scholarly journals Assessing the Ecosystem Health of Coastal Wetland Vegetation (Suaeda salsa) Using the Pressure State Response Model, a Case of the Liao River Estuary in China

2022 ◽  
Vol 19 (1) ◽  
pp. 546
Author(s):  
Ziming Song ◽  
Yingyue Sun ◽  
Peng Chen ◽  
Mingming Jia
Keyword(s):  
Coastal Wetland ◽  
Anthropogenic Impacts ◽  
River Estuary ◽  
Liaoning Province ◽  
Suaeda Salsa ◽  
State Response ◽  
Aquaculture Ponds ◽  
Tourism Resource ◽  
Original Vegetation ◽  
Pressure State

Suaeda salsa (S. salsa) is an important ecological barrier and tourism resource in coastal wetland resources, and assessing changes in its health is beneficial for protecting the ecological health of wetlands and increasing finances. The aim was to explore improvements in the degradation of S. salsa communities in the Liao River Estuary National Nature Reserve since a wetland restoration project was carried out in Panjin, Liaoning Province, China, in 2015. In this study, landscape changes in the reserve were assessed based on Sentinel-2 images classification results from 2016 to 2019. A pressure-state-response framework was constructed to assess the annual degradation of S. salsa communities within the wetlands. The assessment results show that the area of S. salsa communities and water bodies decreased annually from 2016 to 2019, and the increased degradation indicators indicate a state of continued degradation. The area of types such as aquaculture ponds and Phragmites australis communities did not change much, while the estuarine mudflats increased year by year. The causes of S. salsa community degradation include anthropogenic impacts from abandoned aquaculture ponds and sluice control systems but also natural impacts from changes in the tidal amplitude and soil properties of the mudflats. The results also indicate that the living conditions of S. salsa in the Liao River estuary wetlands are poor and that anthropogenic disturbance is necessary to restore the original vegetation abundance.

scholarly journals Evolutions of 30-Year Spatio-Temporal Distribution and Influencing Factors of Suaeda salsa in Bohai Bay, China

2021 ◽  
Vol 14 (1) ◽  
pp. 138
Author(s):  
Hongyan Yin ◽  
Yuanman Hu ◽  
Miao Liu ◽  
Chunlin Li ◽  
Yu Chang
Keyword(s):  
Influencing Factors ◽  
Coastal Wetlands ◽  
Yellow River ◽  
River Estuary ◽  
Google Earth ◽  
River Delta ◽  
Liaoning Province ◽  
Suaeda Salsa ◽  
Bohai Bay ◽  
Dynamic Changes

Suaeda salsa (L.) Pall. (S. salsa) acts as a pioneer species in coastal wetlands due to its high salt tolerance. It has significant biodiversity maintenance, socioeconomic values (e.g., tourism) due to its vibrant color, and carbon sequestration (blue carbon). Bohai bay region, the mainly distributed area of S. salsa, is an economic intensive region with the largest economic aggregate and population in northern China. The coastal wetland is one of the most vulnerable ecosystems with the urbanization and economic developments. S. salsa in Bohai Bay has been changed significantly due to several threats to its habitat in past decades. In this paper, we analyzed all available archived Landsat TM/ETM+/OLI images of the Bohai Bay region by using a decision tree algorithm method based on the Google Earth Engine (GEE) platform to generate annual maps of S. salsa from 1990 to 2020 at a 30-m spatial resolution. The temporal-spatial dynamic changes in S. salsa were studied by landscape metric analysis. The influencing factors of S. salsa changes were analyzed based on principal component analysis (PCA) and a logistic regression model (LRM). The results showed that S. salsa was mainly distributed in three regions: the Liao River Delta (Liaoning Province), Yellow River Delta (Shandong Province), and Hai River Estuary (Hebei Province, Tianjin). During the past 31 years, the total area of S. salsa has dramatically decreased from 692.93 km2 to 51.04 km2, which means that 92.63% of the area of S. salsa in the Bohai Bay region was lost. In the 641.89 km2 area of S. salsa that was lost, 348.80 km2 of this area was converted to other anthropic land use categories, while 293.09 km2 was degraded to bare land. The landscape fragmentation of S. salsa has gradually intensified since 1990. National Nature Reserves have played an important role in the restoration of suitable S. salsa habitats. The analysis results for the natural influencing factors indicated that precipitation, temperature, elevation, and distance to the coastline were considered to be the major influencing factors for S. salsa changes. The results are valuable for monitoring the dynamic changes of S. salsa and can be used as effective factors for the restoration of S. salsa in coastal wetlands.

scholarly journals Continuous Change Mapping to Understand Wetland Quantity and Quality Evolution and Driving Forces: A Case Study in the Liao River Estuary from 1986 to 2018

2021 ◽  
Vol 13 (23) ◽  
pp. 4900
Author(s):  
Jianwei Peng ◽  
Shuguang Liu ◽  
Weizhi Lu ◽  
Maochou Liu ◽  
Shuailong Feng ◽  
...  
Keyword(s):  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Driving Forces ◽  
Land Reclamation ◽  
River Estuary ◽  
Tidal Flats ◽  
Liaoning Province ◽  
Coastal Zones ◽  
Continuous Change ◽  
Landsat Images

Coastal wetland ecosystems, one of the most important ecosystems in the world, play an important role in regulating climate, sequestering blue carbon, and maintaining sustainable development of coastal zones. Wetland landscapes are notoriously difficult to map with satellite data, particularly in highly complex, dynamic coastal regions. The Liao River Estuary (LRE) wetland in Liaoning Province, China, has attracted major attention due to its status as Asia’s largest coastal wetland, with extensive Phragmites australis (reeds), Suaeda heteroptera (seepweed, red beach), and other natural resources that have been continuously encroached upon by anthropogenic land-use activities. Using the Continuous Change Detection and Classification (CCDC) algorithm and all available Landsat images, we mapped the spatial–temporal changes of LRE coastal wetlands (e.g., seepweed, reed, tidal flats, and shallow marine water) annually from 1986 to 2018 and analyzed the changes and driving forces. Results showed that the total area of coastal wetlands in the LRE shrank by 14.8% during the study period. The tidal flats were the most seriously affected type, with 45.7% of its total area lost. One of the main characteristics of wetland change was the concurrent disappearance and emergence of wetlands in different parts of the LRE, creating drastically different mixtures of wetland quality (e.g., wetland age composition) in addition to area change. The reduction and replacement/translocation of coastal wetlands were mainly caused by human activities related to urbanization, tourism, land reclamation, and expansion of aquaculture ponds. Our efforts in mapping annual changes of wetlands provide direct, specific, and spatially explicit information on rates, patterns, and causes of coastal wetland change, both in coverage and quality, so as to contribute to the effective plans and policies for coastal management, preservation, and restoration of coastal ecosystem services.

scholarly journals Watershed Sustainability Index for Langat UNESCO HELP River Basin, Malaysia

2018 ◽  
Vol 7 (3.14) ◽  
pp. 187
Author(s):  
Rahmah Elfithri ◽  
Mazlin Mokhtar ◽  
Mat Pauzi Abdullah ◽  
Mohd Raihan Taha ◽  
Mohd Ekhwan Toriman ◽  
...  
Keyword(s):  
River Basin ◽  
Catchment Area ◽  
Economic Conditions ◽  
Environmental Condition ◽  
Sustainability Index ◽  
State Response ◽  
Maximum Value ◽  
Langat River ◽  
Basin Hydrology ◽  
Pressure State

The study on Watershed Sustainability Index (WSI) has been conducted to analyst the environmental condition in the area incorporating ecological baseline and socio-economic conditions. WSI is an integrated indicator based on basin Hydrology, Environment, Life and Policy (HELP) state condition. It is suitable to be applied in the Langat River Basin in Malaysia which has similar catchment area (up to 2,350 km2) and is one of the UNESCO HELP River Basin since 2004. The WSI analysis which uses a pressure–state–response function based on basin HELP Indicator was done for Langat River Basin by using relevant available 5 years data for the period of 2009 to 2013. It is found that Langat River Basin is having WSI value of 0.68 which falls under the category of medium sustainability (between 0.5-0.8). Based on the maximum value (i.e. 1) or high sustainability (i.e. WSI value more than 0.8) it can be said that Langat is in the good side in term of sustainability. Few management aspects need to be improved and maintained well to be more sustainable. The assessment provides Langat River Basin with more information that is crucial in managing the basin through the adoption of UNESCO’s HELP Framework.   

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