Impacts of Climate Change on Different Sectors in Thua Thien Hue Province, Vietnam

Submitted by Ben Smith | published 11th Feb 2012 | last updated 11th Feb 2012

Apart from assessing the impacts of climate change on water resources, the project has also looked into the impacts of climate change on other sectors in Thua Thien Hue Province and Phu Vang district. In addition, more detailed assessments have been carried out in order to better understand the potential impacts of climate change on two specific areas in the province: Phu Vang District and Chan May-Lang Co Special Economic Industrial Zones.

Climate change impacts on agriculture

  • Most of the current rice paddies could be flooded during wet season and salinity intrusion could take place during the dry season, especially in areas of low elevation and land near the river/lagoon, leading to a decrease in food yield and a threat to food security.
  • Some riparian protective forests could become flooded and saline intrusion could lead to the disappearance of some rare and valuable genetic resources.
  • Rice plants, short-term and long-term planted trees and long-term, newly developed industrial trees such as rubber, may suffer more damage when the frequency of natural disasters increases. The crop pattern, seasons and even productivity could also expect to be affected by climate change.
  • An increase in animal, livestock and crop diseases and infections through the spread and introduction of new pests and pathogens and crop diseases may take place. More pesticides and chemicals might be used to combat this, increasing the danger and risk of pollution.
  • An increase of erosion and soil degradation, leading to lower crop productivity may occur. 

 

Impacts on natural fisheries and aquaculture

  • Disruption of the fisheries due to changes in the seasons for aquatic farming and shortening the lifetime of certain farming tools.
  • Changes in the currents at some river mouths, affecting the itinerary of fishing boats and other ships and fish migration/spawning routes.
  • Changes in the natural environment, leading to changes of biodiversity, the behavior of aquatic animals and changes of genetic diversity of aquatic species.
  • When temperatures exceed 40°C, the growth of animals in aquaculture ponds is slowed, and they may even die, affecting farm productivity. In addition, bacteria and fungi multiply more profusely, resulting in epidemics and eutrophification of farming ponds in the lagoon.
  • Infrastructure (e.g. electricity, roads, levees and canals inside the fields) serving the aquaculture and fishery sectors will degrade more quickly

    Fishing is affected by disasters and climate change

     
    Impacts on biodiversity

    Climate change and sea level rise may increase the salinity of the brackish lagoon water, adversely affecting the ecosystems of the Tam Giang-Cau Hai wetland and current conservation efforts aimed at protecting areas such as the unique bird habitat of O Lau and the mangrove forest in Ru Cha. Many endangered species would be placed at high risk of extinction. The projected extension of the lagoon and frequently flooded area would alter the shoreline and estuary and destroy the large mangrove forest and habitat of many species, including those that are endangered.

    The solutions proposed and implemented (weir, dam, etc.) to address salinization due to sea level rise could affect migratory animals and micro organisms, including the migration for reproduction of ‘native” species such as the flower eel, ebony eel and spotted sardine. This could also restrict the transition and interaction between the freshwater, brackish-water and marine ecosystems, potentially limiting the adaptation capacity of wildlife, domestic animals and crops.

    A rise in sea temperature could also affect coastal and marine ecosystems such as coral reefs.

    Climate change also impacts the coastal zone, tourism, and the Chan May-Lang Co Special Economic Industrial Zones.

    Climate change and disasters in Phu Vang district and Thuan An commune

    With agriculture, fisheries and aquaculture being the mainstay of the local economy, Phu Vang district faces serious challenges from disaster events and the potential effects of climate change. Results from the stakeholder consultation process as well as the results from the participatory rural appraisal and other surveys indicate that the types of disasters and climate change impacts witnessed in the district are similar to those of other coastal and lagoon areas of Thua Thien Hue Province. However, a number of findings specific to Phu Vang district were exposed:

     

    The most threatening disasters as perceived by local people are floods and storm events, which could trigger a sudden and strong change of the sand bars and lagoon basement, the so-called ‘lagoon gate opening' effect. Such an event did occur in Hoa Duan commune in 1999, where 64 households were washed out to sea and hundreds of people died or went missing (Phu Vang DPC, 2006). Coastal hydrodynamic change can lead to the destruction of important infrastructure like dykes as well as houses. Very deep erosion (up to hundreds of meters) may be seen in one place and heavy sedimentation in another. Engineered structures, such as the H-form concrete bars built by the French during colonial times at 30m from the shoreline, could help prevent some erosion. Additional studies should be done to better understand this hydrodynamic process and identify proper solutions. Indigenous knowledge has proved very useful to local communities in predicting and coping with disasters but in recent years it has become less effective as weather and climatic patterns shift.

    Calculations of projected flooding in Phu Vang district are as follows:

    The flooded area is likely to become more extensive due to climate change, with the effects of a November 1999 catastrophic event (when 36.4% of the area flooded) potentially reaching up to 40.4% if a similar event were to occur in the future.

    Drought and salinity intrusion are also expected to increase in Phu Vang based on the climate change scenarios. By the end of the century, salinity in the Huong River mouth could increase by 20 to 40%, and saline intrusion may penetrate 2 to 3km further upstream than at present, if proper counter measures are not undertaken.

    Thuan An town in Phu Vang district is located on the depressed estuary plain of the Huong River Basin. Part of the lagoon area houses of Thuan An's villages, while another seven are near Tam Giang-Cau Hai lagoon and five are close to the sea (Figure 11).

    A number of interviews, group discussions and workshops were carried out in Thuan An to help identify the real-life local context of disasters and climate change impacts, the socioeconomic and environmental situation (Thuan An PC, 2005), autonomous adaptive capacity and relevant indigenous knowledge and local customs. This has resulted in a number of area specific outputs, including a detailed vulnerability map (see figure 12) and some village specific adaptation measures. Apart from collecting information about vulnerable areas, the group discussions have also greatly increased the awareness of local people about the potential threats of climate change.