by Delgollage Senevirathne, Assistant General Manager (Sociologist) at the National Water Supply & Drainage Board (NWSDB), Sri Lanka.
(8) The social consequences of failure to control excessive ground water extraction
There are many instances where excessive groundwater extraction affects the availability of groundwater for other users leading to social consequences. Over extraction of ground water from a plot of land has a negative impact on the use of groundwater from the adjacent land users in case of simultaneous extractions are affected. If one party continuously extracts groundwater it will impact the aquifer and will become unsustainable in recharge levels.
In Sri Lanka, there is no legal provision to control use/ extraction of groundwater in terms of quantity and quality parameters. Hence there is a need to introduce controlling legislation to manage the groundwater resources which is impacting on social consequences.
(9) The impact on community of climate change and natural variability (of floods and droughts) and required responses
Climate-related risks come not only from direct exposure to natural hazards such as floods or droughts, but also from the vulnerability of social and economic systems to the effects of these hazards. Responses to these risks should combine two approaches: short-term measures to react to hazards when they occur, and structural reforms that enhance the capacities of communities to adapt.
Climate change adaptation is an adjustment in natural or human systems, which occurs in response to actual or expected climatic changes or their effects. In human systems, adaptation can reduce harm or exploit opportunities. Disaster Risk Reduction (DRR) is the development and application of policies and practices that minimize risks to vulnerabilities and disasters.
DRR is an essential part of adaptation – It is the first line of defense against climate change impacts, such as increased flooding or regular droughts. DRR is now lending its expertise and humanitarian experience to climate change adaptation programmes. For example, DRR’s knowledge and expertise about building resilience to existing climate variability is a useful starting point for developing adaptation policies. In turn, the DRR community is paying more attention to longer term changes in the climate and the shifting hazard burden that this may cause.
Urbanization worsens flooding. It restricts where floodwaters can go, as large parts of the ground are covered by roofs, roads and pavements, and it obstructs natural channels. Building drains ensures that water moves to rivers faster than it does under natural conditions. As more people crowd into cities, even moderate storms produce dramatic flows.
There is frequent localized flooding because the ground is compacted and drains are blocked by waste. Small streams rise quickly after heavy rain: culverts carrying water under roads are no longer adequate and have not been maintained. Rivers flowing through urban areas are affected by land use changes: dams trap sediment, causing rivers to erode their banks downstream while building on floodplains has reduced the areas into which floods can naturally overflow. In coastal cities wet season flooding can now last for months as tidal surges and rainfall combine to raise the levels of water in swamps.
Urban flooding has disproportional impacts on poor people. It increases waterborne diseases, damages food stocks, causes further deterioration of sanitation and reduces access to schools and health-care facilities. It is vital to invest in improved drainage, regulate developments upstream and give urban residents greater security of tenure so that they can invest in making their homes more flood resistant.
The changes in climate will lead to more extreme weather patterns, meaning that some places will receive more rainfall, and in other areas, less rainfall, or more intense rainfall but of a shorter duration which will result in droughts. Droughts for a long period can have other effects such as placing forests at high risk from fires. Droughts will also harden the soil, thus making it less able to absorb rain when it eventually comes.
Climate change will affect the health of communities subjected to impacts of climate change. The changes in the climate, and the effects of climate change such as the increases in temperature, flooding, and contaminated water, will increase the level of waterborne and vector-borne diseases, such as cholera, typhoid, malaria and dengue.