Assessment of connectivity in a water‐stressed wetland (Kaabar Tal) of Kosi‐Gandak interfan, north Bihar Plains, India

Abstract

Landscape elements respond to the processes acting on them, and this response connects with neighboring landscape units. The propagation, superposition, and interference of these responses are functions of the connectivity among the landscape units. Such landscape units are referred to as 'Connectivity Response Units' or CRUs that are in turn influenced by topography and landuse/landcover (LULC). The CRUs are obtained by the application of diffusion-kernel based smoothing technique over the connectivity potential maps. A framework has been designed using the CRUs to understand the impacts of changing LULC on the connectivity structure in a relatively flat terrain under pre-and post-monsoon scenarios. The proposed framework has been applied to a water-stressed wetland occurring in an interfan setting in north Bihar plains, eastern India. It has also been demonstrated that CRUs can be used as a viable option for understanding the seasonal and temporal dynamics of connectivity structure in and around such wetlands and for guiding a rehabilitation strategy for such fragile ecosystems.

Geomorphic connectivity and its application for understanding landscape complexities: a focus on the hydro‐geomorphic systems of India

“…However, most of the indices provide an understanding of structural connectivity (Keesstra et al ., 2018; Turnbull et al ., 2018), although they can also provide an understanding of functional connectivity (Turnbull et al ., 2008; Bracken et al ., 2015; Turnbull et al ., 2018) if the hydro‐meteorological factors are included in the calculation of these indices (Heckmann et al ., 2018). The concept of connectivity response units (CRUs) has been developed to quantify the wetland‐catchment connectivity by defining the fundamental unit of connectivity in terms of response units and frameworks at spatial (Singh et al ., 2017) and spatio‐temporal (Singh and Sinha, 2019) scales. A theoretical framework to implement the fundamental unit‐based approach, namely ‘geomorphic cell concept’ has also been proposed by Poeppl and Parsons (2018).…”

“…Two important contributions on conceptualization of connectivity that are worth mentioning here include the large scale (dis)connectivity framework of Jain and Tandon (2010) for the Ganga dispersal system, and the CRU concept of Singh et al . (2017) applied on a large wetland system.…”

“…The agriculture system of India depends heavily on irrigation from groundwater and limited surface water infrastructure (e.g. Singh et al ., 2017). This has led to an unchecked and uncontrolled abstraction of groundwater, and over‐exploitation of surface water has stressed the hydrological regimes of the country by changing the natural hydrological connectivity among different components such as lakes/wetlands, river channels, and the water table.…”

“…To understand the factors behind wetland dynamics, it is imperative to understand the structural and functional connectivity of the wetland to its catchment and other waterbodies (Singh et al ., 2017; Singh and Sinha, 2019). A few studies (Mozumder et al ., 2014; Pal, 2016; Singh et al ., 2017; Pal and Talukdar, 2018; Singh and Sinha, 2019) have adopted the geomorphic connectivity framework to understand the wetland‐scale hydro‐geomorphic dynamics. While we note the importance of ecological connectivity and ecosystem structure in the context of wetland research, this article is focused on two aspects of wetlands, i.e.…”

“…For example, erosion prediction can be upscaled by using the sediment travel distance with an entrainment parameter (which is a function of a system's frequency–magnitude response) (Bracken et al ., 2015). Anthropogenic factors are known to have modified the geomorphic connectivity by altering the river courses, topography, and land cover (Pringle, 2003; Hooke, 2006; Fryirs, 2013; Poeppl et al ., 2017; Singh et al ., 2017; Singh and Sinha, 2019). The connectivity concept has also emerged as a meaningful way to study the impact of climate change and land‐use change on the movement of water (Smith et al ., 2010) and sediments (López‐Vicente et al ., 2013; Lane et al ., 2017) in‐between the landscape compartments.…”