Abstract: Based on the field investigation and long term remote
sensing data, the dynamics of the alpine wetland in the river basin and
their response to climate change were studied. Results showed the
alpine wetlands accounted for 3.73% of total basin in 2010. Lake and
river appeared an increasing trend in the past 30 years, with an
increase of 34.36 % and 24.57%. However, swamp exhibited a
tendency of decreasing with 233.74 km2. Annual average temperature,
maximum temperature, minimum temperature and precipitation in the
river basin all exhibited an increasing trend, whereas relative humidity
exhibited a decreasing trend. Ice and snow melting are main reasons of
lake and river area enhancement and swamp area descend. There
existed 91.78%-97.86% of reduced swamp converted into lakes on the
basis of remote sensing image interpretation. China-s government
policy of implementing development in the river basin is the major
driving force of artificial wetland growth.
Abstract: Today, incorrect use of lands and land use changes,
excessive grazing, no suitable using of agricultural farms, plowing on
steep slopes, road construct, building construct, mine excavation etc
have been caused increasing of soil erosion and sediment yield. For
erosion and sediment estimation one can use statistical and empirical
methods. This needs to identify land unit map and the map of
effective factors. However, these empirical methods are usually time
consuming and do not give accurate estimation of erosion. In this
study, we applied GIS techniques to estimate erosion and sediment of
Menderjan watershed at upstream Zayandehrud river in center of
Iran. Erosion faces at each land unit were defined on the basis of land
use, geology and land unit map using GIS. The UTM coordinates of
each erosion type that showed more erosion amounts such as rills and
gullies were inserted in GIS using GPS data. The frequency of
erosion indicators at each land unit, land use and their sediment yield
of these indices were calculated. Also using tendency analysis of
sediment yield changes in watershed outlet (Menderjan hydrometric
gauge station), was calculated related parameters and estimation
errors. The results of this study according to implemented watershed
management projects can be used for more rapid and more accurate
estimation of erosion than traditional methods. These results can also
be used for regional erosion assessment and can be used for remote
sensing image processing.
Abstract: The Mahin area is a part of Tarom- Hashtjin zone that
located in west of Qazvin province in northwest of Iran. Many copper
and base metals ore deposits are hosted by this zone. High potential
localities identification in this area is very necessary. The objective of
this research, is finding hydrothermal alteration zones by remote
sensing methods and best processing technique of Advanced
Spaceborne Thermal Emission and Reflection Radiometer (ASTER)
data. Different methods such as band ratio, Principal Component
Analysis (PCA), Minimum Noise Fraction (MNF) and Least Square
Fit (LS-Fit) were used for mapping hydrothermal alteration zones.
Abstract: The research study evaluated the performance of
irrigation system by using special scientific tools like Remote
Sensing and GIS technology, so that proper measurements could be
taken for the sustainable agriculture and water management.
Different performance evaluation parameters had been calculated for
the purposed data was gathered from field investigation and different
government and private organizations. According to the calculations,
organic matter ranges from 0.19% (low value) to 0.76% (high value).
In flat irrigation system for wheat yield ranges from 3347.16 to
5260.39 kg/ha, while the total water applied to wheat crop ranges
from 252.94 to 279.19 mm and WUE ranges from 13.07 to 18.37
kg/ha/mm. For rice yield ranges from 3347.47 to 5433.07 kg/ha with
total water supplied to rice crop ranges from 764.71 to 978.15 mm
and WUE ranges from 3.49 to 5.71 kg/ha/mm. Similarly, in raised
bed system wheat yield ranges from 4569.13 to 6008.60 kg/ha, total
water supplied ranges from 158.87 to 185.09 mm and WUE ranges
from 27.20 to 33.54 kg/ha/mm while in rice crop, yield ranges from
5285.04 to 6716.69 kg/ha, total water supplied ranges from 600.72 to
755.06 mm and WUE ranges from 6.41 to 10.05 kg/ha/mm. Almost
51.3% water saving is observed in bed irrigation system as compared
to flat system. Less water supplied to beds is more affective as its
WUE value is higher than flat system where more water is supplied
in both the seasons. Similarly, RWS values show that maximum
water deficit while minimum area is getting adequate water supply.
Greater yield is recorded in bed system as plant per square meter is
more in bed system in comparison of flat system Thus, the integration
of GIS tools to regularly compute performance indices could provide
irrigation managers with the means for managing efficiently the
irrigation system.