Ecological Indicators (Jan 2021)
Measuring the degree of hydrological variability of riparian wetland using hydrological attributes integration (HAI) histogram comparison approach (HCA) and range of variability approach (RVA)
Abstract
Hydrological variability (HA) in the river due to damming is well explored but there is a dearth of research about the HA on the riparian wetland. Time series data scarcity perhaps withstands against such research. The present work intended to measure the degree of HA of the river using flow data of gauge station and riparian wetland using time-series remote sensing data derived wetland indices as a proxy of water depth. For the first time, it is attempted to measure the degree of HA of wetland at pixel levels multi-analytical approaches like image-based hydrological attributes integration (HAI) approach, Histogram comparison approach (HCA), and Range of variability approach (RVA). The result has demonstrated that both river and wetlands have experienced significant HA after damming over the Atreyee river basin of India and Bangladesh. The degree of HA of the river in pre-monsoon and post-monsoon seasons respectively are 35.73% and 20.90% as per HCA and 27% and 28% as per RVA. In the wetland, this degree is quite higher (>66%) as per HCA and <33% as per RVA over 68% to 84% area. Image centric HAI shows that 14.85% and 22.75% hydrologically rich wetland area is converted lower hydrological zones for NDWI and MNDWI indices. Remote sensing data based HA analysis is successful and can be used in other environments. This HA in consequence of the dam on river and wetland may lead to a reverse impact on wetland habitat and ecosystem. Maintenance of ecological flow is necessary to make the situation ecologically relevant.
