Escola de Tecnologias, Artes e Comunicação

With the Internet growth, the production and amount of available geographic data also increased. There are, at the moment, many servers around the world providing spatial information to several users, and many of them are accessing this information through different Geographic Information Systems (GIS) applications. Therefore, it becomes necessary to develop standards in order to solve the interoperability problem inherent to this heterogeneous and distributed data. This work aims at showing the significance of standards, particularly the Web Feature Service - Transaction (WFS-T) standard in the Geographic Information (GI) domain. A prototype that provides GI according with this standard is also implemented, based on PostgreSQL/PostGIS, GeoServer, uDig, Apache and MapFish.

Land Cover mapping plays a very important role on a vast number of research fields, such as land use monitoring and modeling, monitoring of tropical deforestation, climate changes, among others. Its production is based on imagery interpretation and classification made by highly trained and skilled people. One of the most important phases is the assessment phase, where groups of people goes to the field, which makes it a very expensive one. We believe that it is possible to use Volunteered Geographic Information to help in the assessment phase of the Land Cover mapping production, making it less expensive. Thus, a robust data model/system is needed for a proper management of this type of data.

The characterization of the of harmful algal blooms (HABs), commonly called red-tide, in terms of location, time of occurrence, and concentration is required to manage the desalination plants over the Arabian Gulf. Several field campaigns have been undertaken over the Arabian Gulf by different organizations such as Regional Organization for the Protection of the Marine Environment (ROPME) and Environment Agency of Abu Dhabi (EAD) to collect the water temperature and chlorophyll samples. In this paper, a geospatial analysis is considered in order to map the distribution of chlorophyll in the Arabian Gulf using the kriging estimators. These maps will allow the identification of the areas mostly affected by the red-tide, periods of occurrences and their concentrations. The cross comparison between chlorophyll and dust concentration obtained from MODIS satellite and some coastal AERONET stations will be considered to clarify the dependency between them since dust contain nutrients which nurture the HABs.

"The Arabian Gulf is known to have very high turbidity compared to other water bodies. This high turbidity is mainly due to the settling of airborne dust carried out from the surrounding desert areas. Other local activities such as land reclamation and desalination plant discharges have also increased the water turbidity in the near-coastal areas. Turbid water could become warmer when the suspended particles absorb the heat coming from the sunlight which leads to reduction in the oxygen levels in the water which could harm the aquatic ecosystem. In addition, high turbidity affects the photosynthetic process of the plants and algae because the presence of suspended particles increases the light scattering which may lead to a decrease in the oxygen concentration in the water. Sediment deposition may also accelerate the filling of shallow areas.
The objective of this project is to develop satellite-based tool to produce daily assessment of water turbidity in UAE coastal areas. Ten years of daily satellite data acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments have been collected for this project. Two MODIS sensors are presently orbiting the earth onboard of the NASA Terra and Aqua satellites (morning pass and afternoon pass) providing twice daily coverage of the UAE coastal areas at medium spatial resolution ranging from 250-m to 1000-m."

This study demonstrated the potentiality of the use of remote sensing and geospatial techniques for urban climate analysis with a case study of Abu Dhabi city area. A first analysis assessed the variation of Land Surface Temperature (LST) at different spatial scales its relationship with land cover, Normalized Difference Vegetation Index (NDVI), and percentage of Impervious Surface Area (ISA) has also been investigated for the period between 2000 and 2010 using data from multiple satellites and ground measurements. In the second analysis, the data were assimilated in a Surface Energy Balance (SEB) model to assess urban energy fluxes in Abu Dhabi metropolitan area during the winter and the summer seasons. The maps produced from LST and SEB projects will be disseminated through the WebGIS Portal of the Research Center for Renewable Energy Mapping and Assessment.

The Research Center for Renewable Energy Mapping and Assessment at Masdar Institute was mandated by the UAE Government to develop the UAE solar and wind atlases as part of the UAE commitment to support the International Renewable Energy Agency (IRENA) in its advancement of a publicly-accessible atlas of solar and wind resources. The purpose of this project is to develop an online platform to make the produced solar and wind maps easily available to end users and stakeholders. The produced maps will be implemented in online interactive geospatial data portal (solar atlas) for easy navigation and analysis. The developed portal is based on Open Source technologies and standards (technology independent). This includes WMS (Web Map Service) and Open Geospatial Consortium (OGC) standards. A platform constituted by the data source, a server and a web application is under development to disseminate the UAE Solar and Wind Atlas through the web. The data source is composed by a collection of GeoTIFF images. The server is based on the GeoServer software and provides maps using OGC specifications, namely Web Map Service (WMS) specification. The web application aims to show the atlas maps over a base map and provide basic data management tools including the possibility to access pixel values and to derive historical histograms of solar and wind resources. This paper will focus on the dissemination of the UAE solar resource web portal, launched in October 2012.

The Global Solar and Wind Atlas (GA) is a unique Global Spatial Data Infrastructure (GSDI) that aims to connect and bring together in a common platform the major databases and information sources around the world in the field of solar and wind energy. The initiative will be expanded to encompass all renewable energies by 2015, and will be the largest information source on renewable energy potentials ever created. It has been developed under the umbrella of the Global Atlas initiative led by IRENA in partnership with the Clean Energy Ministerial. The GSDI is based on open standards and open source and composed by fundamental datasets, a geospatial catalogue and a Web based GIS Interface. The GIS interface provides a way of interaction between users and the other components, including spatial data and tools. The GIS allows users to identify opportunity areas for renewable energy development by searching and loading data listed by the catalogue, overlaying information, and computing locally the technical potential of renewable energy. In this demonstration we aim to show the GA infrastructure and how users can interact with all the different modules with emphasis on the GIS interface.

In the last years, volunteers have been contributing massively to what we know nowadays as Volunteered Geographic Information. This huge amount of data might be hiding a vast geographical richness and therefore research needs to be conducted to explore their potential and use it in the solution of real world problems. In this study we conduct an exploratory analysis of data from the OpenStreetMap initiative. Using the Corine Land Cover database as reference and continental Portugal as the study area, we establish a possible correspondence between both classification nomenclatures, evaluate the quality of OpenStreetMap polygon features classification against Corine Land Cover classes from level 1 nomenclature, and analyze the spatial distribution of OpenStreetMap classes over continental Portugal. A global classification accuracy around 76% and interesting coverage areas’ values are remarkable and promising results that encourages us for future research on this topic.

Volunteered Geographic Information has become exponentially available over the Web in the last years. This availability can hide a vast geographical richness and provides us with both a great opportunity to explore new ways to use it and also big challenges related with its unstructured nature. This paper conducts a preliminary analysis of the adequacy of photos from the Flickr and Panoramio initiatives in order to use them as a source of field data in the quality control of the Land Use/Cover databases production. It evaluates its temporal and spatial distributions over Continental Portugal and also its distribution over Land Use/Cover classes using as a reference the European Corine Land Cover database. It concludes that this source is very valuable but needs to be combined with other sources due to its uneven spatial distribution.

Urban and economic development is affected by the value of land. Therefore, land value appraisal methods are important to determine the significance of land segments. A significant number of these models do not apply geospatial analysis in their estimations. This paper presents a land valuation model based on spatial multi criteria decision analysis (SMCA) to assess land values in Abu Dhabi, UAE. Through this study, criteria maps were generated and combined to produce a final map ranking land segments based on their relative value.