Remote sensing and GIS play an important role in mapping the environment, agriculture, forestry, geology, water, ocean, exploring mineral production, in infrastructure planning and management, and also disaster management, etc.
Remote sensing has many beneficial properties for detecting, mapping and monitoring objects. The diversity of the satellite imagery allows for monitoring the characteristics of the landscape and thus provides a means for detecting changes in land cover and quantifies the extent of changes (Joshi et al. , 2004), especially the changes of different land use types and the related environmental issues. RS is increasingly being applied in assessing environmental changes such as land surface change, water quality change, soil and atmosphere characteristics, etc. The results from satellite image classification are combined with GIS enable to mapping the distribution of ecosystems, landscapes, climatic conditions, biological characteristics and other factors (Stow et al., 1989, 2000; Rowlinson et al., 1999; McCormick, 1999; Haltuch et al, 2000; Los et al., 2002).
We have conducted researches applying remote sensing and GIS and achieved results through bachelor and master theses. The research topics cover:
Land use change and urbanization resulted in the change of geological environment. In this study, GIS and remotely sensed data were integrated into the workflow to create a map of environmental geological zoning. Landsat 8 satellite images were classified with the Fuzzy logic method. The GIS data included geology, topography, hydrogeology maps. The result from the integration was the suitability map of appropriate units for the development of construction sites on the Thi Vai river basin with 3 different levels of geological environmental condition for the development of the construction sites.
The agriculture in Phu My Town has a key role in contributing to the economy of the area. As a consequence of increasing crop yields for high agricultural productivity, the intensive use of nitrogen-containing chemical fertilizers has been adversely affecting the soil environment. It is especially intensified since the topography of Phu My Town has favorable conditions for the release of chemical pollutants to deposit into the sediment, penetrate deeply into different soil layers and to groundwater. The map of nitrogen availability was created by integrating different GIS data in combination with the Analysis of hierarchical process (AHP) method. Land use information was classified from remotely sensed image and field survey data.. The result can provide a guideline for the adjustment to fertilize usage and support regional management.
Ba Ria – Vung Tau is a province with very dynamic marine economic activities along with an important position in the process of developing, exploiting, and transporting oil and gas exports. Therefore, Ba Ria – Vung Tau also has risks of oil spilling. This study applied GIS – Remote Sensing and Multicriteria Analytical Process (AHP) to evaluate the sensitivity of the geo-environmental units of the coastal area to oil spill incidents. There are 4 levels of sensitivity of the geo-environment in this area, they range from low to very high. The result can help prioritizing the plan for emergency response to mitigate the impacts of the oil spill hazard.
Vietnam is among the countries that have been heavily affected by climate change and therefore the evaluation of vulnerability to climate change is important. In this study, the vulnerability of the estuary of Dong Nai river system due to climate change and sea-level rise was evaluated. The Delft3D hydrodynamic model was applied to simulate the salinity and water level in the study area under climate change scenarios. Coastal Vulnerability Index (CVI) was calculated from the inundation, salinity change, shoreline change and mangrove forest maps. The result indicates the level of vulnerability and the extent impacts to mangrove ecosystem by climate change in 2050 and 2100.
The supporting feature of remote sensing and GIS was reflected by the evaluation of land use change in the context of rapid urbanization in the Ease of Ho Chi Minh City. The land use changes had impacts on social and natural ecosystems. In this study, the land use change along with its impacts was evaluated by multi-criteria analysis AHP method. Finally, the environmental impact zoning maps were developed. The results can support the decision makers and regional managers to evaluate and decide the development strategies.