ABSTRACT Surveying is a profession that finds itself increasingly at major crossroads today. This... more ABSTRACT Surveying is a profession that finds itself increasingly at major crossroads today. This fact is perhaps best vindicated by the increasingly less number of students who are opting to study surveying as their first-degree choice at university level. The number of postgraduate students is also relatively low. In an effort to address this stark reality as well as re-engineer itself, the Department of Surveying, University of Nairobi is in the process of launching new academic programs at both undergraduate and postgraduate levels. This paper traces developments in the curriculum review process at the Department of Surveying, University of Nairobi that began almost a decade ago. A review of the basic principles in curriculum development is presented. The objectives of the above new programs are outlined together with their respective regulations. The course structures for both the undergraduate and postgraduate programs are then presented. A proposal for implementing the new programs is finally outlined before conclusions are drawn.
This paper examines the in uence of multisensor data fusion on the automatic extraction of topogr... more This paper examines the in uence of multisensor data fusion on the automatic extraction of topographic objects from SPOT panchromatic imagery. The suitability of various grey level co-occurrence based texture measures, as well as diVerent pixel windows is also investigated. It is observed that best results are obtained with a 3×3 pixel window and the texture measure homogeneity. The synthetic texture image derived together with a Landsat Thematic Mapper (TM) imagery are then fused to the SPOT data using the additional channel concept. The object feature base is expanded to include both spectral and spatial features. A maximum likelihood classi cation approach is then applied. It is demonstrated that the segmentation of topographic objects is signi cantly improved by fusing the multispectral and texture information.
Handbook of Research on Hydroinformatics: Technologies, Theories and Applications InformatIon scIence reference, 2011
The continuing decline in lake water levels is both a concern and daunting challenge to scientist... more The continuing decline in lake water levels is both a concern and daunting challenge to scientists and policymakers in this era, demanding a rethinking of technological and policy interventions in the context of broader political and socio-economic realities. It is self-evident that diverse factors interact in space and time in complex dynamics to cause these water-level changes. However, the major question demanding sound answers is how these factors interact and by what magnitude they affect lake water balance with time. This chapter uses Lake Victoria’s hydrological system to shed light on the extensive and flexible modelling and simulation capabilities availed by modern computer models to understand the bigger picture of water balance dynamics. The study used the 1950-2000 hydrological data and riparian population growth to develop a dynamic simulation model for the lake’s water level. The intuitive structure of the model provided clear insights into the combined influence of the main drivers of the lake’s water balance. The falling lake water levels appeared to be mainly due to dam outflows at the outlet and reduced rainfall over the lake. The ensuing conclusions stressed the need for checks against over-release of lake water for hydropower production and measures for sustainable land and water management in the entire basin.
Investigation of the influence of data compression techniques on the quality and further processi... more Investigation of the influence of data compression techniques on the quality and further processing of satellite sensor imagery is a research and development topic which remains both current and important. In principle, this extends the scope of data compression in remote sensing beyond the classical applications of data transmission and storage. Against this background, the main objective of this study is to examine the effect of data compression on the automatic classification of Landsat imagery. The main focus of this is on the built environment. In order to obtain better segmentation results, the feature base is expanded to include both spectral features, such as spectral signature and texture, and non-spectral features such as shape, structure and topology. This expansion enables the integration of context information into the feature extraction process. The image is systematically compressed (channel by channel) at compression rates ranging from 5 to 100 using wavelet-based software. An integrated, pixel-based classification approach is then used to segment the compressed imagery. The analysis of the results obtained indicates that a compression rate of up to 20 can conveniently be used without adversely affecting the segmentation results. The suitability of wavelet compression schemes for the compression of heterogeneous data is also underlined.
... are to date less than 100 GIS installations in Kenya [14], the human resource pool available ... more ... are to date less than 100 GIS installations in Kenya [14], the human resource pool available ... Human Resources Issues in the Emerging GDI Environment, Geospatial Data Infrastructure: Concepts, Cases ... Computer Society of Kenya, Quarterly Report of the Kenyan ICT Sector, http ...
ABSTRACT A microwave path survey is critical before any wireless communication infrastructure can... more ABSTRACT A microwave path survey is critical before any wireless communication infrastructure can be put into place. It is on the basis of this that the line of sight possibility between any pair of stations is established. This survey can also be used to determine whether there is sufficient space available on existing telecommunication towers, where additional telecommunication facilities can be hosted. This study has demonstrated that differential GPS techniques can successfully be used in microwave path surveys within the framework of telegeoinformatics. The adopted methodology simulated a levelling circuit for the defined observation network. This resulted in an acceptable misclosure of 0.039m which was distributed among the various stations in proportion to the relative length of each link. Natural and man-made obstacles (critical points) along the various telecommunication links were also determined.
ABSTRACT Purpose – To show how the analytical and visualization capabilities of geographic inform... more ABSTRACT Purpose – To show how the analytical and visualization capabilities of geographic information systems (GIS) can enhance the communication, understanding and utility of data and information to be used in marketing planning, as compared with their conventional presentation as text and tables. Design/methodology/approach – A digital map of the study area was generated and a set of market zones. A multiple regression model for predicting sale of the product under study was then developed, taking into account sales figures from specific distribution outlets and the demographic and socio-economic characteristics of the population served by the distribution outlets in the identified market zones. Optimum routes and times between the manufacturing plant and the distribution outlets were derived. Findings – Combining geospatial methods with conventional marketing techniques enables users to visualize the spatial distribution of data in maps, complemented by various statistical graphs and diagrams. This form of presentation yields better insights into the nature of the distribution process and better understanding of the diverse markets served. Research limitations/implications – This is a single case study of the solution to a logistical question in one district of one city in an African country. The findings must therefore be applied to other contexts with due caution. Practical implications – The study nevertheless vividly demonstrates the important role that GIS can play in sales and marketing planning. Originality/value – An application of planning technology normally encountered in applications beyond the marketing discipline, readily transferable with care to more familiar situations and settings.
ABSTRACT It has been postulated that Lake Naivasha, Kenya, has experienced a rapid decrease (and ... more ABSTRACT It has been postulated that Lake Naivasha, Kenya, has experienced a rapid decrease (and fluctuations) in its spatial extent and level between the years 2002 to 2010. Many factors have been advanced to explain this, with horticultural and floricultural activities, as well as climatic change, featuring prominently. This study offers a multi-disciplinary approach based on several different types of space-borne observations to look at the problem bedeviling storage (TWS) variations within a region covering the Lakes Naivasha and Victoria basins; (2) precipitation records based on Tropical Rainfall Measurement Mission (TRMM) products to evaluate the impact of climate change; (3) satellite remote sensing (Landsat) images to map shoreline changes and to correlate these changes over time with possible causes; and (4) satellite altimetry observations to assess fluctuations in the lake's level. In addition, data from an in-situ tide gauge and rainfall stations as well as the output from the African Drought Monitor (ADM) model are used to evaluate the results. This study confirms that Lake Naivasha has been steadily declining with the situation being exacerbated from around the year 2000, with water levels falling at a rate of 10.2 cm/yr and a shrinkage in area of 1.04 km^2/yr. GRACE indicates that the catchment area of 4deg*4deg that includes Lake Naivasha loses water at a rate of 1.6 cm/year for the period from August 2002 to May 2006, and 1.4 cm/year for the longer period of May 2002 to 2010. Examining the ADM outputs also supports our results of GRACE. Between the time periods 2000-2006 and 2006-2010, the lake surface area decreased by 14.43% and 10.85%, respectively, with a corresponding drop in the water level of 192 cm and 138 cm, respectively, over the same periods. Our results show a correlation coefficient value of 0.68 between the quantity of flower production and the lake's level for the period 2002-2010 at 95% confidence level, indicating the probable impact of anthropogenic activities on the lake's level drop.
ABSTRACT Surveying is a profession that finds itself increasingly at major crossroads today. This... more ABSTRACT Surveying is a profession that finds itself increasingly at major crossroads today. This fact is perhaps best vindicated by the increasingly less number of students who are opting to study surveying as their first-degree choice at university level. The number of postgraduate students is also relatively low. In an effort to address this stark reality as well as re-engineer itself, the Department of Surveying, University of Nairobi is in the process of launching new academic programs at both undergraduate and postgraduate levels. This paper traces developments in the curriculum review process at the Department of Surveying, University of Nairobi that began almost a decade ago. A review of the basic principles in curriculum development is presented. The objectives of the above new programs are outlined together with their respective regulations. The course structures for both the undergraduate and postgraduate programs are then presented. A proposal for implementing the new programs is finally outlined before conclusions are drawn.
This paper examines the in uence of multisensor data fusion on the automatic extraction of topogr... more This paper examines the in uence of multisensor data fusion on the automatic extraction of topographic objects from SPOT panchromatic imagery. The suitability of various grey level co-occurrence based texture measures, as well as diVerent pixel windows is also investigated. It is observed that best results are obtained with a 3×3 pixel window and the texture measure homogeneity. The synthetic texture image derived together with a Landsat Thematic Mapper (TM) imagery are then fused to the SPOT data using the additional channel concept. The object feature base is expanded to include both spectral and spatial features. A maximum likelihood classi cation approach is then applied. It is demonstrated that the segmentation of topographic objects is signi cantly improved by fusing the multispectral and texture information.
Handbook of Research on Hydroinformatics: Technologies, Theories and Applications InformatIon scIence reference, 2011
The continuing decline in lake water levels is both a concern and daunting challenge to scientist... more The continuing decline in lake water levels is both a concern and daunting challenge to scientists and policymakers in this era, demanding a rethinking of technological and policy interventions in the context of broader political and socio-economic realities. It is self-evident that diverse factors interact in space and time in complex dynamics to cause these water-level changes. However, the major question demanding sound answers is how these factors interact and by what magnitude they affect lake water balance with time. This chapter uses Lake Victoria’s hydrological system to shed light on the extensive and flexible modelling and simulation capabilities availed by modern computer models to understand the bigger picture of water balance dynamics. The study used the 1950-2000 hydrological data and riparian population growth to develop a dynamic simulation model for the lake’s water level. The intuitive structure of the model provided clear insights into the combined influence of the main drivers of the lake’s water balance. The falling lake water levels appeared to be mainly due to dam outflows at the outlet and reduced rainfall over the lake. The ensuing conclusions stressed the need for checks against over-release of lake water for hydropower production and measures for sustainable land and water management in the entire basin.
Investigation of the influence of data compression techniques on the quality and further processi... more Investigation of the influence of data compression techniques on the quality and further processing of satellite sensor imagery is a research and development topic which remains both current and important. In principle, this extends the scope of data compression in remote sensing beyond the classical applications of data transmission and storage. Against this background, the main objective of this study is to examine the effect of data compression on the automatic classification of Landsat imagery. The main focus of this is on the built environment. In order to obtain better segmentation results, the feature base is expanded to include both spectral features, such as spectral signature and texture, and non-spectral features such as shape, structure and topology. This expansion enables the integration of context information into the feature extraction process. The image is systematically compressed (channel by channel) at compression rates ranging from 5 to 100 using wavelet-based software. An integrated, pixel-based classification approach is then used to segment the compressed imagery. The analysis of the results obtained indicates that a compression rate of up to 20 can conveniently be used without adversely affecting the segmentation results. The suitability of wavelet compression schemes for the compression of heterogeneous data is also underlined.
... are to date less than 100 GIS installations in Kenya [14], the human resource pool available ... more ... are to date less than 100 GIS installations in Kenya [14], the human resource pool available ... Human Resources Issues in the Emerging GDI Environment, Geospatial Data Infrastructure: Concepts, Cases ... Computer Society of Kenya, Quarterly Report of the Kenyan ICT Sector, http ...
ABSTRACT A microwave path survey is critical before any wireless communication infrastructure can... more ABSTRACT A microwave path survey is critical before any wireless communication infrastructure can be put into place. It is on the basis of this that the line of sight possibility between any pair of stations is established. This survey can also be used to determine whether there is sufficient space available on existing telecommunication towers, where additional telecommunication facilities can be hosted. This study has demonstrated that differential GPS techniques can successfully be used in microwave path surveys within the framework of telegeoinformatics. The adopted methodology simulated a levelling circuit for the defined observation network. This resulted in an acceptable misclosure of 0.039m which was distributed among the various stations in proportion to the relative length of each link. Natural and man-made obstacles (critical points) along the various telecommunication links were also determined.
ABSTRACT Purpose – To show how the analytical and visualization capabilities of geographic inform... more ABSTRACT Purpose – To show how the analytical and visualization capabilities of geographic information systems (GIS) can enhance the communication, understanding and utility of data and information to be used in marketing planning, as compared with their conventional presentation as text and tables. Design/methodology/approach – A digital map of the study area was generated and a set of market zones. A multiple regression model for predicting sale of the product under study was then developed, taking into account sales figures from specific distribution outlets and the demographic and socio-economic characteristics of the population served by the distribution outlets in the identified market zones. Optimum routes and times between the manufacturing plant and the distribution outlets were derived. Findings – Combining geospatial methods with conventional marketing techniques enables users to visualize the spatial distribution of data in maps, complemented by various statistical graphs and diagrams. This form of presentation yields better insights into the nature of the distribution process and better understanding of the diverse markets served. Research limitations/implications – This is a single case study of the solution to a logistical question in one district of one city in an African country. The findings must therefore be applied to other contexts with due caution. Practical implications – The study nevertheless vividly demonstrates the important role that GIS can play in sales and marketing planning. Originality/value – An application of planning technology normally encountered in applications beyond the marketing discipline, readily transferable with care to more familiar situations and settings.
ABSTRACT It has been postulated that Lake Naivasha, Kenya, has experienced a rapid decrease (and ... more ABSTRACT It has been postulated that Lake Naivasha, Kenya, has experienced a rapid decrease (and fluctuations) in its spatial extent and level between the years 2002 to 2010. Many factors have been advanced to explain this, with horticultural and floricultural activities, as well as climatic change, featuring prominently. This study offers a multi-disciplinary approach based on several different types of space-borne observations to look at the problem bedeviling storage (TWS) variations within a region covering the Lakes Naivasha and Victoria basins; (2) precipitation records based on Tropical Rainfall Measurement Mission (TRMM) products to evaluate the impact of climate change; (3) satellite remote sensing (Landsat) images to map shoreline changes and to correlate these changes over time with possible causes; and (4) satellite altimetry observations to assess fluctuations in the lake's level. In addition, data from an in-situ tide gauge and rainfall stations as well as the output from the African Drought Monitor (ADM) model are used to evaluate the results. This study confirms that Lake Naivasha has been steadily declining with the situation being exacerbated from around the year 2000, with water levels falling at a rate of 10.2 cm/yr and a shrinkage in area of 1.04 km^2/yr. GRACE indicates that the catchment area of 4deg*4deg that includes Lake Naivasha loses water at a rate of 1.6 cm/year for the period from August 2002 to May 2006, and 1.4 cm/year for the longer period of May 2002 to 2010. Examining the ADM outputs also supports our results of GRACE. Between the time periods 2000-2006 and 2006-2010, the lake surface area decreased by 14.43% and 10.85%, respectively, with a corresponding drop in the water level of 192 cm and 138 cm, respectively, over the same periods. Our results show a correlation coefficient value of 0.68 between the quantity of flower production and the lake's level for the period 2002-2010 at 95% confidence level, indicating the probable impact of anthropogenic activities on the lake's level drop.
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Papers by J. Kiema
of broader political and socio-economic realities. It is self-evident that diverse factors interact in space and time in complex dynamics to cause these water-level changes. However, the major question demanding sound answers is how these factors interact and by what magnitude they affect lake water
balance with time. This chapter uses Lake Victoria’s hydrological system to shed light on the extensive
and flexible modelling and simulation capabilities availed by modern computer models to understand
the bigger picture of water balance dynamics. The study used the 1950-2000 hydrological data and
riparian population growth to develop a dynamic simulation model for the lake’s water level. The intuitive
structure of the model provided clear insights into the combined influence of the main drivers of the lake’s water balance. The falling lake water levels appeared to be mainly due to dam outflows at the outlet and reduced rainfall over the lake. The ensuing conclusions stressed the need for checks against over-release of lake water for hydropower production and measures for sustainable land and water management in the entire basin.
of broader political and socio-economic realities. It is self-evident that diverse factors interact in space and time in complex dynamics to cause these water-level changes. However, the major question demanding sound answers is how these factors interact and by what magnitude they affect lake water
balance with time. This chapter uses Lake Victoria’s hydrological system to shed light on the extensive
and flexible modelling and simulation capabilities availed by modern computer models to understand
the bigger picture of water balance dynamics. The study used the 1950-2000 hydrological data and
riparian population growth to develop a dynamic simulation model for the lake’s water level. The intuitive
structure of the model provided clear insights into the combined influence of the main drivers of the lake’s water balance. The falling lake water levels appeared to be mainly due to dam outflows at the outlet and reduced rainfall over the lake. The ensuing conclusions stressed the need for checks against over-release of lake water for hydropower production and measures for sustainable land and water management in the entire basin.