检索结果-南通市图书馆

Uncertainty analysis of hydrological modeling in a tropicalarea using different algorithms

Frontiers of Earth Science 2018年第4期12卷 661-671页

作者： Ammar RAFIEI EMAM Martin KAPPAS steven fassnacht Nguyen Hoang Khanh LINH Department of Cartography GIS and Remote SensingUniversity of Goettingen37077GoettingenGermany Colorado State University Fort CollinsCO 80523-1476USA Faculty of Land Resources and Agricultural Environment (FLRAE) Flue University of Agriculture and Forestry (F1UAF)Hue UniversityHue City 0084Vietnam

Hydrological modeling outputs are subject to uncertainty resulting from different sources of errors (e.g., error in input data, model structure, and model parameters), making quantification of uncertainty in hydrological modeling imperative and meant to improve reliability of modeling results. The uncertainty analysis must solve difficulties in calibration of hydrological models, which further increase in areas with data scarcity. The purpose of this study is to apply four uncertainty analysis algorithms to a semi-distributed hydrological model, quantifying different source of uncertainties (especially parameter uncertainty) and evaluate their performance. In this study, the Soil and Water Assessment Tools (SWAT) eco-hydrological model was implemented for the watershed in the center of Vietnam. The sensitivity of parameters was analyzed, and the model was calibrated. The uncertainty analysis for the hydrological model was conducted based on four algorithms: Generalized Likelihood Uncertainty Estimation (GLUE), Sequential Uncertainty Fitting (SUFI), Parameter Solution method (ParaSol) and Particle Swarm Optimization (PSO). The performance of the algorithms was compared using P-factor and Rfactor, coefficient of determination (R2), the Nash Sutcliffe coefficient of efficiency (NSE) and Percent Bias (PBIAS). The results showed the high performance of SUFI and PSO with P-factor>0.83, R-factor 0.91, NSE>0.89, and 0.18<0.32. Hence, we would suggest to use SUFI-2 initially to set the parameter ranges, and further use PSO for final analysis. Indeed, the uncertainty analysis must be accounted when the outcomes of the model use for policy or management decisions.

关键词： SWAT-CUP GLUE SUFI2 ParaSol PSO Vietnam

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Scales of snow depth variability in high elevation rangeland sagebrush

引用

Frontiers of Earth Science 2017年第3期11卷 469-481页

作者： Molly E. TEDESCHE steven R. fassnacht Paul J. MEIMAN Watershed Science Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523-1476 USA Intemational Arctic Research Center Water & Environmental Research Center Institute of Northern Engineering University of Alaska Fairbanks Fairbanks AK 99775 USA Cooperative Institute for Research in the Atmosphere Fort Collins CO 80523-1375 USA Natural Resources Ecology Laboratory Fort Collins CO 80523-1499 USA Abt. Kartographie GIS & Femerkundung Geographisches Institut Georg-August-Universitat Gottingen 37077 Gottingen Germany Rangeland Ecosystem Science Department of Forest and Rangeland Stewardship Colorado State University Fort Collins CO 80523 USA

In high elevation semi-arid rangelands, sage- brush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush （Artemisia tridentata Nutt.） at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions （0.05 to 25 m） and extents （2 to 1000 m）. Finer scale data were collected specifically for this study to examine the correlation between snow depth; sagebrush microtopogra- phy, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Vario- grams were used to identify the spatial structure and the Moran＇s I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

关键词： snow hydrology high elevation rangelands,spatial statistics variograms snow pack spatial variability,snow drifts

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Headwater regions- Physical, ecological, and social approaches to understand these areas： introduction to the special issue

引用

Frontiers of Earth Science 2017年第3期11卷 443-446页

作者： steven R. fassnacht Ryan W. WEBB William E. SANFORD ESS-Watershed Science Colorado State University Fort Collins CO 80523-1476 USA Geographisches Institut Abt. Kartographie GIS & Femerkundung Georg-August-Universitat Gottingen 37077 Gottingen Germany Cooperative Institute for Research in the Atmosphere Fort Collins CO 80523-1375 USA Geospatial Centroid Colorado State University Fort Collins CO 80523-1101 USA Natural Resources Ecology Laboratory Fort Collins CO 80523-1499 USA Institute of Arctic and Alpine Research University of Colorado Boulder Boulder CO 80309-0450 USA Geosciences Colorado State University Fort Collins CO 80523-1482 USA

Around the world human communities and natural ecosystems both rely on headwater regions for vital resources. Resources provided include groundwater sto- rage （Flint et al., 2008; Clilverd et al., 2011; Cao et al., 2012） in addition to soil moisture and forest ecosystem dynamics （McNamara et al., 2005; Williams et al., 2009; Jencso and McGlynn, 2011; Smith et al., 2011; Harpold et al., 2015; Webb et al., 2015）. Furthermore these regions are ecologically vital zones （Schlosser, 1995; Lowe and Likens, 2005） that impact downstream water quality （Peterson et al., 2001; Alexander et al., 2007）.

关键词：

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Usingvery long-range terrestriallaser scanner to analyze the temporal consistency of the snowpack distribution in a high mountain environment

引用

Journal of Mountain Science 2017年第5期14卷 823-842页

作者： Juan I.LOPEZ-MORENO Jesús REVUELTO E.ALONSO-GONZALEZ Alba SANMIGUEL-VALLELADO steven R.fassnacht Jeffrey DEEMS Enrique MORAN-TEJEDA Pyrenean Institute of Ecology CSICZaragozaSpain Meteo-France-CNRS CNRM(UMR3589)Centre d'Etudes de la NeigeGrenobleFrance Colorado State University Fort CollinsColoradoUSA National Snow and Ice Data Center NSlDCBoulderColorado University of Balearic Islands MallorcaSpain

This study demonstrated the usefulness of very long-range terrestrial laser scanning(TLS) for analysis of the spatial distribution of a snowpack, to distances up to 3000 m, one of the longest measurement range reported to date. Snow depth data were collected using a terrestrial laser scanner during 11 periods of snow accumulation and melting,over three snow seasons on a Pyrenean hillslopecharacterized by a large elevational gradient, steep slopes, and avalanche occurrence. The maximum and mean absolute snow depth error found was 0.5-0.6 and 0.2-0.3 m respectively, which may result problematic for areas with a shallow snowpack, but it is sufficiently accurate to determine snow distribution patterns in areas characterized by a thick snowpack. The results indicated that in most cases there was temporal consistency in the spatial distribution of thesnowpack, even in different years. The spatial patterns were particularly similar amongst thesurveys conducted during the period dominated by snow accumulation(generally until end of April), or amongst those conducted during the period dominated by melting processes(generally after mid of April or early May). Simple linear correlation analyses for the 11 survey dates, and the application of Random Forests analysis to two days representative of snow accumulation and melting periods indicated the importance of topography to the snow distribution. The results also highlight that elevation and the Topographic Position index(TPI) were the main variables explaining the snow distribution, especially during periods dominated by melting. The intra-and inter-annual spatial consistency of the snowpack distribution suggests that the geomorphological processes linked to presence/absence of snow cover act in a similar way in the long term, and that these spatial patternscan be easily identifiedthrough several years of adequate monitoring.

关键词： Snow Terrestrial laser scanner(TLS) Topography Random Forests Spatial distribution Pyrenees

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Variability and change of climate extremes from indigenous herder knowledge and at meteorological stations across central Mongolia

引用

Frontiers of Earth Science 2020年第2期14卷 286-297页

作者： Sukh TUMENJARGAL steven Rfassnacht Niah BHVENABLE Alison PKINGSTON Maria EFERNANDEZ-GIMENEZ Batjav BATBUYAN Melinda JLAITURI Martin KAPPAS GADYABADAM ESS-Watershed Science Colorado State UniversityFort Collins ColoradoCO 80523-1476USA Cabinet Secretariat of Government of Mongolia State HouseUlaanbaatar City 14201Mongolia Natural Resources Ecology Laboratory Fort Collins ColoradoCO 80523-1499USA Cooperative Institute for Research in the Atmosphere Fort Collins ColoradoCO 80523-1375USA Cartography GIS and Remote Sensing DepartmentInstitute of GeographyGeorg-August Universität GöttingenGöttingen 37007Germany FRS-Rangeland Science Colorado State UniversityFort Collins ColoradoCO 80523-1472USA Center for Nomadic Pastoralism Studies Ulaanbaatar 210620Mongolia Institute of Meteorology Hydrology and the EnvironmentUlaanbaatar 210620Mongolia

In semi-arid regions,air temperatures have increased in the last decades more than in many other parts of the *** has an arid/semi-arid climate and much of the population are herders whose livelihoods depend upon limited water resources that fluctuate with a variable *** were surveyed to identify their observations of changes in climate extremes for two soums of central Mongolia,Ikh-Tamir in the forest steppe north of the Khangai Mountains and Jinst in the desert steppe south of the *** herders’indigenous knowledge of changes in climate extremes mostly aligned with the station-based analyses of *** were warming with more warm days and nights at all *** were fewer cool days and nights observed at the mountain stations both in the summer and winter,yet more cool days and nights were observed in the winter at the desert steppe *** number of summer days is increasing while the number of frost days is decreasing at all *** results of this study support further use of local knowledge and meteorological observations to provide more holistic analysis of climate change in different regions of the world.

关键词： climate change climate extreme indices indigenous knowledge systems temperature precipitation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：