Tag Archive: GIS Mapping services

Integration of GIS and IOT

IOT can have a profound impact on the lives when integrated with GIS and this is definitely the way the world is moving. Linking products, devices, networks, objects and data opens up infinite possibilities. In the new paradigm of computing outside the desktop, the information and communication systems will become embedded in our environment and, unseen by us, will be transmitting and receiving information and communicating with a myriad of other devices, objects and networks. What were previously sensing devices used for gather information of GIS technologies will now evolve into ‘smart’ decision making and implementation systems. An example would be people-centric sensing where low cost sensing of the environment specifically localized to the user can be conducted.

When this capability builds it would be possible to provide solutions real time specific to the user needs based on the environment and context in which an event occurs. Data visualization and analysis will improve in leaps and bounds when integrating GIS with IOT. Predicting environmental changes and events will be enhanced by this union. The uses are varied and numerous, for e.g.- insurance companies can track driving behavior real time, supply chain management and inventory management can happen remotely, you can receive status updates from your home devices and control them while away. The implementation of this can also greatly impact waste management, urban planning, home automation, environmental monitoring and management and emergency response systems. To enable this, emerging technologies such as real-time localization, embedded sensors and near field communications also need to be developed simultaneously.

Disaster management through spatial modeling

The geographic information system (GIS) has a great role to play in disaster management activities at all stages of its operations. Disasters are emergency situations which cannot be managed locally. Disasters can be manmade or natural or combination of both. Geographic information system is used in all disaster management activities irrespective of its source as manmade or natural. GIS is stool which can be effectively used in disaster management activities in its all phases. It has a pre event phase, during phase and post disaster phase. Disaster preparedness required. Disaster management is altogether a cyclic operation composed of mitigation, preparedness, response and recovery. GIS can be effectively used in all these phases of operations and in most of the cases no other techniques can provide such solutions.

Mitigation is the advance prevention and identification of vulnerable zones so that emergencies cannot be turn into a disaster all together. Role of GIS in this phase is the map all vulnerable areas and safe areas in terms of all types of disasters. For this we need to identify all possible disasters in the area, classify them into zones of high risk, medium risk and low rick zones. Here lies the role of GIS. Through GIS technique available spatial domain can be classified. For example, in case of a floods from the major rivers, mapping and modeling using various themes and elevation data in the forms of digital terrain models will ease out in classification of high to low risk areas and provide in the form of map so that planners and decision makers can take better information based decision. SBL multidisciplinary geo spatial team can cater all such mapping and modeling services.

Preparedness phase of the disaster management also require geo spatial services. GIS will help in site selection of shelter areas, location for emergency resource storing facilities. Selection and modeling of evacuation routes is also can be done using GIS techniques. This include road capacity versus population size, direction of travel, where to place relief camps, identification of key tactical and strategic facilities, marking of nearest safe hospitals and public safely facilities. Identifying supply chain of relief materials and its pre routing, mass awareness and training to concerned officers and aiding agencies. The far most important part of GIS at this phase is that to identify the locations of impact, area it will influence, model to how it is spread etc. To achieve comprehensive preparedness, a great deal of information must be gathered and managed. When disasters strike, the right information must be available at the right place to support emergency decision requirements.

When an emergency strike an area, the already amazed spatial data can be effectively used to combat the disaster. Unfolding impact influence area, marking of areas in harm’s way and mass notification can be possible through GIS. Optimizing shelters, routings, estimating effected population and property, assessing quantity of relief materials, advance warnings to nearby possibly affected areas etc will be ease out with the help of GIS

GIS will act as a central data base repository during the recovery phase of a disaster. GIS couples with remote sensing act as an apt tool in assessment of damage and losses incurred. These kinds of spatial data assessment give information on degree of damage to individual properties and aerial extent of the damage. These will enable the planners and decision makers to estimate the reconstructions cost, prioritizing the areas for development.

Role of GIS in disaster management

Natural disasters and catastrophes bring to light major dares for federal controls and local authorities. Earthquakes, floods, cyclones, epidemics, tsunamis, and landslides have become of regular occurrence many parts of the world, continually taking a heavy toll of life and property. Under serious disaster conditions, the major task for establishments is the protection of life (both human and animal), property, and the dynamic life-supporting infrastructure necessary for disaster alleviation. To give an edge in preparing and management of disasters, GIS technology could provide a crucial inputs for preparing a decision support and management system for authorities at times of disaster-related crises.
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Over the past few eons, Space expertise and Geographic Information Systems (GIS) Applications have become obligatory part of the modern information civilization. As the frequency of disasters become more and more regular and penetrating, the demand for these technologies is swelling in order to save lives, to minimize economic losses and to build resilience of the disaster affected region. It is imperious that the policymakers and decision makers make determined efforts to widen and expand the use of space technology and GIS applications in catastrophe prone areas to diminish the effect of disasters.

ROLE OF GIS TECHNOLOGY
GIS technology is a crucial component of information, communication, and space technologies (ICST), enabled disaster controlling systems because it remains predominantly untouched during disasters unlike in the instance of both information and communication technologies which are based on ground arrangement are wide-open to natural disasters.

The scope of GIS in disaster administration is as follows:

  • A large volume of data can be collected.
  • Data collection can be focused across a widespread area.
  • Data accuracy can fit in to the purpose of application.
  • Transfer of data is more consistent and safe even during disasters.
  • Communication is faster in various locations.
  • Communication is reliable across a wide area and remote distances.

TECHNOLOGY OPTIONS
The wide continuum of ICSTs used in disaster alertness, alleviation, and supervision include:

  • Airborne Remote sensing;
  • Geographical Information System (GIS);
  • Global Positioning System (GPS);
  • Satellite navigation system;
  • Internet, e-mail; and
  • Special software packages, on-line management databases, disaster information networks.

Range of Applications
The following phases of Disaster management areas are the point of interest for professionals who hinge on ICSTs for critical solutions.

  • Database generation
  • Information assimilation and analysis
  • Disaster charting and consequence simulation
  • Hazard valuation and observing
  • Disaster tendency forecasting
  • Susceptibility assessment
  • Emergency response decision support
  • Logistics preparation for disaster relief
  • Needs calculation for disaster reclamation and reconstruction
  • Risk analysis and assessment

Data integration is one of the strongest points of GIS. In general the following types of data are required:

  • Data on the disastrous phenomena (e.g. landslides, floods, earthquakes), their location, frequency, magnitude etc.
  • Data on the environment in which the disastrous events might take place: topography, geology, geo-morphology, soils, hydrology, land use, vegetation etc.
  • Data on the elements that might be destroyed if the event takes place: infrastructure, settlements, population, socio-economic data etc.
  • Data on the emergency relief resources, such as hospitals, fire brigades, police stations, warehouses etc.

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When an emergency strike an area, the already amassed spatial data can be effectively used to combat the disaster. Unfolding impact influence area, marking of areas in harm’s way and mass notification can be possible through GIS. Optimizing shelters, routings, estimating effected population and property, assessing quantity of relief materials, advance warnings to nearby possibly affected areas etc will be ease out with the help of GIS
GIS will act as a central database repository during the recovery phase of a disaster. GIS coupled with remote sensing will act as an apt tool in assessment of damage and losses incurred. These kind of spatial data assessment give information on the extent of damage to individual properties and aerial coverage of the damage. This will enable the planners and decision makers to estimate the reconstructions cost, prioritizing the areas for development.

2D Feature mapping from High Resolution Satellite images

Remote sensing is a vital system to acquire information of earth resources and environment. Remotely sensed images comprise of spectral, spatial and temporal resolution. The introduction of High-resolution satellite imagery is projected to reduce cost for medium and small scale topographic mapping. Since high-resolution satellite imagery has a much close-fitting field angle, the projection of images is nearly calculated by parallel rather than central systems. Using high resolution we can extract valuable information that will serve as a reference to bigger data needs and planning.

The feature extraction stage is intended to obtain a solid, non-redundant and evocative demonstration of observations. It is accomplished by removing repetitive and irrelevant material from the data.

satimageinterpretation

satimageinterpretation


SBL has perfected its capabilities in 2D feature mapping in the form of base mapping, land use land cover mapping and other types of thematic mapping. This kind of remote sensing services requires the knowledge of pre-processing on the satellite images. These pre-processing steps includes geo-referencing for geometric corrections and image enhancement for radiometric corrections. Digitally enhanced and geo-referenced images can be (re)projected to real world co-ordinate systems to put it in use for 2D feature extraction.
map digitisation

map digitisation

GIS data represents real world entities and features such as roads, land use, elevation, trees, waterways, etc. In GIS all features are grouped under the classes of point, line or polygons. Points are the smallest entity in GIS. Land marks, spot heights and point features such as locations of wells, ATM’s etc. can be represented in the form of points. Lines constitute a series of points called vertices and nodes with a start point and an end node point. Transportation network, drainage network, telecommunication lines, power transmission lines, sewerage network and other utility and transport networks can be represented in the form of lines. Polygons are closed features in which a line has start point and end point the same and which will encompass an area within it. Parks, water bodies, residential areas and forests can be represented in the form of polygons.

For 2D feature extraction services SBL will follow a classification schema derived after the requirement and need study established with the end-client. For example, for a forest department forest land parcels along with hydrographic and transportation network will be captured. For a mining firm during their replacement and rehabilitation process residential buildings, plantations, and orchards may be the main concentration. The thematic mapping using 2D features will be established as per the project and need requirements and is designed with a long term vision of serving the future changes and developments.

GIS mapping for 2D features extraction can be possible through aerial photographs as well. The features can be extracted using image interpretation keys such as tone texture, size, shape, association ext. SBL’s experienced image interpreters will deduce the images to useful thematic categories based on the classification schema. The final stage of the GIS based mapping services is the cartographic layout preparation. Each and every mapped 2D features will be given with a suitable standard symbology and layout can be prepared based on standard cartographic norms. The above notes explains in general the 2D mapping approach adapted by SBL.

Use of Airborne LIDAR in Transmission Line Projects

The growing energy demand is an issue that power utility authorities incessantly face. The creation of new transmission lines is not always probable due to complications in acquiring rights-of-way and obtaining environmental approvals. Airborne LIDAR uses a precise laser scanning technology that offers decidedly accurate terrain and tower elevation data for the transmission line corridor. The advanced software tools allow the analysis of critical distances, obstacles identification, slackness calculation, catenary shape calculation, and location of structures besides allowing data to be exported to specialized engineering softwares.
GIS plays an important role regarding operation planning, data maintenance and design of transmission lines. A great amount of data is required for the operation and maintenance of data related to transmission lines, which includes property ownership data, corridor land use/land cover (LULC), transmission line situation and characteristics. The physical features of the lines and corridor LULC are determined during construction but has to be updated due to the constant change in surroundings during the lifetime. Automation of technological procedures involved in data collection, integration and processing will ensure increased efficiency in the management of the utilities. Dispensation of the data discusses to the production of complete topographic GIS products including their custom-made presentation and analysis.
LIDAR (Light Detection and Ranging) is a contemporary remote sensing technique for the collection of high density and accurate topographic data, which allows high-speed and economical data acquisition of power utility networks. LIDAR together with GIS technology offers efficient tools for database management and analysis.

Fig 1. LIDAR components

Fig 1. LIDAR components

Further to range measurements, some LiDAR systems are also adept in registering the intensity of the backscattered laser pulse. Intensity is defined as the ratio of strength of reflected laser to that of emitted laser, and is influenced mainly by the reflectance of the reflecting object (Song, 2002). Reflectance deviates with material characteristics so that different materials have different reflectance. Therefore intensity images may be supplementary information for a LULC classification. The merging of intensity images with Elevation information produces an image where features can be easily identified. Intrinsic to the collection process the above mentioned images are ortho-rectified images facilitating in the collection of required data for a GIS System. These ortho-images can be used as location image references to maintain or to update an existing GIS database.

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Figure 2 – (a) Intensity Image (b) Image obtained by fusing intensity information with elevation information.

Results of the managed LIDAR data consists of 3D information about cables, structures as well as all hindrances along the corridor in a form of a point cloud with X, Y, Z coordinates and intensity value. Post-processing actions are needed in order to classify features and to develop additional information. Ground and cable points are categorized using algorithms available in TerraScan software.

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Among the non-ground points power lines strings can be captured using top views and need to ensure that it connects all the towers. This classification is the result of analysis by an automated filter developed which detects all LIDAR hits returns from the power lines and can be categorized as wires. Towers were also can be detected in a similar way. Critical points can be detected along the transmission lines and exact height needs to be assigned to each object. 50m either side of the transmission lines can be considered for object search and exact height of the objects can be derived. The objects encountered will be houses and vegetation in general. A vegetation clearance report will help to details location of the critical points and its complete information.
LIDAR technology provides a well-organized collection of high density and accurate topographic data, being one of the most recognized cost-effective and high-speed method to such projects. Above and beyond the obstacles and vegetation along the corridor, the location and height of the prevailing towers can be derived precisely. The high density of the laser points enables accurate delineation of the cables as well as the derivation of the connection points. LIDAR in concurrence with GIS methodologies provides efficient database updating and analysis.

Parcel mapping through GIS technique

New Image

A digital record of land parcels or plots is a necessity of modern day administration of any country. In general these data is available in old paper maps and cloth mounted maps which are poorly maintained. In modern era, with every aspect of life is going digital, it is imperative to get the parcel/plot boundaries also in digital form for effective administration and as part of the e-governance initiatives. Land administration will be much easier with parcel boundaries in digital parcel map or Cadastral map. The Cadastral map is one of the basic registers that administration at village, town, city and country can have.

SBL Geospatial Services division is having in-house experience and expertise in executing such GIS services. Geographic Information System (GIS) is an appropriate tool used in mapping parcel boundaries. First step in such mapping process is geo-referencing of the parcel maps after converting the paper maps into raster format by scanning method. The ground control points required to register scanned images to the ground is possible through field surveying, from other georeferenced maps, from open source data. Geo-referenced parcel map can be used digitize the parcel boundaries through heads-up digitization. The mapped objects can be point, line or polygon. Added advantage of parcel mapping in this way is that, one can incorporate any number of attributes to the digitized parcel boundaries. This will explicitly give ownership details, history of ownership, change details of the properties and any other relevant information deemed fit for the purpose.

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The digital parcel map is the vital component of any cadastral system and is used for legal, administrative and economic decision making and an irrefutable input for planning and development. One of the most important and basic benefit is that individuals can easily come to know about the area of land under their ownership and other details of their own property. This will help government directly by getting right amount of tax without any evasion due to poor record maintenance and difficult retrieval process of the same. It will greatly help urban development departments by assessing accurately parcels and properties affected by any developmental program and decision making will be much easier as we know the impact beforehand. Municipality planning will also be much easier with a digital parcel map, as the department is having accurate details of properties under its jurisdiction.

Most suitable GIS software, ArcGIS is nominated for carrying out the parcel mapping work. Besides digitizing, attribute assignment and management and geo database management, topology building and checks will be very easy in this software platform. Parcel mapping services also include mosaicking or seamless joining of adjacent maps so that village, taluk or district level data can be viewed and analyzed simultaneously. This will be highly helpful for the decision makers. Unlike paper maps and cloth mounted maps, digital parcel will be easy to analyze for area calculations and other statistics. The final results of the parcel maps can be represented in the form of ready to print maps by applying cartography techniques to the mapping process. Standard mapping symbology can be used to demote boundaries of parcels and other details thus mapped.

The paper or cloth parcel map was observed as a static, plain view of preselected areas, available at fixed scales, but due to the advances of the geospatial technology, it is now progressing into a dynamic, recurrently updated network of interconnected databases with large amounts of geographically referenced information linked to a comprehensive central digital parcel database.

GROUND WATER REGIME MONITORING AND ROLE OF GIS IN ITS ANALYSIS

Ground water is a hidden and precious resource. Its availability in quantitative and qualitative means is difficult to ascertain. The behaviors of water present underground and its properties such as transmissivity and storitivity can be obtained only through measurement of water levels present in the ground water extraction structures. As water level is the manifestation of the stress undergone by the aquifers, its measurement and monitoring is essential for knowing about this resource.

Why ground water monitoring is required?

The nature and present situation of the any water bearing underground formations can be obtained only through water level measurements. Ground water is an extensive resource, concealed underground and in most of the area it is inaccessible for any physical measurement. So it is very essential to measure its levels which are indicative of hydrostatic balanced plane of underground gradient for water flow and over ground pressure on it. The changes in quantity and quality of the ground water occur through slow process. In order to understand this slow changes long term measurement and monitoring is very essential. Other than water level measurements, quick monitoring of this resource is not possible by any other means. As water levels are indicatives of hydrologic stresses undergone by the aquifer which is having impacts on ground water recharge, storage and discharge, its monitoring in short as well in long terms are very essential. Groundwater regime monitoring will also help in design, implementation and monitoring the effectiveness of the ground water management, protection and conservation programs.

What is ground water regime monitoring?

In its simplest definition ground water regime monitoring is water level measurements from a network of observation wells. It is a collection of data, generally at set locations and depths and a at regular time intervals in order to provide information which may be used to determine the state of groundwater both in quantitative and qualitative sense, provide the basis for detecting trends in space and time, and enable the establishment of cause-effect relationships. Objective of any ground water regime monitoring is to record information on ground water level and quality through representative sampling in space and time.

When can it be measured?

Hydrologically India is a monsoon centric country with heavy precipitation during few months and long span of lean period. This pattern is having an impact in ground water monitoring phases as well. In general ground water will be monitored four time of the year.

January – 1st to 10th of the month- represents the recession stage of ground water level
April\May – 20th to 30th of the month – represents water level of Pre-monsoon period. April is for southern portion of the country where monsoon arrives in first week of June and May for northern stages where monsoon arrives around middle of July
August – 20th to 30th of the month – represents peak monsoon water level
November – 1st to 10th of the month- represents water level of Post-monsoon period

How can we do ground water regime monitoring?

Ground water regime monitoring is part of the ground water management process. It is a cyclic process which starts with ground water management and end up with the same. The first activity in any ground water management program is to define the objectives of the program. Then the regime monitoring strategy will be defined. This will be followed by network design and data collection. Data collection will be for quantitative measurements as well as qualitative data collection. Then followed by data processing, analyses and report generations. This information will be later utilized in the ground water management programs. The steps involved in ground water regime monitoring are

Establishment of monitoring stations: A groundwater monitoring network is a system of dedicated ground water monitoring wells in a geo hydrological unit at which ground water levels and water quality are measured at pre-determined frequency.

Criteria:
It should be representative for hydro geological set up
There should be optimum number of stations based on management criteria
There should not be any immediate abstraction or drawdown effect
Station should be accessible
Station should be permanent and is representative of local area
There should be replacement possibilities
Due consideration of hydrological process in the unit

Monitoring stations can be:
A key hole to aquifer
An abstraction well (tube well, bore well, or dug well)
Observation well
Piezo meters

Base line data collection: During the stage of construction of the monitoring wells information such as various logs, like litho logs and first struck water levels etc were recorded as base information to compare the rest of the year’s data.

Done at the time of development of a well
A static water level will be recorded as m bgl
Estimate altitude of the location with respect to mean sea level in a msl
A well log will also be prepared
Water samples will be collected for individual aquifers
The analysis results will be recorded and retained for further comparison

Data collection: Ground water levels can be measured both manually and automatically. Frequency of measurement will be varied based on the purpose. For a pumping test water levels will be measured in minutes or less than a minute duration, but for long term analysis measurement will be done four times in a year. Various instruments used to measure water levels commonly are:

For Non-flowing wells
-Steel tape and chalk
-Electric tape
-Pressure transducers
-Acoustic probe
-Ultrasonic
-Floats
-Poppers
-Air Lines

For flowing wells
-Transducers

Data storage: The collected data will be first stored in a firm field book and later entered into firm registers as well as in digital format which later will be transferred to a central data repository after necessary quality controls

Role of GIS in data analysis: Once the data is in digital form various analysis can be done on the data for deriving useful information for the effective ground water management. The data can be plotted in GIS platforms both in 3D and 2D forms. Contour maps which are the basis for further flow net and related analysis and modeling can be performed on the data. The collected data with the help of GIS software can be plotted in space and time. When the data is of multiple year’s duration, time series analysis and trend analysis can also be performed on the data along with numeric and statistical analysis.

Interpretation: The analysis results can be brought out in the form of reports where long term and shot term trends can be established. The results will be implemented in further ground water management processes.

How regime monitoring will influence ground water management?

Ground water regime monitoring results can influence ground water management in following ways:

Monitor impacts of abstraction on ground water system on a regional and local scale
Ground water balancing and budgeting
Calibration of numeric aquifer models
Determining pump usage and horse power
Determining the usage of water (potable, irrigable, industrial etc)
Early warning of potential threats in quantity and quality of ground water
Monitoring and managing of salt water intrusions
Monitoring of health hazards
To establish legal liabilities for pollution incidents and quantity issues
Monitoring droughts and floods
Monitoring water logging

What are the challenges in ground water regime monitoring?

Data loss during and after measurement
Inefficient use of man power and machinery
Expensive instruments and logistics
No visible return of investment
Difficulty in vertical variation in quantity and quality
Accuracy of the data
Monitoring of deeper and confined aquifers is difficult