(2015) A novel hybrid evidential belief function-based fuzzy logic model in spatial prediction of rainfall-induced shallow landslides in the Lang Son city area (Vietnam), Geomatics, Natural Hazards and Risk, 6:3, 243-271, DOI: 10.1080/19475705.2013 The main objective of this study is to investigate potential application of an integrated evidential belief function (EBF)-based fuzzy logic model for spatial prediction of rainfall-induced shallow landslides in the Lang Son city area (Vietnam). First, a landslide inventory map was constructed from various sources. Then the landslide inventory map was randomly partitioned as a ratio of 70/30 for training and validation of the models, respectively. Second, six landslide conditioning factors (slope angle, slope aspect, lithology, distance to faults, soil type, land use) were prepared and fuzzy membership values for these factors classes were estimated using the EBF. Subsequently, fuzzy operators were used to generate landslide susceptibility maps. Finally, the susceptibility maps were validated and compared using the validation dataset. The results show that the lowest prediction capability is the fuzzy SUM (76.6%). The prediction capability is almost the same for the fuzzy PRODUCT and fuzzy GAMMA models (79.6%). Compared to the frequency-ratio based fuzzy logic models, the EBF-based fuzzy logic models showed better result in both the success rate and prediction rate. The results from this study may be useful for local planner in areas prone to landslides. The modelling approach can be applied for other areas.

Flooding is a natural disaster that occurs in most parts of Vietnam, causing a lot of damage to people, assets and influence on socio-economic activities. This article analyzes the impact of floods on population in the Vu Gia – Thu basin. In this study, the authors used the result of the hydrolic modeling, the simulated floods in conjunction with the use of GIS software (ArcGIS) to analyze the impact on the population of downstream the Vu Gia – Thu Bon river basin. From there, the study indicated the impact and influence of floods caused on flooded areas in the river basin. The ArcGIS software is used to prepare data, integrate and analyze the spatial data that is included with the attribute information. This study show that GIS provides more accurate solutions for flood impact assessment and this assessment method can be applied to any river basin.

The architectural heritages are symbols of culture, social, historical, and religion and the exciting points of every city or country, especially for tourism development. In the world, thousands of architectural heritages are preserved and protected. UNESCO and many international organizations work together with all governments and local people to keep the heritages. Their efforts are great, but sometimes, the heritages are damaged and destroyed by a natural disaster and human activities. In Vietnam, many architectural heritages are in danger. Therefore, preservation of these architectural heritages is essential with all efforts from the government and scientists. This paper presents the results of applying UAV and Terrestrial laser scanners to model the architectural heritage in 3D with high quality for the purpose of preserving and protecting these works. The study was done by modeling the Dieu Son Pagoda in Bac Ninh Province. The result shows that the model is very detailed and precise enough to retain the building's main architectural characteristics.

Along with the development of mapping technologies, the data acquisition system through the aerial laser scanning system has created a huge LiDAR point cloud data source. This is an essential and detailed data source that effectively serves various fields such as making maps and 3D maps, etc. The process of building 3D city models requires processing many types of data, at which point cloud data processing and classification play an essential role in creating an input data source for the model. Study on workflow for acquiring, processing, and classifying point cloud data is meaningful. It plays a vital role in the development and application of LiDAR technique in the current period, especially in building smart cities. The article introduces a method for acquiring, processing, and classifying LiDAR point cloud data to establish 3D city models. Based on the proposed approach, a pilot 3D model of the city in Thuong Ly ward, Hong Bang district, Hai Phong city was generated. The result of point cloud classification’s accuracy is very good, ranging from 92% to 99% depend on type of object. Based on the classification, the city’s 3D model is established with 2nd Level of Detail (LOD2) for Thuong Ly ward. The model is very useful in urban planning and management, and in the number of managing task such as infrastructure development, rescues and disaster prevention, military services and real estate business.

Cadastral maps are an important part of cadastral documents, they are legal component of land administration in local authorities. Traditionally, a cadastral map is established by using land surveying methods which can provide high accuracy as required. In recent years, the UAV devices are developed and can provide an accurately tool for cadastral mapping on arable lands. This paper presents an evaluation of UAV application in cadastral mapping in comparison with traditional surveying for arable land. The results show that using UAV images in the mapping of agricultural land can achieve ground accuracy of 1,7 cm and height accuracy of 0,6 cm; In addition, when comparing the average accuracy of the 30 plot vertices and the mean lengths from 29 pairs of edges between the newly created map from the UAV image data and the map provided by the Department of Natural Resources and Environment of Phu Tho province, respectively is: 0,181 m and: 0,051 m.