Monthly Archives: May 2013

Drought management in Kompong Thom, Cambodia: The impact of irrigation on food security

By Paul Wyrwoll

ICEM’s Paul Wyrwoll reports from farming communities in Cambodia, where the recent rehabilitation of the Stung Chinit irrigation scheme has enabled many households to harvest a dry season rice crop and improve their food security.
However, the overall distribution of benefits and costs turns out to be much more complex than he expected.

Rice is the most important crop in Kompong Thom province, as it is across the Lower Mekong Basin. Situated north-east of the Tonle Sap, this province encompasses a large and flat floodplain. Farmers typically rely on a single rice crop, grown during the wet season in a lush landscape of endless rice fields. But in the dry season, the land is transformed into an arid dustbowl. Household food security is contingent on a store of the previous season’s harvest. Alternative income opportunities do exist, but they are limited, meaning that this livelihood cycle is highly precarious for poor households. Food security for families here can be completely undermined by a single adverse event, such as a destructive pest outbreak or the devastating 2011 flood.

The answer to this dramatic shift between rainfall abundance and deficit is well understood: irrigation of fields during the dry season with water from a reservoir, groundwater aquifer, or an alternative water source. But these solutions can be expensive, difficult to maintain, and/or entail external social and environmental costs.

Irrigation: ebbs and flows
Cambodia has a long history of irrigation construction. The long-lived prosperity of the Khmer Empire (AD 802- AD 1431) was founded on an extensive system of canals and reservoirs supplying an abundant agriculture sector. During the late 1970s the Khmer Rouge conscripted almost the entire population to build a vast irrigation infrastructure. The regime envisaged a […]

By |May 30th, 2013|Blog|0 Comments

River bank protection in the Mekong Delta

by Simon Tilleard

ICEM’s Simon Tilleard travels to the Mekong Delta with his father, visiting a unique project his father managed 13 years ago to prevent river erosion from destroying communities. This environmentally sensitive approach is proving effective and could provide a model for river bank protection today.

“It’s working!” my father exclaimed on a recent trip to the Mekong delta where 13 years ago he designed bank protection works for the My Thuan Bridge.

The bridge links the rice basket of the Mekong Delta to Ho Chi Minh, Vietnam’s largest city. At the time the bridge was Australia’s largest foreign aid investment ever.

The bank protection design was radical. The design aimed to stop erosion more than 500m upstream of the bridge. Rather than the standard concreting of the top segment of the bank where the erosion was obvious, the design instead incorporated a series of pile grovnes to slow the river flow velocity, encourage sedimentation and reduce the cause of the erosion from at the base of the bank and the bed of the channel. This was designed to treat the cause of the erosion – not the symptom.

Fifteen years ago my father sat drinking tea in the tropical heat with a man whose house was next in line for the river’s inevitable erosion. From a maximum rate of over 20m a year retreat during the 1960 and 70s the erosion had slowed to a still formidable six metres a year.

The man smiled and slyly joked “I have waited 20 years for a riverfront house, when the river destroys my house then I will just have to go to the back of the queue again”. But the old man is still grinning, drinking his tea and enjoying his river view.

Climate change is unlikely to affect the unique design […]

By |May 17th, 2013|Blog|0 Comments

Climate change endangers the rare Siamese Crocodile

HANOI, VIETNAM – 13 May 2013: ICEM researchers have identified that the effects of climate change in the vulnerable Mekong wetlands will add to the threats on the critically endangered Siamese Crocodile.

Temperature changes during their breeding and hatching season are projected to become a critical climate change concern for the species. Climate change in the Mekong region is expected to cause temperature variability – which will affect the sex ratio of hatching reptiles.

Crocodile hatchlings – usually emerging in June or July – may become a completely female or male brood, depending on temperatures during incubation. Temperature is the critical component which defines the embryo sex of crocodiles. If the incubation temperature is higher than about 32oC, the brood will be female. In addition, warmer temperatures are also known to increase appetite in crocodiles, which combined with decreasing habitat may place further stress on the Siamese Crocodiles in the lower Mekong Basin.

The vulnerability of the Siamese Crocodile (Crocodylus siamensis) was identified during a case study was conducted in 2011 – 2012 in the Xe Champhone Wetlands by ICEM’s local partners in IUCN Lao. The study was part of a basin wide assessment of climate change threats, vulnerability and adaptation options for the wetlands in the Lower Mekong Basin and adaptation commissioned by the Mekong River Commission and carried out by ICEM and its partners, the International Union for the Conservation of Nature, WorldFish Centre & Southeast Asia Regional START Centre. The Xe Champhone Wetlands covers approximately 450 km2 of central Lao PDR – part of the Xe Bang Hieng River basin. The Siamese Crocodile is the species of highest conservation concern in the region, which holds the largest population of this species in Lao PDR with […]

By |May 13th, 2013|Climate change news, News|0 Comments