land use conditions (1996–2001, 2002–2007, and 2008–2013). Land use maps for 1994, 2000, 2006, and 2013 were acquired from satellite images. A Soil Water Assessment Tool model was calibrated for the baseline period and applied to the altered periods with and without land use change. Incorporating land use change resulted in a Nash–Sutcliffe efficiency of 0.7 compared to 0.6 when land use change is ignored. In addition, the model performance for simulations without land use change gradually decreased with time. Land use change appeared to be the important driver for changes in the water balance. The main land use changes during 1994–2013 are a decrease in forest area from 48.7% to 16.9%, an increase in agriculture area from 39.2% to 45.4%, and an increase in settlement area from 9.8% to 34.3%. For the catchment, this resulted in an increase of the runoff coefficient from 35.7% to 44.6% and a decrease in the ratio of evapotranspiration to rainfall from 60% to 54.8%. More pronounced changes can be observed for the ratio of surface runoff to stream flow (increase from 26.6% to 37.5%) and the ratio of base flow to stream flow (decrease from 40% to 31.1%), whereas changes in the ratio of lateral flow to stream flow were minor (decrease from 33.4% to 31.4%). At sub‐catchment level, the effect of land use changes on the water balance varied in different sub‐catchments depending on the scale of changes in forest and settlement area. 相似文献
83.
考虑径流成分的雅鲁藏布江月径流模拟 总被引:3,自引:0,他引:3
通过构建雅鲁藏布江流域分布式水文模型SWAT,并以1989~1998年为率定期,1999~2005年为验证期对3个水文站(奴各沙、羊村、奴下)的月径流进行了模拟。从模型参数组里选取径流成分模拟不同的2组参数,以Nash-Sutcliffe效率系数(NS)、相关系数(R~2)及相对误差(PBIAS)为评价指标,来分析模型的模拟结果好坏。结果表明:率定期内,在径流成分1下奴各沙、羊村站和奴下站的R~2值高达0.9以上,NS系数分别为0.9、0.92和0.72,PBIAS的值为7.1%、18.5%及34.2%,但径流成分与实际情况出入较大。而径流成分2下,模拟得到的评价指标虽然不是很高,但径流成分比较合理。验证期总体结论一致。因此,建议在模型率定验证中要充分考虑径流成分的作用,从而提高模型模拟的精度。 相似文献
84.
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86.
The non-point source pollution in livestock-breeding areas of the Heihe River basin in Yellow River 总被引:4,自引:0,他引:4
Hongguang Cheng Wei Ouyang Fanghua Hao Xiyan Ren Shengtian Yang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(3):213-221
A GIS-based distributed soil and water assessment tools (SWAT) model was used to simulate the runoff, sediment yield and the
load of the non-point source pollution in the Heihe River basin, which is a tributary and main water supply source of the
Yellow River. It is a typical stockbreeding area, and its industry and agriculture are not well developed. The main pollution
source of the Heihe River was livestock related non-point source pollution. With GIS and remote sensing techniques, a database
of non-point source pollution in the Heihe River basin was established. The SWAT model was parameterized for this area. The
pollution load and transportation rules such as nitrogen were illustrated. After several years of hard work, the situations
of point source pollution were more and more accurate. This paper provided an effective way to assess and calculate the pollution
load in the wide agriculture area in China. With the help of historical data formulated parameters, the non-point source load
and the theory of pollution load distribution were illustrated about the Heihe River basin. In 2000, the soluble N load in this area was 1.06 × 106 kg. By the simulation, the main pollution sources were in the south east of the basin, where
the pasturing areas located in the south-east of Ruoergai County and in north of the Hongyuan County. 相似文献
87.
Simulating the impacts of climate variation and land-cover changes on basin hydrology: A case study of the Suomo basin 总被引:3,自引:0,他引:3
CHEN Junfeng LI Xiubin & ZHANG Ming . Institute of Remote Sensing & GIS Peking University Beijing China . Institute of Geographical Sciences Natural Resources Research Chinese Academy of Sciences Beijing China 《中国科学D辑(英文版)》2005,48(9):1501-1509
1 Motivation In the summer of 1998, areas along the middle and lower reaches of the Yangtze River suffered a damag- ing flood. Causes of the flooding became a hot topic on mass media after the disaster. Deforestation on the upstream areas was widely blamed as the major reason for the flooding. Some scientists, however, disproved the point of view. They believed that the impact of land use and land cover changes (LUCC) was over- stated[1]. Actually, the controversy over forest hydrol- ogy h… 相似文献
88.
基于SWAT模型的漳卫南流域水量模拟 总被引:4,自引:0,他引:4
结合2000~2004年的资料,用SWAT模型构建了漳卫南流域分布式水文模型,对漳卫南流域的水量过程和水量平衡进行了模拟分析,并将模型模拟结果与海河流域水资源公报和实测水文站数据进行了比较。水平衡分析结果表明,流域内的来水项主要是降雨和灌溉水量,去水项主要是腾发量和汛期的径流量;该模型对于漳卫南流域水量模拟与实际比较一致。 相似文献
89.
Qichun Yang Xuesong Zhang James E. Almendinger Maoyi Huang Guoyong Leng Yuyu Zhou Kaiguang Zhao Ghassem R. Asrar Xia Li Jiali Qiu 《水文研究》2019,33(5):864-875
Insufficiently calibrated forest parameters of the Soil & Water Assessment Tool (SWAT) may introduce uncertainties to water resource projections in forested watersheds. In this study, we improved SWAT forest parameterization and phosphorus cycling representations to better simulate forest ecosystems in the St. Croix River basin, and we further examined how those improvements affected model projections of streamflow, sediment, and nitrogen export under future climate conditions. Simulations with improved forest parameters substantially reduced model estimates of water, sediment, and nitrogen fluxes relative to those based on default parameters. Differences between improved and default projections can be attributed to the enhanced representation of forest water consumption, nutrient uptake, and protection of soil from erosion. Better representation of forest ecosystems in SWAT contributes to constraining uncertainties in water resource projections. Results of this study highlight the importance of improving SWAT forest ecosystem representations in projecting delivery of water, sediment, and nutrients from land to rivers in response to climate change, particularly for watersheds with large areas of forests. Improved forest parameters and the phosphorus weathering algorithms developed in this study are expected to help enhance future applications of SWAT to investigate hydrological and biogeochemical consequences of climate change. 相似文献
90.
Global sensitivity analysis of hydrologic processes in major snow‐dominated mountainous river basins in Colorado 下载免费PDF全文
The performance of watershed models in simulating stream discharge depends on the adequate representation of important watershed processes. In snow‐dominated systems, snow, surface and subsurface hydrologic processes comprise a complex network of nonlinear interactions that influence the magnitude and timing of discharge. This study aims to identify critical processes and interactions that control discharge hydrographs in five major mountainous snow‐dominated river basins in Colorado, USA. A comprehensive watershed model (Soil and Water Assessment Tool) and a variance‐based global sensitivity analysis technique (Fourier Amplitude Sensitivity Test) were used in conjunction to identify critical models parameters and processes that they represent. Average monthly streamflow and streamflow root mean square error over a period of 20 years were used as two separate objective functions in this analysis. Examination of the sensitivity of monthly streamflow revealed the influence of parameters on flow volume, whereas the sensitivity of streamflow root mean square error also exposed the influence of parameters on the timing of the hydrographs. A stability analysis was performed to investigate the computational requirements for a robust sensitivity analysis. Results show that streamflow volume is mostly influenced by shallow subsurface processes, whereas interactions between groundwater and snow processes were the key in the timing of streamflows. A large majority of important parameters were common among all study watersheds, which underlies the prospect for regionalization of process‐based hydrologic modelling in headwater river basins in Colorado. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献