scholarly journals Effects of spatial grain size on different types of cultivated land landscape pattern in fragmented agricultural landscapes based on GF-2 imagery

2020 ◽  
Vol 502 ◽  
pp. 012044
Author(s):  
Jingjing Wang ◽  
Ling Sun ◽  
Zhiming Wang ◽  
Jie Shan ◽  
Xiaojun Huang ◽  
...  
Keyword(s):  
Grain Size ◽  
Landscape Pattern ◽  
Agricultural Landscapes ◽  
Cultivated Land ◽  
Different Types ◽  
Spatial Grain

scholarly journals Spatial Distribution and Land Use of Traditional Villages in Southwest China

2021 ◽  
Vol 13 (11) ◽  
pp. 6326
Author(s):  
Xiye Zheng ◽  
Jiahui Wu ◽  
Hongbing Deng
Keyword(s):  
Cultural Heritage ◽  
Influencing Factors ◽  
Landscape Pattern ◽  
Southwest China ◽  
Spatial Clustering ◽  
Interaction Mechanism ◽  
Cultivated Land ◽  
River Population ◽  
Local Conditions ◽  
Countermeasures And Suggestions

Traditional villages are the historical and cultural heritage of people around the world. With the increases in urbanization and industrialization, the continuation of traditional villages and the inheritance of historical and cultural heritage are facing risk. Therefore, to grasp the spatial characteristics of them and the human–nature interaction mechanism in Southwest China, we analyzed the distribution pattern of traditional villages using the ArcGIS software. Then, we further analyzed the spatial clustering characteristics, influencing factors and landscape pattern, and put forward relevant protection countermeasures and suggestions. The results revealed that traditional villages in Southwest China were clustered, being mainly distributed in areas with relatively low elevation, gentle slopes, low relative positions, nearby water sources, and convenient transportation. They can be divided into four categories due to obvious differences in influencing factors such as elevation, slope, relative position, distance to the nearest river, population density, etc. The landscape pattern of traditional villages differed among the different clusters, being mainly composed of forests, shrubs, and cultivated land. With the increase in the buffer radius, the landscape pattern of them changed significantly. The results of this study reflect that traditional villages and the natural environment are interdependent, so the protection of traditional villages should carry out measures according to local conditions.

Multiscale Effects of Grain Size on Landscape Pattern Analysis

Annals of GIS ◽  
2000 ◽  
Vol 6 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Joyce M. Francis ◽  
Jeffrey M. Klopatek
Keyword(s):  
Grain Size ◽  
Landscape Pattern ◽  
Pattern Analysis ◽  
Landscape Pattern Analysis

scholarly journals Woodlot farming by smallholder farmers in Ganderbal district of Kashmir, India

2021 ◽  
Vol 13 (2) ◽  
pp. 752-759
Author(s):  
Azeem Raja ◽  
M. A. Islam ◽  
T. H. Masoodi ◽  
P. A. Khan ◽  
A. A. Wani ◽  
...  
Keyword(s):  
Land Use ◽  
Smallholder Farmers ◽  
Geographical Area ◽  
Sampling Technique ◽  
Forest Degradation ◽  
Agricultural Landscapes ◽  
Primary Data ◽  
Cultivated Land ◽  
Secondary Sources ◽  
Growing Stock

Forest degradation and deforestation are serious threats to resource conservation, subsistence livelihoods and rural income diversification. Woodlot farming on farms has been established as a potential option to increase forest resources from agricultural landscapes and remove human pressure from forests. The study investigated the land-use and landholding pattern, woodlots types and species preference and extent of spatial distribution, land allocation and growing stock of woodlots in the Ganderbal district of Kashmir. Multistage random sampling technique was employed to select 349 farm woodlots from 12 sample villages. Secondary sources were used to collect village-level data on land-use and landholding pattern. Primary data concerning the trees were collected through farm woodlot inventories. The data were analyzed using simple descriptive statistics. Results revealed that the total land area in the sample villages is 888.60 ha; 521.60 ha (58.70%) is cultivated land, which is mostly (80.78%) occupied by 1244 marginal farmers. The prevalent woodlots established were plantations of Populus, Salix, Robinia or mixed species. The farm woodlots (61.59 ha) contributed 11.81% of cultivated land and 6.93% of the total geographical area. The average growing stocks of woodlots were estimated to be 204.05 m3/ha for Populus, 191.77 m3/ha for Salix, 109.51 m3/ha for Robinia and 62.31 m3/ha for Mixed. The findings suggested that woodlot farming is the key alternative for forest resource production, livelihood resilience and socioeconomic improvement; hence, the policy must be implicated towards the promotion of woodlot farming by re-orienting the land use through farmer’s motivation and technical, financial and farming input assistance.

The Correlation Theory of 2D Normal Grain Growth

2004 ◽  
Vol 467-470 ◽  
pp. 1081-1086 ◽  
Author(s):  
M.W. Nordbakke ◽  
N. Ryum ◽  
Ola Hunderi
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Growth ◽  
Grain Size Distribution ◽  
Computer Simulations ◽  
Mean Field Theory ◽  
Mean Field ◽  
Grain Structures ◽  
Spatial Grain ◽  
Kinetics Of

Computer simulations of 2D normal grain growth have shown that size correlations between adjacent grains exist in 2D grain structures. These correlations prevail during the coarsening process and influence on the kinetics of the process and on the grain size distribution. Hillert’s analysis starts with the assumption that all grains in the structure have the same environment. Since computer simulations contradict this assumption, the mean-field theory for normal grain growth needs to be modified. A first attempt was made by Hunderi and Ryum, who modified Hillert’s growth law to include the effect of spatial grain size correlations. In the 1D case the distributions derived by means of the modified growth law agreed well with simulation data. However, the distribution derived for 2D grain growth retained unwanted properties of the Hillert distribution. We review some recent progress in developing a mean-field statistical theory. A paradox related to curvilinear polygons is shown to support the expectation that the grain size distribution has a finite cutoff.

The anatomy and interpretation of an Archean volcaniclastic sequence, Noranda region, Quebec

1978 ◽  
Vol 15 (6) ◽  
pp. 874-888 ◽  
Author(s):  
Normand Tassé ◽  
Jean Lajoie ◽  
Erich Dimroth
Keyword(s):  
Grain Size ◽  
Primary Structure ◽  
Debris Flows ◽  
Fragment Size ◽  
Type A ◽  
Type B ◽  
Pyroclastic Rocks ◽  
Different Types ◽  
Vertical Variations ◽  
Bed Thickness

Archean pyroclastic rocks at Reneault and D'Alembert in the Noranda region are composed of crystals and lithic, vitric and pumiceous fragments. The pyroclastic rocks contain two types of beds, whose primary structure sequences and other characteristics show that the deposits accumulated from different types of density flows. The first bed-type (A) is characterized by greater bed-thickness, reverse grading and the coarsest fragments in the deposit. Closest to source, the primary structure sequence in Type A beds is indicative of deposition from debris flows, but in more distal sections it suggests deposition from turbulent suspensions. The second bed-type (B) is characterized by a smaller fragment size, thinner beds, normal grading and the presence of parallel and (or) oblique stratifications. The primary structure sequence in Type B beds is similar to that observed in turbidites, which suggests deposition from turbulent suspensions of low density.Lateral and vertical variations of grain size, bed thickness and structure sequences indicate that the vent was south of Reneault and that the volcanic activity increased with time. Pillowed flows both underlie and overlie the pyroclastic units which suggests accumulation under water, but there is evidence that some eruptions were subaerial.

Effects of Processing Factors on Microstructure and Diffusivity of Diethylbenzene Dehydrogenation Catalyst

2010 ◽  
Vol 297-301 ◽  
pp. 233-238
Author(s):  
Mohammad Ebrahim Zeynali ◽  
I. Soltani
Keyword(s):  
Grain Size ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Bulk Diffusion ◽  
Effective Diffusivity ◽  
Catalyst Pellet ◽  
Different Types ◽  
Effective Diffusivities ◽  
Processing Factors

In this study, different mechanisms of diffusion such as Knudsen and bulk were investigated for diethylbenzene diffusion into a catalyst and it was concluded that the pore sizes should be in the range that permit transitional diffusion (both Knudsen and bulk diffusion). The catalyst grain size can be controlled and varied by different parameters such as speed and time of mixing, type of alkali, temperature and pH. Particle size distribution experiments were conducted for different types of alkali and speed of mixing to characterize the catalyst. The effects of grain size formed during coprecipitation on pore size distribution of the catalyst pellet which affect the effective diffusivity were discussed. Pore size distribution of the model catalyst was obtained and the effective diffusivities were calculated by numerical integration of Johanson-Stewart equation.

scholarly journals Relation between grain-size and correlation length of snow

2002 ◽  
Vol 48 (162) ◽  
pp. 461-466 ◽  
Author(s):  
Christian Mätzler
Keyword(s):  
Grain Size ◽  
Correlation Length ◽  
Granular Media ◽  
Structural Information ◽  
Volume Ratio ◽  
Measurement Procedure ◽  
Different Types ◽  
Long Time ◽  
Points Of View ◽  
Two Parameters

AbstractIn the past it has often been difficult to compare results of different types of snow-structural information. Grain-size and correlation length are such parameters of granular media, and there exist different definitions and different measurement methods for both of them. The relation between these parameters is analyzed from theoretical and from experimental points of view, considering optical and microwave properties. For spherical ice grains the connecting formulas are simple, but for other shapes the two parameters are not directly related. Care must be taken in the measurement procedure. Especially if grain-size is regarded as the maximum extent of connected ice particles, the results are likely to lead to extreme overestimates. Therefore it is concluded that grain-size should be complemented by an additional size parameter, namely, the surface-to-volume ratio of equivalent spheres, i.e. a measure of the correlation length. Methods to determine this quantity in the laboratory have been known for a long time. Methods to obtain such measurements in the field are described here.

Delineation of river bed-surface patches by clustering high-resolution spatial grain size data

Geomorphology ◽  
2014 ◽  
Vol 205 ◽  
pp. 102-119 ◽  
Author(s):  
Peter A. Nelson ◽  
Dino Bellugi ◽  
William E. Dietrich
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Surface Patches ◽  
River Bed ◽  
Spatial Grain ◽  
Size Data

scholarly journals Effect of Roughness on Discharge

2013 ◽  
Vol 4 (3) ◽  
pp. 29-33 ◽  
Author(s):  
T.W. Lau ◽  
N.R. Afshar
Keyword(s):  
Grain Size ◽  
Flow Rate ◽  
Roughness Coefficient ◽  
Coefficient Increase ◽  
Different Types ◽  
Channel Slope ◽  
Experimental Works ◽  
Bed Roughness ◽  
Material Grain Size ◽  
Effect Of Surface

These Water resource projects and hydraulic engineering works have been developing rapidly throughout the world, thus prediction of water roughness coefficient is becoming an importance criteria for the designs of hydraulic related structure like open channel, and dam structure. The purposes of this research are to determine the effect of roughness on discharge and study on the factors that affect roughness coefficient. The roughness coefficient for this study is expressed in terms of Manning’s n. Experimental works were carried out to study the effect of roughness by using flumes (8m x 0.3m x 0.4m) with different types of roughened bed such as 2mm grain size plate and 5mm grain size plate. The experiments were being tested with various flow rates for slope equal to 1:300, 1:600 and 1:900 to determine the effect of slope on roughness coefficient. The results of the experimental study were presented and shown that the effect of surface roughness, material grain size, channel slope, and Manning’s roughness coefficient on flow rate. For the range of conditions tested, the discharge was found to be decreased as roughness coefficient increase. From the experiments, it shows smoother surface is having lower roughness coefficient and less retarding effect on the water flow, higher flow rate is produced. As conclusion, flow rate and roughness coefficient were influenced by bed roughness and slope.

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