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TopIntroduction
This article is about the essence of data sources specific for geo-spatial science (Bossler et al., 2002) information for land cover mapping. The use of geospatial science techniques provides opportunities and challenges in many aspects of life including for land cover, forestry for climatic change measurements and agricultural engineering which is vital for food security (Opara, 2003).
First, it elaborated about developments of digital world in remote sensing and geographical information system (GIS) as modern day techniques for Earth surface monitoring (Mather & Koch, 2011). Satellites whose data has widespread international applications for the past four decades are discussed in details and compared (Figure 3). Second, it puts emphasis on the importance of the human side of information reference services that is essentially the brain behind machine based data. The human thinking is applied in the interpretation of this machine data and it acts as knowledge substitute where the remote sensing and GIS data are inadequate or unavailable. The 2012 study on the reconstruction of historical landscape for the investigation of land cover change in (Maphanyane, 2012), the human side of information reference services based method on Ramotswa, Botswana case, had sufficiently proved that it can be applied to fill in the gap where modern technology is inadequate or unavailable (Figure 1 and Table 1). For emphasis, graphical examples are given, where the aerospace based Ramotswa digital data; its analytical techniques and their resultant information are compared to the same area data, but those that had been derived from the systems based on the human side of information reference services (Figure 2). This too has shown that the human side of information reference services was complementary.
Figure 3. Landsat (LN) and SPOT satellites 1-4 generations panchromatic (GP) and multispectral (GM) resolutions
Figure 1. Botswana: south east district locational map
Table 1. Botswana – south east district data, comparison of the two methods for the investigation of land cover change
| Analysis of the results on how reconstruction of historical landscape compares to remote sensing method(Maphanyane, 2012) |
| No. | Test Area | 1973 | 1990 | 2002 |
| 1 | Gaborone/Tlokweng | 66.94% | 66.13% | 77.42% |
| 2 | Ramotswa | 80.00% | 71.79% | 71.88% |
| 3 | Otse | 65.27% | 65.87% | 67.07% |
| 4 | Mogobane | 77.88% | 70.72% | 67.31% |
Key Terms in this Chapter
Platform: In order for the sensor to capture and record reflected or emitted energy from a target it must reside on a stable platform which can be on the ground (hand held camera), within the atmosphere (airplanes), and in space (the space shuttle or satellite).
Biostratigraphic Markers: Biostratigraphy is a sub-discipline of sedimentary geology that relies on the physical zonation of biota, both in time and space, in order to establish the relative stratigraphic position (i.e. older, younger, same age) of sedimentary rocks between different geographic localities.
Multi-Spectral: A multispectral image is one that captures image data at specific frequencies across the electromagnetic spectrum, the visible light range, and infrared. Spectral imaging sees beyond what human eye can perceive.
Temporal Resolution: Temporal resolution: Other than: Spatial, Spectral and radiometric resolution; there is temporal resolution. This is the time it takes to image the exact same area at the same viewing angle a second time: Revisit Time.
Classification: The process of classification identified and assigned each pixel of all channels of the multi-spectral images to a particular class or theme based on the statistical characteristics of the pixel brightness values known as spectral signatures.
Panchromatic: Black and white aerial photograph or satellite images.
Radiometric Resolution: The radiometric resolution of an imaging system describes its ability to discriminate very slight differences in energy.
Land Cover Change: Land cover change forms a fundamental part of sustainable resource management. It is actually the main indicator of natural resource use.
Electromagnetic Waves Energy: The electromagnetic (EM) spectrum describes the range of wavelengths of energy that can be recorded using remote sensing and It can be broadly divided (by increasing wavelength) into Gamma rays, X-rays, Ultra-violet light, Visible light, Infrared light, Microwave and Radio waves.
Geo Spatial Science (GSS): Geospatial Science is a discipline that focuses on using information technology to understand people, places, and processes of the earth. Spatial analysis of human and physically variables is fundamental to the discipline. Remote Sensing, Geographic Information Systems, and Global Positioning Systems technologies are commonly used as measurement, observation, and analysis tools for this ( Radford University, 2014 ).
Geographical Information Systems (GIS): Geographical Information Systems (GIS) is defined as a technique which people employ using computers and specific computer software and hardware to locate physical features and describe their characteristics and condition on a raster based or vector co-ordinate based digital map by interrogating attribute data and to engage in spatial analysis, and this is a sound basis for informed decision making ( Burrough & McDonnell, 1998 ).
Geo-Synchronized and Sun-Synchronous: The platforms are designed to follow a north-south orbit and in conjunction with the Earth’s west-east rotation, they are able to capture the entire Earth’s surface over a certain period of time. These satellite platforms orbits are often sun-synchronous: - They are able to cover each particular area on the Earth’s surface at a constant local time of day. This ensures consistent illumination conditions for images of the same area that have been acquired at different times.
Spectral Resolution: Different classes of features and details in an image can often be distinguished by comparing their responses over distinct electromagnetic wavelength ranges. Spectral resolution describes the ability of a sensor to define fine wavelength intervals.
Remote Sensing: Remote Sensing is the art, science, and technology of obtaining reliable information about physical objects and the environment through the processes of recording, measuring, and interpreting photographic images and patterns of electromagnetic radiant energy and other phenomena ( Lillesand & Kiefer, 2004 ).
Reconstruction of Historical Landscape (ROHL): Reconstruction of historical landscapes is defined as a method of building and mapping past landscapes by finding out how communities lived in a given historic period in a particular geographical area. This is achieved by identifying, reading and analysing marks made at the time and left behind from certain period. A historical landscape basically depicts a type of cultural landscape that contains, within a specific geographical area, both natural and human-made features that typify connected human activities, past events or patterns of physical development ( Maphanyane, 2012 AU65: The citation "Maphanyane, 2012" matches multiple references. Please add letters (e.g. "Smith 2000a"), or additional authors to the citation, to uniquely match references and citations. ).
Spatial Resolution: Spatial Resolution, Pixel Size, and Scale. With remote sensing instruments, the distance between the target being imaged and the platform, plays a large role in determining the detail of information obtained and the total area imaged by the sensor.
Sensor: Sensors are devices that functions like a human eye. They detect the reflected or emitted electromagnetic radiation from natural sources (Passive Remote Sensing) or detect responses from objects which are irradiated from artificially generated energy sources such as radar (Active Sensors).
Traditional Ecological Knowledge (TEK): The traditional ecological knowledge as a cumulate body of knowledge and beliefs, handed down through generations by cultural transmission, about the relationship of living beings with one another and with their environment. These are gained through the teaching of family history and cultural values. They have been recorded for thousands of years by storytelling, praise-singing, and songs as oral history, and are passed on to and learned by the descendents through the recitation of the narrative at events and during ceremonies (Berkes, 2000 AU66: The in-text citation "Berkes, 2000" is not in the reference list. Please correct the citation, add the reference to the list, or delete the citation. )
Archaeology: The importance of archaeology lies in the fact that it seeks to learn about culture from the fragmentary remains of the products of human activity ( Deetz, 1992 ).
Geo-Stationary: Geostationary satellite Platforms are platforms that revolve at speeds which match the rotation of the Earth so they seem stationary, relative to the Earth's surface. This allows the satellites to observe and collect information continuously over specific areas.