Andrea Favretto

Demographic data and remote sensing to monitor urban growth: the Ho Chi Minh City (Vietnam) case study

In the last decades Ho Chi Minh City (HCMC), Vietnam, has experienced a rapid urbanization. This town grows from 2.3 millions of inhabitants in the 1975 until 8 millions in the 2014. Therefore, understanding the land-cover changes is one of the main topics in order to monitor the process of urban development. In this paper we study the urban dynamics of HCMC using two Landsat scenes acquired on June of 1988 (sensor TM) and on February 2017 (sensor OLI/TIRS). We relate our main results with other sources, like demographic data and the participative maps of OpenStreetMap. So, we identify main land cover changes in this period, such as the most important demographic variations within the urban districts of HCMC.

Il Balloon Mapping per lo studio di due castellieri sul Carso isontino e triestino

Il contributo presenta i primi risultati di alcune indagini compiute con la tecnologia Balloon Mapping (BM) su due castellieri del Carso isontino e triestino. Nello specifico, viene presa in esame una serie di immagini acquisite con il pallone aerostatico sui siti di San Polo, presso Monfalcone (Provincia di Gorizia) e di Monte Trmun, presso Caresana (Provincia di Trieste). Dopo una selezione delle immagini telerilevate, sono stati creati degli ortomosaici, utilizzando in rete l’ambiente operativo di MapKnitter. Per il sito di Caresana sono stati inoltre elaborati due ulteriori ortomosaici, ottenuti da immagini scattate con una macchina fotografica sensibile all’infrarosso vicino. Su tali ortomosaici è stato creato l’indice di vegetazione NDVI (Normalized Difference Vegetation Index). Infine è stata prodotta una cartografia dedicata, riportante un presunto crop mark positivo, ottenuto sulla base dell’interpretazione visiva dell’indice di vegetazione, opportunamente classificato in dieci classi di intervallo. In the paper we present the first results of a research carried on using Balloon Mapping techniques over two ‘castellieri’ (ancient fortified boroughs) in the karstic areas of Trieste and Gorizia Provinces (North East of Italy). Several remote sensed images, taken from a helium filled balloon in the two areas of San Polo (Monfalcone Municipality, Gorizia Province) and Trmun mountain (Caresana Village, Trieste Province), have been considered. After a first selection, several orthomosaics have been realized, using the MapKnitter cloud computing environment. Besides, two additional orthomosaics for the Caresana location have been produced using some near infrared images. NDVI (Normalized Difference Vegetation Index), has been calculated for the Caresana site and the two obtained NDVI layers have been classified in ten classes of interval. A positive crop mark on the Caresana site have been recognized and drawn on one classified NDVI layer.