The model was constructed based on GIS spatial analyses, combined with Analytic Hierarchy Process (AHP) and Multi-Criterion Analysis method (MCA). The data gathered for the study were mainly from remote-sensing images, statistical data and surveys. Field experiments were conducted in Trinh Tuong Commune, Bat Xat District, Lao Cai province. This is a typical remote mountainous region of Vietnam in which flash floods often occur. The study analyzes and evaluates six primary factors that incite flash flood, namely: geomorphological characteristics, soil properties, forest and fractional vegetation cover types, local drainage basin slopes, maximum average rainfall of various years, and the river/stream density of the region. The zoning map showing flash flood potentials has determined that 19.91% of the area had an extremely high risk of flash flood occurrence, 64.92% of the area had a medium risk, and 15.17% had a low or very low risk. Based on the employment of daily maximum rainfalls as the primary factor, an online flash flood warning model was constructed for areas with a “high” or “very high” risk of flash flood occurrence.

In the mining industry, conventional methods such as GPS and total station technology are used most extensively for data collection and in return used to compute volume of extracted materials (ore and waste). In situation where the ore body is bigger in size, and changes dynamically, the use of conventional method to measure volume of ore is not practicable and economically viable because of the workload involved, precision and accuracy of the survey and safety of workers. In this paper a method and work flow of ore heap volume measurement by using 3D laser scanning technique to acquire point cloud data was introduced. RiSCAN PRO and Geomagic studio was used to process the original data (registration, noise elimination, georeferencing, resampling etc.), 3D modeling and volume computations. A comparison on precision of geodetic control points coordinate measured by GPS receivers and 3D laser scanner was carried out. The results indicate that 3D laser scanning technique can effectively be applied to ore output volume measurement since it satisfies the requirement of ore volume measurement.

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This study demonstrates the steps of building a spatial analysis model that is applicable in synthetically assessing the sensitivity of landscape erosion in mountainous regions. Field testing was carried out at Ngu Chi Son commune, Sa Pa district, Lao Cai Province, Vietnam. The primary basis is the application of the GIS spatial analysis model in mapping the landscape structure. Subsequently, depending on the landscape structure map, the analysis model of erosion levels due to erosion factors (rainfall, terrain, the thickness of soil layers, mechanical compositions, vegetation cover, and cultivation measures of human beings) was constructed. The employed algorithms included spatial overlay, spatial interpolation, attribute reclassification, and average indexes. The results of this study have indicated the erosion sensitivity of every landscape unit, which is categorized into five levels: very low, low, medium, high, and very high. Obtained appraisals and sensitivity categorization are important fundaments to issue exploitation orientations and reasonable usages of resources within the researched region. This proves to be a new direction of research with overall potentials in assessing mountainous landscapes.

The Etropy problem has been widely applied in the assessment and analysis of landscape ecology. Research results are just at the indicators, not able to describe the spatial distribution of the landscape. In this paper, we will simulate the results of the application Etropy problem in landscape assessment based on a GIS. A GIS is used to store the information of layers on landscape structure, indicator analysis and map-layer assessment. This is a new research direction, research results of Etropy problem will be simulated by the evaluation map. Research have been applied in Sa Pa area - one of Vietnam's most mountainous district. Research results shown the landscape diversity in the research area and landscape area identification to be conserved.