INTRODUCTION
Vietnam's over 3,200 km of coastline and numerous estuaries highlight the critical importance of its mangrove ecosystems, which play a vital role in natural disaster prevention, flood control, coastal environmental protection, climate regulation, and economic development Mangroves absorb significant amounts of CO2 from industrial and daily activities, produce oxygen, and help purify the air, contributing to improved air quality As one of the countries most affected by climate change, Vietnam faces rising sea levels and destructive storms, with mangroves acting as a “green lung” and a resilient “bioshield” to mitigate wind and wave damage Additionally, mangroves provide substantial economic benefits, offering essential resources such as wood, building materials, seafood, and medicinal products.
XuanThuy National Park, situated at the estuary of the Red River in Nam Dinh province, Vietnam, is approximately 150 km southeast of Hanoi Recognized for its ecological significance, it was Vietnam’s first designated Ramsar site, highlighting its importance as a wetland of international importance.
Since the establishment of Xuan Thuy National Park as a nature reserve in January 1989, the Vietnamese government has actively preserved its ecological value through new laws, policies, and investments In 2003, the area was officially upgraded to a national park by the Prime Minister and recognized as part of the UNESCO Red River Delta World Biosphere Heritage Site in October 2004 Covering approximately 7,100 hectares of core zone and 8,000 hectares of buffer zone, Xuan Thuy National Park is a vast, biodiverse wetland ecosystem rich in alluviums, supporting a wide variety of flora and fauna, especially migratory birds The park continuously faces challenges from human activities, sedimentation, water flow variations, and climate change, which impact its delicate habitat.
XuanThuy National Park faces increasing pressure from sea level rise and environmental challenges, threatening its role as a protected Ramsar site and its ecological integrity Key issues identified in its 2008 strategic plan include degradation of natural resources, unsustainable local livelihoods, and limited institutional capacity for wetlands management, often exacerbated by external factors such as climate change, upstream pollution, and insufficient enforcement of laws The limited awareness and capacity of local authorities and communities hinder effective conservation efforts Protecting and restoring coastal mangroves has become a crucial mission for government and local organizations, as these ecosystems are vital for biodiversity and disaster mitigation Despite its status as Vietnam’s only Ramsar site, XuanThuy suffers from low investment, poor infrastructure, and inadequate staff training, which impede effective protected area management Mangroves in Nam Dinh province are among the most threatened resources, but recent initiatives, including the formation of specialized forest protection teams and extensive mangrove planting campaigns, demonstrate a concerted effort to combat the impacts of storms and rising sea levels.
In response to climate change, coastal communities in XuanThuy have planted tens of thousands of hectares of trees to promote reforestation efforts To support forestation initiatives, land has been allocated to households for forest management, enabling local residents to participate actively in planting and caring for the forests These growers receive funding from district and commune authorities for their efforts and gain access to marine resources derived from the forests As a result, community involvement has significantly contributed to the transformation of forest scale and quality, leading to substantial environmental and socioeconomic benefits in the region.
Geographic Information Systems (GIS) are widely used tools for environmental management worldwide, and recently, new GIS developments have emerged in Vietnam to enhance field applications in the environmental sector One notable GIS tool is the vegetation index NDVI, derived from remote sensing data, which utilizes near-infrared, infrared, and red spectral bands to assess various vegetation characteristics NDVI can indicate biomass, leaf area index, photosynthetic capacity, and seasonal biomass production, all of which are closely related to plant type, weather, physiology, biochemistry, and insect activity Multispectral satellite imagery with multi-resolution capabilities allows for rapid, objective monitoring of environmental factors such as temperature and humidity affecting forests in Xuan Thuy However, understanding this technical tool remains challenging for some users in Vietnam, which led our group to select the project name "Return" to reflect our efforts in applying remote sensing technology for environmental management.
“ Using Landsat 8 data and GIS to estimate above-ground biomass and carbon stocks of coastal mangroves in XuanThuy National Park, Nam Dinh province”
LITERATURE REVIEW
Overview of mangroves coastal
2.1.1 Roles and function of coastal significance
Mangrove forests are among the most biodiverse ecosystems on the planet, typically found along tropical and subtropical coastlines They serve as significant carbon sinks, with estimates indicating they generate approximately 1.5 tons of carbon annually, and about 10% of this carbon is stored in their sediments As a vital component of carbon sequestration, mangrove ecosystems store large amounts of organic carbon in the ground, reducing CO2 emissions to the atmosphere Additionally, mangrove trees act as carbon reservoirs through photosynthesis, storing carbon in their biomass and contributing to climate change mitigation.
Mangroves are coastal ecosystems composed of trees, shrubs, palms, or ground ferns that typically grow above mean sea level in the intertidal zones of marine and estuarine environments These plants generally exceed half a meter in height and thrive in tidal habitats characterized by periodic flooding and exposure As vital coastal habitats, mangroves support diverse marine life and protect shoreline areas from erosion.
Mangroves play a vital role in supporting the ecological, economic, and social development of coastal areas Their rehabilitation is a top priority to prevent widespread, irreversible damage caused by mangrove loss These ecosystems protect shorelines from storms, hurricanes, waves, and floods, reducing the risk of destruction Additionally, mangroves help prevent erosion by stabilizing sediments with their intricate root systems They also maintain water quality by filtering pollutants and trapping sediments from land, ensuring cleaner and clearer coastal waters.
Mangrove soils are actively regenerating as mangroves capture riverine and coastal sediments while adding organic matter from roots, leaves, and woody debris, leading to increased soil volume Their fine roots trap and bind particles, stabilizing the soil in waterlogged conditions The lack of oxygen in these soils impairs organic matter decomposition, causing it to accumulate and form deep peaty layers Additionally, mangrove root growth pushes the soil upward, raising the overall soil level and supporting the expansion of these vital coastal ecosystems.
2.1.2 Mangrove biomass and coastal services
Biomass refers to the total amount of organic matter in a specific area at a given time, typically measured in tons per hectare Forest biomass is categorized into above-ground and below-ground biomass; above-ground biomass includes fresh terrestrial components such as stems, roots, branches, bark, seeds, and leaves, while below-ground biomass comprises all living root biomass of the trees Understanding forest biomass is essential for assessing carbon storage, forest health, and sustainable resource management.
Biomass refers to the amount of organic matter present in a specific area at a given time, typically measured in tons per hectare Forest biomass is categorized into above-ground and below-ground biomass; above-ground biomass includes all fresh terrestrial components such as stems, roots, branches, bark, seeds, and leaves, while below-ground biomass consists of all living root biomass in the soil Understanding forest biomass is essential for assessing carbon storage, forest health, and sustainable resource management.
The majority of biomass is concentrated on the continent, highlighting the significant advantage of plant biomass in these regions The total volume of biomass in the biosphere is estimated to be around 14 to 2.1016 tons Although Earth’s biomass constitutes only a small percentage of the planet's total weight, it plays a crucial role in ecological balance Compared to the entire hydrosphere and lithosphere, biomass volume remains relatively minimal, yet its importance in sustaining life on Earth is undeniable.
Earth has existed for approximately 3 billion years, shaping its geological history across six distinct periods Biomass sequestration has played a crucial role in transforming large quantities of Earth's materials, significantly impacting the planet's geology Much of Earth's biomass is now stored as sedimentary rocks, including metamorphic and sediment minerals, representing organic materials that have undergone geological processes over time.
Mangroves biomass and carbon stock in worldwide
2.2.1 Mangroves biomass in the world
Golley and Vu Doan Thai (2003) studied about the biomass of Rhizophora mangle
In 1975, researchers discovered the biomass of Rhizophora brevistyla in Panama, revealing that Rhizophora mangle has a total biomass of 62.7 tons per hectare, while R brevistyla reaches 278.9 tons per hectare Lieth (1964) demonstrated the global capacity of biomass production through yield charts, which provided a comprehensive understanding of forest productivity The International Biological Program (IBP) launched in 1964, and the Man and Biosphere (MAB) program initiated in 1971, significantly influenced biomass research efforts During this period, studies primarily focused on grasslands and evergreen rainforests, advancing knowledge of biomass accumulation across different ecosystems.
Canell (1982) published a comprehensive study titled “World Forest Biomass and Primary Production Data,” which analyzed data from over 1,200 forests across 46 nations, focusing on dry biomass of stems, branches, leaves, and other plant parts S Aksornkoae (1987) conducted research on natural mangrove forests in Thailand, examining species such as Soneratia, Rhizophora, and Bruguiera The study revealed that Rhizophora apiculata has the highest biomass, approximately 701.9 tons per hectare, followed by Bruguiera with 243.75 tons per hectare, while Ylocarpus exhibits the lowest biomass at only 20.1 tons per hectare.
G.Saena and D.S Kamat( India,1956 ) have introduced their research : “access biomass by application of remote sensing “ mentioned generally the issue of biomass products and evaluate the biomass by satellite image (Ly Thu Quynh ,2007)
In addition, Transnean (1926),Huber (Germany,1952), Moteith (
England,1960 -1962 ), Lemon ( USA,1960 -1987 ), Inone (Japan, 1965 -1968 ),…used method of carbon to determine biomass Therefore , biomass is evaluated by determining assimilation rate of CO2
Komiyama and his partner (1987) studied below-ground biomass and root size, estimating a total biomass of approximately 437.5 tons per hectare They found that the biomass on the ground of Da Voi (Ceriopstagal) is 1.05 tons per hectare, with stem biomass at 53.35 tons/ha, branches at 23.61 tons/ha, and leaves at 13.29 tons/ha Below-ground biomass, including roots, is significant at 87.51 tons per hectare, and root biomass specifically accounts for 1.99 tons per hectare Additionally, Clough and Attiwil (1982) reported that root biomass can constitute between 14% and 64% of the total biomass, according to Ha Quang Anh (2003).
To define the above ground biomass, we use the structure of Komiyama (2005)
DBH: Diameter at breast height
Table 2.1 About wood density of tree in mangrove forest
Species Science name Proportion-Volume
Vẹt trụ Bruguiera cylindrical ( L ) Blume 0,668 ± ,057 (n=6)
Vẹt tách Bruguieraparviflora ( Roxb) Wright
Dà vôi Ceriopstagal ( Perr ) C.B Rob 0,6952 ± 0,028 (n= 6)
8 Đước Đôi RhizophoraapiculataBlume 0,7417 ± 0,032 (n= 6) Đưng Rhizophoramucronata Lam 0,6723 ± 0,054 (n= 6)
Cui Biển Heritieralittolaris ( Dryand ) Aiton 0,6010± 0,105 (n= 6)
Source: Mida Creek, Kenya, Komiyama (1987)
Ngo Dinh Que (1971) estimated the biomass of Pine forest in Lam Dong province with density of 2500 trees/hectare, valued at 330 tons/hectare (Ly Thu Quynh, 2007) In
In 1986, Nguyen Hoang Tri pioneered the "Tree Model" method to estimate the biomass yield of Duoc Doi forest communities (Rhizophora apiculata) in Minh Hai's coastal mangroves, marking a significant advancement in ecological and coastal mangrove research His findings revealed that biomass in different forest types—natural regeneration, jungle, and plantations aged seven years in Ca Mau—were 119,335, 33,159, and 34,853 dry tons per hectare, respectively For mature mangrove forests, the total biomass reached approximately 276,892 kilograms per hectare, comprising stems (158,034 kg), bark (8,990 kg), branches (4,015 kg), support ground roots (34,159 kg), root bark (4,767 kg), leaves (9,304 kg), and buds (812 kg) These insights contribute valuable data for ecological studies and sustainable management of coastal mangrove ecosystems.
(0,29%); flowers and fruits: 6771,91 kg/hectare (2,44%) and below ground root: 19701,60 kg/hectare (7,11%) (My Thi Hong, 2006)
Ha Van Tue (1994) utilized the "tree model" method developed by Newboul D.J (1967) to study productivity and biomass in pulpwood plantations in the Midlands of Vinh Phu Research by Ly Thu Quynh (2007) evaluated the growth, development, biomass, and forest production of Pinus Keysia Roillex Gordm in Da Lat, Lam Dong province Nguyen Trong Binh (1996) identified patterns in biomass development and the structural composition of tree stems, analyzing the proportions of fresh and dry biomass in stems, branches, leaves, and roots, as well as fallen parts He also examined total biomass at the individual and community levels and developed software models illustrating the relationship between biomass and other tree components in trees with a diameter of 3 meters.
Ly Thu Quynh (2007) studied the biomass and carbon sequestration capacity of Manglietia conifer Dandy in Tuyen Quang and Phu Tho, revealing that its biomass structure comprises four parts: leaves, stems, roots, and fallen objects The fresh biomass distribution is approximately 60% in stems, 8% in leaves, 7% in roots, and 24% in fallen objects The total fresh biomass per hectare ranges from 30,968.9 kg to 53,440 kg, with 86% of biomass concentrated in wood floors, 6% in shrub vegetation, and 8% in fallen debris, highlighting the species' significant role in biomass accumulation and carbon sequestration.
In addition,several other research projects as Vien Ngoc Nam and Nguyen Duong Thuy
Research by Nguyen Van Be (1999) and Dang Trung Tan (2001) highlights the significance of mangrove biomass across various regions in Vietnam Specifically, Nguyen Van Be studied mangrove biomass in Ben Tre, while Dang Trung Tan’s work, titled "Mangrove Forest Biomass," quantified the total dry biomass in Ca Mau at 327 m³/ha Additionally, in 1991, studies focused on forest biomass in the Can Gio mangrove forest, providing valuable data on the ecological importance and carbon storage capacity of these vital ecosystems.
XuanThuy National Park is wellknown by its mangrove forest biosphere in reserve areas of the Red River Delta This is the first mangroves in Vietnam are internationally
Xuan Thuy National Park in Giao Thuy district, Nam Dinh Province, is Vietnam’s 10th recognized Ramsar site and the country’s 50th globally important wetland Covering approximately 7,100 hectares, it features a diverse mangrove ecosystem comprising 3,100 hectares of floating forests and 4,000 hectares of mangrove land The park’s core zone includes mangrove areas on three key dune estuaries—Con Ngan, Con Lu, and Con Xanh—situated in Giao Thien district, while the entire buffer and core zones span Giao Thien, Giao An, Giao Lac, Giao Xuan, and Giao Hai communes This protected area plays a vital role in local biodiversity conservation and ecological balance.
This area serves as a crucial migratory stopover for approximately 100 species of migratory birds annually, accounting for about one-fifth of the world's population of Re Mo Thia The garden is home to an estimated 215 water bird species, including many that are critically endangered and listed in the Red Book, such as Re Mo Thia, Mong Bien, and Diec Dau Do The salty wetlands and tidal waters support a rich biodiversity, harboring around 165 species of zooplankton and 154 species of bottom-dwelling animals, totaling approximately 500 animal species.
The mangrove ecosystem comprises approximately 120 species of vascular plants, encompassing key mangrove species across 101 genera and 41 families Additionally, it includes 112 floating aquatic plant species spanning 43 genera, highlighting the rich plant diversity within this unique habitat.
This study assesses the current status and spatial distribution of mangroves at Xuan Thuy National Park in Nam Dinh It selects appropriate methods to calculate above-ground biomass and estimates the carbon stored within this biomass The research offers strategies to enhance the sustainable management of mangrove forests, contributing to regional climate change mitigation efforts.
Application of GIS and Remote sensing to estimate mangrove biomass and carbon stock
GIS and Remote sensing to estimate mangrove biomass and carbon stock:
Remote sensing is a useful tool for rapidly mapping large areas that are difficult to study by means of conventional field surveys, as is the case for mangrove forests
Traditional biomass assessment methods based on field measurements are highly accurate but are often impractical for large areas due to their high costs, time consumption, and labor intensity Recently, remote sensing (RS) technologies have been increasingly applied in natural resource management, offering a practical alternative for large-scale biomass estimation RS is widely utilized to monitor forest above-ground biomass (AGB), vegetation structure, and productivity by analyzing spectral reflectance, especially in infrared bands which are sensitive to vegetation characteristics such as crown size and tree density While optical RS does not directly measure AGB, it provides valuable indirect indicators, making it a reliable tool for large-scale biomass assessment in tropical regions Its ability to obtain consistent, large-area data at a reasonable cost with minimal effort has led to its widespread adoption in forestry and biomass monitoring studies.
Estimating of above ground biomass of mangroves
Estimating above-ground biomass (AGB) in mangroves is challenging due to their complex forest structures and diverse species Many studies highlight that using relationships between field measurements and remote sensing (RS) data, then extrapolating these relationships across large areas, is highly effective (Michael A Wulder, 2008; Nagesh Kumar, 2012) Researchers typically employ linear regression models—sometimes with log transformations of biomass data—or multiple regression techniques, including stepwise selection, to accurately relate AGB to RS data.
Numerous modeling techniques, including 12 neural networks, semi-empirical models, nonlinear regression, and nonparametric estimation methods, have been employed to analyze complex relationships in biomass estimation While no single model can definitively capture this complexity, researchers frequently rely on multiple regression models as a reliable and effective option Vegetation index models are widely used across studies to accurately estimate biomass, leveraging remote sensing data for improved precision.
Vegetation indices (VIs) are derived from mathematical transformations of spectral reflectance data and are essential for interpreting land vegetation cover They effectively minimize variations caused by factors such as soil background, sun-view angles, and atmospheric conditions while highlighting biophysical properties of vegetation Numerous studies have demonstrated strong positive correlations between biomass and VIs, though some research reports weaker relationships Landsat imagery, a widely used medium-resolution satellite data source, enables the mapping and estimation of above-ground forest biomass through direct correlations or regression analyses involving spectral bands and ratios While land-cover change mapping using low- and medium-resolution satellite images can be challenging, Landsat’s accessibility and low cost make it a popular tool for diverse remote sensing applications.
A combination of many data sources (e.g., forest inventory, land use, elevation, and
RS data can effectively predict vegetation variables across large areas By combining a hybrid supervised/unsupervised classification approach with GIS analysis, land use and land cover mapping accuracy for Landsat data is significantly enhanced This integrated method improves the precision of vegetation mapping, supporting better environmental management and planning.
In tropical regions, forest plot-based field measurements have been correlated with remote sensing (RS) data to improve the accuracy of carbon stock estimation These measurements indicate that carbon stocks are limited, especially in Southeast Asian countries The present study aims to thoroughly characterize the carbon stock in these regions, providing valuable insights for sustainable forest management and climate change mitigation efforts.
This study identifies 13 mangrove forest types through combining forest-plot-based field measurements with remote sensing (RS) data to develop a simple RS-based methodology Integrating field data and RS techniques enhances the accuracy of forest carbon estimation, supporting efforts to reduce emissions from deforestation and forest degradation (REDD+) This approach also aids in designing effective incentive programs and improves forest management strategies aimed at climate change mitigation.
Remote Sensing and Forest Inventory Data in Savannakhet.)
GOAL, OBJECTIVES, CONTENT AND METHODOLOGY
Goal and objectives
Study aims to provide a scientific basis for proposing quantitative methods of above ground biomass and carbon stock in mangroves
- Evaluate the current situation of mangroves in Xuan Thuy National Park
- Quantify above ground biomass of mangrove forest on the study field
- Propose solution to improve the managed effect to mangrove forest to distribute reducing the impacts of climate change on study field.
Scope and framework of study
Scope of study: The entire coastal area of XuanThuy National Park while focus ofs livelihoods of residents of communes includes GiaoHai, GiaoXuan, Giao Lac, GiaoAn, GiaoThiên,
Framework of study: In this study, effectiveness of coastal mangroves should be understood as dynamics of mangroves area, improvement of local livelihoods and mangroves quality
3.3.1 Examining the status of mangroves and management schemes in XuanThuy National Park, Nam Dinh province
3.3.2 Quantifying spatial distribution of mangrove extents in XuanThuy National Park, Nam Dinh province
3.3.3 Quantifying above-ground biomass and carbon stocksof mangroves
3.3.4 Proposing solutions to improve the management of mangrove inXuanThuy National park
Methods
3.4.1 Examining the status of coastal mangrove management in XuanThuy National Park, Nam Dinh Province
Status of coastal mangrove management
This study involves conducting direct interviews with households contracted for mangrove forest protection, focusing on those born and residing near coastal mangroves to leverage their in-depth knowledge of local resources Additionally, interviews are carried out with households responsible for managing and protecting the mangroves, as well as personnel directly involved in mangrove protection management, such as ranger station staff, social forestry officials, and representatives from contracting units overseeing forest conservation efforts.
The interview content highlights that farmers are familiar with coastal mangroves, their local species, and their appearances Recognizable species such as Kandelia obovata and Rhizophora mucrolata serve as key indicators for accurate image classification To enhance understanding, the study provided color photographs and drawings to farmers, aiding species identification and offering additional information about the habitat When uncertain about species growth or location details, farmers consult experts for reliable guidance.
Questionnaires were conducted to interview the local people In this questionnaire:
• Target groups include local administrators; communities who live in coastal zone Totally, 30 local households were chosen in each commune GiaoHai, GiaoXuan, Giao Lac, Giao An, GiaoThiên
This article examines the historical development and dynamic changes of mangrove ecosystems in Xuan Thuy National Park over various time periods It highlights key policies and conservation projects implemented to protect and restore mangroves, demonstrating their impact on ecosystem health Additionally, the study explores how local livelihoods have evolved in response to these environmental and policy changes, illustrating the interplay between conservation efforts and community livelihoods.
3.4.2 Quantifying spatial distribution of mangrove extents in XuanThuy National Park, Nam Dinh province
Advancements in remote sensing technology have enabled the development of techniques and algorithms to detect changes in objects across different phases, utilizing space characteristics, spectral, thermal, and temporal data Change detection methods often involve comparing two images to identify differences, as established by Singh (1989) In this study, the Normalized Difference Vegetation Index (NDVI) is employed to effectively detect alterations in coastal mangroves and other land use/cover types along the coast.
Remote sensing data for study:
The multi-temporal Landsat images were used in this study (Table 3.1)
Table 3.1 Landsat and Sentinel data used in the study
ID Landsat and sentinel image code Date
Source : http://glovis.usgs.com, https://scihub.copernicus.eu/dhus/#/home
Questionnaires were conducted to interview the local people In this questionnaire:
• Target groups include the local administrators; communities who live in coastal zone Totally, 30 local households were chosen in each commune GiaoHai, GiaoXuan, Giao Lac, Giao An, GiaoThiên
The article provides a comprehensive overview of the history and dynamics of mangroves in Xuan Thuy National Park, highlighting how their extent and health have evolved over different time periods It examines various policies and conservation projects implemented to protect and restore mangrove ecosystems in the region, emphasizing their impact on environmental sustainability Additionally, the study explores how local livelihoods have transformed over time in response to changes in mangrove availability and management, reflecting the socio-economic significance of these ecosystems for surrounding communities.
Sampling method (stratified random sampling) and plot establishment
Before plot establishment, this study was carried out a survey of vegetation in study areas and used visual interpretation on the Landsat images to determine location of plots
Stratified random sampling: A stratified random sampling is obtained by separating the population elements into non-overlapping groups, called strata, then selecting a simple random sample from each stratum:
Plots were randomly selected based on visual interpretation and strategically located along the coastal mangrove area The coordinates of each plot were recorded using GPS devices prior to conducting fieldwork, ensuring accurate spatial data collection for the study.
Totally, 4 square plots were conducted with the total area 400m 2 (20m x 20m) Each big plot had five sub – plots (four plots at the corners and one plot at the center of plot)
Fig 3.1 Layout of sampling plot and subplots this study
After establishing the plots, we collected essential data such as species names, species count, tree height, canopy diameter, and health status to assess the quality and condition of the mangrove forests Key points were marked using GPS devices, and their coordinates were recorded and integrated into ArcMap within ArcGIS software for detailed spatial analysis.
Table 3.2 Sampling of data collection form
Latitude (X): Date of survey: Investigator:
Remark Scientific name Local name
H cv : Total height of mangrove tree; D canopy : Diameter of mangrove canopy; N: total number of mangrove tree;
This study calculated the coverage ratio for each plot by counting steps along the edge of control plots and recording the coverage at each step The coverage ratios were observed at interval steps to monitor changes across the plot edges After collecting data at 100 steps, all results were summed to determine the final coverage ratio for each plot This method provides a comprehensive assessment of coverage distribution and ensures accurate, repeatable measurements for analysis.
3.4.3 Quantifying above-ground biomass and carbon stocks of mangroves
3.4.3.1 Mapping status and distribution of mangroves in 2015
The process of interpretation of Landsat 8 satellite images in 2016 and mangrove distribution map, need to use ArcGIS 10.1 following diagram:
Diagram 3.1 Methods of constructing mangrove maps using NDVI
Six steps to remote sensing image processing:
Secondary data: maps, DEM, reports, etc
Image Classification: Normalized Differences Vegetation
Assess the accuracy of the method: The data from the field, Google Earth
Above- ground biomass, carbon stocks of mangroves Preprocessing of Landsat 8 images
Step 1: Collect data serve to research
To have a good report Firstly, we need to collect enough necessary information about subjects of research
Primary data collection involves two main sources: conducting fieldwork and retrieving data from the national park This process includes gathering detailed information on tree species, measuring their density, assessing age, determining the area they occupy, and identifying their distribution within the park.
Secondary data collection involves two key steps: first, obtaining satellite images from Landsat 8, and second, processing the data using GIS tools This process includes downloading the satellite images, determining precise coordinates to accurately locate XuanThuy, and mapping the distribution of mangroves These steps enable a comprehensive analysis of mangrove habitats and their spatial distribution.
Step 2: Landsat image preprocessing: including downloading from the satellite map, set boundaries, cropping, processing images and choose the color band for the best photos …
Step 3: Construct mangrove distribution maps by vegetation index NDVI
NDVI = (BandơNIR – BandRed)/(BandNIR+Bandred)
In the Landsat 8: BandNIR = Band 5, Bandred = Band 4
Step 4: Assess the accuracy of classification method: the report is only valid when its accuracy is reliable and has been recognized by many people So we need to assess the accuracy of the information by comparing it with other materials which has high accuracy and are widely recognized
Step 5: Using Sentinel image to check the accuracy of the results
Sentinel is new satellite image was development by ESA (European Space Agency) to missions carry a range of technologies, such as radar and multi-spectral imaging
21 instruments for land, ocean and atmospheric monitoring There are 6 kinds of sentinel image, but in this study using Sentinel 2
Sentinel-2 is a high-resolution, polar-orbiting multispectral imaging mission designed for land monitoring, providing detailed imagery of vegetation, soil, water cover, inland waterways, and coastal areas It plays a crucial role in supporting emergency services with timely environmental data Sentinel-2A launched on June 23, 2015, followed by Sentinel-2B in the second half of 2016, ensuring continued Earth observation capabilities.
Step 6: Handling post-classified map: The quality of the remote sensing images can be improved by the addition of a colored band again to increase the image resolution To save time in image processing and classification, we need to edit in the picture is not included in the study area Then, a set of data (boundaries mangroves in XuanThuy) was used to divide the study area into Landsat images
This approach involves dividing Landsat images into multiple groups, each containing points with similar spectral signals Consequently, mangroves are effectively distinguished from other land cover types such as residential areas, water bodies, agriculture, and industrial layers This segmentation enhances the accuracy of land use and land cover classification, facilitating better environmental monitoring and resource management.
→ Throughout that process, we will obtain distribution map of mangrove forest
3.4.3.2 Research and definition above the ground biomass of mangrove in XuanThuy National Park
To calculate above the ground biomass, we use two data from 2 different scientific studies:
- Biomass formula of Kandelia Obovata established by professor : MdNabiul Islam Khan(2009)
Base on this formula we will find out through two criteria D0.1: Distance from stump to position measured is: 10cm
Field survey, plot establishment: survey some criterions, structure of mangrove forest above the ground, topic carries out by the way using plot establishment in field survey process Concrete:
Study establishes a plot in survey process By this way, we define species of tree which have in mangrove forest (Bruguiera gymnorrhiza, c, Aegiceras corniculatum,
Kandelia Obovata); types of mangrove forest (plantation forest, primary forest, protection forest…), the age of mangrove forest; distribution density; D01 measurement
3.4.3.3 Estimatingcarbon stocks of mangrove forest in XuanThuy National Park
Calculate the amount of carbon according to the IPCC (2016)- Intergovernmental Panel on Climate Change
3.4.4 Proposing solutions to improve the management of mangrove forests in XuanThuy National park
This study explores potential solutions for mangrove management by incorporating insights from local inhabitants and administrators through interviews It emphasizes strategies such as effective governance, resource allocation, and improved communication These approaches aim to enhance sustainable mangrove conservation and address community needs Implementing targeted management strategies and fostering collaboration between stakeholders are essential for effective conservation efforts.
STUDY SITE, NATURAL AND SOCIAL FEATURE
Study area
XuanThuy National Park is located in GiaoThuy District (Nam Dinh Province),
Located 150 km southeast of Hanoi, the largest coastal ecosystem in northern Vietnam is situated in the south of the Red River mouth, encompassing a Core Zone of 7,100 hectares that includes 4,000 hectares of low tide wetlands and 3,100 hectares of land covering islands such as Con Ngan, Con Lu, and Con Xanh Con Ngan, the largest island, features aquaculture farms and mangrove forests, while Con Lu is characterized by sandy areas, alluvial flats, and expanding alluvium from the Red River The Buffer Zone spans 8,000 hectares and supports coastal mangroves and mudflat ecosystems within delta and estuary islands around the Ba Lat river mouth This area includes land enclosed by sea dikes with fringing marshes and is renowned for its unique human ecological model (VAC), integrating vegetable gardening, fish ponds, and animal husbandry Historically, the region has cultivated wet rice, constructed dikes, and undergone land reclamation, reflecting a rich tradition of sustainable wetland management in Giao Thuy District.
Fig.4.1 Study site (National Park Management, 2016)
XuanThuy National Park, located at the mouth of the Red River where it meets the sea (Ba Lat), is a coastal reserve characterized by extensive dunes, mudflats, and intertidal marshes Con Ngan is the largest sand dune, predominantly used for aquaculture ponds and covered with mangroves, serving as a vital habitat for diverse species Con Lu features expansive sandy beaches, mudflats, marshes, and a smaller area of aquaculture ponds, offering rich biodiversity Con Xanh is the smallest and thinnest sand dune, gradually built up by silts from the Red River, with its areas often flooded during high tide The southern boundary of the park is periodically affected by tidal flooding, shaping its unique ecosystems.
25 park is the river mouth In protected areas, where the highest absolute height of 3 m, and the deepest seas of 6 m
GiaoThuy district is located in a tropical monsoon climate, characterized by two distinct seasons: a hot, rainy season from April to October, and a cold, dry season from November to March The area experiences an average annual temperature of 24°C, with summer temperatures reaching up to 40.3°C and winter lows dropping to 6.8°C Humidity remains high at around 84%, while annual rainfall totals between 1,700 mm and 1,800 mm The region experiences approximately 133 rainy days per year, predominantly during summer and winter months August is the month with the highest rainfall, receiving between 15 to 18 rainy days, whereas autumn and winter are generally drier with fewer rainy days.
From July to October, the Red River region experiences flooding influenced by the northeast monsoon, impacting local communities and agriculture The area typically sees a steady rainfall of about 50 mm per month during this period In winter, the prevailing winds come from the north, while in summer, they shift to come from the east, shaping the region's climate patterns July and August are the stormiest months of the year, characterized by intense storms followed by heavy rainfall, with three major storms hitting northern Vietnam during this season.
2005 (28 July one wind with level 7, 18 September with level 9 and on 28 September with level 12)
The Red River area features two primary types of soil formed from alluvium: alluvial mud, which transforms into loam, and sandy soil These soils are transported by water and include coastal soils such as light soil (consisting of sand and light loam), medium soil, and heavy soil (comprised of loam and clay) The region’s soil composition is primarily made up of silt deposited by the Red River and the East Vietnam Sea, contributing to its diverse and fertile landscape.
Were recorded in the study area in XuanThuy National Park with the distribution of
XuanThuy National Park hosts 115 species of vascular plants, including key mangrove species and inland migrants adapting to local conditions, spanning 101 genera with 41 families The flora comprises seven fern species across seven genera and five families, 80 dicotyledonous species from 70 genera and 30 families, and 28 monocotyledonous species from 24 genera and six families This record is lower than Phan Nguyen Hong's 2007 manual data, which listed 192 vascular plant species, as this report excludes species from agricultural ecosystems and neighboring areas within five communes along the BZ dike In the mangrove ecosystem, there are seven prominent species, including Aegiceras corniculatum, Sonneratia caseolaris, Kandelia obovata, Rhizophora stylosa, Acanthus ilicifolius, Acanthus ebracteatus, and Derris trifoliata, highlighting the rich biodiversity resource of XuanThuy National Park.
XuanThuy features 14 types of habitats, including both natural and artificial environments (Pedersen and Nguyen Huy Thang, 1996) The most biodiverse habitats are the mudflats and mangroves, which are relatively undisturbed and ecologically valuable Mangrove species such as Kandelia are dominant, providing critical habitat for various wildlife, while areas with sparse planting include Sonneratia caseolaris Additionally, naturally growing species like Aegiceras corniculatum and Acanthus ilicifolius are scattered throughout the region, contributing to the area's rich biodiversity.
Many mangrove forests once covered mature aquaculture farms, with large areas of mudflats planted with monoculture crops In 1996, approximately 300 hectares of Phragmites sp were cultivated in the lagoon area of Con Ngan, highlighting the extent of aquaculture activities during that period (Pedersen and Nguyen Huy Thang, 1996) However, by 2000, these reed beds had disappeared, indicating significant ecological changes in the region (J Eames).
2000) On Con Lu, Casuarina equisetifolia was planted Cassuarina large area, this is an
The forest habitat serves as a crucial stopover for migratory birds, boasting diverse and relatively intact ecosystems that support their needs during migration This area is especially important for the wintering of migratory water birds, providing a vital habitat for their survival Surveys conducted in 1988 (Scott et al., 1989) and 1994 (Pedersen et al.) highlight the site's significance as a key habitat for these avian species during migration periods.
1996) has observed over 20,000 individual birds in the region Middle Spring 1996, there are over 33,000 sea birds flying over national parks (Pedersen and Nguyen HuyThang,
XuanThuy National Park is a critical habitat where eight bird species are classified as threatened or near-threatened globally, including the Spoonbill (Platalea minor), White Stork (Ciconia ciconia), Egretta eulophotes, Large Redshank (Tringa guttifer), Gull (Larus spp.), Spot-billed Pelican (Pelecanus philippensis), Calidris pygmeus, Mycteria leucocephala, and Large Dowitcher (Limnodromus semipalmatus) (Tordoff, 2002) Notably, XuanThuy hosts the largest population of Spoonbills in Vietnam, with up to 65 individuals recorded in recent years, emphasizing its significance for this species (Nguyen Duc Tu, 2003) The park serves as a vital stopover for migratory waterfowl in winter, including Black-tailed Godwit (Limosa limosa), Redshank (Tringa erythropus), and Eurasian Curlew, highlighting its importance for seasonal bird migration Due to its international significance for bird conservation, XuanThuy has been designated as one of Vietnam’s Important Bird and Biodiversity Areas (IBA) (Tordoff, 2002).
XuanThuy and GiaoXuan are key communes within the ecotourism community buffer zone of the XuanThuy National Park, showcasing unique coastal features such as mangroves and mudflats that support local aquaculture These areas benefit from a moderate climate and hospitable residents, reflecting the rich cultural heritage of the Red River Delta Their distinctive natural and cultural characteristics position GiaoXuan as an excellent demonstration site for community-based ecotourism, promoting sustainable tourism development in the region.
Socio-economic conditions
GiaoThuy District in Nam Dinh Province had a population of 51,109 residents across 13,740 households in 2014, with a high population density of over 6,546 people per square kilometer The district's working-age population comprised 25,771 individuals, including 2,175 farmers and 676 fishermen GiaoThuy is recognized as one of the districts in Nam Dinh with a high standard of living, with the average income rising from 9 million VND in 2008—marking a 50.8% increase since 2000.
Recent statistics from Nam Dinh province highlight significant economic growth in GiaoThuy district, driven by innovative management mechanisms, supportive government policies, and strong leadership from the Party Between 2006 and 2010, the district experienced an impressive average annual growth rate of 10.71%, reflecting robust economic development The regional economic structure shifted positively, with increased contributions from industry, construction, and services, while the agricultural sector's share decreased By 2010, per capita income had reached 11.2 million VND per year, indicating tangible improvements in residents' income levels.
+ Agriculture - forestry - fisheries: gradually developed towards production of goods and increase the value of 1 unit of arable land Total per capita food production: 101
166 tones / year Value production / ha cultivated reach 66.7 million The production value of agriculture - forestry - fishery increased on average 3.5% / year Structure of agriculture
- forestry - fishery has shifted towards increasing the proportion of animal husbandry and fisheries, particularly the fisheries sector with an average growth rate of 15.15% / year
The manufacturing and handicraft industries have experienced significant growth, with an average annual increase of 18.91%, leading to expanded production scales for enterprises Key products such as sauces, with an output of 934,000 liters; iodized salt, totaling 13,588 tons; clothing items, with 1,319,000 products; and earthenware, reaching 97,812 thousand units, have shown high growth rates Sectors including mechanics, repair, shipbuilding, wood processing, construction materials, textiles, knitting, embroidery, and food processing have played a vital role in boosting economic development These industries have created numerous jobs, contributed to poverty alleviation, and increased revenues for local budgets.
In 2010, salt production in the district covered an area of 482 hectares, with over 9,000 employees involved in manufacturing The industry supplied approximately 42,000 tons annually, generating a total income exceeding 65 billion VND Additionally, the district has established 8 salt harvesting bases dedicated to producing clean and iodized salt for domestic consumption and export to Laos.
The Industry Rural District currently hosts 1,325 manufacturing establishments and numerous households engaged in rural trades across five villages, attracting over 7,000 workers Key production sectors include rattan stretching, crochet, embroidery, mushroom cultivation, food processing, textiles, carpentry, mechanics, and construction, reflecting a diverse and rich manufacturing base However, many small-scale owners operate spontaneously without advanced techniques, relying on immediate demand and traditional methods rather than systematic training Over the past five years, the total average production value has reached 117.6 billion VND annually, with an impressive growth rate of 13.5% per year, highlighting significant development potential in the district’s rural manufacturing sector.
The service sector experienced significant growth, with total retail sales reaching $493.6 billion in 2010, representing a 152% increase since 2006, reflecting a vibrant market that meets both production and everyday needs Industries such as transportation, postal and telecommunications, finance, tourism, and trade have thrived, with a production value of $414.2 billion in 2010, growing at an average annual rate of 12.8% Notably, tours in Quat Lam Resort achieved an average annual revenue of several billion dollars, indicating strong tourism demand Currently, the region hosts 42 hotels and motels, along with 111 tourist service kiosks, welcoming approximately 172,000 visitors annually.
RESULTS AND DISCUSSION
Mangrove structures and its management in study sites
Mangrove features and structures in Xuan Thuy NationalPark
Coastal mangroves stretch along the southeastern coast of Nam Dinh, predominantly in the coastal communes of Giao Thuy district, covering approximately 7,100 hectares according to Xuan Thuy National Park Management (2014) These mangrove areas offer stunning scenery, making them ideal for sightseeing, eco-tourism, and attracting investment in aquaculture projects The mangrove ecosystems are characterized by muddy soils, low oxygen levels, high water levels, and low salinity during slow tides, creating a unique environment for local biodiversity and economic activities.
As the result of field survey showed that there were three main mangrove species identified, namely Kandelia obovate and Aegiceras corniculatum, Sonneratia caseolaris
Sporobolus virginicus and Scirpus kimsonensis are found in Ba lat Mouth on muddy tidal areas, indicating their adaptation to dynamic tidal environments Higher land areas along pond banks host communities of Clerodendron inerme, Hibiscus tiliaceus, and Ecocarya agallocha, which are less affected by tidal fluctuations Additionally, Daturametel, Ricinus communis, and Ruellia tuberosa thrive on higher elevations such as the tops of dikes, experiencing minimal tidal influence Moreover, Casuarina equisetifolia primarily concentrates on sand dunes outside the mangrove forest, highlighting its role in stabilizing sandy coastal areas.
Con Lu, Con Ngan (GiaoThien Commune), Nha (GiaoXuan commune) and other area;
The study highlights diverse coastal and brackish water communities, including Halophila ovalis, Halophila minor, and Myriophyllum dicoccum, thriving on brackish land It also features the Cyperus malaccensis – Phragmites karka community in aquatic ponds, showcasing wetland plant diversity Additionally, the mangrove ecosystem comprises Aegiceras corniculatum, Sonneratia caseolaris, Avicennia marina, and Acanthus ilicifolius, forming a vital coastal habitat Artificial communities include Kandelia obovata and Aegiceras corniculatum, complemented by communities of A corniculatum and Avicennia marina, emphasizing the importance of habitat restoration and conservation efforts.
A field survey and interviews with 30 households in Giao Thuy district's core and buffer zones revealed that coastal mangroves were planted between 1995 and 1998 under the Greening Bare Land (327 Program) These mangroves, primarily located in Con Lu, consist of species such as Aegiceras corniculatum, Sonneratia caseolaris, Avicennia marina, and Acanthus ilicifolius, forming mixed forests adjacent to buffer zone dykes Monoculture areas feature species like Kandelia obovata and Aegiceras, planted separately Casuarina forests are mainly established outside Con Lu and along the coast beyond Bai Trong Recently, new planting efforts have focused on the clam beach area, with dominant species including Kandelia obovata and Rhizophoraceae, contributing to coastal protection and ecological restoration.
In July 2015, a study on stratification in the mangrove forests of XuanThuy National Park revealed minimal renovation of forest floors, yet a dominance of Kandelia obovata among the trees and plants Despite the abundance of mature mangrove species, there was a notable scarcity of re-born seedlings, indicating limited natural regeneration The research was conducted across four study sites, each representing different plant community types within the park's typical mangrove ecosystems.
Table 5.1 Plots information and mangrove characteristics in study site
No Plots/routes Position Coordinates Vegetation
Mangrove forest, only Kandelia candel (L.) Druce
Sonneratia caseolaris (L.) Engl.; Rhizophora stylosa Griff And Kandelia candel (L.) Druce, , Aegiceras corniculata (L.) Blanco
Our study focuses on a sample plot within Xuan Thuy National Park, encompassing both the mangrove area and surrounding regions The survey includes core and buffer zones, focusing on the structural characteristics of key plant communities Standard sampling units were established based on the core components of the park’s ecosystems, primarily examining the mangrove forest dominated by Sonneratia caseolaris (L.) Engl., to assess biodiversity and ecological health.
Rhizophora stylosa Griff And Kandelia Candel (L.) Druce,Aegiceras corniculata (L.)
This regional standard plot is designed to monitor and assess the growth and development of specific species within the ecosystem It aims to identify the key factors affecting mangrove health, including both natural vulnerabilities and human-induced impacts Understanding these influences is essential for effective conservation and management of mangrove habitats.
In recent years, increasing awareness has highlighted the vital role of mangroves in protecting coastal areas However, ongoing exploitation of coastal resources has led to significant reductions in mangrove forests, threatening both the environment and local communities To address this, GiaoThuy district in Nam Dinh recommends implementing effective management policies that balance resource utilization with conservation efforts, ensuring the sustainable use and preservation of mangroves.
GiaoThuy district administration in Nam Dinh has implemented effective management measures for coastal areas, focusing on social issues and mangrove forest conservation The program empowers local families by assigning them responsibility for managing and protecting mangroves, providing government support and incentives This approach not only enhances local community involvement but also significantly improves the sustainability and effectiveness of mangrove preservation efforts.
In recent years, the rising demand for fishery and aquaculture products has led to the reduction and scaling down of mangrove areas To address this, the company has allocated mangrove management responsibilities to local households, providing annual payments as incentives This approach aims to balance resource utilization with conservation efforts.
34 this work provides employment for local people, a large mangrove area is declining at the study sites
Abandoned shrimp farms along coastal areas have become sources of environmental pollution and pose risks due to disease outbreaks, hindering replanting efforts Most pond owners remain under long-term lease agreements, preventing the restoration of mangroves in these areas As a result, the insufficient mangrove belt fails to provide adequate coastal protection, increasing vulnerability to disasters and threatening the safety of local residents.
Effective mangrove management remains limited due to low public awareness and inadequate scientific research support Coastal fisheries authorities often lack the capacity to manage saline soils effectively, hindering conservation efforts In GiaoThuy, Nam Dinh, restoring abandoned lands through targeted recovery measures can help reestablish mangrove forests, providing essential coastal protection and economic opportunities Strengthening community engagement, implementing proper land acquisition policies, and offering fair compensation are crucial for securing local support and enhancing fishermen's livelihoods while expanding fishing zones on tidal flats.
Spatial distribution of coastal mangroves in XuanThuy National Park
- Landsat mapping of mangroves in GiaoThuy, Nam Dinh
This study used Normalized Difference Vegetation Index (NDVI) to identify spatial distribution of mangroves in Xuan Thuy Nation Park as indicated in Fig 5.1
Fig5.1 Spatial distribution of mangroves using NDVI (Lansat8, 2016)
The NDVI values in the study area range from -0.22 to 0.473, with higher NDVI values indicating denser mangrove vegetation, while negative values correspond to water bodies and bare soil, as confirmed by Khairul (2011).
Fig 5.2.Spatial distribution of mangrove extents in XuanThuy National Park 2016
This study used the Sentinel image (10m x 10m) to compare with Landsat 8 for accuracy assessments purpose as shown in Fig 5.3
Fig 5.3: Spatial distribution of mangrove extents in XuanThuy National Park in 2016
Results showed that there is no much difference between Landsat 8 and Sentinel image about spatial distribution of mangroves However, Landsat 8 results completely trustworthy
Assessing accuracy of classified map
This study evaluates the accuracy of training samples for coastal mangrove classification by using the same set of test data points collected in the field, with GPS identification, across different sample sets and various objects within the study area.
Then comparing actual image with classified image, which evaluated the accuracy of the Landsat image interpretation methods
The training samples for distribution mangroves accuracy of the final results were evaluated based on field investigation results, as follows:
Table 5.2 Assessing accuracy of classified map(Landsat 8)
Water Total Accuracy(%) Classifed map by GPS
The classified map from 2015 achieved an overall accuracy of 88.3%, reflecting high reliability but still containing some errors These inaccuracies may be attributed to potential errors in selecting the classification model, variations in the turbulence spectrum of the images, effects of the angle of photography, and residual shadows in the topography that could not be fully eliminated during image processing Nonetheless, training samples used for classifying coastal mangroves are valuable for improving analysis and image interpretation in these regions and can be effectively applied to similar mangrove coastal features across Vietnam.
5.3 Quantifying above-ground biomass and carbon stocks
Field surveys identified three main mangrove species, with Kandelia obovata being the dominant species, followed by Aegiceras corniculatum and Onneratia caseolaris As the most prevalent species, Kandelia obovata was selected for biomass and carbon stock calculations in this study, ensuring accurate assessment of mangrove ecosystem contributions.
Calculate biomass and Carbon in Xuan Thuy National park:
The study calculate mangroves biomass base on the value of mangroves extents as shown in Table 5.3
Table 5.3 Total area of mangroves by using NDVI
Base on the result of plot investigation the structures of mangroves were measured, results were then:
As below: D 01 =2.8(cm) equivalent to 0.028 (m) (1)
Based on formula calculate biomass of Kandelia Obovata by professor MdNabiul
D 2 0.1: Distance from stump to position measured is: 10cm
The result after investigate showed that in general in one plot the study made have
AGB in 4 plot = 0.684x10 -5 x 240 x 4 x10000 = 65.66 (ton/ha)
Therefore: AGB in XuanThuy national park 65.66 x1909.625344.94(ton)
Study used a formula of carbon stock developed by IPCC-2016 as shown: Carbon Biomass x 0.47
As a results total Carbon of Kandeliaobovata in XuanThuy- Nam Dinh is:
The biomass of mangrove forests in Xuan Thuy National Park exceeds the results reported in previous studies (Saenger, 2002; Komiyama et al., 2008; Alongi, 2009) However, biomass varies across different areas, with some locations exhibiting low biomass due to smaller tree sizes Overall, the mangrove biomass in Xuan Thuy National Park is considered to be of an average level, reflecting its general forest condition.
Numerous studies have focused on high forest trees, but data collection in Xuan Thuy National Park's mangroves encompasses diverse forest types, including young forests, areas with felled trees, and barren zones This comprehensive approach reveals that forest biomass may be lower than previously reported figures, highlighting the importance of examining various forest conditions to accurately assess ecosystem health and productivity.
5.4 Effective measures to improve the management of mangroves
Mangroves play a vital role in providing essential ecosystem services and are among the most carbon-rich habitats worldwide, with twice the biomass of tropical forests on average Protecting these vital ecosystems is crucial for climate mitigation and biodiversity conservation, and implementing effective solutions involves active participation from governments and local communities Based on survey findings, the study recommends targeted conservation strategies, community engagement, and policy initiatives to ensure the sustainable management and preservation of mangroves for future generations.
Improvement of REDD+ program for mangrove forests
Policies of government in payment environmental services (PES) and the mechanisms of (REDD+) distribute sustainable forest management and reduce the impacts of climate change
REDD+ is a critical mechanism that promotes forest carbon sequestration services, aiming to reduce emissions from deforestation and forest degradation while enhancing forest carbon stocks The government has approved a comprehensive national action plan to implement REDD+ efforts, serving as the foundation for reducing greenhouse gas emissions from the forestry sector This strategy not only supports climate change mitigation but also promotes sustainable forest management practices.
Payments for Environmental Services (PES) aim to incentivize local communities to conserve environmental resources by compensating for their management efforts and associated costs In 2004, Vietnam pioneered a nationwide PFES program based on the PES concept, institutionalized through the revised Forest Protection and Development Law to promote forest conservation and sustainable management.
Strengthening media propaganda through newspapers, radio, and television is essential to raising awareness about climate change and its impacts Educating the public on the critical role of mangrove forests and coastal protection forests in mitigating coastal erosion and reducing damage from natural disasters is vital Organizing specialized training for staff and social groups on effective construction methods and livelihood deployment models can improve local incomes and promote sustainable mangrove conservation These efforts collectively support the protection and development of mangroves, contributing to resilience against climate-related challenges.
Implementing education and training activities is essential for mangrove conservation This includes hosting seminars on mangrove-related issues, providing specialized staff training, and organizing training courses for social organizations Focused on constructing and deploying coastal livelihoods models, these initiatives aim to enhance local income, thereby supporting the protection and sustainable development of mangroves.
There is an urgent need for clear and transparent regulations to address indiscriminate exploitation, deforestation, and excessive feeding in aquaculture Currently, many mangrove forests are being replaced by aquaculture farms, which supports economic growth but has led to a significant decline in forest cover due to overuse The government should implement stricter policies on forest land allocation, balancing economic development with environmental preservation This includes limiting mining licenses and regulating aquaculture practices to ensure sustainable seafood production.
A study conducted in Giao Thuy, Nam Dinh, revealed that local residents rely heavily on mangrove fisheries, consuming them 20-30 times per month The average annual income of the community ranges from 35 to 40 million VND, highlighting the economic importance of mangroves for their livelihood Given this dependence, it is essential for the government to implement policies that promote the protection and sustainable management of mangrove ecosystems to ensure the community's well-being and environmental preservation.
GENERAL CONCLUSION, LIMITATIONS AND FURTHER
General conclusion
Mangroves cover extensive areas and are vital for supporting local livelihoods and contributing to national development However, Vietnam's mangrove management faces numerous challenges, including technical, social, economic, and institutional issues Despite these obstacles, ongoing efforts have yielded some positive results, highlighting the need for integrated solutions to ensure sustainable mangrove conservation and utilization.
Using satellite imagery, Landsat data, and GIS remote sensing technology, a comprehensive forest status map for 2016 was developed, along with detailed maps of forest ecosystems These tools facilitated the creation of a vegetation index (NDVI) map to monitor ecosystem health and assess biodiversity changes in Xuan Thuy National Park The study forecasts how external environmental factors and human activities may impact the park's biodiversity, enabling targeted conservation efforts Based on these insights, a series of measures have been proposed to enhance the protection, management, and sustainable development of the coastal mangrove ecosystems.
- Determine the values of AVB and carbon stock of mangroves from that propose a number of measures contributing to the protection, management and sustainable development of mangrove ecosystems
This study of coastal mangrove management in Xuan Thuy National Park, Nam Dinh province, highlights that combining effective policies with social livelihood development can significantly improve conservation outcomes Implementing solutions that enhance the livelihoods of local communities in the buffer zone is essential for sustainable mangrove management Sharing the benefits derived from wetland resources encourages community participation and supports the long-term preservation of these vital ecosystems.
Effective wetland conservation and sustainable use are crucial for preserving biodiversity, with priority actions including implementing a detailed management plan for Xuan Thuy National Park Establishing a comprehensive biodiversity monitoring program within the park will create a valuable database to facilitate timely identification of biodiversity issues Strengthening overall management practices of Xuan Thuy National Park is essential to ensure the protection and sustainable utilization of its natural resources.
Limitations and further study 44 REFERENCE
Although it has achieved some significant results, study still remains shortcomings The scope of study is quite large, some coastal areas with mangroves could be missing
To improve accuracy in mangrove change mapping, future research should increase sampling points and utilize higher spatial resolution images Incorporating factors such as bare soil and other plant types will enhance classification precision Conducting further studies will address current limitations and lead to more reliable results.
Understanding the social drivers of mangrove change is essential for effective mangrove management Examining how financial policies and land use planning influence these ecosystems can inform targeted strategies to mitigate degradation Integrating insights on social factors into mangrove policy can enhance conservation efforts and promote sustainable land use practices.
1 Kuimi T Vashum and S Jayakumar (2012) :“Methods to Estimate Above-Ground
Biomass and Carbon Stock in Natural Forests”
2 Gibbs (2007) “Healthy forests sequester and store more carbon compared to any other terrestrial ecosystem and are considered to be an important natural brake on climate change”
3 GIS.com.vn: “Các chỉ số thực vật trong Viễn Thám”
4 Yong Manko Wetland (2009): “Biomass and aboveground net primary production in a subtropical mangrove stand of Kandelia obovata”
5 el al Phutchard Vicharnakorn (2014): “Carbon Stock Assessment Using Remote
Sensing and Forest Inventory Data in Savannakhet, Lao PDR”
6 Ban quản lý khu bảo tồn Thần Sa (2007): “Xây dựng bản đồ hiện trạng cacbon rừng tại khu bảo tồn thần sa, khu vực xã nghinh tường, huyện võ nhai, tỉnh thái nguyên”
7 Rafiqul Hoque (2011).“Above and Belowground Carbon Acquisition of Mangrove
Kandelia obovata Trees in Manko Wetland, Okinawa, Japan”
8 Sandro Federici (2011)“General methods for estimating stock changes in carbon pools”
9 Wikimedia:“Information about Normalized Difference Vegetation Index”
10 John A Dutton (2014):“Indices and Band Ratios”
11 Nguyen Thi Bich Huong, Hanoi, 2012"Application of Remote Sensing and GIS thematic mapping service integrated coastal management in Thanh Hoa province"
12 Jiraporn Kongwongjan (2012) “Comparison of vegetation indices for mangrove mapping using THEOS data”
13 Khairul Azwan Mohamad (2011) “Assessment of mangrove vegetation based on remote sensing and ground-truth measurements at Tumpat, Kelantan Delta, East Coast of Peninsular Malaysia”
Photo 1: Core area of national parks
Photo 2 : Plot area in core zone of national park
Photo 3: Aquaculture areas in the core zone