Room for the River

How will the river be given more room?
(Source: www.roomfortheriver.nl)

On 29th of September, we attended the workshop on "Production Ability for Climate Change Adaptation in Coastal Areas of Mekong Delta", at Ngoc Thu hotel, Soc Trang. It was an introductory workshop to the collaborative project between Can Tho university and Wageningen university (Netherlands) on developing agriculture, aquaculture and environment - based climate change adaptation strategies for the Mekong Delta of Vietnam. 

Because of its high vulnerability to climate change and sea level rise as a coastal province, Soc Trang has been chosen for first pilot studies. As the workshop aimed to initiate preliminary discussions to collect information, opinions, ideas from local people, the afternoon session's time was used for working groups' discussions. Participants were mostly representatives of Soc Trang provincial/district institutions and authorities. Besides, there were also participants from An Giang (represented for upstream provinces), and the research groups in Can Tho university and Wageningen university (2 professors.and one master student). 

The project's key approach to climate change adaptation is the idea of "Room for the River", rebuilding extra room for water instead of putting much investment in hard infrastructure measures. Originated from a governmental programme in Netherlands (2006-2015), it is a more natural friendly flood protection strategy in contrast to past response to floods, where rivers were confined by increasing higher dykes (as more and more people live behind the dyke, the land would sink, creating more and more risk).


"Room for the River", on the other hand, restores the river's natural flood plain (lowering and broadening it), liberating river's flow, creating river diversion and temporary water storage areas. Marshy riverine landscapes would be restored to serve again as natural water storage sponges, providing biodiversity, aesthetic and recreational values. This approach is also considered as "Living with Water", living harmoniously with nature, embracing flood, cherishing water as an asset but not something to fear and keep out of sight. Moreover, retention of water in the rural areas can help reduce  urban flood. [Even in urban area, excess water can be incorporated into infrastructure, creating high quality public space (ex., water plaza design idea from Netherlands)].River can be given more room through measures such as placing and moving dykes, lowering of river foreland, depoldering, creating/increasing the depth of flood channels, removing hydraulic obstacles, flood bypass...


Applying that approach for Mekong Delta, "Room for the Mekong Floods" implies climate change adaptation services such as seasonal flood retention and dry season reserves; recession agriculture, fresh fish culture in flooding season.


In addition to flooding, climate change also exacerbates salinization and freshwater scarcity. Dropping of groundwater level is currently a serious issue in coastal district areas of Soc Trang. Therefore, creative adaptation to brackish water, more open attitude toward sea water suggests some modification in farming systems into more water-saving and salt-tolerant crops.

There was one helpful comment of Mr. Stefan from DRAGON institute that i would like to note here, which was about the no-use zone. Sometime, non-use zone is not just no-use zone because it can be preserved as buffer zone that increases resilience of the area to climate change.

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Workshop notes

 Production Ability for Climate Change Adaptation in Coastal Areas of Mekong Delta

Soc Trang, 29.09.2011

Room for the Mekong Floods:  climate change adaptation services - seasonal flood retention and dry season reserves; recession agriculture, fresh fish culture in flooding season.


Climate change: assessment shows huge impact on hydrology (water resources: saline, brackish and fresh water)
- sea level rise and typhoon surges
- fresh water floods (peak river flows and runoff)
- high intensity rainfall and dry spells.

How to cope with changing water condition?
- increase room for brackish water retention
- increase high rain water retention (reduce floods)
- increase fresh water storage (flood protection and dry spell reserves)

Climate Change Adaptation challenges:
- how to provide future water storage/regulation capacities?
- where to provide for those water storage capacities?
- climate change has potentially drastic impacts on agriculture/aquaculture/nature (AAN)
- can we transform threats into opportunities?
- change goal of natural resources planning and management. --> In past, optimize land and  water  for farming systems. In future CCA, optimize systems to water regulation requirements.

Project strategies:

- look at, and work with present water user in climate change  adaptation relevant aquatic environments (fresh water/brackish water/saline water). What changes/innovations are needed in today?

- flood protective: "room for river” instead of investing in infrastructure such as dykes. Benefits: sedimentation for next year (provide alternative income), reduce flood, cheaper; retention of water in the rural areas, reduced  urban flood. ---> risk distribution.


- diversify income: introduce crop resistant to salinity (seaweeds...).

Process phases and outputs:

- identify and quantify climate change adaptation needs for saline - brackish - fresh water storage/ regulation

- define scope and water interrelation of AAN systems (aquaculture, crops, mangroves) providing these needs

- design innovation AAN systems with improved climate change adaptation (CCA) of their water interrelations

- integrate the AAN innovation into a CCA plan (provincial level)

- quantify the capacity of these CCA water retention/regulation services

- define the potential for up scaling these CCA strategies in Mekong Delta plan.


Groundwater issues: limitation of groundwater resources → the situation only become worse if we continue like this. There is need for sustainable groundwater management.

Adapt & optimize farming systems to climate change

Fresh water sone - rice, climate change adaptation service: rainwater retention

Coastal brackish environment - climate change adaptation service: coastal defence (mangrove) and brackish water retention (shrimp (mixed), sea grass - shrimp)

 

Brackish - fresh transition zone: find way to use them together

Room for the Mekong Floods:  climate change adaptation services: seasonal flood retention and dry season reserves; recession agriculture, fresh fish culture in flooding season.

Adaptability of land use to climate change in An Giang

In the acid water zone: Melaleuca land can be used as a reservoir  to keep and control flood water in the rainy season (allow water to exchange and  sediment feeding to the farms) and then irrigate paddy rice field in the dry season. This will restore 700 000 ha Melaleuca forest, supplying enough irrigation water to 1 million hectares paddy rice land and saving at least 10500 million cubic meters of surface water of the Mekong river.

In the deep flooding zone: netting aquaculture during flooding period (Jul-Dec) thus allowing water flow through the whole area and sediment loads to the farms.

Climate change scenarios: 


- increasing average max. temperature in March-April-May 


- rainfall in early Summer (15/5-15/6) will be reduced in the future → early rainy season drought may be more serious. Significant decrease of annual rainfallSoc Trang, 72 km coastal line, in which 18 km is exposed to erosion. Soc Trang is strongly influenced by sea level rise. With the available dykes/sluice gates (2005), the saline intrusion pattern will not be srtongly changed when the sea level rise of 30 and 50 cm.

Next to do: 

- research on changing of saline intrusion along the time under the influences of changing in upstream discharge and precipitation

- study the possible impacts of hydrological condition changes on the land use (and farming sytems) changes

- evaluate possible impacts of the upstream activities (in the VMD) on the saline intrusion pattern in Soc Trang.


Discussion in 3 groups:


1. What are the important changes in fresh water/ brackish water/ saline water resources in the local area?
2. Which farming systems need to adapt to the changes mentioned above?
3. What are the most important difficulties that the farming systems have to face, relating to:
- the natural adaptibility of these agricultural production system?
- the sustainable management capability of resources (fresh water, mangrove forest) at district/ provincial levels?
4. In Soc Trang, define specific areas that the project can conduct studies?

Group 1 matrix:

	Past	Present	Future
Fresh water (from Ke Sach district to upstream districts)	1-2 rice crops/year orchards (mixed) non-rice crops (few)	Thanks to the development of the irrigation systems and cultivation techniques: 2-3 rice crops/year orchards, non-rice crops - starting of salinization	- preventing salinization - less rain (climate change), hydropower in upstream areas → lack of fresh water.
Brackish water (Districts of My Xuyen, Thanh Tri, Long Phu, Cu Lao Dung)	natural shrimp/ rice	Due to economic benefits: shrimp farming/ rice half intensive shrimp farming - shrimp disease	shrimp/ rice non-rice crops (vegetables, onion) - Half intensive shrimp farming systems should be reduced for sustainability
Saline water (Districts of Vinh Chau, Tran De)	(seasonal) rice/ non-rice crops salt production	shrimp farming (both half intensive and intensive) onion production salt production - groundwater exploitation for crops and shrimp - shrimp diseases - salinization - influences of tide regimes - water pollution	- Need appropriate plants and animals species that can adapt/resist to the future salinity. - saving water techniques - sea dyke needs to be consolidated to protect soil/ land erosion - protective mangrove forests - wastewater treatment - cultivation techniques that can slow down salinity.