A Framework to Quantitatively Assess the Influence of Lulc on Coastal Wetland Hydrological Connectivity from a Landscape Resistance Perspective

Abstract

Land use and land cover (LULC) change is one of the dominant factors contributing to coastal wetland degradation and loss. Most studies focused on LULC changes or their influence on specific ecosystem components. However, LULC's influence on the hydrological connectivity of coastal wetlands has yet to be studied, especially in quantitatively assessing the influence on spatial and temporal scales. This study aimed to understand how LULC affected hydrological connectivity in the coastal wetlands in the Yellow River Delta (YRD), China, from 1985 to 2020. A framework from a landscape resistance perspective was used to evaluate the LULC's influence. LULCs were converted into a series of resistance surfaces whose values represent the degree to which LULC facilitated or restricted hydrological connectivity. The hydrological connectivity of coastal wetlands was based on the hydrological distance between key hydrological nodes in each tidal creek. LULC's influence was evaluated by parameterizing the resistance surfaces using observed hydrological connectivity. The results showed that most resistance surfaces are related to human activity (90.9%). The critical time of LULC's influence on hydrological connectivity was 1985‒1990 (offshore water with a resistance value of 1.000 and tidal flat, 0.922) and 2010‒2015 (mariculture, 0.915), and the critical areas were Zone II (tidal flat, 0.993), Zone VI (river, 0.739), and Zone I (grass, 0.728). This study provided a framework to identify and evaluate the influence of LULC on hydrological connectivity. It could guide the management of LULC in coastal areas to mitigate the adverse effects on hydrological connectivity.

Keywords: LULC, hydrological connectivity, tidal creek, landscape resistance, Coastal Wetland, Yellow River Delta