scholarly journals Models for analyzing the driving force of cultivated land supply change

2004 ◽  
Vol 7 (1) ◽  
pp. 18-23
Author(s):  
Liu Yanfang ◽  
Zhang Yuqian ◽  
Xiao Bin
Keyword(s):  
Driving Force ◽  
Cultivated Land ◽  
Land Supply ◽  
Cultivated Land Supply

An Analysis on the Landscape Pattern Dynamic Changes and Driving Force in Huihe Basin

2014 ◽  
Vol 955-959 ◽  
pp. 4078-4082
Author(s):  
Zhao Yan Diao ◽  
De Rong Su ◽  
Sheng Xing Ye ◽  
Zhi Rong Zheng ◽  
Chao Yang Feng
Keyword(s):  
Land Use ◽  
Landscape Pattern ◽  
Driving Force ◽  
Land Use Type ◽  
Cultivated Land ◽  
Forest Land ◽  
Type Conversion ◽  
High Coverage ◽  
Open Woodland ◽  
Low Coverage

An application of GIS and the landscape pattern analysis software FRAGSTAS were used for research the changes of landscape structure nearly 14 years of Huihe basin in the hulunbuir prairie. The results show that, (1) from 1995 to 2010, cultivated land, grassland, basin forest area decreased, other land use type area were increased, and sand was the most obvious. From the grass internal structure change, low coverage in the grass and grassland area coverage in the proportion of total area decrease by 0.4% and 7.2% respectively in 14 years, and the high coverage grassland area ratio increases by 3.3%. Internal composition structure of forest land, the most significant change was shrubbery area, the area is reduced by 2.57%, the proportion of forestland of increased by 2.05%, and the proportion of open woodland area does not change significantly. (2) the land use type conversion frequently in basin area, large area and large proportion of the land use type conversion mainly in farmland, forest land, meadow and the sand. In the province, the main cultivated land into high, medium, and in the forest coverage grass, shrub and grass high coverage into cultivated land; Wetland overall increased; Sand of forest area into grass and open woodland, medium and low coverage grass coverage into the sand in the grass province. landscape pattern driving force analysis shows that the climate warming and human activities on the trend and rational use of natural resources, which lead the Huihe basin in the service function of ecological to degradation.

Land Use Dynamic Change and Driving Force Analysis in Qingdao

2012 ◽  
Vol 518-523 ◽  
pp. 6004-6007
Author(s):  
Xing Yuan Xiao ◽  
Tao Jiang
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Driving Force ◽  
Driving Forces ◽  
Dynamic Change ◽  
Fuzzy Comprehensive Evaluation ◽  
Base Number ◽  
Cultivated Land ◽  
Unused Land ◽  
Land Use Types

Using GIS and such models as dynamic degree, analyzed the land-use change in Qingdao according to the statistics of land-use data from 2000 to 2010 years and based on these, the author selects eight natural and socio-economic indexes, and takes districts as the study unit to calculate the driving force indexes with the fuzzy comprehensive evaluation method, and makes the spatial-division thematic maps of the driving forces which cause the land-use change in this region base on GIS. The results show that in Qingdao the land-use types which have the largest change rate is residential area and mining sites, followed by the unused land, water and cultivated land, and the garden plot is the smallest. There is a decreasing of cultivated land and unused land while other types have increased; because of a large base number, cultivated land reduces most among all land-use types. There exists a big spatial difference among these driving forces for land-use change. According the driving force indexes we divided them into four regions.

scholarly journals Assessing spatio-temporal patterns and driving force of ecosystem service value in the main urban area of Guangzhou

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi He ◽  
Wenhui Wang ◽  
Youdong Chen ◽  
Haowen Yan
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Urban Area ◽  
Ecosystem Service ◽  
Driving Force ◽  
Natural Ecosystem ◽  
Land Use Land Cover ◽  
Cultivated Land ◽  
Ecosystem Service Value ◽  
Service Value

AbstractIncreasing human activity around the world has greatly changed the natural ecosystem and the services it provides. In the past few decades, a series of significant changes have taken place in land use/land cover (LULC) in China due to the rapid growth in population, particularly in the cities of the Zhujiang Deita. However, there have been few attempts to study the co-evolution of land use/land cover change and ecosystem service value (ESV) in the main urban area of Guangzhou. Therefore, based on Landsat TM/OLI images from 1987, 1993, 1999, 2005, 2011 and 2017, the weight vector AdaBoost (WV AdaBoost) multi-classification algorithm was utilized to extract LULC data sets, and the spatiotemporal patterns of LULC over these periods were studied. The ESV was estimated and the driving force was analysed. The effect of LULC dynamics on the ESV was evaluated. The results showed that great changes have taken place in LULC in the main urban area of Guangzhou from 1987 to 2017, of which the most significant was the large-scale expansion of the built-up area that occurred through degradation of the forest and cultivated land. The proportion of forest and cultivated land decreased from 43.12% and 34.23% to 25.88% and 12.59%, respectively. The results between periods revealed a decrease in total ESVs from 5.63 × 109 yuan in 1987 to 5.27, 4.16, 4.62, 3.76 and 4.47 × 109 yuan in 1993, 1999, 2005, 2011 and 2017, respectively. In total, ESVs decreased by 1.16 billion yuan (20.61%) from 1987 to 2017. Water supply, food production, nutrient cycling and gas regulation were the four principal ecosystem service functions that affected the total ESVs. Forest, water body and cultivated land areas played a key role in ecosystem services. Therefore, we advocate that when protecting natural ecosystems in the future land use management in Guangzhou should be prioritized.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

The nucleation of cavities at grain boundaries

1987 ◽  
Vol 45 ◽  
pp. 288-291
Author(s):  
P. J. Goodhew
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Grain Boundaries ◽  
Radiation Damage ◽  
Impurity Concentration ◽  
Driving Force ◽  
Nucleation And Growth ◽  
Phase Boundaries ◽  
Cavity Nucleation ◽  
Spherical Bubble

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.

The driving force of craniopharyngioma growth

2014 ◽  
Vol 122 (03) ◽  
Author(s):  
C Stache ◽  
A Hölsken ◽  
SM Schlaffer ◽  
A Hess ◽  
M Metzler ◽  
...  
Keyword(s):  
Driving Force
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