dc.description.abstract |
The study was conducted in Lake Hayq watershed which covers 86 km2.The aim of
this study was to assess the Lake morphometric change and to identify the causes and
extent of Lake morphometric change using data from multi-sources. The cause of the
Lake morphometric change detected through multi-temporal bathymetry surveys was
the research problem for the present study. In order to address the main research
problem, the study applied an integrated approach that includes remote sensing and
Geographic Information System (GIS), soil erosion/deposition modeling and ground
survey. The individuality and newly of this research is integrating multi-source data
as well as multi-disciplinary approaches in improving knowledge and information on
surface water resources related problems. The soil erosion/deposition from 1980 to
2019 is estimated by unit Stream Power Erosion Deposition(USPED) model through
Arc GIS 10.1. The annual average soil erosion, deposition and net soil loss was
321,283, 209,642 and 111,641 tons/year respectively. The average sediment depth
accumulated in Lake Hayq during the assessment periods was 3.8 cm. An average
annual sediment deposition was 0.4 cm. The water abstraction was estimated to
1,268,809 m3 which reduces the Lake depth by 0.9 cm. The Lake evaporation was
estimated for 8 years (1985 -2019) by Penman’s method and the average annual Lake
evaporation was 1.69-meter. From those different data source assessments, the cause
factor of Lake level reduction corresponding to Lake morphometric change was
assessed and the conclusion was made. This research established the conclusion that
the cause for the Lake level reduction, evaporation and abstraction has impacts, while
the change in Lake depth shows a positive of 0.5 meter. This difference could be
accounted for internal openings. For the estimated patchy bathymetry results it is
concluded that there is instrumental, measurement or calculation error. |
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