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Land Use Analysis
MDA understands how land is being used in other countries and can assist governments in dealing with issues ranging from environmental degradation to drought and famine.
One of the most powerful applications of satellite imagery is towards the analysis of land use for a given region of the Earth. While the developed world is easily accessible and well mapped, much of the developing world is not. Understanding how the land is being used in other countries is an important step in being prepared to deal with issues ranging from environmental degradation to drought and famine. A growing archive of historical imagery can be compared to current data to assess and monitor long-term trends and assess land cover change. With the advent of global climate change, increasing population pressures and the possibility of international conflicts over food and water security, MDA's experience can provide insight to current conditions and change over time.
New Delhi Urban Growth
This image set compares a 1974 Landsat MSS image to a Landsat 7 Thematic Mapper data set collected in 1999. The two lower panels reflect land use in and around the city for the respective dates. The color red is used to depict the presence of urbanized areas. Clearly the city has demonstrated a significant growth in area over the past 25 years. The population of New Delhi increased from approximately 5 million in 1975 to over 13 million in 2001 (projected). Urban expansion around existing population centers results in a number of problems with policy and management issues. Prime agricultural land is often lost, additional transportation and other infrastructure services are required, and natural ecosystems are destroyed or disrupted with resultant pollution problems. Change analysis such as this can aid in identifying and quantifying the problems associated with such transformations and provide invaluable information to the decision-making process.
Agricultural Analysis and Crop Production
Remote sensing and GIS tools provide an outstanding platform from which to identify, monitor and quantify agricultural activity. Given the spatial nature of these tools it is possible to accurately estimate crop production values once a standard metric is established (such as yield per hectare of crop planted). GeoTools combines Remote Sensing and GIS analysis with statistically optimized sampling of high-resolution imagery to estimate the total cultivated area using area frame or multi-area frame sampling approaches. Unique about this process is the stratification of the study area based upon spectral properties of imagery. Landsat data (30m resolution) can be used to stratify the study area into as many as 255 spectrally unique strata.
A sampling technique is then established using high-resolution imagery such as that from Space Imaging's IKONOS satellite (1-4m resolution) to identify and quantify the proportion of each of the spectrally defined strata under cultivation. The values can be extrapolated by strata to provide a remarkably accurate assessment of total cultivated area and, by extension, total crop production for a given season. MDA and the U.S. Government worked together to design and prototype the GeoTools sampling process. The GeoTools approach has been used successfully on both licit and illicit crop area inventories. MDA is working with ERDAS Inc. to produce "GeoTools" extensions to ERDAS IMAGINE. The "GeoTools" software suite provides tools for the area frame and nested area frame sampling approaches used in crop area analysis.
