Land system transformations govern the trophic status of an urban wetland ecosystem: Perspectives from remote sensing and water quality analysis

Abstract

Globally, urban wetlands are facing immense pressure from land use land cover changes (LULCCs) and associated water quality degradation that is severely affecting the trophic status of these ecosystems. This study analyzed water quality degradation resulting from land system changes in the vicinity of Khushalsar, an urban Wetland, in Srinagar City from 1980 to 2017. The analysis of satellite data indicated that this Wetland lost ~18.1 ha from 1980 to 2017. During the same period, the urban area within the Wetland increased from 0.2% to 16.5%. The land cover changes assessed in the vicinity of Wetland indicated an increase of 119% and 62.8% in built‐up and roads respectively. The analysis of surface water quality of the Wetland showed widespread degradation. The Trophic state index ranged from 73.4 to 84.6 indicating hyper‐eutrophic waters. A snapshot of comparative water quality data from 2002 to 2018 revealed that the mean concentration of NO3−‐N increased from 219 to 433 μg L−1 and that of total phosphorus increased from 135.4 to 1,236 μg L−1 indicative of continuous nutrient enrichment. Hierarchical cluster analysis (HCA) grouped eight sampling sites into four clusters based on likeliness of water quality characteristics. Similarly, discriminant analysis showed the formation of similar patterns of clusters, corroborating the HCA. Principal component analysis suggested three principal components accounting for a cumulative variance of 90.61%. The unplanned land system changes vis‐a‐vis human‐induced water quality degradation together with the lack of a monitoring mechanism have brought the Khushalsar Wetland to its current hyper‐eutrophic state.

Land use changes, degradation, and impact on ecosystem services in Asia and Southeast Asia

“…Shi et al (2021) explore the complex relationship between rapid urbanization and ecosystem services in Northwestern China, advocating for balanced urban planning models. Further, Dar et al (2021) study water quality degradation from land use changes around India's Khushalsar Wetland, underlining the importance of steering land‐use modifications. Additionally, Rajbanshi and Das (2021) assess land‐use impacts on soil carbon dynamics, estimating the economic consequences.…”

Editorial: Ecosystem and Hydrological Responses in Mountain Environments to the Changing Climate

“…The prevailing warming scenario and increased anthropogenic interferences have not only led to the degradation of the pristine montane landscapes but increased the risk of the communities to various climate-induced disasters posing a threat to the life and infrastructure downstream. Landscape degradation primarily manifests through land system changes (Prăvălie, 2021), vegetation composition and distribution changes (Li et al, 2021), eutrophication of water bodies (Dar et al, 2021), and increased frequency of hazards associated with Earth surface processes (Smiraglia et al, 2016). The cumulative effects of the anthropogenic footprint and exacerbated warming in high-elevation environments have also resulted in enhanced glacier melt, glacier area loss, formation of new-moraine dammed lakes, and destabilization of permafrost that could affect upstream-downstream linkages and also increase the vulnerability of downstream communities to Glacial Lake Outburst Floods (GLOFs), Landslide Lake Outburst Floods (LLOFs), snow avalanches, glacier detachments, landslides, debris flows and rock-ice avalanches (Kääb et al, 2021;Shugar et al, 2021;Zheng et al, 2021).…”

Dynamic Modeling of the Trophic Status of an Urban Tropical Wetland under ENSO Conditions

“…There are different methods for assessing and classifying trophic status in lentic systems [2]. However, studies on these ecosystems report that the trophic status varies depending on the parameters and classification methods used, and the sampling site location within the ecosystem [9,10]. The trophic status index (TSI) provides information on the nutrient flow regime responsible for the proliferation of primary producers, that reflects the ecological functioning of an aquatic ecosystem [11].…”

“…Vollenweider et al [18] proposed a new trophic index (TRIX) to categorize the trophic status of inland waters, by focusing on Chl-a, mineral and total nitrogen and phosphorus, and oxygen saturation. Lastly, the most accepted limits for assessing trophic status are those suggested by the Organization for Economic Cooperation and Development-OECD [10].…”