Sources of variability in springwater chemistry in Fool Creek,a high-elevation catchment of the Rocky Mountains,Colorado, USA     

Charles C. Rhoades  Timothy S. Fegel  Timothy P. Covino  Kathleen A. Dwire  Kelly Elder 《水文研究》2021,35(3):e14089

Springs are the point of origin for most headwater streams and are important regulators of their chemical composition. We analysed solute concentrations of water emerging from 57 springs within the 3 km² Fool Creek catchment at the Fraser Experimental Forest and considered sources of spatial variation among them and their influence on the chemical composition of downstream water. On average, calcium and acid neutralizing capacity (bicarbonate-ANC) comprised 50 and 90% of the cation and anion charge respectively, in both spring and stream water. Variation in inorganic chemical composition among springs reflected distinct groundwater sources and catchment geology. Springs emerging through glacial deposits in the upper portion of the catchment were the most dilute and similar to snowmelt, whereas lower elevation springs were more concentrated in cations and ANC. Water emerging from a handful of springs in a geologically faulted portion of the catchment were more concentrated than all others and had a predominant effect on downstream ion concentrations. Chemical similarity indicated that these springs were linked along surface and subsurface flowpaths. This survey shows that springwater chemistry is influenced at nested spatial scales including broad geologic conditions, elevational and spatial attributes and isolated local features. Our results highlight the role of overlapping factors on solute export from headwater catchments.  相似文献   

METEOR-L Device on the Lunar Orbital Vehicle Luna-26: Space Dust Detector     

Slyuta  E. N.  Vysochkin  V. V.  Ivanov  V. V.  Makovchuk  V. Yu.  Nazarov  A. I.  Pogonin  V. I.  Roskina  E. A.  Safronov  V. V.  Tatsiy  L. P. 《Solar System Research》2021,55(5):437-445

Solar System Research - The ionization-type cosmic dust detector METEOR-L is being developed for the lunar orbiter Luna-26 and is designed to study the distribution of meteoric bodies in space by...  相似文献   

基于地理国情数据的城市扩张和生态格局分析——以武汉市为例   总被引：1，自引：0，他引：1  

厉芳婷  张过  贾继鹏 《测绘通报》2020,(11):93-98

城市扩张是城镇化的主要特征，研究城市扩张规律对城市空间规划、高质量发展提供决策依据。本文以武汉市为研究区，以2015—2018年地理国情监测成果为主要数据源，通过数据整理与提取、计算城市扩张特征指数、提取城市格局变化、计算生态景观指数等处理，对研究区城市扩张和生态格局变化特征进行分析。研究结果表明：2015—2018年间，武汉市从快速扩张阶段逐渐减缓，紧凑度逐渐下降；中心城市扩张主要以种植土地破坏为代价；远城区快速扩张主要以林草面积减少为代价；在生态指数上，各生态景观类型破碎度均有下降，但水域面积保持良好。  相似文献   

A comparison of network model creation algorithms based on the quality of wayfinding results     

Jinwoo Park  Daniel W. Goldberg  Tracy Hammond 《Transactions in GIS》2020,24(3):602-622

Various network model creation algorithms have been introduced to demonstrate a better approximation of the actual walking pattern and to provide a better wayfinding guide. However, it is under‐investigated which algorithm creates the most appropriate indoor navigation network model in the context of wayfinding applications. Due to the lack of discussion, some studies unconsciously extended an algorithm designed for creating an outdoor navigation network model to indoor space applications. This is problematic because indoor space has different spatial contexts from outdoor space, such as non‐linear space and no‐designated walking space. Our solution is to select five well‐known algorithms that have been introduced, to reproduce the algorithm for the automated construction of the indoor navigation network model, and to evaluate the applicability of algorithms for indoor wayfinding applications. This article compares the quality of wayfinding results from the output of the indoor navigation network model against two criteria: route efficiency (i.e., length) and route simplicity (i.e., number of directions). Our statistical analysis illustrates that the visibility graph algorithm is the most appropriate for indoor wayfinding applications.  相似文献   

Estimates of Extragalactic Background and Confusion Noise Parameters for the Millimetron Telescope     

Ermash  A. A.  Pilipenko  S. V.  Lukash  V. N. 《Astronomy Letters》2020,46(5):298-311

Astronomy Letters - The sensitivity of future far-infrared telescopes, such as Millimetron, will be limited by the confusion noise produced by distant galaxies. We have constructed a model of the...  相似文献   

Quantifying sand delivery to deep water during changing sea-level: Numerical models from the Quaternary Brazos Icehouse continental margin     

Oriol Falivene  Bradford E. Prather  John Martin 《Basin Research》2020,32(6):1711-1733

Sequence stratigraphy for clastic continental margins predicts the development of sand-rich turbidite deposits during specific times in relation to base-level cycles. It is now widely understood that deltas can extend to the shelf-edge forced by high sediment flux and/or base level, providing a direct connection to transfer sediment and sand to the slope and basin floor even during high base level periods. Herein, we build a stratigraphic forward model for the last 120 kyr of the fluvio-deltaic to deep-water Brazos system (USA) where sediment partitioning along an Icehouse continental margin can be evaluated. The reduced-complexity stratigraphic forward model employs geologically constrained input parameters and mass balance. The modelled architecture is consistent with the location of depositional units previously mapped in the shelf. Sand bypasses the shelf and upper slope between 35 to 15 kyr before present and only about 20%–30% of all the sediment and sand supplied to the system is transferred to deep water. Several scenarios based on the initial Brazos model investigate the relationships between base level and deep-water sand ratio (DWSR). DWSR is defined as the relative amount of sand transferred to the deep-water portions of the system subdivided by the total sand input to the model. Linear correlations between DWSR and base level change rates or base level are very poor. Short-term variability due to local processes (for example avulsions) is superimposed to the long-term trends and mask the base level signal. DWSR for an entire base-level cycle is mainly controlled by the proportion of time the delta stays docked at the shelf-edge. Stratigraphic forward models are useful to complement field observations and quantify how different processes control stratigraphy, which is important for making predictions in areas with limited information.  相似文献   

Retrieving Sea Wave Spectra Based on High Resolution Satellite Imagery under Different Conditions of Wave Generation     

Bondur  V. G.  Vorobyev  V. E.  Murynin  A. B. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(9):887-897

Izvestiya, Atmospheric and Oceanic Physics - A method for retrieving sea wave spectra from space images of high spatial resolution has been developed for various conditions of wave generation based...  相似文献   

Plant Steroid Hormones As Unique Constituents of Devonian Oils of Belarus     

Garetsky  R. G.  Gribik  Ya. G.  Litvinovskaya  R. P.  Savchuk  A. L.  Mardosevich  M. A.  Khripach  V. A. 《Doklady Earth Sciences》2020,494(1):688-690

Doklady Earth Sciences - The content of plant hormones (brassinosteroids) in oil samples from a number of oilfields in Belarus is determined using an enzyme immunoassay method. Brassinosteroids of...  相似文献   

Content and Composition of Hydrocarbons in Water and Sediments in the Area of Kerch Strait     

Nemirovskaya  I. A.  Zavyalov  P. O.  Konovalov  B. V.  Khramtsova  A. V. 《Doklady Earth Sciences》2020,492(1):387-391

Doklady Earth Sciences - The results of studying the content and composition of aliphatic hydrocarbons (AHCs) and polycyclic aromatic hydrocarbons (PAHs) in the suspended particulate matter of the...  相似文献   

Geochemical Composition of Dolerites as an Indicator of the Distance of a Dike Swarm from the Mantle Plume Center (Case Study of Proterozoic Dike Swarms,Siberian Craton)     

Gladkochub  D. P.  Donskaya  T. V. 《Doklady Earth Sciences》2020,491(2):243-246

Doklady Earth Sciences - Based on investigation of Proterozoic mafic dike swarms of the Siberian Craton, we inferred how the geochemical and isotopic characteristics of dike swarms of dolerites of...  相似文献