An Analysis on the Applicability of a National Digital Elevation Model - Essay Example

AN ANALYSIS ON THE APPLICABILITY OF A NATIONAL DIGITAL ELEVATION MODEL By School Location Executive summary Developing digital elevation models has been in the recent years relied upon to provide modern means of addressing the geological navigation issues within given countries or regions within a country. This is because the digital elevation models provide more accurate tools that simulate the real-time situation within the respective geological navigation demands. Nevertheless, the development of digital elevation models more precise data collection methods and may be resource intensive as compared to the development of normal topographical maps. The national Mapping agency is the major national organization tasked with addressing the maps and other geological navigation instruments for the country. Following the requirement to develop a reliable tool for analyzing the country’s geological situation, the National mapping agency requires to develop a digital elevation model that will be applied in major parts of the country. This will include the ability to respond to urban and rural geological situations without inhibiting the functionality of the model. Additionally, the proposed digital elevation model will be required to be viable concerning the usability dependability and consumption of resources. Problem statement The development of digital elevation models relies on the integration of apt technical skills and resource management ability in order to develop an accurate and resource conservative geological management projects. As a result, the following business and technical case is aimed at providing viable solutions for the National mapping agency with regard to developing dependable digital elevation model based on an integration of technical and business skills. Analysis of the situation The issue at hand is based on delivering the most efficient digital elevation model for the country at affordable costs in order to provide a viable solution for the National mapping agency’s geological projects. The national mapping agency just like any other national mapping body in any given country requires development of reliable digital elevation models that allow the state to effectively manage projects that require intense geographical navigation. Based on the National mapping’s requirement of implementing an efficient digital elevation model it is essential to develop the most appropriate digital elevation model based on the issues at hand. The digital elevation model is aimed at providing a reliable 3 D model of the entire nation’s terrain. In this case, this includes the ability to navigate the rural and the urban terrain. Therefore, the digital elevation model will be based on analyzing the issues at hand with regard to developing the most applicable digital elevation model for the nation. One of the most important issues with regard to the development of the applicable digital elevation model is the assessment of the terrain. The ability of the digital elevation model will be based on the ability to navigate through rough terrain and through regions affected by adverse weather conditions in the country. For instance, based on the unpredictable weather patterns in adverse weather regions, digital elevation models may be unreliable with regard to monitoring areas affected with natural calamities such as floods. In this case, digital elevation models are essential for the development of water catchment distribution systems. This would require a reliable digital elevation model that would consider the most flood-affected areas in order to develop convenient and an efficient water catchment distribution system (Zhou, Pilesjo & Chen, 2011). Therefore, the model will require an appropriate approach in order to provide a reliable assessment of the high flood risk areas. On the other hand, evaluation factors in the rural areas will be because the most dominant economic activity in the rural areas is agriculture. However, based on the agricultural practices in most of these regions there are high chances of soil erosion in these areas. Soil erosion is one of the most critical factors with regard to determining the dimension of terrain in a digital elevation model (Gertner et al, 2002). This is because soil erosion often disrupts the actual topography of land hence rendering most of the digital elevation models in the country to be inaccurate. Subsequently, the inability to provide viable methods of determining the prevalent soil erosion trends in rural areas proves to be the reason why most digital elevation model cannot produce accurate results in rural areas (Gertner et al, 2002). In addition, because soil erosion consists of the milder forms of earth movement the most severe cases of earth movement also require apt digital elevation models in order for the government to facilitate proper planning. In this case, severe cases of earth movement such as landslides often require effective digital elevation models. For instance, landslides often take place abruptly yet they always take place in landslide prone areas. Therefore, the most required tools for combating landslides are statistics gathered by digital elevation models in order to develop reliable landslide management remedies. Nevertheless, most landslides have been poorly dealt with because the digital elevation models used in analyzing the topography of the area have been providing inaccurate results (Gertner et al, 2002). As a result, the required digital elevation models for the national mapping agency will require incorporating viable topographical models that will be able to deal with landslide issues. On the other hand, the urban requirements of the prospective digital elevation models will be based on eliminating the redundancy of the modern models. The essence of digital elevation models in urban areas is mainly based on two purposes. The first purpose is to ensure that there is updated information with regard to dealing with the respective regions geographical needs. The second purpose on the other hand involves the integration of relevant geographical information in order to enhance easy retrieval where necessary (Lollino, 2014 pp. 927). Therefore, the development of the system will require accurate data collection methods in order to define the accurate parameters of the digital elevation model. One of the most essential procedures with regard to gathering data for digital modeling elevation is stereo matching (Elaksher & Bethel, 2010 pp. 68). In this case, the proposed digital elevation models for the national mapping agency will require development of calculation procedures that eliminate “stereo matching” inaccuracies. In most cases, the stereo matching process becomes complex and overwhelms the user of the digital elevation model (Elaksher & Bethel, 2010 pp. 68). Therefore, it will be essential to integrate the relevant parameters of the nation’s topography in order to develop a reliable stereo matching process. Consequently, the modeling requirements of the development of the digital elevation model will be based on the need to address the rural and urban needs of the digital elevation model. Therefore, the proposed digital elevation model will be required to serve adequately its main purposes. This will include gathering the entire nation’s geological data in an integrated system in order to enhance the information database of the National mapping agency. Subsequently, the information gathered will require being easily accessible and easy to update in order to enable the periodic assessment in order to guarantee accuracy of the country’s geographical information. In addition, the easy access to be country’s accurate information will be essential for the government in the future land planning and demands of the country. Solution options In order to present the best solution for the appropriate technical and business case for the National mapping agency’s digital elevation model, it will be essential to evaluate the available options in order to embrace the most viable solution. Whereas there are various methodologies applied in the development of digital elevation models, there are two basic approaches used in the development of digital elevation models. Therefore, the solutions available will be based on the analysis of the two basic approaches in order to identify the most relevant approach concerning the requirements of the National mapping agency. One of the approaches used in the development of digital elevation models is cartographic digitizing approach. The cartographic digitizing approach is mostly applied due to the ability to easily translate data form topographic maps. On the other hand, the other approach used in digital elevation models is the photogrammetric method (Weng, 2002 pp. 404). The essence of the two approaches is to collect data that ensures the accuracy of the digital elevation models. Consequently, whereas the collection of data consists of the most critical aspect of digital elevation models, the representation of data is also critical sine it is important to ensure that the collected data can be well translated into useful information. Moreover, representation of data plays a significant role in the interpretation of the information, which in this case will be essential for the National mapping the agency’s planning process. Cartographic digitization This solution involves converting the data represented in topographic maps into computerized 3 D models. This approach involves converting the basic features in ordinary topographical maps into models that can virtually display the three dimensional view of the topographical features represented in the map (Woodsford, n.d pp. 490). Therefore, in the event this method seems to be an option for the national mapping Agency low resolution cameras will be required to capture these topographical features in order to portray them in the three dimensional formats. On the other hand, the digital elevation model using this format will require showing the infrastructure present in the respective regions portrayed in the model. As a result, based on the cartographic digitization approach infrastructure represented always forms the large-scale aspects of the topographical maps (Woodsford, n.d pp. 490). Therefo0re in order to portray this information in the digital elevation model the infrastructure will require to be precisely displayed on the model. Therefore, this will prompt a development of a high capacity data storage feature for the model. This is because the representation of infrastructure in digital elevation models will require a lot of space (Woodsford, n.d pp. 490). The dependability of this approach relies on the fact that a more accurate translation of data from the topographical map requires complete coverage of the area represented on the map. However, this entails a lot of costs in developing the digital elevation model. Nevertheless, in the event reducing costs may be the main aim of the project the actual digitized model will require to be scaled down and the model will require more emphasis on basic topographical features (Woodsford, n.d pp. 491). However, this is not appropriate since it results to the distortion of the actual topographical representation hence leading to many inaccuracies. Importantly, for this approach to be various factors should be considered in the conversion of the map form topographical form to the digital elevation model. For instance, the quality of the digital elevation model will depend on the condition of the topographical map the information will be derived from (Woodsford, n.d pp. 491). Hence, it is essential for the material used to provide data for the digital elevation model to be in good condition. In addition to the dependability on the quality of the topographical map material, the classification of the physical features in the digital elevation model requires to be more complicated than the classification in the topographical map. This is because the digital elevation model requires more distinguishing features than the topographical map since it is meant to be more inclusive as compared to the topographical map (Woodsford, n.d pp. 491). Photogrammetric method Another proposed solution for the National mapping agency will involve photogrammetric methods. Photogrammetric usually involves two approaches. The first approach is the close range photogrammetric (Walford, 2007). Close range Photogrammetry involves taking geological photos of the relevant objects by placing the camera near the objects. This approach only produces simulated output from the objects as opposed to displaying the real object (Walford, 2007). The other approach used in photogrammetric is the aerial Photogrammetry. Aerial photogrammetry is based on using cameras that are attached on drones or airplanes in order to derive a vertical image of the required area of study. Aerial photogrammetry is the appropriate tool for the proposed digital elevation model unlike the close range photogrammetric model (Walford, 2007). Aerial Photogrammetry relies on the analysis of the aerial photographs of the respective land surface from different angles in order to establish the relevant land surface dimensions (Johanning, 2005). The applicability of this option will be based on the ability of the model to provide precise representation of the relevant surface. In this case, the surface under the photogrammetric study is illuminated with a high precision camera that provides the dimensions of the objects on the surface. Based on stereo mapping, the dimensions of the illuminated object are collected and used to generate 3 D map recording data. Because the photographic methods used in the process may be inhibited by obstruction from various objects such as heavy industrial machines and thick forestry, it is essential to apply the appropriate methodology that can calculate the height of the various physical features on the ground surface. Project description Because the digital elevation model will be aimed at analyzing the terrain of both rural and urban settings the premises behind the model will be based on the ability to navigate through any type of terrain. Therefore, the following project will be based on the essential elements of digital elevation models. In this case, based on the requirement to provide reliable and cost efficient methods for the National mapping agency the photogrammetric method will be used. The proposed project will involve stakeholders from the relevant fields that require geographical data in order to enhance stakeholder’s involvement. Some of the stakeholders involved with the application of digital elevation models include miners, industrialists and meteorologists (Johanning, 2005). In order to serve the major requirements of the National mapping agency’s geological projects the project will be implemented through a series of stages as outlines below: (i) Development of the surface scale Based on the requirements of the geological study a scale will be generated in order to cover the relevant measurement objects. This is due to the fact that the objects being identified do not have specific dimensions. Therefore an appropriate scale will be critical in ensuring the objectivity and accuracy of the data. In addition to the surface scale, the angle of elevation in the relevant field will also be taken into considerations. This will be in order to ensure that the appropriate object height will be recorded. (ii) Identifying the relevant features on the ground surface This step will be in line with the National mapping agency’s goal of delivering a multi-purpose model. This is because the basis of using digital elevation model will vary. Hence, the approach used will depend on the nature of the surface. This is because several land surfaces such as forests and industrial grounds may inhibit the quality of the digital elevation models (Zagalikis, Camron & Miller, 2005). (iii) Taking photographs Consequently, based on the type of ground surface identified the aerial photographs will be taken. The photographing will involve taking the photograph form various angles of elevation and also from various side angles. This will enable the photograph to cover the entire surface in order to derive various dimensions that will be resourceful based on the National mapping agency’s requirement. In addition, because there may be varying results with regard to the clarity of the photograph due to the nature of the surface additional technology will be integrated at this level. For instance, stereo matching will be required in areas where the terrain is irregular and the thickness of the surface is required. This is because basic photographing may ignore critical factors such as water bodies and the surface below the water bodies (Bertin et al, 2014). This stage will be critical since the measurements in the next stage will be accurate if the photographing will be precise. Therefore, in order to save costs incurred the different photogrammetric shots will be taken once. However, different levels of photogrammetric shots will be required in order to ensure that the photographs collected will be accurate. Additionally, the emphasis on the different level of photogrammetric shots will be emphasized based on the fact that the data will be expected to be resourceful for the National mapping agency in future. It is noteworthy, that the photograph taking process also takes into consideration weather conditions and climatic factors such as temperature and humidity (Zagalikis, Camron & Miller, 2005). (iv) Deriving measurements from the photographs In order to provide the appropriate digital elevation method for the various purposes of the National mapping agency with regard to urban and rural mapping requirements; the photographs taken will be analyzed in order to develop a scale for all the features on the ground. This will involve creating a statistical analysis of the ground surface elevation according to the different terrains. Therefore, in respect to the need to develop a dynamic digital elevation model the photographs from different backgrounds of the urban and rural setting will be analyzed in order to develop a consistent measurement scale. The measurement will be required to be applicable in the rapid geological demands of the national mapping agency. (v) Developing a 3-D model from the derived measurements During this stage, many stakeholders from various state organizations that require geological data will be involved. This will be in order to ensure that the digital elevation model will cover all the needs of the National mapping agency and the state. Basing the measurements on photographs from various resolutions the 3 D elevation model will be aimed to provide the most precise details form the measurements collected from the photographs. The measurements will be expected to be mapped accurately with the respective region the data was collected from. Because the photogrammetric process will involve taking photos from different angles of different levels of elevation, the 3 D model will be expected to use the measurements to create an entire simulation of the objects and regions on the ground surface. Consequently, a coding process will be developed at this level in order to ensure that regions with different heights and varying terrain will be distinguished by color-coding. The color-coding will also enable the identification of regions with unstable tectonic plate and areas, which can be, classified as high land movement risk areas. This will also include the various climatic conditions taken into consideration and the drainage system of the country. The considerations of the drainage system will involve the natural drainage and the also the artificial drainage systems. (vi) Using the 3- D model for the relevant purpose. Following the development of the digital elevation model using while involving different stakeholders, the model will be expected to offer dynamic solutions to the National mapping agency. The model will take into consideration the various applications of digital elevation models as opposed to developing a mere 3 –D model of a topographical map. The digital elevation model will be required to be resourceful in activity such as mining, adverse climatic conditions monitoring and potential land instabilities that can cause major land movements such as landslides. Cost viability of the project The viability of the project will be determined by the efficiency in terms of performance and also in terms of cost management. Due to the analysis of the various options concerning the development of the digital elevation model, the photogrammetric approach has been evidently the more reliable approach as compared to the cartographic digitization. This is because the cartographic digitization always relies on the development of data values form translating a topographical map into a digital elevation model. As a result, the quality of the digital elevation model based on the cartographic model is dependent on the quality of the topographic map. Furthermore, the accuracy of this model may be easily compromised in the translation of the data. This makes the cartographic digitization model to be less reliable than the photogrammetric approach. Nevertheless, another critical factor with respect to the viability of the model in use for this project will be the conservation of costs. Whereas, the photogrammetric method is more efficient based on its performance its efficiency may be hampered by the costs incurred. Therefore, the following cost analysis will be aimed at establish a reliable cost effective means of employing photogrammetric tools in the project. Based on an analysis on previous photogrammetric approaches the major costs incurred involve the level of data collection per square kilometers that the photogrammetric tools can capture. In this case, the average costs that are usually incurred in the capture of the images per square kilometers usually ranges between $ 40 – $50 for high precision capture and an approximate value of $10 for high precision capture (University of Southern Queensland, 2007 pp. 28). This figure is based on a generalized value that can be applicable globally hence; the approximated value may be different from the actual value. Nonetheless, the project requires the collection of high precision images. Therefore the budget for the project will require the appropriation if the image capturing methods based on the square kilometers to be covered and multiplied by 50 dollars. The $ 50 dollar cost is based on the most viable option with regard to collecting accurate data at a cost effective and time saving manner since data collection may also range up to an approximate figure of $ 500 per square kilometer (University of Southern Queensland, 2007 pp. 28). Subsequently, the data recording equipments and data capturing tools may also contribute to the costs of the project. However, the costs will not be allocated in the project since the proposed project is based on tools that are already available with the project team. The only equipment costs that will be taken into consideration will be the photograph sheets and the software and hardware tools used for calculating the measurements and simulating the model since the software tools will require maintenance. In relation to the photograph sheets, the average estimate for one sheet in a normal photogrammetric exercise is approximated at 2 dollars per sheet (University of Southern Queensland, 2007 pp. 28). Therefore, the proposed project will identify the photogrammetric sheets required and multiply the costs by two dollars. The software maintenance costs will be expected to be an approximate value of 100 dollars. The value will not be expected to be high regardless of the expected high data storage since the software and hardware systems will be required for storage and calculation purposes. Moreover, other costs will be incurred during the navigation process since the transportation costs will be high because the process will require moving from one region to another. Since the data collection, process will most likely be based on a contract basis the transport costs will be included within the contract costs based on the prospective negotiations between the National mapping agency and the project managers. Since the estimations for the entire project are required to take two months, it will be viable if the project is delivered within the designated period. Hence, the estimations for the viability of the project will be based on the benefits of the project after completion. Therefore, based on the cost estimations the project will be an applicable business model since cost pricing will be based on utilizing the best alternative through the lowest price scale. This is due to the fact the contracting process will be incur majority of the costs. Since the aerial photogrammetric approach considered for this project will be based fast, the project will be cost effective. The entire project will require approximately one million dollars in order to complete within sixty days. However, the applicability of the model will not be restricted to sixty days after completion. In this case, the model can be used for ten consecutive following, which the model can be reviewed to ascertain its applicability. During the proposed ten-year period, the model will be expected to assist industrialists, miners, meteorologists and other geological activities that contribute to major economic activities that will be beneficial to the country. Hence, the project will be expected to have undergone through a short-term development process while delivering long-term goals. Likewise, the project will be expected to have little or no negative social and environmental implications. Since the photogrammetric model used will be aerial based, the method will not disrupt the natural surface environment. Hence, the vegetation drainage, and any other type of natural ground cover will be left intact during the examination of the topography. Similarly, the aerial photogrammetric methods will not disrupt normal economic activities on the ground. Recommendations In order to ensure the objectivity in the delivery of the results for the project at a cost effective approach the project will require apt business and technical decisions in order to be viable. Therefore, based on the analysis of the prospective project procedures the following recommendations are based on the requirement to enhance maximum efficiency of the project. The contract for the project should be based on time rate as opposed to the work peace in order to minimize the costs incurred. Since the photogrammetric method identified for this project is fast and efficient, the allocation of costs based on time will also be a viable solution. This is because the faster the completion of the project the more the project costs will be saved. Regardless of the need to implement the project on a timely basis, the project will require to spend more time on the photogrammetric process. This will enable the project to guarantee the accuracy of the measurements. The more the accuracy of the measurements in the photogrammetric process the more the project increases the likelihood of sustaining the long-term application of the digital elevation model. Since the project is based on the premises that the photogrammetric approach is the more effective means of developing the digital elevation model, the cartographic digitization may be ignored completely. However, it is may be critical to analyze the topographical maps that may be used in the cartographic digitization in order to allow comparison with the new model. This would also create an opportunity to develop more efficient calculation algorithms. Moreover, the topographical maps may also highlight the genesis of potential deviation in the measurements of the new model. Conclusion In conclusion, the prospective digital elevation model for the National mapping agency requires a development process that consists of adept stakeholders in order to deliver the required results. Therefore, based on the analysis provided in the business and technical case the photogrammetric approach will be the viable solution towards providing the required model. Nevertheless, the model will require rigorous consultations prior and during the development process in order to ensure that, the model tackles the deliverables of the National mapping agency. List of references Bertin, S., Friedrich, H., Delmas, P., Chan, E. and Gimelfarb, G., 2014. Dem quality assessment with a 3d printed gravel bed applied to stereo photogrammetry. The Photogrammetric Record, 29(146), pp. 241-264. Elaksher, A. and Bethel, J, 2010. Refinement of Digital Elevation Models in Urban Areas Using Break lines Via a Multi-Photo Least Squares Matching Algorithm. Journal of terrestrial observation. 2 (2), pp. 67- 79. Gertner, G., Wang, G., Fang, S. and Anderson, A.B., 2002. Effect and uncertainty of digital elevation model spatial resolutions on predicting the topographical factor for soil loss estimation. Journal of Soil and Water Conservation, 57(3), pp. 164-174. Johanning, G., 2005. Photogrammetry Provides Picture Perfect Accuracy. Quality, 44(10), pp. 36-41. Lollino, G., Manconi, A., Guzzeti, F., Culshaw, M., Bobrowsky, P. and Luino, F., 2015. Engineering Geology for Society and Territory - Volume 5. Berlin, Heidelberg: Springer,. University of Southern Queensland, 2007, Digital Elevation model (DEM) scoping study. Spatial analysis group- December 2007. Walford, A., 2007. What is photogrammetry [online] Available at: [Accessed 2 December 2014] Weng, Q., 2002. Quantifying Uncertainty of digital elevation models derived from topographic maps. Advances in spatial data handling, 9, pp 403- 418. Woodsford, P. n.d. Cartographic digitizing - technical trends and economic factors. Laser-Scan Laboratories Ltd. Pp. 489-495. Zagalikis, G., Cameron, A.D. and Miller, D.R., 2005. The application of digital photogrammetry and image analysis techniques to derive tree and stand characteristics. 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