Landscape Analysis Over 30 Years to Assess the Impact of River Damming
On Natural Ecosystem
Abstract
Although there are considerable profits in dam projects, they contribute
to significant environmental changes. Landscape patterns are influenced
by human pressure and are altered continuously. This study investigated
the changes in the landscape pattern of Jask’s coastal area in Iran due
to the Jagin River dam’s construction. A proposed methodology employed
satellite images from 1987 to 2018 and classified them by multiple
approaches to make LULC maps. Eight information categories were
evaluated after classification. The accuracy of the classification was
determined using the error matrix and kappa index. FRAGSTATS software
was applied to calculate several landscape metrics such as edge density
(ED), largest patch index (LPI) and Shannon’s diversity index (SHDI).
The study reported that water right especially in the recent years,
because of excessive use of reserve water, decreased and downstream of
Jagin River was dried. The landscapes were continuously characterized by
anthropogenic pattern features (agriculture land, aquaculture land,
built-up land and residential land) after the dam’s construction.
Rangeland cover and riparian vegetation decreased, and agriculture land
increased with in filling pattern. The sand dune area has been spread to
the residential area and roots of mangrove forests, because of this
reason some parts of mangrove forest dried and roads are covered by sand
dune. Their temporal comparison allowed us to localize the change in
landscape patterns under the study time. The results can help
decision-makers to evaluate the net benefits acquired as a result of the
dam projects.