Gis App 4

Remote Sensing and GIS application studies at national institute of hydrology

The success of planning for developmental activities depends on the quality and quantity of information available on both natural and socio-economic resources. It is, therefore, essential to devise the ways and means of organising computerised information system. These systems must be capable of handling vast amount of data collected by modern techniques and produce upto date information. Remote Sensing technology has already demonstrated its capabilities to provide information on natural resources such as crop, land use, soils, forest etc on regular basis. Similarly, Geographic Information Systems (GIS) are the latest tools available to store, retrieve and analyze different types of data for management of natural resources. GIS facilitates systematic handling of data to generate information in a devised format. Thus it plays an important role in evolving alternate scenarios for natural resources management. Remote Sensing (RS) data and Geographical Information System (GIS) play a rapidly increasing role in the field of hydrology and water resources development. Although very few remotely sensed data can be directly applied in hydrology, such information is of great value since many hydrologically relevant data can be derived from remote sensing information. One of the greatest advantage of using RS data for hydrological modeling and monitoring is its ability to generate information in spatial and temporal domain, which is very crucial for successful model analysis, prediction and validation. However, the use of RS technology involves large amount of spatial data management and requires an efficient system to handle such data. The GIS technology provides suitable alternatives for efficient management of large and complex databases. Image data have been used as a primary source of natural resources information in thematic mapping which in turn is utilised in various hydrological studies. The remote sensing data provides synoptic view of a fairly large area in the narrow and discrete bands of the electromagnetic spectrum at regular intervals. The space borne multispectral data enable generating timely, reliable and cost effective information on various natural resources, namely surface water, ground water, land use/cover, soil, forest cover and environmental hazards, namely waterlogging, salinity and alkalinity, soil erosion by water etc. For many hydrological purposes, remote sensing data alone are not sufficient and need to be merged with data from other sources. Hence a multitude of spatially related (i.e. geographic) data concerning topography, rainfall, evaporation, vegetation, geomorphology, and soils have to be considered. Also of interest are social and economic data related to where the demand is for water for urban and industrial supplies, irrigation, etc. In addition, technical data are required, such as locations and types of tubewells, rain and river gauges, etc. GIS provides an extremely useful technology for considering the interaction between spatially distributed resources. Some typical hydrological studies carried out in National Institute of Hydrology involving application of remote sensing and geographic information system are discussed in following sections. CASE STUDIES CARRIED OUT IN NIH The National Institute of Hydrology, with its Head Quarters at Roorkee (U.P.) and six regional centres located in different parts of the country viz. Belgaum (Karnatka), Jammu (J&K), Guwahati (Assam), Patna (Bihar), Kakinada (A.P.) and Sagar (M.P.), has been carrying out research on various aspects of hydrology and water resources using remote sensing and GIS techniques. These studies cover different hydrologic processes occurring in a catchment e.g. rainfall-runoff modelling, soil erosion, reservoir sedimentation, land use/cover and land capability studies, watershed studies, snow and glacier melt etc. Soil erosion assessment using remote sensing and GIS technique This study was carried

out for the estimation of soil erosion based on the Geomorphological Characteristics for Jawai dam catchment in India using GIS technique. In this study satellite data IRS-1B was used to determine the land cover, the other input variables have been determined from topographic and hydromet data. The geomorphological characteristics of a catchment represent the attributes of the watershed that can be employed in its hydrologic behaviour. The important characteristics from the hydrological studies point of view include the linear, areal and relief aspects of the catchments, morphometric characteristics of different sub-catchments and their interrelationship. Regression analysis has been carried out for Jawai dam catchment using Integrated Land and Water Information System (ILWIS). GIS Based Integrated Approach For Land Capability Classification In Bargi Command Area Land capability is the basis of watershed management programs. The basic principle of soil and water conservation is to use the land according to its capability and treat the land according to its needs. Land capability classification indicates the hazards of soil and water erosion, waterlogging etc. and these hazards limit the use of land for particular purposes only. For studying land capability classification beside the climatic factors, parameters related with watershed characteristics are required. For such parameters GIS is one of the best available tools. In the present study soil type, land use/land cover is input in GIS for analysis. From GIS analysis small scale land capability map is obtained. Integration of GIS and remote sensing in soil erosion studies In this study USLE has been applied to a part of Banjar sub-basin in Narmda basin. All the parameters required were generated in GIS package ILWIS. After integration of these parameter in GIS environment the soil loss was estimated. The erosion estimation was made without management (considering only the physical factors), during monsoon season and non-monsoon season. Under first condition, maximum potential erosion losses were estimated under prevailing rainfall erosivity without crop cover or supporting control practices. In monsoon season and non-monsoon season the factors C and R were changed and the effect were analysed. The rate of erosion is high under physical conditions reflecting the effect of rainfall and harsh topography SLURP Model and GIS for estimation of runoff in a part of Satluj In this study the SLURP watershed model was applied in a part the Satluj catchment located in the western Himalayas, India. The SLURP model, developed at NHRI, Canada, is a distributed conceptual model which simulates the behaviour of a watershed by carrying out vertical water balances for each element of a matrix of land covers and sub-areas of a watershed and then routing the resulting runoff between sub-areas. It has been shown that the SLURP hydrological model can be applied to a basin in India using available meteorological data, topographic data and satellite imagery. A GIS was used to bring the different data sets together and to compute parameters for the hydrological model, showing that a GIS can play an important role in hydrological modelling. The GIS database can be readily updated from time to time if any change occurs in the basin. In this study, the model was eventually applied for six years of daily data showing good results. The model results show that the local runoff from rainfall is a small proportion of the total runoff (including snowmelt) and that improved results will be expected when we include upper portion of the catchment

Soil Erosion and sediment yield modelling using kinematic Wave in GIS Environment In this study GIS techniques have been utilised for spatial discretization of a catchment in to a timearea segments to be used in numerical solutions of the governing differential equations in rainfallrunoff-erosion process. Various thematic layers such as soil, land use, slope, flow direction, DEM were generated for the Karso catchment in Bihar using various tools available in GIS. These thematic layers were further utilised to generate attribute information such as Manning's "n", USLE "K" and "C" parameters for use in rainfall-runoff-soil erosion model. Based on DEM and

related attribute information of the catchment, time-area map of the catchment was prepared and used for spatial discretization of the catchment. Watershed Modelling With GIS Based Distributed Unit Hydrograph Approach In this study a spatially distributed unit hydrograph for Temur watershed at railway bridge no.293 (M. P.) has been developed. The method of distributed unit hydrograph computation allows for spatial nonuniformity of excess rainfall. Consequently, it is based on the time-area method derived using GIS. The GIS allows development of a watershed's channel network for calculation of realistic travel times, it handles the distributed excess rainfall in calculating local surface runoff rates as inputs for channel flow and it compiles the time-area diagram from which distributed unit hydrograph is derived. Flood estimation using a GIUH based on a conceptual rainfall-runoff model and GIS Estimation of design flood for hydrological design of various water resources structures, particularly for medium and major water resources schemes, has been one of the most active areas of research for the hydrologists and water resources engineers. Geomorphological Instantaneous Unit Hydrographs (GIUH) have been proposed by several engineers as a tool to simulate runoff hydrographs from rainfall for ungauged catchments. The important geomorphological parameters which represent the linear, areal and slope aspects of the catchement are required to be evaluated either from toposheets or from other indirect means. Application of GIS package provides an efficient and accurate means for the evaluation of these characteristics. GIS for estimation of direct runoff potential For the estimation of the amount of direct runoff that will be produced from a basin, various hydrologic models are available. Soil Conservation Services (SCS) model is most widely used for the estimation of direct runoff. All the factors of SCS model are geographic in character. Due to the geographic nature of these factors, SCS runoff model can easily be modelled into GIS. In this study, Kolar subbasin of Narmada has been chosen for carrying out runoff potential estimation using ILWIS. For the rainfall events of 12, 13 and 14th. August 1989, direct runoff was computed using SCS equation. Reservoir sedimentation study for Ukai dam using satellite data In the present study, the sedimentation rate and volume was determined in the Ukai reservoir using the remote sensing data. Based on the annual maximum and minimum observed levels, the post-monsoon period of the year 1993-94 was chosen for analysis. Remote sensing data of IRS-1B satellite and LISS-II sensor was acquired for eight different dates and revised water spread area was extracted. The standard signature characteristics of different surface features (water, soil and vegetation) were utilised for separating water pixels from other surface features. The resulting imagery of water pixels was compared with the standard FCC and near-IR imagery. General Remarks In order to meet the growing demand for food, fuel and fodder of ever increasing population land and water resources need to be optimally utilised. It requires timely and reliable information on available land and water resources which could be derived from space borne multispectral data. GIS has evolved as a highly sophisticated data management system to put together and store the voluminous data typically required for hydrological studies. Thus remote sensing and GIS together provide information base for efficient management of water resources. The synoptic view provided by satellite remote sensing and the analysis capability provided by GIS offer a technologically appropriate method for studying these resources. The National Institute of Hydrology has carried out above mentioned studies and many other studies related with land use/land cover mapping, reservoir sedimentation, snow cover and snow melt modelling, soil erosion studies, rainfall runoff modelling in various parts of India. These studies have demonstrated capabilities of remote sensing and geographic information system in hydrological applications.

While application of remote sensing and GIS techniques in hydrology has made considerable progress, still more remains to be done to make these tools operationalised. Sustained efforts in consolidating results obtained so far and in developing operational methodology packages are needed. There is need to evolve a well co-ordinated programme in this area with focus on developing of standard methodologies and software as well as training and technology transfer. There is also need for wide spread availability of remote sensing and GIS outputs in digital mode for various applications in water sector. Remote sensing and geographic information system have to play a vital role in decision support system for various activities related with development and management of land and water resources in an environmentally sound and sustainable manner.

GIS applications in soil data analysis Abstract Soil survey is an integral part of an effective agricultural research and advisory program. It provides complete information about soils and is an inventory of the soil resource of the area. It gives the information needed for planning landuse and soil management programs. In Tamil Nadu Soil survey is being conducted by "Soil Survey and Landuse Organization," Coimbatore. The Soil survey reports are available for the users. This paper explains the use of GIS in storage, retrieval and visualization of soil data. If the soil information is available in GIS and maintained by an organization like" Soil Survey and Land use Organization," then many professionals could access the information for development purposes. Minjur and Panchetty area, part of Chennai basin, situated in the northern part of the Chennai City is taken for the present study. It lies within the Latitude of 13 ° 13' 00" N to 13° 25' 00" N and Longitude of 80° 05' 00" E. to 80° 20 ' 00"E and has a length of 28 km in the East West direction 26 km in the North South direction. The study area is 496 sq. km in extent. A soil survey of the study area was conducted during 81-82, by the soil survey and land use organization, Coimbatore. The soil survey report (Report no.59 Soil survey and land use organization.1985) and field samples were used to create a database on soil characteristics. The soil survey report is based on low intensity survey however, it can be used for many planning purposes and hence, it is used to demonstrate the usefulness of GIS in analysis and interpretation of soil data. GIS software Arc/info and Arcview are used to create the soil database. The attribute data of the soils are depth, texture, drainage, pH, salinity and alkalinity conditions, run off, erosion etc. The attribute data are linked with spatial data. Hence, linking spatial aspect of the soils with non-spatial characteristics forms the soil model. The necessary information and thematic maps could be easily generated using the model. Some applications are explained in this paper. The usefulness of the GIS will be enhanced if these capabilities are operated through the Internet. Introduction Soil survey is an integral part of an effective agricultural research and advisory program. It provides complete information about soils and is an inventory of the soil resource of the area. It gives the information needed for planning land use and soil management programs. In Tamil Nadu soil survey is being conducted by Soil Survey and Land use Organization, Coimbatore. The soil survey reports are available in for the users. This paper explains the use of GIS in accessing soil information and interpreted maps. If the soil information available in GIS and maintained by an organization then it could be accessed by many professionals who want to get the information for development purposes.

Need for the study Agriculture is the backbone of Indian economy. In order to produce food for increasing population the land and water resources have to be used more sustainable manner. Soil and water are the two main component of the agricultural system and they are undergoing degradation in many

aspects. Soils are being degraded due to erosion, water logging, salinity etc. Hence, knowledge about the soils is important for any project planning in order to satisfy the environmental conditions. In this context many professionals may need the soil data and at present the details are available in publications of Soil and Land use organisations. Soil data is spatial in nature and they can be easily handled and analysed using GIS. Sharing and dissemination of information is easier when the information is stored in digital form. Also the data in GIS can be analysed with other type of data to get the desired information. Hence advantages in use of GIS in handling soil data are demonstrated in this paper. Review of Literature Fayer et al. (1995) carried out a study to estimate the recharge using GIS. It was used to identify all possible combinations of soil type and vegetation and to assign to each combination, an appropriate estimate of recharge. Procedures to assess erosion in a catchment in Northwest Iran were evaluated using GIS and Remote Sensing (Meijerink et al.1996). The spatial segmentation of the catchment and derivation of the physical parameters related to erosion in the cells are performed through a GIS technique using the Integrated Land and Water Information System (ILWIS) package (Kothyari 1997). Rahman et al (1997) evaluated an alternative methodology for producing soil maps through a process of model construction and projection into a map base using ARC/INFO geographical information system. Soil Salinization risk at regional level was assessed using geographical information system by Bui et al (1995). Assessment of the risk of regional salinization involves integration of hydrology, hydrogeology, soil, and land management issues. The article discusses an example of the use of soil survey data integrated with water resources and digital elevation data in GIS, to estimate the risk of salinization after tree clearing at upper Burdekin river basin in the wet /dry tropics of North Queensland. Study area and methodology The study area (fig.1) Minjur and Panchetty area, part of Chennai basin, situated in the northern part of the Chennai City is taken for the present study. It lies within the Latitude of 13 ° 13' 00" N to 13° 25' 00" N and Longitude of 80° 05' 00" E. to 80° 20 ' 00"E and has a length of 28 km in the East West direction 26 km in the North South direction. The study area is 496 sq. km in extent. A soil survey of the study area was conducted during 81-82, by the soil survey and landuse organization, Coimbatore - 40. The soil survey report (Viswanathan et al 1985) and field samples were used to create a database on soil characteristics. The map is prepared by conducting low intensity survey however the interpretation is made to demonstrate the use of GIS in analysis and interpretation of soil data. Type of soil present in the study area The distribution of different soil families and soil association is as follows. 1. 2. 3. 4. 5. 6. 7. 8. 9.

Typic ustipsamments (TUSMP) Coarse loamy, Typic Ustorthents (CLTUT) Fine loamy, Fluventic ustochrepts (FLFUC) Fine loamy, Udic Ustochrepts (FLUUC) Fine loamy Udic Haplustalfs (FLUHLT) Fine, Vertic Haplustalfs (FVHLT) Fine loamy Udic Paleustalfs (FLUPUT) Fine, Entic Chromusterts (FECM) Loamy skeletal, Udic Ustochrepts (LSUUC)

Soil associations The following soil associations are found in the study area. 1. Typic ustipsamments- Fine loamy, Fluventic ustochrepts (1-3)

2. Fine, Vertic Haplustalfs- Fine, Entic Chromusterts- Fine loamy, Fluventic ustochrepts (68-3) 3. Typic ustipsamments-Fine, Entic Chromusterts- Fine loamy, Fluventic ustochrepts (1-8-4) 4. Fine, Entic Chromusterts, Fine loamy, Fluventic ustochrepts (8-3) 5. Fine loamy Udic Haplustalfs, Typic ustipsamments (5-1) 6. Fine loamy, Fluventic ustochrepts- Fine,Vertic Haplustalfs- Typic ustipsamments (3-6-1) 7. Fine loamy,Udic Haplustalfs - Fine,Vertic Haplustalfs (5-6) 8. Fine loamy,Udic Ustochrepts- Fine loamy Udic Paleustalfs (4-7) 9. Fine loamy,Udic Haplustalfs -Fine loamy, Fluventic ustochrepts (6-9) 10. Fine loamy, Fluventic ustochrepts - Typic ustipsamments (6-1)

Soil survey interpretation Soil survey interpretation comprises the organization and presentation of knowledge about characteristics, qualities and behavior of soils, as they are classified and outlined on soil maps. A well-prepared soil map, based on a sound classification system is useful as a base for different forms of interpretation. Soil survey data can be made use of in the development of agriculture, irrigation purposes, forestry, several engineering purposes, and so on. Land capability, soil irrigability and soil suitability classifications are made based on the soil survey interpretation. Based on the interpretation the potentialities and limitation of the soils can be obtained and such information are used to construct database using GIS. The soil map that is obtained from soil survey report is (1:50 000 scale) digitized. A database using Arc/info is formed. Each polygon in the digitized map represents the classes of soil family and soil associations. The attribute data of the soils are depth, texture, drainage, pH, and susceptibility to water logging, salinity and alkalinity, erosion, field capacity, nutrient-holding capacity respectively. Hence linking spatial aspect of the soils with non-spatial characteristics forms the soil model. The soil map of the study area is shown in the fig.2. The necessary information and thematic maps can be easily generated using the model. Some applications are explained in this paper as follows. Results and discussion Using the soil model it is possible to get desired thematic map like the crop suitability map, land irrigability map etc. In this paper application on assessing salinity and water logging problem is demonstrated one by using with soil model. Potentialities and limitation of soils of the first seven types of soil except sixth (1-5 and 7) are free from salinity, alkalinity, and water logging problem. The soil six Fine loamy Udic Haplustalfs is moderately drained and potential to become the alkaline soil as per the soil survey interpretation. The soil type Fine, Entic Chromusterts FECM (8) is very deep, fine texture, high water holding capacity, poor drainage, slow permeability. Hence, water logging and salinity problem is higher in this type of soil. This family of soil will cause problem to sustainable agriculture. Using GIS soil types are ranked according to the salinity or water logging risk. Then by analysis thematic maps were prepared. The areas prone to water logging and soil salinity are shown in the fig. 3. From above illustrations it is clear that use of GIS in soil data handling makes decision-making process easier for planners. Incidentally, it is felt that the data collection process will be easier and comfortable if data owning department puts the information in Internet. Geological mapping: Geological mapping is done to show geological features. It provides geographical and physical data required for computational services for industries working world wide. We outsource geological mapping services with cost effective means. This data is produced to depict the shape, size, structure of the objects shown on geographical maps.

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Provides enormous knowledge about Earth's geology and hence provides data for comparison with other planets.

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Geologists identify the areas suitable for urban development and agriculture practices.

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To locate natural resource deposits like coal, petroleum, natural gas etc.

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To locate areas prone to geological hazards like landslide, flood, volcanoes, earthquakes, tsunamis etc.

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To locate mineral deposits and ground water resources.

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Helps building infrastructure like roadways, pipelines, dams, railway track, highways, buildings etc.

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Tracks the hazardous waste disposals for smooth administration.

Geologic mapping is complex analysis that requires a lot of hard work, consideration and manipulation of spatial and georeferenced data using the informative GIS tool. It is a useful scientific and commercial process to produce a list of maps that have number of uses. These maps produce beneficiary analysis and saves potential losses. Geologists strive to know the composition and structure of Earth matter and depict information in GIS format. This provides basis for comparisons and facilitates analysis to offer results that can benefit our future. These maps are so useful that these have because the most requested scientific product. These mapping services constitute a fundamental and commercial scientific basis; that is the foundation on which resource use is based. These maps keep a record of soil, water, forest etc on the land surface and protects valuable resources, avoiding risks of hazards by making the right use of land. We focus on practical aspects of geology, this is facilitated by the use of aerial photography, GIS based cartography, satellite imagery and GPS technology. Geological mapping services involves obtaining information from the GIS and remote sensing methods. Geologists use this information and analyze it; to map range of geological characteristics that include mountains, rivers, valleys, rock structures etc. This even helps in the following field:

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Business

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Government

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Agriculture

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Telecom

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Environmental management

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Public safety

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Real estate and planning

These mapping services work a lot to improve the infrastructure requirements and at the same time helps in minimizing possible economic losses that might cause due to geological hazards. Several geologists are dependent on this technique to produce reports and work in the direction of improvement for the world. We provide help to these intelligent geologists by rendering our geological mapping services all over the world.

Use of GIS in transportation management Introduction: The burgeoning number of vehicles in the Country , especially in an Urban setting which are choking the cities in India is the main concern of the Government as well as the urban Planners . The reason for this are many.With the liberalization of the Indian economy  

The large Indian middle class has that extra money to afford 'necessities'(vehicles being one of them) which was considered as a 'luxury' not very long ago. The availability of state of the art Vehicles in India which is too tempting to be ignored by the affluent.

However every care has to be taken to see that these 'necessities' do not become a bane in day to day life. This calls for an effective transportation management in an Urban setting. Since 'Transportation Management' is a spatial phenomenon GIS can be used as an effective tool in Managing and Planning transportation. This paper gives a comprehensive insight as to how GIS can be used effectively to manage and plan Transportation and make commuting easier (if not pleasure) in an Urban setting. Need for transportation management: The growth of any urban area is driven by two factors. One being, the establishment of Businesses which open up tremendous employment opportunities and secondly the large influx of people to the urban areas.This results in large number of people commuting from a large number of residential pockets, to the Central Business Districts where majority of the business establishments are located. On an average an urban commuter spends about 2 - 3 hours every day on the roads to reach the work place , school or home where as a decade back the same distance would have been covered in about half the time as that of now. Considering the exponential growth of the number of Vehicles and the ever increasing population the situation is bound to reach alarming levels in the near future. At the same time all the Technical advancements made in various fields of Science and Technology provide effective tools to check,manage and plan the ‘Vehicular traffic’. Challenges : The challenges in effective Transportation management are many. The number of Vehicles on the roads is steadily increasing where as the roads and the land available for building new roads are very limited. Managing , redirecting and decongesting the traffic within the existing roads and space is indeed a challenging task. Methodology: Geographical Information systems (GIS) in the recent past has acquired tremendous importance in various applications.In general any application which has a spatial phenomenon can leverage the GIS technology. By the use of GIS and GPS (Global Positioning Systems) it is possible to continuously track the location of Vehicles at any given point of time. So far this Technology which is very popularly referred as Automatic Vehicle Location (AVL) is being effectively used for fleet management and is provided by AVL service providers. This technology with its high cost of implementation and

specific use has been limited as it is used mainly by companies owning large fleet of vehicles to track their Vehicles. But with all the advancements made in the fields of GIS and especially the decreasing size and cost of GPS it is possible to use the same AVL technologies, to track any Vehicle that is just out of the assembly line. All the trucks,cars and even two wheelers can be fitted with a GPS which is as small as a chip and which gives an accurate position of the Vehicle in terms of longitude and latitude. Once the vehicles are fitted with the GPS a centralized traffic control room which has all the necessary equipments to view and analyse the location of every vehicle on the road can be made use of. This centralized traffic control room can have many computer terminals, each of them concentrating on viewing and analyzing the Vehicular traffic at the important junctions, roads of the city which has a large flow of traffic. The system also can be built as an intelligent system which is capable of generating alternate routes if there is a jam at any point of time. The system can be used to know the average number of vehicles plying on each road on a daily basis. The same data can be stored in a database and later mined which can be very useful in various activities of traffic planning and management . The question is how a person like you and I can make use of this intelligent system when in the middle of the road battling the traffic.The results of the analysis put together by the Centralised traffic control room can be made use of to effectively manage the traffic. All important data like the number of Vehicles on each road, information about the roads where there are jams and the details of alternate roads that can be taken can be displayed on huge electronic sign boards that can be installed at important traffic junctions, roads and even on the internet. Another way of keeping the users updated is by making use of the radio with traffic updates at some time intervals.

Benefits: Transportation management being a spatial phenomenon can be managed effectively using the GIS technology. Following are the benefits of effective transportation management.  

Ease of traffic movement Lesser time on roads

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Reduced tempers while driving Increased Personal safety. Effective transport planning.

Introduction In a broad sense a Geographic Information System (GIS) is an information system specializing in the input, storage, manipulation, analysis and reporting of geographical (spatially related) information. Among the wide range of potential applications GIS can be used for, transportation issues have received a lot of attention. A specific branch of GIS applied to transportation issues, commonly labeled as GIS-T, has emerged. Geographic Information Systems for Transportation (GIS-T) refers to the principles and applications of applying geographic information technologies to transportation problems [Miller and Shaw, 2001]. GIS-T research can be approached from two different, but complementary, directions. While some GIS-T research focuses on issues of how GIS can be further developed and enhanced in order to meet the needs of transportation applications, other GIS-T research investigates the questions of how GIS can be used to facilitate and improve transportation studies [Shaw, 2002]. In general, topics related to GIS-T studies can be grouped into three categories: • • •

Data representations. How can various components of transport systems be represented in a GIS-T? Analysis and modeling. How can transport methodologies be used in a GIS-T? Applications. What types of applications are particularly suitable for GIS-T?

2. GIS-T Data Representations Data representation is a core research topic of GIS. Before a GIS can be used to tackle real world problems, data must be properly represented in a digital computing environment. One unique characteristic of GIS is the capabilities of integrating spatial and nonspatial data in order to support both display and analysis needs. There have been various data models developed for GIS. The two basic approaches are object-based data models and field-based data models [Lo and Yeung, 2002]. •

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An object-based data model treats geographic space as populated by discrete and identifiable objects. Features are often represented as points, lines, and/or polygons. On the other hand, a field-based data model treats geographic space as populated by real-world features that vary continuously over space. Features can be represented as regular tessellations (e.g., a raster grid) or irregular tessellations (e.g., triangulated irregular network - TIN).

GIS-T studies have employed both object-based and field-based data models to represent the relevant geographic data. Some transportation problems tend to fit better with one type of GIS data model than the other. For example, network analysis based on the graph theory typically represents a network as a set of nodes interconnected with a set of links. Object-based GIS data model therefore is a better candidate for such transportation network representations. There also exist other types of transportation data that require extensions to the general GIS data models. One well-known example is linear referencing data (e.g., highway mileposts). Transportation agencies often measure locations of features or events along transportation network links (e.g., a traffic accident occurred at the 52.3 milepost on a specific highway). Such a one dimensional linear referencing system (i.e., linear measurements along a highway segment with respect to a pre-specified starting point of the highway segment) cannot be properly handled by the two dimensional Cartesian coordinate system used in most GIS data models. Consequently, the dynamic segmentation data model was developed to address this specific need of the GIS-T community. Origin-destination (O-D) flow data are another type of data that are frequently used in transportation studies. Such data have been traditionally represented in matrix forms (i.e., as a two-dimensional array in a digital computer) for analysis. Unfortunately, the relational data model widely adopted in most commercial GIS software does not provide an adequate support of handling matrix data. Some GIS-T software vendors therefore have developed additional functions for users to work with matrix data within an integrated GIS environment. The above examples illustrate how the conventional GIS approaches can be further extended and enhanced to meet the needs of transportation applications. In recent years, the development of enterprise and multidimensional GIS-T data models has occurred. Successful GIS deployments at the enterprise level (e.g., within a state department of transportation) demand additional considerations to embrace the diversity of application and data requirements. An enterprise GIS-T data model is designed to allow "each application group to meet the established needs while enabling the enterprise to integrate and share data." [Butler and Dueker, 2001, p. 17]. The needs of integrating 1D, 2-D, 3-D, and time for various transportation applications also have called for an implementation of multidimensional transportation location referencing systems [Koncz and Adams, 2002]. In short, one critical component of GIS-T is how transportation-related data in a GIS environment can be best represented in order to facilitate and integrate the needs of various transportation applications. Existing GIS data models provide a good foundation of supporting many GIS-T applications. However, due to some unique characteristics of transportation data, many challenges of developing better GIS data models that will improve rather than limit what we can do with different types of transportation studies still exist. 3. GIS-T Analysis and Modeling GIS-T applications have benefited from many of the standard GIS functions (query, geocoding, buffer, overlay, etc.) to support data management, analysis, and visualization

needs. Like many other fields, transportation has developed its own unique analysis methods and models. Examples include shortest path and routing algorithms (e.g., traveling salesman problem, vehicle routing problem), spatial interaction models (e.g., gravity model), network flow problems (e.g., user optimal equilibrium, system optimal equilibrium, dynamic equilibrium), facility location problems (e.g., p-median problem, set covering problem, maximal covering problem, p-centers problem), travel demand models (e.g., the 4-step trip generation, trip distribution, modal split, and traffic assignment models), and land use-transportation interaction models. While the basic transportation analysis procedures (e.g., shortest path finding) can be found in most commercial GIS software, other transportation analysis procedures and models (e.g., facility location problems) are available only selectively in some commercial software packages. Fortunately, a recent trend of moving towards component GIS design in the software industry provides a better environment for experienced GIS-T users to develop their own custom analysis procedures and models [e.g., Shaw and Xin, 2003]. It is essential for both GIS-T practitioners and researchers to have a thorough understanding of transportation analysis methods and models. For GIS-T practitioners, such knowledge can help them evaluate different GIS software products and choose the one that best meets their needs. It also can help them select appropriate analysis functions available in a GIS package and properly interpret the analysis results. GIS-T researchers, on the other hand, can apply their knowledge to help improve the design and analysis capabilities of GIS-T. 4. GIS-T applications GIS-T is one of the leading GIS application fields. Many GIS-T applications have been implemented at various transportation agencies over the last two decades. They cover much of the broad scope of transportation, such as infrastructure planning, design and management, transportation safety analysis, travel demand analysis, traffic monitoring and control, public transit planning and operations, environmental impacts assessment, hazards mitigation, and intelligent transportation systems (ITS). Each of these applications tends to have its specific data and analysis requirements. For example, representing a street network as centerlines and major intersections may be sufficient for a transportation planning application. A traffic engineering application, however, may require a detailed representation of individual traffic lanes. Turn movements at intersections also could be critical to a traffic engineering study, but not to a region-wide travel demand study. These different application needs are directly relevant to the GIS-T data representation and the GIS-T analysis and modeling issues discussed above. When a need arises to represent transportation networks of a study area at different scales, what would be an appropriate GIS-T design that could support the analysis and modeling needs of various applications? In this case, it may be preferable to have a GIS-T data model that allows multiple geometric representations of the same transportation network. Research on enterprise GIS-T data model and multidimensional, multimodal GIS-T data model

discussed above aims at addressing these important issues of better integrating various GIS-T applications. With the rapid growth of the Internet and wireless communications in recent years, a growing number of Internet-based and wireless GIS-T applications can be found. Such applications are especially common for ITS and for location-based services (LBS). Another trend observed in recent years is the growing number of GIS-T applications in the private sector, particularly for logistics applications. Since many businesses involve operations at geographically dispersed locations (e.g., supplier sites, distribution centers/ warehouses, retail stores, and customer sites), GIS-T can be useful tools for a variety of logistics applications. Again, many of these logistics application are based on the GIS-T analysis and modeling procedures such as the routing and the facility location problems. GIS-T is interdisciplinary in nature and has many possible applications. Transportation geographers, who have appropriate backgrounds in both geography and transportation, are well positioned to pursue GIS-T studies.

Intelligent transport system using GIS 1. Introduction Mobility enables us to separate home from work and visit friends and family, as well as to allow us to do business across a wider region. Transportation has the ability to provide some powerful benefits to society. In addition to supporting specialization, transportation provides us with the sort of mobility and accessibility we need to live our lives in the way we want to live them. Generally, there is widely accepted link between economic wellbeing and good transportation. However, the picture is not all rosy. There is a price to pay for good transportation. This comes in the form of undesirable side effects such as environmental impacts, energy consumption, land take, congestion, casualties and money required to build infrastructure. Growing concern about the impact of these undesirable side effects has influenced most developed countries to move away from the “build it and they will come,” infrastructure-intensive, capital-intensive transportation strategies, toward more balanced and sustainable transportation solutions. There Intelligent Transport System (ITS) comes into picture and it holds the promise of sustainability. Intelligent Transport Systems (ITS) is the name given to the application of computer and communications technologies to transport problems. In a rapidly changing society the emphasis on road technology improvements to assist in road management has been identified. The rapid advances in ITS technologies have enabled the collection of data or intelligence which provides relevant and timely information to road managers and users. Japanese seems to have initiated the whole modern day notion of ITS with work carried out in the 1980s. The United States was also addressing the application of ITS at an early stage in the course of the Electronic Route Guidance project (ERGS) in the 1970’s. The European Union picked up the theme, and referred to it as Road Transport Informatics. In the course of time the name of this technology subjected to many changes until USA had given a name called ITS to it. Intelligent Transport systems include wider application of technology to transit systems as well as private car and highways. Benefits given by ITS to any transportation system by introducing it are, improved safety, improved traffic efficiency, reduced congestion, improved environmental quality & energy efficiency and

improved economic productivity. Keeping traffic moving is the big challenge that all levels of government are facing worldwide. Private travelers, commercial road users, and the public sector are continually searching for new and faster travel routes. Without quality and dynamic data, route selection is often a hit and misses guessing game. The old adage, ‘knowledge is power’ is the obvious solution to the traffic problem. Customers want real-time information to help them select the best route to take at any given time. They need to know traffic speeds, incidents (accidents or lane closures), and road conditions. With Advanced Traveler Information Systems (ATIS) information, drivers make informed decisions and are better equipped to plan their route and estimate their travel time. Fast and accurate information translates into several benefits for ATIS customers such as reduction in travel time, reduction in stress levels, the avoidance of congestion, and perhaps the most important benefit, the avoidance of unsafe driving conditions. The ultimate solution has a big mandate. Critical features include accuracy, timeliness, and reliability. The ideal solution is an up-to-the minute traffic information system that enables drivers to make more intelligent travel decisions at any time of the day and any day of the week. There is wide scenario of problems, which are specific to India, and indigenous solutions are required to suit its requirement. The countries like USA, Canada, Japan, U.K., Australia and Germany which have embarked upon intelligent transport system (ITS) don’t have scarcity of funds. Considering these facts, India needs a system, which is cost effective, and efficient, at the same time is also compatible with the present level of development in the country in the related areas. 2. Package Development 2.1 Mechanism Developing Advanced Traveler Information System (ATIS) in Geographic Information System (GIS) is main objective of current project. In this system shortest path, closest facility and city bus routes were included. Besides these features location wise information and inter city traveler information like bus, train and airways timing are also included. Mechanism involved in the development of package is described in following sections. 2.1.1 Shortest path Route planning is a process that helps vehicle drivers to plan a route prior to or during a journey. It is widely recognized as a fundamental issue in the field of transportation. A variety of route optimization criteria or planning criteria may be used in route planning. The quality of a route depends on many factors such as distance, travel time, travel speed and number of turns. These all factors all can be referred as travel cost. Some drivers may prefer the shortest path based on distance and some prefer based on travel time [11]. The route selection criteria can be either fixed by a design or implemented via a selectable user interface. In the current project route selection is via user interface. In the optimization of the travel distance (road segment length), distance was stored in digital data base and the route planning algorithm was used. In the optimization of travel time, road segment length and speed limit on that road are stored in digital data base and travel time was calculated (distance/speed limit). The calculated travel time was used as travel cost in the performance of path optimization. 2.1.2 Closest facility In the closest facility problem route length and travel time (drive time) were considered as travel costs. Different facilities like hospitals, bus stations, and tourist places were taken as themes in the project. Closest facility algorithm calculates all the routes from selected origin to facilities based on travel cost. It compares travel costs of these routes and gives one optimal route as output [1].

2.1.3 City bus routes City buses with their numbers were stored in a data base in a compressed format because on one road segment there will be more than one bus. A search algorithm was used to find bus service number from selected origin and destination. According to bus number, road segments on the map were selected and highlighted with different color. The schematic flow chart of the package is shown as Fig 1. 2.3 Source Program The source program for this package has been written in Avenue programming language. Avenue is object-oriented and scripting language for ArcView GIS. Customization of the package was done in Avenue. The source code was divided into many numbers of scripts because in Avenue language functions or procedures are not available. Each script is used for a specified purpose. 2.4 Software Development for Hyderabad City Software used in the development of current project is   

ArcView GIS version 3.1 Network Analyst version 1.1b Avenue programming language

Brief description of the software is as follows

Fig 1 Flow chart of mechanism in the package

2.4.1 ArcView GIS version 3.1 ArcView GIS software is a desktop GIS with an easy-to-use, point-and-click graphical user interface (GUI) that lets us easily load spatial and tabular data so we can display the data as maps, tables, and charts. ArcView provides the tools we need to query and analyze the data

and present results as presentation-quality maps. 2.4.2 Network Analyst The ArcView Network Analyst is an extension product designed to use networks more efficiently. It can solve common network problems on any theme containing lines that connect. .4.3 Avenue ArcView scripts are macros written in Avenue, ArcView's programming language and development environment. With Avenue we can customize almost every aspect of ArcView, from adding a new button to run a script we write, to creating an entire custom application that we can distribute. Work plan for present study is shown in the flow chart shown as Fig 2. The different steps involved in the work plan are: 2.5 Geo-Referencing Raster data is obtained by scanning maps or collecting aerial photographs and satellite images. Scanned maps don’t usually contain information as to where the area represented on the map fits on the surface of the earth. The location information delivered with aerial photos and satellite imaginary is often inadequate to perform analysis or display in proper alignment with other data. To establish the relationship between an image (row, column) coordinate system and a map (x, y) coordinate system we need to align or georeference the raster data (image).

Fig 2 Work plan flow chart

2.6 Digitizing Digitizing is a process of encoding geographic features in digital form as x, y coordinates. It is carried out in order to create spatial data from existing hardcopy maps and documents. In the present work, the geo-referenced raster images of Hyderabad city are digitized using ArcView GIS 3.1. This type of digitization is called on-line digitization. Road network of the study area is digitized as line features. Lakes and rivers are digitized as polygon features. Bus stations, railway stations, hospitals, places of tourist interest, offices, educational institutions and stadiums are digitized as point features. The above spatial data is organized in layers or themes in the current project.

2.7 Input Data 2.7.1 Description of Area Twin cities Hyderabad and Secunderabad have been selected for present study. Hyderabad city, an administrative and commercial center and capital of Andhra Pradesh state is the fifth biggest city in India. The study area (Hyderabad-Secunderabad twin cities) is bounded by latitude 17030’-00’’ N and 170-19’-48’’ N and longitude 780-22’-12”E and 780-34’-48” E and area covered is about 500 square kilometers 2.7.2 Input Data Sources Following data was collected and used in the development of package. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Topographical map at scale 1:25000 numbered 56-K/ 7 / NE Topographical map at scale 1:25000 numbered 56-K/ 7 / SE Topographical map at scale 1:25000 numbered 56-K/ 7 / NW Topographical map at scale 1:25000 numbered 56-K/ 7 / SW Information of one-way road segments Speed limits on roads Road names City bus routes Time tables of inter city bus, train and air services Description of Themes and Data Base

All the necessary information for each feature is to be entered into its theme’s attribute table, to analyze it in later stage. This is done by adding required number of fields (columns) to the table and entering the data for all the features in their corresponding records (rows). Conclusions 1. Digital traveler information system for Hyderabad city has been developed in geographic information system (GIS) using ArcView GIS software package and it was customized using Avenue programming language. 2. This package is having point-and-click graphical user interface (GUI) and it is user friendly also. 3. The developed package has the following capabilities 1.Finding shortest path based on distance and drive time 2.Finding closest facility and its path based on distance and drive time 3.City bus routes 4.Search engine - which searches different facilities in Hyderabad city 5.Provides intercity bus, train and airways information (timings, distance and service name) 6.Site tour planning

2. The developed package can be used in the following areas to give information to the travelers

1. 2. 3. 4. 5.

Bus stands Railway stations Airports Tourist information centers In personal computers