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Abstract
The paper presents the use of Geographic Information System (GIS) in management of Electricity Distribution Facilities. With inherent limitations faced by traditional system of keeping and managing information, an automated system is developed for National Electric Power Authority (NEPA), Onitsha District in Onitsha-North L.G.A., Anambra State of Nigeria. The administrative\street and electricity distribution network maps were collected from relevant agencies. Electricity distribution facilities spatial database was designed and created using relational database model approach. The paper maps were converted to digital form, through scanning. The raster images were sent to AutoCAD Map R2 environment for geo-referencing and on-screen vectorization. The drawings were edited and exported to ArcView 3.2a environment. The graphics were linked with the created spatial database. The developed system was put to the test by carrying out a number of GIS operation and analysis. Results obtained were displayed in graphics and tables. It was ascertained from the results that GIS is a competent and effective tool for managing electricity distribution network. In this context, conclusions and some useful recommendations were proffered.

1.0 Introduction
Generally, electricity could be accepted to mean supply of electric current. This involves generation, transmission and distribution of the electric current to consumers. Electricity is an aspect of the utility sector that is very essential to the smooth and meaningful development of a society. It supports the economy and promotes the well-being of individuals. Efficient functioning of this utility is of paramount importance for the sustenance of its growth and consequential realization of its planning and managerial objectives.

In recent times, the Federal Government of Nigeria (FGN), worked very hard to see to the realization of steady power supply by the end of 2001 in the country. The President made this clear when he gave a mandate to the National Electric Power Authority (NEPA) to ensure uninterrupted power supply to the nation by 31st December 2001. It was noted that NEPA has raised electricity output from as low as 1,600 megawatts to 4,000 megawatts and over one billion dollars spent in order to meet up with the mandate (This Day Newspaper, 2002). Yet, erratic power supply and outages remain a major problem confronting the nation today.

In this context, in as much as efforts are made towards efficient power generation, the subsequent transmission and distribution of the generated power should not be overlooked. Efficient functioning of the generated power cannot be achieved without proper record keeping and monitoring of the transmission and distribution network system. According to Pickering et al 1993, any organization that expects to run an efficient day-to-day operation and to manage and develop its services effectively must know what asset it has, where they are, their condition, how they are performing, and how much it costs to provide the service. Emengini (2004) noted that knowledge about physical assets of the enterprise is necessary to make strategic and operation decisions. Thus, to take wise decisions vital to the operations, growth and management of electricity distribution facilities, information must be collected and analysed to its full extent, such information contributes not only to efficient services, but also to the operation and maintenance of assets, and to the sensible planning of extensions and new works.

1.1 Problems at Hand
The creation, updation, maintenance and general management of electricity distribution network in terms of spatial and non-spatial data is a herculean task. The voluminous nature of data involved for proper record keeping is indeed cumbersome, and cannot effectively be handled by traditional system of record keeping. The analogue system means acceptance of inflexibility resulting from data storage in fixed forms and formats. The system becomes less useful for may purposes and are rarely updated because of costs implication. The maps are easily displaced or destroyed because many different people at different locations use them. More of the limitations faced by the traditional system of record keeping are given by Adetoro (2002).

An alternative approach of maintaining a coherent database in a scientific and efficient manner by use of advanced information technology is therefore, required. Hence, there will be improvements in planning, implementation and operation of the electricity sector through provision of timely, reliable, sufficiently and accurately detailed data which will facilitate its decision making activities. Uluocha (1998) noted that if the noble objective of mapping for proper utility design and maintenance is to be satisfactorily achieved, the more sophisticated computer-based Automated Mapping /Facility Management (AM\FM) or a Geographic Information System (GIS) must be embraced. The potentials and challenges of using the GIS technique in utility mapping in a developing country as Nigeria, have to some extent been demonstrated by the work of Adekunle (1995). With the use of GIS, NEPA can collect, input, edit, store, retrieve, query, process, analyze and output large amount of data at desired scales and projections (Fig. 1).

Fig. 1.0: National Electricity Power Authority’s Overhead Transmission Cables (Their Locations and Attribute Information can be Managed by GIS) The benefits of, and hence, factors favoring automated utility information system are numerous, some of which have been chronicled by Antenucci (1988), Maguire (1989), Tomlison (1990), Jones (1997), Ezeigbo (1998), and Adeoye (1998).
1.2 The Study Area
The study area (Fig. 3.0) is Onitsha-North Local Government Area with headquarters at Onitsha in Anambra State of Nigeria. It is situated between latitudes 060 021 N and 060 081 N and longitudes 060 471 E and 060 591 E. It serves as the gateway between southeastern and southwestern Nigeria.

The area situates where a high ground underlain by the sandstones of the Bende-Ameke formation, comes very close to River Niger. It provides a stretch of well-drained, healthy site in the flood plains of the River Niger. Such favorable site at the meeting point of two contrasting regions east and west of the Niger, and the Niger itself, which provides a link with the savanna zone to the north and the forest and delta region to the south, enabled the area to develop as an important commercial center, south east of Nigeria. The area is heavily populated resulting in high electricity consumption. Fig 2. Shows a transformer station within the study area.

Fig. 2: A NEPA Transformer Station at Onitsha-North L.G.A. (GIS can facilitate routine maintenance)


Fig. 3.0: Map of Nigeria and Location of The study area
2.0 Methodology
Data used for this study are:

1. The Administrative / Street Map
2. The Electricity Distribution Network Map
3. Attribute Data collected on the ground
4. Data on the end-users

The administrative/street map was acquired from Anambra State Ministry of Lands, Survey and Urban Planning, Awka. The Electricity Distribution Network map and some of the attribute data were collected from National Electric Power Authority (NEPA), Onitsha District. Using on-spot observation and personal interview, some attribute data and data on the end-users were acquired.

A number of application software packages were used for data processing. Such packages include: photo-plus for scanning and AutoCAD map R2 for geo-referencing and on-screen digitizing. ArcView 3.2a was used for GIS overlay operation and analysis of spatial and spatial queries.

2.1 User-Requirement Survey
User-requirement survey was carried out to determine actually what the end-users would want the system to do for them. From the survey carried out, the types of analysis to carry out were known. It also guided in knowing the configuration of the hardware and software systems required of the work and in the choice of appropriate model and structure to use. Other possible benefits derived from good user-requirement survey have been given by Kufoniyi (1998).

2.2 Design of Database
In the design of database, four basic steps were taken. These include: articulation of reality, translation of reality to conceptual model, translation of conceptual model to logical design and physical design. Realities were articulated based on geographic data within the study area with respect to electricity distribution facilities. In this case, reality includes the following geographic features: Administrative Areas, Roads, Streets, NEPA Transmission, 11kv Lines, Power Transformer, Distribution Transformer.

In translation of reality to conceptual model, the articulated realities were represented in a simplified manner and at the same time satisfied the information required by the users. Hence, vector data modeling was adopted. The realities were represented and displayed as points, lines or area (polygon), with their attributes defined by pair of plane coordinates (X, Y). The objects together with the spatial relationships among them were carefully identified and analysed.

Translation of conceptual model to logical design involves representation of the designed data model to reflect the recording of the data in the computer. The data were structured to describe logically the organization of data in the database. Relational data structure was chosen to implement the model because of its flexibility capability and very wide deployment both within and outside GIS. During physical design, the designed data structure was represented in a form that is acceptable to the implementation hardware and software. The tables' names, the attributes, data type, and the width of the data were specified in Data Declaration as shown in Table 1.0
TABLE 1.0: DATA DECLARATION

TABLE NAME	ATTRIBUTES	DESCRIPTION	DATA TYPE	WIDTH
ADMIN. AREA	AD.A_id	Administrative Area identifier	Number	5
	AD.A_Loc	Place where the Administrative Area is located	String	20
ROADS	RD_id	Road identifier	Number	5
	RD_name	The name of the road	String	20
	N_Surface	The nature of the road’s surface	String	15
	R_Class	The class in which the road belongs	String	15
STREETS	St_id	Street identifier	Number	5
	St_name	The name of the street	String	20
	N_Surface	The nature of the street’s surface	String	15
NEPA TRANSMISSION	NT_id	NEPA transmission identifier	Number	5
	NT_Loc	The place where the NEPA transmission is located.	String	20
IIKV LINE	IIKV_id	IIKV Line identifier.	Number	5
	IIKV_Cap	The capacity of IIKV Line.	Number	6
	A _ served	The area or section of the town 11kv Line is serving.	String	20
	PT_Feed	The power transformer feeding the I1kv line.	Number	10
POWER TRANSFORMER	PT_id	Power transformer identifier.	Number	5
	NF_Serv	The number of feeders that depend on it.	Number	5
	PT_Cap	The Capacity of the power transformer.	Number	6
	PT_Loc	The location of the power transformer.	Number	20
DISTRIBUTION TRANSFORMER	DT_id	Distribution transformer identifier.	Number	5
	DT_ Loc	The location of the distribution transformer.	String	20
	A _ Serv	The area or section of town the distribution transformer is serving.	String	20
	Yr_inst	The year the distribution transformer was installed.	Number	6
	DT_Cap	The capacity of the distribution transformer.	Number	6
	N_cons	The number of consumers the d t is serving.	Number	6
	IIkv_serv	The identifier of the IIKV line the distribution transformer is serving.	Number	5
	Population	The no. of people the distribution transformer is serving.	Number	6

2.3 Creation of Database
The database was created by inputting the relevant spatial and attribute data into the system. The tables were populated with the attribute data. The spatial data were captured by scanning the paper maps using A3 scanner with photo-plus. The raster images were geo-referenced and digitized on-screen in AutoCAD map R2 environment. The images were separated and digitized under the following layers:

MAP 1 (BASE MAP)
Administrative areas
Roads
Streets
MAP 2 (ELECTRICITY DISTRIBUTION NETWORK)
NEPA transmission
11kv line
Power transformer
Distribution transformer

2.4 Quality Assurance and Quality Control
The digitized drawings were edited and subjected to quality assurance test. The edited drawings shown in Figs. 4.0 and 5.0 were exported to ArcView 3.2a environment and linked with the created database after converting them to shapefiles. The linkage was possible by unique identifiers assigned to each of the entities; GIS operation and analysis were carried out.

Fig. 4.0: The Digitized and Edited Drawings of Administrative/Street Map of Onitsha-North Local Government Area.



Fig. 5.0: The Digitized and Edited Drawings of Onitsha-North Electricity Distribution Network
3.0 Data Analysis and Presentation
The following GIS operation and analysis were carried out: Overlay operation, spatial query, and aspatial query.

3.1 Overlay Operation
The essence of overlay operation is to superimpose two or more data layer that occupies the same location (Sun et al, 2001). The base map was superimposed with the electricity distribution network. The result of the overlay operation is shown in fig. 6.0.

Fig.6.0: The map of Onitsha-North Local Government Area overlaid with Electricity Distribution Network.
3.2 Spatial Query
Spatial query was carried out to get all information about a given electricity distribution facility located in a given area. In this case, the system was queried to search and display all available information about the existing distribution transformer located within “Otu” area. The result was displayed as shown in Fig. 7.0.

Fig. 7.0: Distribution Transformer located within “Otu” area with its Attribute Information.
3.3 Aspatial Query
This task was carried out in order to know the location(s) of a given facility with a known attribute. For example, the location(s) of all the distribution transformers with capacity 15mva along Old Market Road could be known as provided by the system. The result is shown in Fig. 8.0.

Fig. 8.0: Distribution Transformers with Capacity 15mva along Old Market Road.
4.0 Discussion of Results
In Fig. 6.0, the base map (administrative/ Street map) was overlaid with the electricity distribution network, hence revealing the spatial distributions and locations of electricity distribution facilities. The facilities on ground such as 11kv line, power transformer, distribution transformer, transmission station etc, were shown and the extents at which they occur were also revealed. With this result, NEPA will be able to know the spatial relationships that exist among their facilities. Such knowledge will help them know the area(s) or sections(s) of the town that lack their services. It will also guide them in knowing where they could extend or improve their services and equally areas that need new installation.

In addition to these, the results can equally provide good information for other professionals, for example Urban Planners, Construction Managers, Civil Engineers etc. The knowledge of the spatial locations of the distribution facilities will help to avoid or reduce damages done to these facilities during construction works. To the Town Planners, it will help to plan better. When damages occur in any of the facilities, GIS will assist in quick location of problem areas and best approach to solution. Overlay operation can be used during map revision and up-dating GIS environment and in identification of dangers due to time in a given area.

The result in Fig. 7.0, revealed the attributes of the distribution transformer. The identify results table displayed, shows descriptive information about the object. The distribution transformer was installed on 6th October 1977. The transformer depends on AK7 feeder via 11kv line. The capacity of the transformer is 45mva while 62 households depends on it. In Fig. 8.0, the selected distribution transformers with capacity 15mva along old market were displayed in yellow circles. The result indicated that they are three in number. Their associated records were highlighted in yellow colour on the attribute of NEPA transformer table.

These results demonstrated some of the capabilities of GIS in handing and managing electricity distribution spatial data. With GIS, one can manipulate and carry out tasks that are vital in management of electricity for proper and efficient results. When new facilities are installed, the GIS database and graphical (map) components can be updated easily to accommodate the new features. So, map revision and digital mapping become easy in GIS environment.

4.1 More Benefits of the Developed System
In addition to the use of the system in fault management, and network extensions and optimization, the following benefits can also be obtained:

1. In planning of routine maintenance.
2. In easy handling of customer’s inquiries.
3. In network configuration.
4. In improved revenue management.
5. In right of way and compensation.
6. In provision of back-up system that eliminates the problem of data loss.
7. In easy and speedy retrieval of information.
8. In data update and possible sharing of data among different users simultaneously.

5.0 Conclusions and Recommendation
Spatial and attribute data of electricity distribution network of Onitsha-North Local Government Area, which are presently acquired, processed, managed, stored and presented in analogue form, can be digitalized. Digital system provides timely, accurate, and easier way of acquiring information, which are very vital in taken prompt and accurate decisions necessary in the economic development of any enterprise. Ayeni et al (2003) noted that Geospatial Information (GI) is very essential to economic planning and national development. This is buttressed further by Alamu and Ejiobih (2002), when they concluded that a well maintained utility information infrastructure gives up-to-date information on what is where, the state of it, the reaction other actions on it would cause, how it can be harnessed for optimum use of the people and economy.

In conclusion therefore, the following recommendations are preferred: -

1. There is need for greater awareness to be created at all levels of government. Taking off from national level through the municipal, down to individual managers, of what is required to establish GIS.
2. NEPA as well as other Utility organizations in developing countries that have dealings with spatial data should embrace digital system of keeping and managing spatial data.
3. There is need for briefings, training and re-training sessions among staff of NEPA, Nigeria and other municipal authorities in GIS.
4. The increased services of Geometricians are needed in NEPA. They will champion the responsibility of spatial data acquisition, processing, management and presentation of outputs in usable form.
5. The international body with their vast strength and power should encourage the developing countries to establish GIS in different areas of human endeavour through adequate funding.
6. Good institutional framework should be established at all levels of governments down to individual who will be coordinating the affairs of producers and users of geo-spatial data.

References

• Adekunle, A.A. (1995), “Utility Mapping Using GIS Technique: A Case Study of University of Lagos”, Unpublished B. Sc. Project Submitted to the Department of Geography and Planning, University of Lagos.
• Adeoye, A. (1998), “Geographic/Land Information Systems: Principles and Applications”, Information Management Consultants, Ebute-Metta, Lagos, Nigeria, pp.73-79, 172-175.
• Adetoro, S. A. (2002), “Developing Geographic Information System for Utility Management: A Case Study of Electricity Distribution Lines and Transformer Stations in Obafemi Awolowo University: Ile-Ife”, Proceeding of the Technical Session of the 37th Annual General Conference and Meeting of Nigerian Institution of Surveyors, Owerri, Imo State, Nigeria, pp.57-62.
• Alamu, E.O. and H.C. Ejiobih (2002), “Utility Information Infrastructure Needs in Utility Organisations in Nigeria: (A Case Study of Niger State Water Board,” Proceedings of the Technical Session of the 37th Annual General Conference and Meeting of Nigerian Institution of Surveyors, Owerri, Imo State, Nigeria, pp. 85-88.
• Antenucci, J. C. (1988), “Technical Trends in AM/FM and the Institutional Factors Driving Them”, Paper Presented at the IBM GFIS Users Group Work-shop, Kentucky, USA.
• Ayeni, O.O., Kufoniyi, O. and J.O. Akinyede (2003), “Towards a National Geospatial Information Policy for Nigeria”, Proceeding of the Technical Session of the 38th Annual General Conference and Meeting of Nigeria Institution of Surveyors, Lokoja, Kogi State, Nigeria, pp. 21.
• Emengini, E. J. (2004), “Application of Geographic Information System (GIS) to Utility Information Management: A Case Study of Onitsha-North L.G.A., Anambra State, Nigeria,Unpublished M.Sc. Thesis Submitted to the Department of Surveying and Geoinformatics, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
• Ezeigbo, C. U. (1998), “Application of Geographic Information Systems (GIS) to Utility Mapping”, in C. U. Ezeigbo (ed.), Principles and Applications of Geographic Information Systems, Lagos, Panef Press, pp. 124-131.
• Jones, C. B. (1997), “Geographical Information Systems and Computer Cartography”, Essex, Addison Wesley Longman Ltd.
• Kufoniyi, Olajide (1998), “ Database Design and Creation”, in C. U. Ezeigbo (ed.), Principles and Applications of Geographic Information Systems, Lagos, Panef Press, pp. 1-15.
• Maguire, D. J. (1989), “Computers in Geography” Essex, Longman Group UK Limited.
• Mukoro, M. I., S. A. Adetoro, and H. C. Ejiobih (2002), “Evaluation of National Electric Power Authority (NEPA) Utility Information Infrastructure Towards Steady Power Supply by the End of 2001: A case Study of Bida NEPA”, Proceedings of the Technical Session of the 37th Annual General Conference and Meeting of Nigerian Institution of Surveyors, Owerri, Imo State, Nigeria, pp. 63-67.
• Pickering, David, J. M. Park and D. H. Bannister (1993), “Utility Mapping and Record Keeping for Infrastructure”, Urban Management and Infrastructure, Urban Management Programme, Washington, D.C. Vol. 10, pp. ix-11.
• The Punch, (2001), “NEPA Ensures Stable Power Supply to Sokoto”, Punch Nigeria Ltd, Lagos, 24th December,3.
• This Day, (2002), “Obasanjo Gives NEPA Fresh Mandate: Orders 10,000mw by 2005”, Leaders and Company Ltd, Lagos, 24 January, pp.1.
• Sun, Y., C. J. Van Westen and E. J. Sides (2001), “Spatial Data Analysis”, in A.D. B. Rolf (ed.), Principles of Geographic Information Systems, pp. 134-156.
• Tomlison, R. F. (1990), “Current and Potential Uses of Geographic Information Systems: The North American Experience” in D. Peuquet and D. Marble (eds.), Introductory Readings in Geographic Information Systems, New York, Taylor and Francis.
• Uluocha, N. O. (1998), “Mapping for Utility Management in Nigeria” in O.Y. Balogun and N. O. Uluocha (eds.), Cartography and Challenges of the 21st Century in Nigeria, pp. 183-192.
• Vijay, Kumar and Anjuli Chandra (2001),“Role of Geographic Information Systems in Distribution Management”, www.gisdevelopment.net/application/urban/overview/power/index.htm