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Keywords
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Flow regime alteration, Catchment-Estuary-Coastal systems
Climate change, River regulation, Mond River, NDVI
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Abstract
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The construction of large dams along rivers has significantly changed the natural flow regime,
reducing the inflow into many lakes and terminal wetlands. However, the question of the impact of
dam operation on downstream estuarine wetlands has less been taken into account. Spatio-temporal
flow regime alteration in the Mond River shows the complexity of drivers affecting the estuary-coastal
system named the Mond-Protected Area in southern Iran. To this end, we applied river impact (RI) and
Indicator of hydrological alteration (IHA) methods on monthly and daily river flow data across the
basin. Based on the river impact method, a “drastic” impact below two in-operation (Tangab and
Salman Farsi) dams, with RI values of 0.02 and 0.08, diminish to a ‘severe’ impact with RI value of0.35 at the last gauge (Ghantareh) on the main corridor of the Mond river due to the addition of flow
from a large mid-basin (about 20254 km2). Furthermore, the degree of hydrological alteration (daily
flow analysis) at mid-stream (e.g., Dehram gauges) was similar to the unregulated upstream tributaries
(e.g., Hanifaghan gauges). The remote sensing analysis in the Mond Protected Area showed the
prevailing impact of sea-level rise in the Persian Gulf with the inundation of the coastal area and a shift
of vegetation in a landward direction which complied with standardized precipitation index (SPI)
values as a meteorological drought indicator. Thus, the consequence of climate change (e.g., sea-level
rise, draught) has a higher impact on the protected area than the upstream river regulation and land-use
change in the Mond basin. The holistic approach and the catchment-level study allowed us to see the
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