Mapping the extent and dynamic change of mangrove forests in Southeast Asia

Scale: Regional

Study area: Southeast Asia

Mangrove forests are swampy woody plant communities that from natural disasters such as hurricanes and tsunamis.

Mangrove forests are swampy woody plant communities that grow on the intertidal zone of tropical and subtropical coasts.They have special sea-land characteristics and enormousecological, economic, and social benefits. Mangrove forestsplay an important role in highlighting global climate andenvironmental changes. Additionally, they are important formaintaining biodiversity, protecting coastal environments,purifying coastal waters, and protecting farmland and villages from natural disasters such as hurricanes and tsunamis.  The distribution of mangroves along the Maritime Silk Road  accounts for more than half of the world’s total mangrove forest  area. They are mostly located in tropical-subtropical regions  with Southeast Asia having a large mangrove forest area.  Currently, mangrove forests in the coastal areas of Southeast  Asia are under threat from ecological disturbances and are experiencing continuous degradation.

This case study employed long-term time series remote their spectral characteristics, textural features, and spatial

sensing data obtained from Landsat satellites to monitor configuration with references from Google Earth images for the

dynamic changes in mangrove forests in Southeast Asia from same period. These areas were then vectorized and mapped.

The 1990 to 2015. The satellite images were first pre-processed results of this study were compared with the existing mangrove

using radiometric calibration, and atmospheric correction and datasets provided by FAO and World Mangrove Forests (WMF).

registration. The mangrove areas were then identified using.

◎ A total of 1,836 Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) images from 1990 to 2015

were used for long-term change monitoring of mangrove forests.

◎ FAO and WMF mangrove datasets were used to verify the accuracy of results. 

The top three countries with the largest area of mangroves in the Philippines, Thailand, Myanmar, Indonesia, Malaysia, and

Southeast Asia were Indonesia (68%), Malaysia (10%), and Cambodia were observed to continue to decrease, while the

Myanmar (9%) (Figure 3-7). During the period from 1990 to areas in Singapore remained unchanged. China’s mangrove area

2015, the area of mangrove forests in Southeast Asia revealed a was observed to slightly increase in recent years. (Figure 3-7).

decreasing trend (Figure 3-6). The mangrove areas in Vietnam,

Big Earth Data in Support of the Sustainable Development Goals

Figure 3-6. The change in mangrove area in Southeast Asia from 1990 to 2015.

The mangrove forest area in Southeast Asia was observed environmental pollution, further damaging mangrove wetland

to decrease from 1990 to 2015, especially in Vietnam, the habitats and decreasing their total surface area. Conversely,

Philippines, Thailand, Myanmar, Indonesia, Malaysia, and China’s mangrove area has been observed to be increasing in

Cambodia. This was caused by the rapid economic development recent years, reflecting the nation’s emphasis on ecological

in Southeast Asia, especially in Vietnam and Thailand. and environmental protection, and implementation of relevant

Aquaculture has been vigorously developed, resulting in the policies. Such policies include returning ponds to forests and

accelerated loss of mangrove wetlands and their transformation wetlands, which leads to an increase in the area of mangrove

into aquaculture ponds. Meanwhile, aquaculture has enabled wetlands.

Figure 3-7. Distribution and change in mangrove area in Southeast Asian countries from 1990 to 2015.

SDG 6 Clean Water and Sanitation

Highlights

During the period from 1990 to 2015, the area of mangrove forests in Southeast Asia has revealed a

decreasing trend. The mangrove areas in Vietnam, the Philippines, Thailand, Myanmar, Indonesia,

Malaysia, and Cambodia continue to decrease, while the area in Singapore remains unchanged.

China’s mangrove area has slightly increased in recent years.

Recently, the area of mangrove forests in China has shown an increasing trend, reflecting the

effectiveness of conservation measures such as returning ponds to forests and wetlands.

Mangrove wetlands are open, fragile, and complex ecosystems. (1) Mangrove forests will be monitored using multi-source

They grow in coastal areas where economic development remote sensing data. High-resolution, hyperspectral, and radar

occurs at a rapid pace. In addition to the influence of natural remote sensing data will be used for monitoring mangrove

factors, human activities directly and indirectly affect the forests. Moreover, deep-learning methods will be used to

growth, distribution, health, and diversity of mangrove forests. enhance the identification and extraction of mangrove forests

The dynamic change in mangrove area reflects human activity from remote sensing imagery.

Mangrove forest