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E. Iwasaki et al.
winter wheat are comparatively low and those for winter wheat are almost the
same as for clover hay.
11. Aanalysis using remote sensing, GIS and climate data technologies highlighted
variation of soil properties in Dakhla Oasis, and explained how to use them
for optimal use under these conditions. The soils of Dakhla Oasis are highly
productive and suitable for most crops. The most predominant limiting factors
are salinity, soil depth and topography.
12. Combination of statistical data with geographical information is efficient for
the study of oasis societies. Integrating visual interpretation with supervised
classification leads to an increase in the overall accuracy of land use/cover classification. Integrating GIS and Remote Sensing provides valuable information
on the area and spatial distribution of urban expansion.
13. Dakhla Oasis has undergone significant land cover changes during the past
30 years (1988–2018), with significant increases in urban settlements and agricultural lands, because of population growth and land reclamation. Generally, it
was found that the annual rate of agricultural land growth is greater than the rate
of built-up land sprawl during the period of study. Despite of that, the built-up
area increased by 480.6% (of the built-up area in 1988), and the agricultural
land increased by 197.2% (of the agriculture area in 1988).
14. The land use/cover analysis and its relation with groundwater wells using satellite images on Rashda village from 1968 to 2018, showed that although the
difficulty of using Corona satellite image of 1968, there was a clear change in
land use/cover during the past 50 years (1968–2018). This is mainly brought by
the conversion of desert land to agricultural land, and in lesser extent to built-up
land.
15. The expansion of agricultural lands in Rashda Village was closely associated
with drilling of wells: governmental wells until 1980s, and surface springs
from the period after 1988. The latter type of wells started under the economic
liberalization by small and medium investors (farmers and enterprises). Thus, it
is pointed out that the expansion of agricultural lands in Rashda Village during
the observed period (1968 till now) was mainly driven by the investors under
the economic liberalization.
16. Well development is associated with complex phenomena, one of which is the
increase of water bodies (drainage lakes).
17. Empirical results, measuring the technical and scale efficiency of farmers based
on the survey of agricultural households in Rashda village in Dakhla Oasis
during 2009, suggest the average scores of technical efficiencies was 17.5%
under the CRS assumption, whereas it was 20.2% under the VRS assumption.
The estimated efficiency scores of farms in Rashda were generally lower, but
they suggest that the level of output can be increased by 82.5% and 79.8% under
the CRS and VRS specifications, respectively, using the current levels of inputs.
18. Farmers, mostly small-scale cultivators, prefer to grow more rice and fodder
crops despite their low efficiencies and water intensity. This could be understood
from the consumption side; i.e., from a household consumption perspective, it
is rational to secure the household’s basic food needs.
E. Iwasaki et al.
winter wheat are comparatively low and those for winter wheat are almost the
same as for clover hay.
11. Aanalysis using remote sensing, GIS and climate data technologies highlighted
variation of soil properties in Dakhla Oasis, and explained how to use them
for optimal use under these conditions. The soils of Dakhla Oasis are highly
productive and suitable for most crops. The most predominant limiting factors
are salinity, soil depth and topography.
12. Combination of statistical data with geographical information is efficient for
the study of oasis societies. Integrating visual interpretation with supervised
classification leads to an increase in the overall accuracy of land use/cover classification. Integrating GIS and Remote Sensing provides valuable information
on the area and spatial distribution of urban expansion.
13. Dakhla Oasis has undergone significant land cover changes during the past
30 years (1988–2018), with significant increases in urban settlements and agricultural lands, because of population growth and land reclamation. Generally, it
was found that the annual rate of agricultural land growth is greater than the rate
of built-up land sprawl during the period of study. Despite of that, the built-up
area increased by 480.6% (of the built-up area in 1988), and the agricultural
land increased by 197.2% (of the agriculture area in 1988).
14. The land use/cover analysis and its relation with groundwater wells using satellite images on Rashda village from 1968 to 2018, showed that although the
difficulty of using Corona satellite image of 1968, there was a clear change in
land use/cover during the past 50 years (1968–2018). This is mainly brought by
the conversion of desert land to agricultural land, and in lesser extent to built-up
land.
15. The expansion of agricultural lands in Rashda Village was closely associated
with drilling of wells: governmental wells until 1980s, and surface springs
from the period after 1988. The latter type of wells started under the economic
liberalization by small and medium investors (farmers and enterprises). Thus, it
is pointed out that the expansion of agricultural lands in Rashda Village during
the observed period (1968 till now) was mainly driven by the investors under
the economic liberalization.
16. Well development is associated with complex phenomena, one of which is the
increase of water bodies (drainage lakes).
17. Empirical results, measuring the technical and scale efficiency of farmers based
on the survey of agricultural households in Rashda village in Dakhla Oasis
during 2009, suggest the average scores of technical efficiencies was 17.5%
under the CRS assumption, whereas it was 20.2% under the VRS assumption.
The estimated efficiency scores of farms in Rashda were generally lower, but
they suggest that the level of output can be increased by 82.5% and 79.8% under
the CRS and VRS specifications, respectively, using the current levels of inputs.
18. Farmers, mostly small-scale cultivators, prefer to grow more rice and fodder
crops despite their low efficiencies and water intensity. This could be understood
from the consumption side; i.e., from a household consumption perspective, it
is rational to secure the household’s basic food needs.