The Impacts of Groundwater Chemistry on Wetland Vegetation Distribution in the Northern Qinghai–Tibet Plateau

Groundwater chemistry has an important impact on the vegetation distribution in inland areas. An in-depth understanding of the impact of groundwater chemistry on vegetation can help in developing an effective management strategy to protect the inland ecosystem. The aim of this study was to identify the influence of groundwater chemicals on species diversity and the distribution characteristics of wetland plants at multiple scales based on the groundwater chemical data from 15 sampling points and the distribution data of 13 plants in the Sugan Lake Wetland in 2016. The results show that the groundwater of the Sugan Lake Wetland is weakly alkaline, with high salinity and hardness; the water chemical type is Na-SO4-Cl; the concentration of the major water chemical parameters is significantly different and is the highest in the northwest, followed by the southwest, and is the lowest in the east; with an increase in the groundwater depth, the concentration of major water chemical parameters first showed an increasing trend followed by a decreasing trend; Artemisia frigida Willd, Poa annua L. and Triglochin maritimum L. were adapted to the environment with a higher ion concentration of the groundwater, and their salt resistance was the strongest; Blysmus sinocompressus and Polygonum are more adapted to the environment with lower salinity and hardness of groundwater; Thermopsis lanceolata has stronger adaptability to the ion concentration, salinity, and hardness of groundwater; other plants are adapted to environments where the ion concentration, salinity, and hardness of the groundwater are moderate.

Download Full-text

Submikroninių aerozolio dalelių kilmės ir fizikinių-cheminių parametrų įtaka atmosferos šiluminei pusiausvyrai

10.15388/vu.thesis.102 ◽

2020 ◽

Author(s):

◽

Julija Pauraitė-Dudek

Keyword(s):

Chemical Parameters ◽

Radiative Balance ◽

Submicron Aerosol ◽

Physical Chemical ◽

The Impact ◽

Aerosol Source

The impact of submicron aerosol source and physical-chemical parameters on atmospheric radiative balance

Download Full-text

Impact of COVID-19 Pandemic on Retail Structure in Barcelona: From Tourism-Phobia to the Desertification of City Center

Sustainability ◽

10.3390/su13158215 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8215

Author(s):

Lluís Frago Clols

Keyword(s):

Multiple Scales ◽

Real Estate Market ◽

Structured Interviews ◽

City Center ◽

Urban Theory ◽

The Real Estate ◽

Tourist Flows ◽

Before And After ◽

The Impact ◽

The City

COVID-19 has meant major transformations for commercial fabric. These transformations have been motivated by the collapse of consumer mobility at multiple scales. We analyzed the impact of the collapse of global tourist flows on the commercial fabric of Barcelona city center, a city that has been a global reference in over-tourism and tourism-phobia. Fieldwork in the main commercial areas before and after the pandemic and complementary semi-structured interviews with the main agents involved highlight the relationship between global tourist flows and commercial fabric. The paper shows how the end of global tourism has meant an important commercial desertification. The end of the integration of the city center into global consumer flows has implications for urban theory. It means a downscaling of the city center and the questioning of traditional center-periphery dynamics. It has been shown that the tourist specialization of commerce has important effects on the real estate market and makes it particularly vulnerable. However, the touristic specialization of commercial activities as a strategy of resilience has also been presented. This adaptation faces the generalized commercial desertification that drives the growing concentration of consumption around the online channel.

Download Full-text

Characterizing Hydrological Connectivity of Artificial Ditches in Zoige Peatlands of Qinghai-Tibet Plateau

Water ◽

10.3390/w10101364 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1364 ◽

Cited By ~ 6

Author(s):

Zhiwei Li ◽

Peng Gao ◽

Yuchi You

Keyword(s):

Google Earth ◽

Tibet Plateau ◽

Annual Rainfall ◽

Water Volume ◽

Hydrological Connectivity ◽

Total Water ◽

Zoigê Basin ◽

The Impact ◽

Qinghai Tibet Plateau ◽

Peatland Degradation

Peats have the unique ability of effectively storing water and carbon. Unfortunately, this ability has been undermined by worldwide peatland degradation. In the Zoige Basin, located in the northeastern Qinghai-Tibet Plateau, China, peatland degradation is particularly severe. Although climate change and (natural and artificial) drainage systems have been well-recognized as the main factors catalyzing this problem, little is known about the impact of the latter on peatland hydrology at larger spatial scales. To fill this gap, we examined the hydrological connectivity of artificial ditch networks using Google Earth imagery and recorded hydrological data in the Zoige Basin. After delineating from the images of 1392 ditches and 160 peatland patches in which these ditches were clustered, we calculated their lengths, widths, areas, and slopes, as well as two morphological parameters, ditch density (Dd) and drainage ability (Pa). The subsequent statistical analysis and examination of an index defined as the product Dd and Pa showed that structural hydrological connectivity, which was quantitatively represented by the value of this index, decreased when peatland patch areas increased, suggesting that ditches in small patches have higher degrees of hydrological connectivity. Using daily discharge data from three local gauging stations and Manning’s equation, we back-calculated the mean ditch water depths (Dm) during raining days of a year and estimated based on Dm the total water volume drained from ditches in each patch (V) during annual raining days. We then demonstrated that functional hydrological connectivity, which may be represented by V, generally decreased when patch areas increased, more sensitive to changes of ditch number and length in larger peatland patches. Furthermore, we found that the total water volume drained from all ditches during annual raining days only took a very small proportion of the total volume of stream flow out of the entire watershed (0.0012%) and this nature remained similar for the past 30 years, suggesting that during annual rainfall events, water drained from connected ditches is negligible. This revealed that the role of connected artificial ditches in draining peatland water mainly takes effect during the prolonged dry season of a year in the Zoige Basin.

Download Full-text

Variation of Runoff and Runoff Components of the Upper Shule River in the Northeastern Qinghai–Tibet Plateau under Climate Change

Water ◽

10.3390/w13233357 ◽

2021 ◽

Vol 13 (23) ◽

pp. 3357

Author(s):

Jinkui Wu ◽

Hongyuan Li ◽

Jiaxin Zhou ◽

Shuya Tai ◽

Xueliang Wang

Keyword(s):

Climate Change ◽

Sustainable Use ◽

Reduction Rate ◽

Northwest China ◽

Tibet Plateau ◽

Glacier Area ◽

Rainfall Runoff ◽

Total Runoff ◽

Increasing Temperature ◽

The Impact

Quantifying the impact of climate change on hydrologic features is essential for the scientific planning, management and sustainable use of water resources in Northwest China. Based on hydrometeorological data and glacier inventory data, the Spatial Processes in Hydrology (SPHY) model was used to simulate the changes of hydrologic processes in the Upper Shule River (USR) from 1971 to 2020, and variations of runoff and runoff components were quantitatively analyzed using the simulations and observations. The results showed that the glacier area has decreased by 21.8% with a reduction rate of 2.06 km2/a. Significant increasing trends in rainfall runoff, glacier runoff (GR) and baseflow indicate there has been a consistent increase in total runoff due to increasing rainfall and glacier melting. The baseflow has made the largest contribution to total runoff, followed by GR, rainfall runoff and snow runoff, with mean annual contributions of 38%, 28%, 18% and 16%, respectively. The annual contribution of glacier and snow runoff to the total runoff shows a decreasing trend with decreasing glacier area and increasing temperature. Any increase of total runoff in the future will depend on an increase of rainfall, which will exacerbate the impact of drought and flood disasters.

Download Full-text

Reply to the comment by Morales et al. on “Population genetics reveal Myotis keenii (Keen’s myotis) and Myotis evotis (long-eared myotis) to be a single species”

Canadian Journal of Zoology ◽

10.1139/cjz-2020-0266 ◽

2021 ◽

pp. 423-432

Author(s):

C.L. Lausen ◽

Michael F. Proctor ◽

David Paetkau ◽

David W. Nagorsen ◽

Purnima Govindarajulu ◽

...

Keyword(s):

Population Genetics ◽

Population Structure ◽

Single Species ◽

Distinct Species ◽

Background Information ◽

Distribution Data ◽

Supporting Evidence ◽

Post Mortem ◽

The Impact ◽

New Evidence

A.E. Morales et al. (2021. Can. J. Zool. 99(5): 415–422) provided no new evidence to alter the conclusions of C.L. Lausen et al. (2019. Can. J. Zool. 97(3): 267–279). We present background information, relevant comparisons, and clarification of analyses to further strengthen our conclusions. The genesis of the original “evotis–keenii” study in British Columbia (Canada) was to differentiate Myotis keenii (Merriam, 1895) (Keen’s myotis), with one of the smallest North American bat distributions, from sympatric Myotis evotis (H. Allen, 1864) (long-eared myotis), using something other than the suggested post-mortem skull size comparison, but no differentiating trait could be found, leading to the molecular genetics examination of C.L. Lausen et al. (2019). We present cumulative data that rejects the 1979 hypothesis of M. keenii as a distinct species. A.E. Morales et al. (2021) inaccurately portray C.L. Lausen et al.’s (2019) question and results; present inaccurate morphological and outdated distribution data; overstate the impact of homoplasy without supporting evidence; and misinterpret evidence of population structure.

Download Full-text

A geomorphometric approach to estimate soil volumes stored in agricultural terrace systems

10.5194/egusphere-egu21-1772 ◽

2021 ◽

Author(s):

Sara Cucchiaro ◽

Guido Paliaga ◽

Daniel J. Fallu ◽

Ben R. Pears ◽

Kevin Walsh ◽

...

Keyword(s):

High Resolution ◽

Laser Scanning ◽

Large Scale ◽

Multiple Scales ◽

Anthropogenic Activities ◽

New Technology ◽

Agricultural Systems ◽

Soil Thickness ◽

The Impact ◽

Geomorphological Features

<p>Geomorphometric information can be exploited to study the most extensive and common landforms that humans have ever produced: agricultural terraces. An understanding of these historical ecosystems can only be determined through in-depth knowledge of their origin, evolution, and current state in the landscape. These factors can ultimately assist in the future preservation of such landforms in a world increasingly affected by anthropogenic activities. High-resolution topographic (HRT) techniques allow the mapping and characterization of geomorphological features with wide-ranging perspectives at multiple scales. From HRT surveys, it is possible to produce high-resolution Digital Terrain Models (DTMs) to extract important geomorphometric parameters such as topographic curvature, to identify terrace edges, even if abandoned or covered by uncontrolled vegetation. By using riser bases as well as terrace edges (riser tops) and through the computation of minimum curvature, it is possible to obtain environmentally useful information on these agricultural systems such as terrace soil thickness and volumes. The quantification of terrace volumes can provide new benchmarks for soil erosion models, new perspectives for land and stakeholders for terrace management in terms of natural hazard and offer a measure of the effect of these agricultural systems on soil organic carbon (SOC) sequestration. This work aims to realize and test an innovative and rapid methodological workflow to estimate the minimum anthropogenic reworked and moved soil of terrace systems in different landscapes. This aspect of new technology and its application to terrace soil-systems has not been fully explored in the literature. We start with remote terrace mapping at a large scale (using Airborne Laser Scanning) and then utilize more detailed HRT surveys (i.e., Structure from Motion and Terrestrial Laser Scanning) to extract geomorphological features, from which the original theoretical slope-surface of terrace systems were derived. These last elements were compared with in-field sedimentological recording obtained from the excavations across the study sites to assess the nature of sub-surface topographies. The results of this work have produced accurate DTMs of Difference (DoD) for three terrace sites in central Europe in Italy and Belgium. The utilization of ground-truthing through field excavation and sampling has confirmed the reliability of the methodology used across a range of sites with very specific terrace morphologies, and in each case has confirmed the nature of the reconstructed, theoretical original slope. Differences between actual and theoretical terraces from DTM and excavation evidence have been used to estimate the minimum soil volumes and masses used to remould slopes. Moreover, geomorphometric analysis through indices such as sediment connectivity permitted also to quantify the volume of sediment transported downstream, with the associated and mobilized C, after a collapsed terrace. The quantification of terrace soil volumes provides extremely useful standards for further multi-disciplinary analysis on the terrace sediments themselves, aiding physical geographers, geoarchaeologists, palaeo-environmentalists, and landscape historians in the understanding of terrace systems and the impact of agricultural processes on the landscape.</p>

Download Full-text

Improving Fire Safety by Understanding the Fire Performance of Engineered Floor Systems and Providing the Fire Service with Information for Tactical Decision Making

10.54206/102376/zcoq6988 ◽

2012 ◽

Author(s):

Steve Kerber ◽

◽

Daniel Madrzykowski ◽

James Dalton ◽

Bob Backstrom

Keyword(s):

Decision Making ◽

Multiple Scales ◽

Fire Service ◽

Metal Plate ◽

The Body ◽

Fuel Load ◽

Firefighter Safety ◽

Floor Systems ◽

Floor System ◽

The Impact

This research project was a collaboration of several research organizations, product manufacturers and fire service representatives to examine hazards associated with residential flooring systems to improve firefighter safety. Funding for this project was provided through the National Institute of Standards and Technology’s American Recovery and Reinvestment Act Grant Program. The main objective of this study was to improve firefighter safety by increasing the level of knowledge on the response of residential flooring systems to fire. Several types (or series) of experiments were conducted and analyzed to expand the body of knowledge on the impact of fire on residential flooring systems. The results of the study have been prepared to provide tactical considerations for the fire service to enable improved decision making on the fire scene. Experiments were conducted to examine several types of floor joists including, dimensional lumber, engineered I-joists, metal plate connected wood trusses, steel C-joists, castellated I-joists and hybrid trusses. Experiments were performed at multiple scales to examine single floor system joists in a laboratory up through a full floor system in an acquired structure. Applied load, ventilation, fuel load, span and protection methods were altered to provide important information about the impact of these variables to structural stability and firefighter safety. There are several tactical considerations that result from this research that firefighters can use immediately to improve their understanding, safety and decision making when sizing up a fire in a one or two family home.   This report summarizes the results from each of the experimental series and provides discussion and conclusions of the results.  

Download Full-text

Impact of High-Altitude on Truck’s Climbing Speed: Case study in Qinghai-Tibet Plateau Area in China

Journal of Advanced Transportation ◽

10.1155/2019/8560204 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14

Author(s):

Tian Lei ◽

Jinliang Xu ◽

Xingli Jia ◽

Leyu Wei ◽

Lin Tian

Keyword(s):

High Altitude ◽

Traffic Safety ◽

Field Tests ◽

Tibet Plateau ◽

Infrastructure Development ◽

Plateau Area ◽

Negative Effect ◽

High Altitude Area ◽

The Impact ◽

Different Altitudes

Truck’s climbing performance is an important consideration in traffic safety, efficiency, and highway geometric design. With the infrastructure development in high-altitude area in China, more attention needs to be paid on truck’s climbing performance in such area. In this article, truck’s climbing speed in high-altitude area was examined through field tests on different grade sections at different altitudes. Truck’s speed-distance curves were built at different altitudes and the impact of altitude on truck’s climbing speed was explored based on the test results. It was shown that, within the altitude range of 3000~5000m, altitude had an obvious influence on test truck’s decelerating and accelerating performance. Truck’s speed decreased faster on steep grades and increased slower on gentle grades with the increase of the altitude. Also, the stable speed that test truck could maintain on a certain grade was lower at a higher altitude. In addition, test truck’s theoretical speed-distance curves at the sea level were estimated through truck’s dynamic model. Compared with the theoretical crawl speed, a negative effect of altitude change (from 0 to the altitude above 3000 m) was found on truck’s climbing performance.

Download Full-text

Evaluation of Noah-MP Land-Model Uncertainties over Sparsely Vegetated Sites on the Tibet Plateau

Atmosphere ◽

10.3390/atmos11050458 ◽

2020 ◽

Vol 11 (5) ◽

pp. 458

Author(s):

Guo Zhang ◽

Fei Chen ◽

Yueli Chen ◽

Jianduo Li ◽

Xindong Peng

Keyword(s):

Heat Flux ◽

Organic Matter ◽

Soil Organic Matter ◽

Tibetan Plateau ◽

Sensible Heat Flux ◽

Limiting Factors ◽

Tibet Plateau ◽

The Tibetan Plateau ◽

Annual Total ◽

The Impact

The water budget and energy exchange over the Tibetan Plateau (TP) region play an important role on the Asian monsoon. However, it is not well presented in the current land surface models (LSMs). In this study, uncertainties in the Noah with multiparameterization (Noah-MP) LSM are assessed through physics ensemble simulations in three sparsely vegetated sites located in the central TP. The impact of soil organic matter on energy flux and water cycles, along with the influence of uncertainties in precipitation are explored using observations at those sites during the third Tibetan Plateau Experiment from 1August2014 to31July2015. The greatest uncertainties are in the subprocesses of the canopy resistance, soil moisture limiting factors for evaporation, runoff (RNF) and ground water, and surface-layer parameterization. These uncertain subprocesses do not change across the different precipitation datasets. More precipitation can increase the annual total net radiation (Rn), latent heat flux (LH) and RNF, but decrease sensible heat flux (SH). Soil organic matter enlarges the annual total LH by ~26% but lessens the annual total Rn, SH, and RNF by ~7%, 7%, and 39%, respectively. Its effect on the LH and RNF at the Nagqu site, which has a sand soil texture type, is greater than that at the other two sites with sandy loam. This study highlights the importance of precipitation uncertainties and the effect of soil organic matter on the Noah-MP land-model simulations. It provides a guidance to improve the Noah-MP LSM further and hence the land-atmosphere interactions simulated by weather and climate models over the TP region.

Download Full-text

A Multiscale Review of Behavioral Variation in Collective Foraging Behavior in Honey Bees

Insects ◽

10.3390/insects10110370 ◽

2019 ◽

Vol 10 (11) ◽

pp. 370 ◽

Cited By ~ 3

Author(s):

Natalie J. Lemanski ◽

Chelsea N. Cook ◽

Brian H. Smith ◽

Noa Pinter-Wollman

Keyword(s):

Individual Differences ◽

Foraging Behavior ◽

Collective Behavior ◽

Individual Variation ◽

Honey Bees ◽

Multiple Scales ◽

Model System ◽

Bee Foraging ◽

Collective Foraging ◽

The Impact

The emergence of collective behavior from local interactions is a widespread phenomenon in social groups. Previous models of collective behavior have largely overlooked the impact of variation among individuals within the group on collective dynamics. Honey bees (Apis mellifera) provide an excellent model system for exploring the role of individual differences in collective behavior due to their high levels of individual variation and experimental tractability. In this review, we explore the causes and consequences of individual variation in behavior for honey bee foraging across multiple scales of organization. We summarize what is currently known about the genetic, developmental, and neurophysiological causes of individual differences in learning and memory among honey bees, as well as the consequences of this variation for collective foraging behavior and colony fitness. We conclude with suggesting promising future directions for exploration of the genetic and physiological underpinnings of individual differences in behavior in this model system.

Download Full-text