American Journal of Geographical Research and Reviews

As a major oilseed crop with high ornamental value, Accurate and timely determination of their distribution and area under cultivation is essential to ensure food security and achieve sustainable development goals. The bright yellow flowers are a unique feature of rapeseed compared to other crops. Therefore, the yellow flower index was previously used to detect rapeseed on aerial images or medium-resolution satellites. However, the impact of its unique topographic terrain structure confuses crop planting structure, while the yellow flower signal of rapeseed is weak in the early stage of rapeseed growth. Therefore, it remains challenging to accurately identify early rapeseed in the southwest mountains. In this study, a new mountain rape index (MWRI) is proposed based on Sentinel-2 time series images. First, the NDVI characteristics of vegetation were used to filter out non-vegetated areas. Secondly, the weak rapeseed signal of non-pure image elements was enhanced by combining the time series reflection variation curves of rapeseed in red, green, NIR, and SWIR bands. The MRM method was used to extract the rapeseed cultivation in Chongqing, a typical mountainous rapeseed growing area in China. Three different previously proposed rapeseed indices: normalized difference yellowness index (NDYI), and yellowness index (RYI) were also calculated for comparison, and validation using high-resolution image interpretation samples in Google earth showed that MWRI has higher rapeseed recognition accuracy OA above 0.97, while other rapeseed indices OA between 0.9 and 0.95. The results indicate that MWRI is an effective index to distinguish mountain rapeseed from other crops.

The method for studying the adsorption characteristics of the coal seam has the density method, the mercury-pressing method and the adsorption method. In this experiment, a low temperature nitrogen adsorption method was used to determine the relative data of the coal-like porosity by using the surface area meter TriStarI3020 to determine the arrangement of the nitrogen molecules on the surface of the coal-like samples. Before the beginning of the experiment, the samples of Yang dong coal reservoir were prepared, weighed, the devaporation time was set at 2h, and the temperature was kept at 105℃.The low temperature nitrogen adsorption experiment was carried out by TriStarII3020.The data of adsorption of nitrogen molecules by coal samples at low temperature are obtained by experiments. The gap characteristics of coal samples are studied by analyzing the characteristic folding points and relative relations of the generated linear diagram. Get coal samples under the condition of low temperature changing with pressure adsorption nitrogen molecular data changes, through the analysis of the linear graph of generated features that are characteristic of fold point and relative relationship to study the space characteristics of the coal sample. Through the analysis can determine the area mainly for both ends of the open pores in coal mine, the porosity of the thin neck bottle type, this research has great significance to the adsorption of gas in the coal reservoir, facilitate monitoring during the coal mining operations have an impact on safety production of the gas such as gas. Can get the conclusion: in the low relative pressure p/p°< 0.1 the surface of the coal samples are distributed in nitrogen molecular monolayer, with the increase of pressure surface of coal samples began to multilayer adsorption intensified will appear the characteristics of the molecular cohesion, condensation of a pressure value after the single nitrogen...

Transportation infrastructure promotes the interconnection of production factors between regions and enhances the efficiency of land use, while land use patterns also have an impact on transportation development patterns and mixes. Although the development of different regions within megacities tends to be integrated, different transportation mixes and land inputs still bring differentiated dynamics to the development of the blocks. In order to explore the relationship between regional traffic conditions and land use efficiency, this paper investigates the traffic development conditions and land use efficiency of each district in Shanghai by using the traffic dominance degree model and the three-stage Super-SBM model, and explores the relevant role relationship between them by using the coupled coordination degree model. The results show that: (1) the central city has the highest traffic dominance, and the suburban areas, especially the distant suburban areas, have low traffic dominance; (2) the land use efficiency of the eastern area of Shanghai is significantly higher than that of the western area, and the land use efficiency of the southern area is higher than that of the northern area; (3) in terms of coupling coordination, the traffic development and land use efficiency of most districts are coordinated, but the degree of coordination varies greatly, with Huangpu District, Yangpu District, Pudong New Area, and Hongqiao District. Yangpu District, Pudong New Area and Hongkou District are at a high level of coordinated development, Chongming District and Changning District are at an uncoordinated development, and the rest of the districts are at a medium level of coordinated development.

Accurate riverbed information, including riverbed shape, sounding data and elevation data, is needed to simulate the process of flooding in flooded areas by using two-dimensional hydrodynamic model. DEM data is an important feature reflecting topographic changes and plays an important role in hydrological model analysis.However, in the plain area where DEM elevation changes are very small, the extraction and simulation of river network are of low accuracy in the process of hydrologic analysis, and there are great errors in watershed division. Taking the Mihe river basin, shouguang city, shandong province as the research object, based on WMS to abnormal proofreading is smoothing the center line of the river, get in line with the physical meaning of vector river network, the inversion to the original elevation data (DEM), and on this basis, with the river elevation information center line interpolation, construct a sounding data of river model, provide technical support for the two-dimensional hydrodynamic model.

This paper examined the concept of fieldwork and its relevance in geographic studies. In particular, the paper evaluates the pros and cons of fieldwork, and gave reasons why fieldwork is important in geographic research. It was further reiterated that like the laboratory of pure sciences, the field is the laboratory of the geographers as well as other related earth science disciplines because it affords the researcher the opportunity to collect first-hand data and relevant information that may eventually assist in carrying out a reliable research. The stages, benefits and the different approaches to fieldwork are examined. Constraints associated with fieldwork and solutions are provided. It was re-emphasized that although fieldwork is capital intensive and time consuming, early preparations together with a well-articulated aim and objectives, scope and methodology will eventually ensure a successful fieldwork. As a proof of concept, an evaluation of the empirical field studies of Charles Darwin that involved detailed fieldwork in its execution reaffirmed that the field remains a major source of data for any successful geographic research.

Spatio-temporal analysis is one of the suitable method in crime analysis. It is ability to visualize the spatial patterns and control emotionally over a time-ordered sequence of spatial variation. It has been involved the spatial modeling and models of location- allocation, spatial interaction, spatial choice with search, spatial optimization and space-time. Spatio-Temporal Analysis of Crime (STAC) is a powerful tool to identify the crime patterns and detect the crime hot clusters in identifying the hotspot areas. The aim of the objective study is to analyze the spatial effects based on space and time difference among the divisions (space and time) and rate of change. The different types of crime occurrence data were collected from fourteen rural police jurisdiction (2003-2006) in Coimbatore district, TamilNadu. For this analysis, crime occurrence data were used through ArcGIS 10.2 version. The study was analyzed the random walk incidences, and moving path of the peak incidences which are effective models used for entire surrounding area. The study was concluded that spatial-temporal dimension of crime in rural police jurisdictions and explaining how these outcomes used to assist the advance development of crime prevention strategies.

To study the grouting anchor cable, high strength anchor cable, constant resistance, large deformation of anchor supporting of coal roadway surrounding rock different control effect, first using drilling into instrument detecting roof inner fracture of surrounding rock and loose circle development situation, again USES the anchor dynamometer, the roof abscission layer meter, convergence rule of surrounding rock of roadway convergence deformation and stress monitoring and supporting artifacts related to data processing and analysis between the drivage and stoping different anchor rope supporting of roadway surrounding rock under the condition of deformation and stress change rule anchor rope.Through the above steps, the grouting anchor cable is found to be the best supporting method.

Over the years, Nigeria as a Nation has been witnessing serious unrest characterized by the ethnic, political, farmer’s-herder’s conflict and activities of the insurgency. The north eastern geo-political zone of Nigeria was not left out of the activities. The activities of the Boko Haram insurgents has led to over ten thousand people losing their life and properties making many homeless. The paper is aimed at providing a comprehensive data and show the spatial distribution of activities of Boko Haram insurgency in Adamawa, Borno and Yobe States between 2009 and 2017. The paper utilizes secondary data from Armed Conflict Data (ACLED), printed materials, newspaper records, journals, and security agencies records. The method of analysis utilized in the study is Geographical Information System (GIS) approach using ArcGIS software and graphs to indicate the activities of the insurgency. The finding of the research shows that Borno State has the highest occurrence of insurgency and Yobe State recorded the lowest. The study concludes that the activities of the insurgents are more at the northern part and along the international boundaries.

Most species of seaweed that are transported through ballast water may have been transferred also by bioincrustration. Macroalgae of the genus Caulerpa, are native to the Mediterranean. C. taxifolia is an algae indicator of conditions, often harmful, and sometimes irreversible, to the ecosystems of the invaded areas. It is necessary to implement control measures to minimize damage to the endemic species and its im-pact on the areas of occurrence. This study aimed to assess the occurrence of exotic algae on and their relationship and distribution on the coast of Pernambuco, during periods of dry and rainy seasons from 2005 to 2009. Macroalgae were fixed in con-solidated and unconsolidated substrates, being also associated with other algae and even occurring as loose fragments in the sandstone reef. These fragments could be the result of anthropogenic activities or local hydrodynamics. The absence of sea ur-chins and other herbivores associated with C. taxifolia sites pointing to an allelopathic action in the process of colonization. We consider that Caulerpa taxifolia may have been introduced recently in our coast being in process of colonization growing itself most often in sandstone reefs, which suggests an action in inhibiting herbivory through the synthesis of allelochemicals.

Increasing urbanisation, poor location of urban amenities and utilities in consideration to population concentration has made many cities face environmental, land use and socio-economic challenges. This can be mitigated against through the analysis of the interactions existing between urban natural and human systems as provided for by the geospatial technology notably Remote Sensing, Geographical Information Systems (GIS) and Photogrammetry. This has made geospatial technology gain primacy in the urban studies and literature on the utility of geospatial techniques in the analysis and modelling of urban morphology has grown over the years. This paper therefore, anchors an understanding on the urban morphology and the role of geospatial techniques in studying the same.