Gis and Remote Sensing: A Foundation for Next Generation Civil Engineering

 

Civil engineering is about developing and sustaining infrastructure. GIS and remote sensing techniques play a crucial role and serves as a complete platform in every aspect of civil engineering. Geographic information system (GIS) technology provides the tools for creating, managing, analyzing, and visualizing the data associated with developing and managing infrastructure. Remote sensing allows correlation of spatial data to their attributes making them useful in various fields in this domain. Different themes such as geology, terrain, drainage, and hydrology can be extracted by the use of remote sensing. It also helps organizations and governments work together to develop strategies for sustainable development. The arena of applications covers all spheres such as urban development, town planning, environment, new road alignment, irrigation project design, by developing models on socio-economic, demographic and information on natural resources. Also GIS enables civil engineers to easily manage, reuse, share, and analyze data, saving time and resources.

 

 

 

Each and every phase of infrastructure life-cycle is greatly advanced by the enrollment of GIS and remote sensing.

 

 

In planning its major contribution is providing information on site location including environmental impacts, economic analysis, regulatory permitting, alternative site analysis, sustainability issues, data overlay, risk analysis, routing of roads and pipelines etc.

 

 

Precise and accurate data is the core driving factor of any successful project. GIS is equipped with almost all tools and functions to collect precise site data used for predesign inspection; design; and calculations with respect to topography, soils, subsurface geology, traffic, imaging, sensitive environmental areas, wetlands, hydrology, and other site specific design-grade data.

 

 

Analysis is one of the major and most influential phases of infrastructure life cycle which allows you to view patterns, trends, and relationships that were not clearly evident without the visualization of data. It provides analysis to support design including hydrology analysis, volume calculations, soil load analysis, Site feasibility, environmental impact, slope stability, materials consumption, runoff, erosion control, and temperature and humidity.

 

 

It allows creation of new infrastructure data for new civil works including grading, contouring, specifications, cross sections, design calculations, mass haul plans, environmental mitigation plans, and equipment staging.

 

 

GIS helps the professionals to understand the site conditions that affect the schedule baseline and cost baseline. To keep the construction within budget and schedule, GIS guides how to utilize the resources on site efficiency by  timely usage of construction equipment, working hours, effects of seasonal fluctuations, optimizing routes, earth filling and cutting, calculation of volumes and areas of constructed phase thereby helping in estimation and valuation.

 

 

Operations are controlled through models of site data and compared to the baselines prepared in planning phase. Modeling of site may be in the form of raster images or CAD drawings. Spatial selection and display tools allow visualizing scheduled work, ongoing activities, recurring maintenance problems, and historical information.

 

 

 

GIS can easily analyze and visualize different types of information and images including both aerial and satellite imageries for site analysis. Using high resolution images allows precise and geographically accurate mapping of the real world scenario which offers a source of visual truth to decision making of the users. The baseman can include parcel maps, zoning and city designations, environmental protection areas, aerial photos, and topographic and soil maps.  The ability to access present and historical imageries of a site can not only detect changes over time but also help to shortlisting pre-qualify sites, saving valuable inspection time.

 

 

 

GIS technology provides a situational awareness tool to engineers responsible for the safety and security of critical infrastructure such as buildings, railways, pipelines and electrical grids and provides assistance in decision-making for emergency assessment, preparation response, and recovery activities. Both natural occurrences such as earthquakes, floods or wind damage and manmade threats such as new construction near current infrastructure like buried powerline/pipelines or civil disturbances, terrorism etc..,  are common threats to infrastructure which can be identified using different remote sensing technology that include optical imagery, SAR imagery and thermal imagery. It can provide a lot of visual information and is helpful for seeing visible changes in infrastructure.
 

-Town Planning and Urban Development

 

For sustainable development of urban agglomeration, optimal urban land use plans and resources development models can be generated by integrating the information on natural resources, demographic and socio – economic data in a GIS domain with the currently available satellite data. The use of medium or high resolution satellite imagery can support urban developers and land managers to monitor and support decision making for sustainable urban development in dense urban environments. Satellite imagery provides detailed analysis for creating or updating GIS maps and detecting major changes in urban land cover and land use which allows for frequent coverage and overlaying of different time sequences to classify environmentally safe and sustainable areas for the proposed development area. This includes:

 

 

 

Planning a new route or highway can be expensive and time consuming process with numerous environmental obligations to be addressed. The problem is aggravated where the alignment is influenced by the location of services, existing roads and buildings, and the financial, social and political costs of land resumption. Remote sensing techniques offer a base to carry out route alignment corridors surveys since it provide information on terrain features such as topography and slope, current land use, forest/vegetation cover, water bodies/drainage, built up areas, road, rail, sanctuaries/parks etc which are the parameters to be considered during feasibility planning of new routes. Further GIS allows the integration of spatial and non-spatial data and the spatial analysis to support the decision process.

 

 
-Water Resources Management

 

The exponential growth of satellite based information over the past decade provides unprecedented opportunities to support and improve water resources management. Lack of water is a perennial problem, through low availability of water supply and poorly managed demand for water that combines to result in water scarcity. Satellite-based sensors are now capable of making direct and indirect measurements of nearly all components of the hydrological cycle and enables conservation of water resources. It can help to monitor the effects of dam construction and perform preliminary investigation of impact assessment of dams and rehabilitation. It can identify the feasibility of inter basin transfer of surplus flood flows and the storage by large reservoir sites by considering land use/land cover, soil and geological mapping, terrain evaluation, construction material inventory etc. It can also calculate the reduced storage limit of reservoirs and tanks due to sedimentation by assessing the sediments volume. Integration remote sensing data with ground based information in a GIS is also useful in interpreting land capability, irrigation suitability, water harvesting areas, estimation of run-off, and monitoring land degradation.
 

Summary

 

The rapid technological advances in the scientific area of Remote Sensing have attracted the interest of several sciences, including civil engineering, regarding the basic principles, methods and applications that may offer a rich source of information valuable to a wide range of issues. Remote Sensing offer a wide area of applications in the domain of civil engineering covering the main fields of interest of a civil engineer as: regional planning and urban development, critical infrastructure protection, natural hazards and environmental issues, road alignment studies, land cover/land use studies, water resources management, etc… Thus GIS and Remote Sensing is playing an increasingly important role in civil engineering companies, supporting all phases of the infrastructure life cycle.