Wednesday, March 23, 2022

WATER IS LIFE
Surface water availability becoming limited: Unesco
Published March 23, 2022 

ISLAMABAD: The United Nations World Water Development Report has projected that while water use is projected to grow by roughly one per cent per year over the next 30 years, overall dependence on groundwater is expected to rise as surface water availability becomes increasingly limited due to climate change.

Released by Unesco, on the occasion of World Water Day, the report points out the low use of water is not due to a lack of renewable groundwater, but rather by a lack of investments in infrastructure, institutions, trained professionals and knowledge of the resource.

The report says groundwater accounts for 99pc of all liquid freshwater on Earth. However, this natural resource is often poorly understood and consequently undervalued, mismanaged and even abused.

It says in order to meet global water and agricultural demands by 2050, including an estimated 50pc increase in food, feed and biofuel demand relative to 2012 levels, it is of critical importance to increase agricultural productivity through the sustainable intensification of groundwater abstraction, and decreasing the water and environmental footprints of agricultural production.

Regions heavily reliant on groundwater for irrigation, and in South Asia, 57pc of the areas equipped for irrigation use groundwater.

Asia-Pacific is the largest region in the world in terms of both area (28 million kilometres) and population (4.7 billion). The region is the largest groundwater abstractor in the world, the report says.

The critical driver of groundwater development in the region is rising demand for water due to growing populations, rapid economic development and improving living standards.

Utilisation of groundwater resources has provided numerous benefits for irrigation, industrial activity, domestic use, drought resilience and livelihood enhancement, according to the report.

These socio-economic benefits have been particularly crucial for the agricultural sector — a sector that is key to economic development in many developing countries in the region, and that accounts for an estimated 82pc of total water withdrawals.

Additionally, groundwater quality is under threat due to a variety of anthropogenic and geo-genic drivers that further contribute to water stress in the region.

It is estimated that agricultural pollution has overtaken contamination from settlements and industries as the major factor in the degradation of inland and coastal waters.

Nitrate, from chemical and organic fertilisers, is the most prevalent anthropogenic contaminant in groundwater globally. Insecticides, herbicides and fungicides, when improperly applied or disposed of, can pollute groundwater with carcinogens and other toxic substances.

Evidence suggests that laws and regulations to prevent or limit groundwater pollution from agriculture, and especially their enforcement, are generally weak. Policies addressing water pollution in agriculture should be part of overarching agriculture and water policy framework at the national, river basin and aquifer scale.

In terms of climate change adaptation, the capacity of aquifer systems to store seasonal or episodic surface water surpluses can be exploited to improve year-round freshwater availability, as aquifers incur substantially lower evaporative losses than surface reservoirs.

Published in Dawn, March 23rd, 2022

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