scholarly journals Statistical analysis of distribution patterns of coal seams in fold zones in Northwest China

2018 ◽  
Vol 28 (5) ◽  
pp. 819-828 ◽  
Author(s):  
Anye Cao ◽  
Guangcheng Jing ◽  
Linming Dou ◽  
Yun Wu ◽  
Chengguo Zhang
Keyword(s):  
Statistical Analysis ◽  
Distribution Patterns ◽  
Northwest China ◽  
Coal Seams

scholarly journals The constraints and driving forces of oasis development in arid region: a case study of the Hexi Corridor in northwest China

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qiang Bie ◽  
Yaowen Xie
Keyword(s):  
Arid Region ◽  
Driving Forces ◽  
Distribution Patterns ◽  
Northwest China ◽  
Hexi Corridor ◽  
Arid Land ◽  
Heat Condition ◽  
Sustainable Planning ◽  
The Index System ◽  
Oasis Area

Abstract The oasis, a special landscape with the integration of nature and humanity in the arid region, has undergone an enormous transformation during the past decades. To gain a better understanding of the tradeoff between economic growth and oases stability in the arid land, we took the oases in the Hexi Corridor as a case to explore the constraints of oases development and the driving factors of oases expansion. The dynamic changes and spatial distribution patterns underwent by the oases were examined using multispectral remote sensing imagery. The constraints of oasis development in arid land were investigated by the grid-transformed model, as well as the index system of driving forces was analyzed using the grey incidence model based on the data from statistics yearbooks. The oasis area in the Hexi Corridor had tremendous changes expanded 40% from 1986 to 2015, the stable oasis area was 9062 km2, while the maximum area reached 16,374 km2. The constraints for oases of topography, hydrology and heat condition are as follow: The elevation of oasis ranged from 1000 to 1800 m, peaked in 1500 m; the slope of oasis distribution was flatter than 3 degrees; the aspect of oases on slope land concentrated in northeast and north, accounting for more than 60%. The main driving forces of oasis spatial expansion in the arid region were population, water resource, economy, policies, and other factors. These results are expected to (1) improve the rationality of oasis development, and (2) promote the sustainable planning and management of oases in the arid land.

Statistical analysis of groundwater chemistry of the Tarim River lower reaches, Northwest China

2011 ◽  
Vol 65 (6) ◽  
pp. 1807-1820 ◽  
Author(s):  
Jianhua Xu ◽  
Yaning Chen ◽  
Weihong Li ◽  
Lijun Zhang ◽  
Yulian Hong ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Northwest China ◽  
Groundwater Chemistry ◽  
Tarim River ◽  
The Tarim River

Mapping and analysis of distribution patterns of lichens on rural medieval churches in north-eastern Germany

2001 ◽  
Vol 33 (3) ◽  
pp. 231-248 ◽  
Author(s):  
Bettina Weber ◽  
Burkhard Büdel
Keyword(s):  
Statistical Analysis ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Lichen Species ◽  
Habitat Factors ◽  
Wide Range ◽  
North Eastern ◽  
Detailed Statistical Analysis ◽  
Stone Walls ◽  
Important Habitat

AbstractLichen communities were examined on 62 churches in Mecklenburg–Vorpommern, Germany. Ninety-six lichen species and subspecies, and three species of lichenicolous fungi identified. Tylothallia biformigera and Lecanora campestris subsp. dolomitica are reported as new Germany, and another 20 species are considered as threatened. This implies that the stone walls churches represent an extremely important habitat in Mecklenburg–Vorpommern, where natural outcrops are rare. The distribution of lichen species was analyzed quantitatively in relation to several habitat factors. Aspect, substratum and inclination were found to be important factors for 35, 34 31 species, respectively. The height of the relevé was a significant factor for many species. Twenty-three species, which are described in the literature with oceanic to suboceanic distributions, occur significantly more frequently near the coast. The ways in which microclimate affects each these habitat factors and contributes to the presence or absence of a species or group of species discussed. Some species have narrow and specific habitat demands, whereas others thrive under wide range of environmental conditions. The advantages of a strictly schematic approach with detailed statistical analysis are discussed.

scholarly journals Biodiversity of wild alfalfa pollinators and their temporal foraging characters in Hexi Corridor, Northwest China

2019 ◽  
Vol 23 (1) ◽  
pp. 4-12 ◽  
Author(s):  
Xiaojuan Wang ◽  
Hongping Liu ◽  
Lichun Huang ◽  
Shuzhen Zhang ◽  
Zhigang Deng ◽  
...  
Keyword(s):  
Distribution Patterns ◽  
Northwest China ◽  
Hexi Corridor ◽  
Wild Bees ◽  
Community Function ◽  
Native Bee ◽  
Diurnal Distribution ◽  
Medicago Sativa L ◽  
Insect Visitors ◽  
Effective Distribution

Seed production of alfalfa (Medicago sativa L.) is important in determining the effective distribution of new cultivars to farmers. However, little is known about the biodiversity and their community function of native wild pollinators of alfalfa in agronomic systems. We investigated the biodiversity of insects which visited alfalfa flowers and their temporal foraging characters in Hexi Corridor, China. A high biodiversity of insect visitors was discovered, 20 insect taxa in all, including 13 species of Hymenoptera, 3 species of Coleoptera, 3 species of Lepidoptera and 1 species of Diptera. Three native bee species, Andrena squamata, Anthophora melanognatha and Megachile abluta,were validated as the principal pollinators. They showed significant variations in tripping mode and their diurnal distribution patterns. Our results indicated that the native wild bees are diverse and they complement each other. This means they have developed a more complex system for the pollination of alfalfa than has been previously found out.

scholarly journals SPATIAL ANALYSIS OF EROSIVE PROCESSES IN PLATEAUS AND DEPRESSIONS OF THE UPPER PARAGUAI RIVER BASIN

GEOGRAFIA ◽  
2018 ◽  
Vol 42 (3) ◽  
pp. 145-157
Author(s):  
Daniel Dias de ANDRADE ◽  
João dos Santos Vila da SILVA ◽  
Vera Aparecida FIGUEIREDO ◽  
Elisa Calhau de CASTRO
Keyword(s):  
Statistical Analysis ◽  
Spatial Analysis ◽  
River Basin ◽  
Spatial Dependence ◽  
Distribution Patterns ◽  
Drainage Basins ◽  
Entire Area ◽  
Mato Grosso ◽  
Natural Characteristics ◽  
Frequency Diagram

Natural characteristics may contribute to the erosion of the soil and to environmental imbalances, and in most cases, they initiate the imbalances that will be exacerbated by human activities. The presence of asymmetry in a frequency diagram is a valuable fact, and may indicate irregularity in the occurrence of events or aggregation of events in preferred locations. Thus, this work aims to demonstrate the use of Geographic Information Systems (GIS) of statistical analysis based on patterns of frequency, density, distribution and spatial dependence of sample points through a cutout of the mapping of the geotechnical aspects conducted for the State of Mato Grosso, generated for the entire area of plateaus and depressions of the Upper Paraguai river basin and its internal units of drainage basins. In most cutouts used in the analysis, the values indicated that is void the possibility that the distribution patterns of erosive events were resulted of chance. The aggregate pattern shown may tend to attract new points, facilitating the transmission of the sample.s qualities through these, favored by your proximity and by the characteristics of the occurrence area

scholarly journals Petrography, Mineralogy, and Geochemistry of Combustion Metamorphic Rocks in the Northeastern Ordos Basin, China: Implications for the Origin of “White Sandstone”

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1086
Author(s):  
Bin Chen ◽  
Yanyan Wang ◽  
Marco Franceschi ◽  
Xiong Duan ◽  
Kuizhou Li ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Ordos Basin ◽  
Northwest China ◽  
Metamorphic Rocks ◽  
Coal Seams ◽  
Quaternary Period ◽  
X Ray ◽  
Coal Fire ◽  
Icp Ms ◽  
Coal Fires

Since the Quaternary period, tectonic uplift and river erosion in the northeastern Ordos Basin (northwest China) have exhumed numerous coal seams, creating the conditions for the development of coal fires following their spontaneous combustion or other types of ignition (e.g., lightning strikes). Coal fires activity is testified by the widespread occurrence of combustion metamorphic rocks. In this study, thin section analyses, scanning electron microscopy, X-ray diffraction (XRD), X-ray fluorescence (XRF), and inductively coupled plasma mass spectrometry (ICP-MS) were used to investigate in detail the mineralogical and geochemical characteristics of combustion metamorphic rocks in the Jurassic succession of the northeastern Ordos Basin. The samples collected in localities distributed over an area of about 8000 km2 were analyzed to determine their mineral association, revealing the presence of tridymite, cristobalite, mullite, and cordierite that are typically produced in pyrometamorphic reactions. XRF and ICP-MS analyses revealed that combustion metamorphic rocks are iron-enriched. Investigations in the study area also highlighted the occurrence of a peculiar, porous, and permeable white sandstone that appears often associated with clinkers or coal seams. It is composed of quartz and feldspar grains and cemented by kaolinite. It is here suggested that the white color of this sandstone could be due to coal fire-related kaolinization of a sandstone protolith produced by the acidic low-temperature hydrothermal circulation of rain waters during times of coal fire activity.

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