A comprehensive approach to evaluating watershed models for predicting river flow regimes critical to downstream ecosystem services

Selection of strategies that help reduce riverine inputs requires numerical models that accurately quantify hydrologic processes. While numerous models exist, information on how to evaluate and select the most robust models is limited. Toward this end, we developed a comprehensive approach that helps evaluate watershed models in their ability to simulate flow regimes critical to downstream ecosystem services. We demonstrated the method using the Soil and Water Assessment Tool (SWAT), the Hydrological Simulation Program–FORTRAN (HSPF) model, and Distributed Large Basin Runoff Model (DLBRM) applied to the Maumee River Basin (USA). The approach helped in identifying that each model simulated flows within acceptable ranges. However, each was limited in its ability to simulate flows triggered by extreme weather events, owing to algorithms not being optimized for such events and mismatched physiographic watershed conditions. Ultimately, we found HSPF to best predict river flow, whereas SWAT offered the most flexibility for evaluating agricultural management practices.     

Simple method of calibration of conventional sodar antenna system

The accurate estimation of sodar antenna parameters, back-scattering cross-section and a knowledge of acoustic absorption in the atmospheric air are needed in case structure parameters are to be computed. In the paper a simple method using a theoretical antenna directivity pattern, together with measurements of transduction characteristics of the acoustic transducer has been suggested. The method has been used for two sodars belonging to the Russian Academy (Sodar Latan-I) and the National Physical Laboratory, New Delhi, The theoretically and experimentally determined directivities of the Sodar Transducer Systems have been compared and it has been found that they coincide rather satisfactorily within the angles at which the paraboloids of sodars are seen from their respective foci. Computed thermal structure parameter values using Sodar Latan-I based on the above approach have been found to be comparable with the values computed from microthermal data collected simulaneously at the same place     

Hydrologic scaling for hydrogeomorphic floodplain mapping: Insights into human‐induced floodplain disconnectivity

Hydrogeomorphic approaches for floodplain modelling are valuable tools for water resource and flood hazard management and mapping, especially as the global availability and accuracy of terrain data increases. Digital terrain models implicitly contain information about floodplain landscape morphology that was produced by hydrologic processes over long time periods, as well as recent anthropogenic modifications to floodplain features and processes. The increased availability of terrain data and distributed hydrologic datasets provide an opportunity to develop hydrogeomorphic floodplain delineation models that can quickly be applied at large spatial scales. This research investigates the performance of a hydrogeomorphic floodplain model in two large urbanized and gauged river basins in the United States, the Susquehanna and the Wabash basins. The models were calibrated by a hydrologic data scaling technique, implemented through regression analyses of USGS peak flow data to estimate floodplain flow levels across multiple spatial scales. Floodplain model performance was assessed through comparison with 100‐year Federal Emergency Management Agency flood hazard maps. Results show that the hydrogeomorphic floodplain maps are generally consistent with standard flood maps, even when significantly and systematically varying scaling parameters within physically feasible ranges, with major differences that are likely due to infrastructure (levees, bridges, etc.) in highly urbanized areas and other locations where the geomorphic signature of fluvial processes has been altered. This study demonstrates the value of geomorphic information for large‐scale floodplain mapping and the potential use of hydrogeomorphic models for evaluating human‐made impacts to floodplain ecosystems and patterns of disconnectivity in urbanized catchments.     

Advancements in the design and validation of an air pollution integrated assessment model for Spain

This paper describes the design and application of the Atmospheric Evaluation and Research Integrated model for Spain (AERIS). Currently, AERIS can provide concentration profiles of NO₂, O₃, SO₂, NH₃, PM, as a response to emission variations of relevant sectors in Spain. Results are calculated using transfer matrices based on an air quality modelling system (AQMS) composed by the WRF (meteorology), SMOKE (emissions) and CMAQ (atmospheric-chemical processes) models. The AERIS outputs were statistically tested against the conventional AQMS and observations, revealing a good agreement in both cases. At the moment, integrated assessment in AERIS focuses only on the link between emissions and concentrations. The quantification of deposition, impacts (health, ecosystems) and costs will be introduced in the future. In conclusion, the main asset of AERIS is its accuracy in predicting air quality outcomes for different scenarios through a simple yet robust modelling framework, avoiding complex programming and long computing times.     

Identification of spectrally similar materials using the USGS Tetracorder algorithm: the calcite-epidote-chlorite problem

A scheme to discriminate and identify materials having overlapping spectral absorption features has been developed and tested based on the U.S. Geological Survey (USGS) Tetracorder system. The scheme has been applied to remotely sensed imaging spectroscopy data acquired by the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) instrument. This approach was used to identify the minerals calcite, epidote, and chlorite in the upper Animas River watershed, Colorado. The study was motivated by the need to characterize the distribution of calcite in the watershed and assess its acid-neutralizing potential with regard to acidic mine drainage. Identification of these three minerals is difficult because their diagnostic spectral features are all centered at 2.3 μm, and have similar shapes and widths. Previous studies overestimated calcite abundance as a result of these spectral overlaps. The use of a reference library containing synthetic mixtures of the three minerals in varying proportions was found to simplify the task of identifying these minerals when used in conjunction with a rule-based expert system. Some inaccuracies in the mineral distribution maps remain, however, due to the influence of a fourth spectral component, sericite, which exhibits spectral absorption features at 2.2 and 2.4 μm that overlap the 2.3-μm absorption features of the other three minerals. Whereas the endmember minerals calcite, epidote, chlorite, and sericite can be identified by the method presented here, discrepancies occur in areas where all four occur together as intimate mixtures. It is expected that future work will be able to reduce these discrepancies by including reference mixtures containing sericite.     

美国地质调查局实时数据产品简介

实时数据是在某事发生、发展过程中的同一时间中所得信息的载体,是用于表示客观事物的未经加工的原始素材。美国地质调查局的科学家们通过定期或连续的现场测量来收集信息,为当前地质现状提供实时视图和信息。美国地质调查局的实时数据产品内容涵盖地震、水资源、洪水、地磁、陆地遥感与陆地卫星、滑坡、火山、干旱、野火。本文通过对美国地质调查局的实时数据产品情况进行综述,为我国实时数据产品的研究和社会化服务提供一些借鉴和科学依据。     

美国地质调查局核心理念的演变与启示

本文概要介绍了美国地质调查局核心理念演变的三个阶段历程,即"为西部大开发服务"、"为国家发展提供地学信息"和"科学为变化的世界服务",并总结了该局核心理念具有体现了机构的定位、使命与职能,已成为机构发展的支柱,以及与时俱进等主要特点。这些对于对中国地质调查局核心理念的构建及建设颇具启示意义,为此本文提出以下建议:一要注重行业特点和社会需求;二要广泛征求意见,提炼核心理念;三要积极扩展理念体系;四要构建沟通渠道;五要与基地建设相衔接。     

自定义的DEM格式与USGS DEM格式间的转换

本文针对当前主流建模软件Creator对数据格式的严格限定要求,在详细分析Creator软件中USGS DEM数据格式的基础上,提出由自定义DEM数据向USGS DEM格式转化的一种方法。实现了异构数据源到标准格式的转化。     

美国地质调查局对全球常规石油储量增长的评估

在对历年美国地质调查局(USGS)储量增长披露报告研究的基础之上,结合大量文献的研究,证实USGS不同时期的储量增长模型尽管存在夸大储量的缺陷,但仍是全球范围最具权威性的储量增长评估机构,2012年提出新的个体聚集分析模型一定程度上弥补了以往模型夸大储量的缺陷,依据新模型对全球范围内地质储量超过5亿桶的1814个油田及美国55个油田的研究发现,全球常规石油的储量增长为7230亿桶。     

Use of existing water, sediment, and tissue data to screen ecological risks to the endangered Rio Grande silvery minnow

A screening-level ecological risk assessment was applied to two extensive, but previously unanalyzed datasets from the middle Rio Grande (MRG) in New Mexico. The assessment evaluated how adverse water-quality effects from aquatic toxicants may have influenced the population decline of the endangered Rio Grande silvery minnow (Hybognathus amarus; silvery minnow). Standardized US Environmental Protection Agency (USEPA) screening-level ecological risk assessment procedures were applied to chemicals assessed in samples collected from the MRG between 1985 and 2003. Since more chemicals have established risk-screening criteria, relative to water-quality criteria, this approach produces more complete assessments. Chemical concentrations at some locations and times were potentially sufficient to affect fish health or produce localized mortalities. Many constituents displaying the highest risks have substantial natural sources within the watershed; native species likely would have adapted to natural instream concentrations such that actual risks might be markedly less than projected by a risk screening based on generic aquatic-life criteria. Also, highest risks found for individual and combinations of contaminants were very inconsistent both within and across the sites. As such, this risk assessment does not support the conclusion that toxicants were a primary factor causing the silvery minnow population to decline in the MRG between 1985 and 2003. The assessment indicates that sediment-borne, relative to water-borne, contaminants appeared to present the greatest risks to the silvery minnow and thus should have increased focus during future assessments of potential contaminant effects in the MRG. Contaminants of greatest concern are identified. This study presents approaches to cost-effectively assess and reduce uncertainties associated with potential water quality effects, and to help direct future assessments of water quality onto those contaminants likely to produce potentially significant effects. The techniques presented and criteria compiled are suitable for aiding similar assessments in other aquatic habitats.