Vector Map Encryption Algorithm Based on Double Random Position Permutation Strategy

Encryption of vector maps, used for copyright protection, is of importance in the community of geographic information sciences. However, some studies adopt one-to-one mapping to scramble vertices and permutate the coordinates one by one according to the coordinate position in a plain map. An attacker can easily obtain the key values by analyzing the relationship between the cipher vector map and the plain vector map, which will lead to the ineffectiveness of the scrambling operation. To solve the problem, a vector map encryption algorithm based on a double random position permutation strategy is proposed in this paper. First, the secret key sequence is generated using a four-dimensional quadratic autonomous hyperchaotic system. Then, all coordinates of the vector map are encrypted using the strategy of double random position permutation. Lastly, the encrypted coordinates are reorganized according to the vector map structure to obtain the cipher map. Experimental results show that: (1) one-to-one mapping between the plain vector map and cipher vector map is prevented from happening; (2) scrambling encryption between different map objects is achieved; (3) hackers cannot obtain the permutation key value by analyzing the pairs of the plain map and cipher map.

VISUAL ANALYSIS OF INCONSISTENCIES IN HYDRAULIC SIMULATION DATA

We present our contribution to the geovisualization and visual analysis of hydraulic simulation data, based on an interdisciplinary research work undertaken by researchers in geographic information sciences and in hydraulics. The positive feedback loop between researchers favored the proposal of visualization tools enabling visual reasoning on hydraulic simulated data so as to infer knowledge on the simulation model. We interactively explore and design 2D multi-scale styles to render hydraulic simulated data, in order to support the identification over large simulation domains of possible local inconsistencies related to input simulation data, simulation parameters or simulation workflow. Models have been implemented into QGIS and are reusable for other input data and territories.

SPATIO-TEMPORAL ASSESSMENT OF MARGALLA HILLS FOREST BY USING LANDSAT IMAGERY FOR YEAR 2000 AND 2018

Environmental imbalance due to human activities has shown serious threat to ecosystem and produced negative impacts. The main goal of this study is to identify, monitor and classify temporal changes of forest cover, build up and open spaces in Margalla Hills National Park, Islamabad. Geographic Information Sciences (GISc) and Remote Sensing (RS) techniques has been used for the assessment of analysis. LANDSAT-7 Enhanced Thematic Mapper (ETM+) and LANDSAT-8 Operational Land Imager (OLI) were utilized for obtaining data of year 2000 and 2018. Temporal changes were evaluated after applying supervised classification and discrimination was analyzed by Per-Pixel based change detection. Results depicts forest cover decrease from 87 % to 74 % whereas build up has increased from 5 % to 7 % over the span. Consequences also justify the presence of open land in study area that has been increased from 2 % to 7 % respectively.

Geography

Geography is the study of the earth, including the physical environment, humans, natural and cultural places/regions, and the complex relationships among human-environment interactions. Geography is relevant to the environmental sciences for many reasons but particularly for its focus on distributions of various environmental- and human-related interactions and the factors controlling such distributions over varied spatial and temporal scales. Geography as an applied discipline provides many field-based and geospatial computational methods, techniques, and tools for analyzing local to global earth surface interactions. Environmental science benefits from these contributions. Geography inherently spans the physical and social sciences, commonly integrating aspects of each as they influence one another. This selection of resources focuses on the subdisciplines of geography that are distinctly environmental, including applied and basic process-based physical geography, human-environmental interactions, geographic information sciences, and considerations of scale. Physical geography is the study of the natural environment and all the components and processes that interact across the earth’s surface to influence the distribution and development of natural phenomena, including weather, climate, landforms, soils, plants, and animals. Physical geography is traditionally subdivided by the three major research areas: climatology, geomorphology, and biogeography. Climatology is the study of weather and climate processes and energy fluxes and the factors that control spatial and temporal variations in temperature and precipitation; such controls range from local topographic influences to global wind and ocean current circulation patterns, to human-influenced climate change. Geomorphology is the study of landforms and the processes (water, wind, ice, tectonics, etc.) that shape different erosional and depositional features of the earth surface. Geomorphology includes (but is not limited to) the study of rivers, mountains, coasts, glaciers, and many other earth surface features and landscapes. Biogeography is the study of the distributions of plants and animals (avian, terrestrial, marine, and freshwater organisms), their interactions within an ecosystem or landscape, and the factors controlling their presence and resilience. Climatology, geomorphology, and biogeography can all be examined across a range of spatial and temporal scales, and there is often an emphasis on explaining and quantifying how natural phenomena within these disciplines change over space and time and how they are influenced directly and indirectly by humans. Human-environmental geography includes natural hazards, environmental management, nature-society interactions, and the global environment. Geographic information sciences include GIS (geographic information systems) and remote sensing technologies designed for studying the earth surface environment. Although not a distinct subdiscipline, the concept of scale and the spatial and temporal dimensions of scale are a central tenet of most geography research. Global environmental change, as influenced by physical and human influences and interactions, is a more recent area of study within geography that is rapidly evolving.

A Model of Fuzzy Topological Relations for Simple Spatial Objects in GIS

The goal of this paper is to present a new model of fuzzy topological relations for simple spatial objects in Geographic Information Sciences (GIS). The concept of computational fuzzy topological space is applied to simple fuzzy objects to efficiently and more accurately solve fuzzy topological relations, extending and improving upon previous research in this area. Firstly, we propose a new definition for simple fuzzy line segments and simple fuzzy regions based on computational fuzzy topology. And then, we also propose a new model to compute fuzzy topological relations between simple spatial objects, an analysis of the new model exposes:(1) the topological relations of two simple crisp objects; (2) the topological relations between one simple crisp object and one simple fuzzy object; (3) the topological relations between two simple fuzzy objects. In the end, we have discussed some examples to demonstrate the validity of the new model, through an experiment and comparisons of existing models, we showed that the proposed method can make finer distinctions, as it is more expressive than the existing fuzzy models.

An eLearning Portal to Teach Geographic Information Sciences

In this chapter the authors describe the implementation of an emerging virtual learning environment to teach GIS and spatial sciences to distance education graduate students. They discuss the benefits and constraints of our mixed architecture with the main focus on the innovative hybrid architecture of the virtual GIS computer laboratory. Criteria that were used to develop the virtual learning environment entailed the following: (i) Facilitating student-instructor, student-computer, and student-student interactivity using a mix of synchronous and asynchronous communication tools; (ii) Developing an interactive online learning environment in which students have access to a suite of passive and active multi-media tools; and (iii) Allowing student access to a mixed web-facilitated / hybrid architecture that stimulates their cognitive geographic skills and provides hands-on experience in using GIS.