Environmental Flow Assessment of a Tropical River System Using Hydrological Index Methods

Tropical rivers and wetlands are recognized as one of the greatest most abundant ecosystems in terms ecological social benefits. However, climate change, damming, overfishing, water pollution, introduction exotic species threaten these ecosystems, which puts about 65% river flow aquatic under a moderate to high level threat. This paper aims assess environmental Selangor River based on hydrological index method using Global Environmental Flow Calculator (GEFC) Indicators Hydrological Alterations (IHA) software. The daily data collected by Department Irrigation Drainage (DID), Malaysia, over 60-year period (1960–2020) was used this study alterations. As per results, has had two distinct periods last 60 years. In first period, flows without any alteration natural with flood pulses low pulses. While second, or post-impact, steady condition throughout year very little fluctuations between dry wet seasons year. From overall comparison pre- post-impact periods, it can be concluded that minimum increased, while maximum decreased monsoon during period. result, Duration Curve (FDC) Management Class (EMC) analysis recommends managed EMC “C” provide sufficient for both human use ecosystem conservation, would also help avoid drop reservoirs. further holistic studies suggested detailed effects dams biodiversity services Basin.