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1.
Calibrating watershed-scale hydrologic models remains a critical but challenging step in the modeling process. The Soil and Water Assessment Tool (SWAT) is one example of a widely used watershed-scale hydrologic model that requires calibration. The calibration algorithms currently available to SWAT modelers through freely available and open source software, however, are limited and do not include many multi-objective genetic algorithms (MOGAs). The Non-Dominated Sorting Genetic Algorithm II (NSGA-II) has been shown to be an effective and efficient MOGA calibration algorithm for a wide variety of applications including for SWAT model calibration. Therefore, the objective of this study was to create an open source software library for multi-objective calibration of SWAT models using NSGA-II. The design and implementation of the library are presented, followed by a demonstration of the library through a test case for the Upper Neuse Watershed in North Carolina, USA using six objective functions in the model calibration. 相似文献
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This paper evaluates a recently created Soil and Water Assessment Tool (SWAT) calibration tool built using the Windows Azure Cloud environment and a parallel version of the Dynamically Dimensioned Search (DDS) calibration method modified to run in Azure. The calibration tool was tested for six model scenarios constructed for three watersheds of increasing size each for a 2 year and 10 year simulation duration. Results show significant speedup in calibration time and, for up to 64 cores, minimal losses in speedup for all watershed sizes and simulation durations. An empirical relationship is presented for estimating the time needed to calibration a SWAT model using the cloud calibration tool as a function of the number of Hydrologic Response Units (HRUs), time steps, and cores used for the calibration. 相似文献
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流域水文信息系统是地理信息系统、互联网和数据库等技术与水文学研究的结合,集成观测和环境信息的水文信息系统已经成为“数字地球”技术在流域科学方面的重要应用。研究回顾了流域科学的研究方法、发展现状和技术背景,提出当前流域科学研究迫切需要建立水文信息系统,而水文信息系统的重点任务是流域数据建模与数据共享服务。针对目前Arc Hydro水文地理数据模型和开源“协同促进水文科学发展大学联盟”--水文信息系统(CUAHSI|HIS)的研究进展,提出了一个适合于黑河流域的在线流域水文信息系统设计即“数字黑河”在线门户,集成流域地理数据、观测数据和数据共享服务于一体的流域水文信息系统将有效推动流域科学各方面的研究。 相似文献
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M. Yasmina Santos L. Alfredo Amaral 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2005,9(5):374-384
Spatial data mining refers to the extraction of knowledge, spatial relationships, or other interesting patterns not explicitly stored in spatial databases. The approaches usually followed in the analysis of geo-spatial data with the aim of knowledge discovery are essentially characterised by the development of new algorithms, which treat the position and extension of objects mainly through the manipulation of their co-ordinates. In this paper a new approach to this process is presented, where geographic identifiers give the positional aspects of geographic data. These identifiers are manipulated using qualitative reasoning principles, which allow for the inference of new spatial relations required for the data mining step of the knowledge discovery process. The analysis of a demographic database, with the proposed principles, enabled the discovery of patterns that are hidden in the explored geo-spatial and demographic data.Acknowledgements Our acknowledgment to NEPS (Núcleo de Estudos da População e Sociedade) of University of Minho, for making the demographic data available. 相似文献
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Scenarios are increasingly used for envisioning future social-ecological changes and consequences for human well-being. One approach integrates qualitative storylines and biophysical models to explore potential futures quantitatively and maximize public engagement. However, this integration process is challenging and sometimes oversimplified. Using the Yahara Watershed (Wisconsin, USA) as a case study, we present a transparent and reproducible roadmap to develop spatiotemporally explicit biophysical inputs [climate, land use/cover (LULC), and nutrients] that are consistent with scenario narratives and can be linked to a process-based biophysical modeling suite to simulate long-term dynamics of a watershed and a range of ecosystem services. Our transferrable approach produces daily weather inputs by combining climate model projections and a stochastic weather generator, annual narrative-based watershed-scale LULC distributed spatially using transition rules, and annual manure and fertilizer (nitrogen and phosphorus) inputs based on current farm and livestock data that are consistent with each scenario narrative. 相似文献
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Climate change is expected to have significant impacts on native, threatened and endangered wildlife. Understanding and modeling these impacts useful for wildlife managers, however, remain difficult due to complex climate change, and costly and high data requirements. Consequently, we proposed an easily-interpretable and data-efficient decision support approach to understand climate change impacts on the abundance of three endangered wetland birds (Hawaiian Stilt, Hawaiian Coot and Hawaiian Moorhen). We coupled a watershed model, AnnAGNPS, and ecological models using fuzzy-cognitive mapping software, Mental Modeler, in Hanalei watershed, Kauaʻi. Results suggested that increased precipitation would increase Stilt abundance, but decrease Coot and Moorhen abundance. Decreasing precipitation might have negative effects for all three species. Moreover, decision-makers should pay equal attention to controlling components (water depth, food availability and disease) with system-wide influence. Finally, besides being adaptable to similar environmental contexts, our approach captured both direct and indirect climate change impacts through ecological connectivity. 相似文献
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水文资料整编工作是水文工作中重要的一部分,传统水文资料整编工作存在数据整编过程复杂、费时费工、数据时效性差、数据成果应用性低等问题。以云南省水文资料在线整编系统设计与应用为案例,介绍水文资料在线整编系统的建设要点、特点及应用效果。通过建设水文资料在线整编系统,可提高水文资料整编效率,加强水文数据服务及时性,提升水文数据利用率,为其他地区水文资料整编工作提供新的思路。 相似文献
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通过在GIS空间数据中隐藏标识数据生产单位版权和用户使用权属的数字水印的数据安全技术,来跟踪、抵制GIS空间数据的非法流通、非法复制,有效保护数据生产单位的合法权益,推动GIS空间数据的安全共享.方法无论是对于地理空间数据安全管理,还是对于数字水印信息隐藏技术应用领域的扩展都属新的探索.运用所研究的技术方法已开发出相应的应用软件,并利用江苏省1∶ 1万数字地形图数据进行了检验测试,证明该技术方法是可行的. 相似文献
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We have implemented the USGS National Climate Change Viewer (NCCV), which is an easy-to-use web application that displays future projections from global climate models over the United States at the state, county and watershed scales. We incorporate the NASA NEX-DCP30 statistically downscaled temperature and precipitation for 30 global climate models being used in the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and hydrologic variables we simulated using a simple water-balance model. Our application summarizes very large, complex data sets at scales relevant to resource managers and citizens and makes climate-change projection information accessible to users of varying skill levels. Tens of terabytes of high-resolution climate and water-balance data are distilled to compact binary format summary files that are used in the application. To alleviate slow response times under high loads, we developed a map caching technique that reduces the time it takes to generate maps by several orders of magnitude. The reduced access time scales to >500 concurrent users. We provide code examples that demonstrate key aspects of data processing, data exporting/importing and the caching technique used in the NCCV. 相似文献
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Satellite-based estimates of groundwater storage variations in large drainage basins with extensive floodplains 总被引：2，自引：0，他引：2
Frédéric Frappart Fabrice Papa Andreas Güntner Joecila Santos da Silva Frédérique Seyler William B. Rossow Marie-Paule Bonnet 《Remote sensing of environment》2011,115(6):1588-1594
This study presents monthly estimates of groundwater anomalies in a large river basin dominated by extensive floodplains, the Negro River Basin, based on the synergistic analysis using multisatellite observations and hydrological models. For the period 2003-2004, changes in water stored in the aquifer is isolated from the total water storage measured by GRACE by removing contributions of both the surface reservoir, derived from satellite imagery and radar altimetry, and the root zone reservoir simulated by WGHM and LaD hydrological models. The groundwater anomalies show a realistic spatial pattern compared with the hydrogeological map of the basin, and similar temporal variations to local in situ groundwater observations and altimetry-derived level height measurements. Results highlight the potential of combining multiple satellite techniques with hydrological modeling to estimate the evolution of groundwater storage. 相似文献
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The study summarizes the current knowledge on infection and recovery of white-tailed deer and cattle, and integrates this knowledge into the Soil and Water Assessment Tool (SWAT) via a new add-on module SIR (Susceptible - Infected - Recovered) for predicting pathogen transmission between livestock and deer. New processes modeled by the SWAT-SIR model include: (a) seasonal changes in deer population and habitat; (b) resource selection and seasonal changes in foliage consumption by deer; (c) ingestion of pathogens with water, foliage and via grooming soiled hide by deer and grazing cattle; (d) infection and recovery of deer and co-grazing cattle; (e) pathogen shedding by infected animals; (f) survival of pathogens in manure; (g) kinetic release of pathogens from applied manure and fecal material. The model output is linked with ARC-GIS to allow spatial and temporal analysis of pathogen distribution across the watershed for specific land use, weather and management scenarios. 相似文献
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区域地理空间数据共享平台与目录服务研究 总被引：1，自引：0，他引：1
肖桂荣 《计算机工程与应用》2009,45(16):155-158
分布式、异构的地理空间数据的整合与共享是空间信息网络服务的关键技术。构建了基于SOA和XML Web Services技术的地理空间数据共享平台和目录服务体系,提出了建设区域地理空间数据共享服务平台的技术流程。研究的共享体系和目录服务体系能够有效地解决地理空间数据共享中信息组织、检索、定位、透明访问和集成应用的关键问题。 相似文献
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研究了乌裕尔河湿地自然径流区和人为控制区各两个样带的土壤有机质、TN、TP在垂直于径流方向上的空间分异特征,结果表明在坡面径流和洪泛作用的影响下,表层土壤有机质、TN、TP表现出较高的空间异质性,在垂直于径流方向上呈现出累积-消减的趋势,0~15 cm土壤累积-消减趋势明显大于15~30 cm土壤,自然径流区的哈塔、龙安桥样带累积-消减趋势明显大于人为控制区的石家店、龙泡子样带,并应用空间输出/累积系数SEC进行量化和模拟,讨论了不同的土壤养分类型、湿地水文情势随机性及缓冲带植被群落结构对土壤养分空间分异的影响。 相似文献
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我国水文数据挖掘技术研究的回顾与展望 总被引：9，自引：0，他引：9
水文科学研究的领域面临来自许多方面的不确定性和非确知问题。引入数据挖掘的理论与技术,结合水文科学发展的需要,充分应用以计算机技术为基础的现代信息技术,研究水文数据挖掘的理论、技术和方法,为解决水文科学研究面临的问题提供了新的思路。当前,水文数据挖掘研究还处于起步阶段,研究内容多集中在水文数据的单项和局部数据的模拟与处理方面,对基于水文数据库的全局性多因素数据挖掘涉及很少,在数据挖掘技术与水文数据适应性方面所进行的研究也还很不够。为了充分发挥数据挖掘发现知识的作用,需要在水文主题数据库和多维数据立方、水文序列的分类、聚类和关联规则挖掘技术及优化算法以及水文序列的相似性、周期性和其它序列模式挖掘方面开展进一步研究,并向形成水文数据挖掘软件及数据平台方向发展。 相似文献
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A multi-level spatial optimization (MLSOPT) approach is developed for solving complex watershed scale optimization problems. The method works at two levels: a watershed is divided into small sub-watersheds and optimum solutions for each sub-watershed are identified individually. Subsequently sub-watershed optimum solutions are used for watershed scale optimization. The approach is tested with complex spatial optimization case studies designed to maximize crop residue (corn stover) harvest with minimum environmental impacts in a 2000 km2 watershed. Results from case studies indicated that the MLSOPT approach is robust in convergence and computationally efficient compared to the traditional single-level optimization frameworks. The MLSOPT was 20 times computationally efficient in solving source area based optimization problem while it was 3 times computationally efficient for watershed outlet based optimization problem compared to a corresponding single-level optimizations. The MLSOPT optimization approach can be used in solving complex watershed scale spatial optimization problems effectively. 相似文献
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The mean climate and its variability are analyzed in a suite of numerical experiments with a fully coupled general circulation model in which subgrid-scale moist convection is explicitly represented through embedded 2D cloud-system resolving models. Control simulations forced by the present day, fixed atmospheric carbon dioxide concentration are conducted using two horizontal resolutions and validated against observations and reanalyses. The mean state simulated by the higher resolution configuration has smaller biases. Climate variability also shows some sensitivity to resolution but not as uniform as in the case of mean state. The interannual and seasonal variability are better represented in the simulation at lower resolution whereas the subseasonal variability is more accurate in the higher resolution simulation. The equilibrium climate sensitivity of the model is estimated from a simulation forced by an abrupt quadrupling of the atmospheric carbon dioxide concentration. The equilibrium climate sensitivity temperature of the model is 2.77 °C, and this value is slightly smaller than the mean value (3.37 °C) of contemporary models using conventional representation of cloud processes. The climate change simulation forced by the representative concentration pathway 8.5 scenario projects an increase in the frequency of severe droughts over most of the North America. 相似文献
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Human exploitation of water resources is widespread and its impact on hydrological fluxes is expected to increase in the future. Water use interacts in a complex manner with the hydrological system causing severe alterations of the hydrological fluxes with multifaceted feedbacks. Implementing this coupling within hydrological models is essential when dealing with the impact of human activities on water resources at all relevant scales. We contribute to the effort in developing models coupling natural and human systems with a distributed continuous model, named GEOTRANSF. The model allows to quantify, within the same framework, alterations in the natural regime and constraints and limitations to water resources availability. After presenting GEOTRANSF, an example of application to a medium-size Alpine catchment with streamflow modified by hydropower and distributed uses is discussed, followed by the analysis of the effect of suitable water uses scenarios in the same catchment. 相似文献
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The curse of dimensionality refers to the problem o increased sparsity and computational complexity when dealing with high-dimensional data. In recent years, the types and vari ables of industrial data have increased significantly, making data driven models more challenging to develop. To address this prob lem, data augmentation technology has been introduced as an effective tool to solve the sparsity problem of high-dimensiona industrial data. This paper systematically explores and discusses th... 相似文献