The Mekong region is renowned for the dramatic variation between the dry and rainy seasons. However, in line with climate change projections, we are already seeing longer and drier dry seasons and shorter, more intense rainy seasons.
At the same time, the timing of the seasons and the patterns of rainfall are becoming less predictable.
Dry seasons are a natural phenomena but what constitutes a drought goes beyond the duration of the season and levels of rainfall.
Droughts in the Mekong region must also be considered as a function of water and land management structures and processes and the quality of water that is available and can be accessed.
Significantly, the impacts of droughts are not even, disproportionately impacting the poor and marginalised, creating new fault lines of vulnerability.
Building water storage infrastructure such as dams has been a linchpin of water management, designed to capture excess rainfall in the rainy season for use in the dry season.
Since the 1960s, governments across the region have invested in large-scale reservoirs and irrigation systems, to provide water for domestic, industrial and agricultural use.
Water storage duringthe rainy season has been anchored in the concept of the rule curve that determines how to maximise water levels in line with rainfall patterns to ensure reservoirs are full by the end of the rainy season.
Changing rainfall patterns
Research in Thailand’s northeast illustrates the emerging challenges of continuing these management practices in the face of climate variability.
For several years, rainfall patterns in the wet season have varied making it difficult to determine at what point maximum storage should be reached.
For example, the rains have often come later than expected, and concerns there might not be sufficient water stored by the end of the rainy season have encouraged reservoir managers to achieve full storage as soon as possible.
However, storms later in the season have resulted in emergency releases to prevent overflowing. But when the storms do not materialise, the reservoirs remain well below peak capacity, meaning insufficient water for dry season needs.
The ensuing shortages are not evenly distributed across different water users. To ensure the needs of domestic consumers in growing urban areas, irrigation is restricted with rice farmers unable to plant a second crop, leading to significant economic hardship.
Such a drought can thus be seen as a function of management decisions as well as changes in rainfall.
The situation is further complicated by the infrastructure that has been put in place. The large reservoirs that were such a feature of state-led development appear to be receiving less of the rainfall that does occur.
Rain in different areas
Rainfall is falling in different areas so the reservoirs built in the 1960s and 1970s are in locations that no longer allow for capturing and storing rainfall and run-off.
There is a degree of path dependency that restricts the ability to accommodate these changes — such large-scale infrastructure cannot be relocated or easily decommissioned — and indeed, the changes and high degree of rainfall variability raise doubts about the viability of such large-scale infrastructure solutions for the future.
Drought tends to be seen in terms of shortages in water availability and access. While these are clearly important, less attention is directed at the quality of water that might be available.
Yet research demonstrates that water quality is a critical issue across all the major river basins in Thailand due to the combined effects of agricultural run-off and pollution from industry and domestic uses.
The lack of water treatment plants, in cities and rural areas, means much of the water is contaminated.
But there are also fundamental governance challenges in addressing water quality.
The systems in place for monitoring water quality are inadequate, with only a limited range of variables being regularly monitored through a limited number of monitoring stations.
The monitoring systems also do not allow for effective enforcement of environmental standards so polluters cannot be held to account.
Much of the responsibility for enforcement falls on local governments which lack the human and financial resources to either monitor or act against pollution.
Water quality overlooked
With much of the focus of attention on water availability, distribution and access the complex challenges associated with water quality are easily overlooked.
For the river basin organisations that have a remit for managing water resources across different users, only a limited part of their budget and activities are focused on either monitoring water quality or enforcing standards.
The impacts of droughts are not evenly distributed across places and people. In a severe drought year, some rivers serve as sewage drainage.
Such highly polluted water puts additional strains on rural water treatment facilities, creating health risks for water users with cascading financial and social consequences.
Dealing with these challenges requires more sophisticated treatment technology and appropriate institutional mechanisms for its management.
There are also significant differences in people’s ability to deal with water shortages and the longer-term environmental consequences of some actions. Farmers within irrigation systems lose the ability to plant irrigated crops with significant economic impacts.
For those outside these irrigation systems, prolonged dry periods compel people to pay for water for both farming and household consumption. The lack of access to water often compels people to drill for groundwater, but the quality of such water is questionable.
Yet droughts are not only a rural problem.
Problems for cities
Failures to meet urban people’s water consumption needs would have a relatively greater impact on poorer people who already pay a substantially greater proportion of their income to meet their day-to-day water needs.
As water shortages become more frequent and severe, urban areas must also consider their ability to provide water to their residents. The ability of urban areas to survive prolonged water shortages would appear to be extremely limited.
As the effects of climate change intensify across the region, managing drought will require a more holistic approach that addresses the institutional, technology and infrastructure dimensions of water storage, distribution and access, and of ensuring that the water that is available, is of suitable quality.
Addressing the multi-faceted challenges associated with droughts requires more effective land management, to protect and rehabilitate natural drainage and storage.
The unequal impacts of droughts and the different capabilities of people to adapt require policy strategies that target their specific needs and circumstances. As we look to a future of intensified climate variability, our ability to plan in the face of uncertainty and risk must also be strengthened.
Dr Richard Friend is with the Department of Environment and Geography, University of York, United Kingdom.
Dr Jutamas Kaewsuk is with the Environmental Engineering and Disaster Management Programme, Kanchanaburi Campus, Mahidol University, Thailand
Dr Pakamas Thinphanga is with the Research Group on Wellbeing and Sustainable Development, Khon Kaen University, Thailand.
Originally published under Creative Commons by 360info™.
