Land Suitability Evaluation for Agricultural Cropland in Mongolia Using the Spatial MCDM Method and AHP Based GIS
In Mongolia, the sown areas rose steadily by 440.6 thousand hectares
between the years 2006 and 2016; however, cropland remained 405.5 thousand
hectares less than in 1989. In this same time period, the total population
increased 3.19 times and the amount of sown area declined by half as compared
with the population growth, which made the main vegetables imports (onion,
garlic, cabbage, turnips and other root seed vegetables) increase from 5438.4
tons in 1995 to 64,107 tons in 2016, an increase of 11.7 times. So the country
is facing challenges (especially local governments and community groups) to
identify new crop areas with enough capacity for cultivation.
The purpose of this study was to prepare a cropland suitability map of
Mongolia based on comprehensive landscape principles, including topography,
soil properties, vegetation, climate and socio-economic factors. The primary
goal was to create a more accurate map to estimate vegetation criteria (above
ground biomass AGB), soil organic matter, soil texture, and the hydrothermal
coefficient by using Landsat 8 satellite imagery.
The analysis used Landsat 8 imagery from the 2016 summer season with a
resolution of 30 meters, time series MODIS vegetation products (MOD13, MOD15,
MOD17) averaged over 16 days from June to August 2000-2016, an SRTM DEM with a
resolution of 30 meters, and a field survey of measured biomass and soil data.
In total, 6 main factors were classified and quality evaluation criteria were
developed for 17 criteria, each with 5 levels. In this research the spatial
MCDM (multi-criteria decision-making) method and AHP based GIS were applied.
This was developed for each criteria layer’s value by multiplying parameters
for each factor obtained from the pair comparison matrix by the weight
addition, and by the suitable evaluation of several criteria factors affecting
cropland. General accuracy was 88%, while PLS and RF regressions were 82.3% and
92.8%, respectively.
In conclusion, in this study the mentioned methods of land suitability
evaluation for cropland can be used to save time for land management in this
study, and allow for the possibility of justifying policy decisions with
science.
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access: http://mrw.so/3yjdNk
Image
by Saffy H, from Flickr-cc.
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