Groundwater recharge occurs disproportionately from heavy rainfalls

Photo credit: Nature World News

Tropical groundwater resources may be more resilient to climate change than previously thought. Pictured here is an artesian well in central semi-arid Tanzania. (Photo : Jasechko, S & Taylor, R.G)

Tropical Groundwater Resources Benefit From Fewer, But More Intense Rainfall

By Samantha Mathewson

Tropical groundwater resources may be able to stand up to the challenges imposed by climate change, researchers from the University College London (UCL) and the University of Calgary report in a new study. Generally speaking, global warming leads to fewer but more intense rainfalls. However, this precipitation pattern seems to adequately recharge vital sources of freshwater.

Groundwater is an invaluable source of freshwater across the tropics, providing safe drinking water and a source of agricultural irrigation. It follows then, the replenishment of these sources is vital for sustaining the livelihoods and ecosystems that depend on the availability of freshwater.

For their study, researchers assessed the chemical signatures in precipitation and groundwater at 15 sites spread out across the tropics. This allowed them to compare the stable isotopes of hydrogen and oxygen found in these water molecules, from which they can interpret how heavy rainfalls impact groundwater recharge in surrounding areas. In terms of their study, heavy rainfall was defined as those exceeding the 50th percentile of local rainfall intensity. Therefore, their results suggest that groundwater recharge occurs disproportionately from heavy rainfalls, but the processes that carry intensive rainfall to groundwater systems and enhance the resilience of tropical groundwater storage as global temperatures rise remains unknown.

Read the full story: Nature World News

Irreversible groundwater depletion

Photo credit: FAO

A Senegalese farmer transfers well water into a holding container.

Global agencies call for urgent action to avoid irreversible groundwater depletion

New vision and global framework for action on groundwater governance released

EXCERPT

FAO, UNESCO, the World Bank, GEF and the International Association of Hydrogeologists have today called for action by the global community to manage the increasingly urgent depletion and degradation of limited groundwater resources.

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Groundwater is indispensable to poverty reduction and shared prosperity. It accounts for more than a third of municipal and industrial supply and services some 40 percent of the planet’s irrigated agriculture. Groundwater has the potential to provide an improved source of drinking water for millions of urban and rural poor people. Many poor farmers and their families depend on it to irrigate their crops and sustain their livelihoods.

The 2030 Vision and Framework for Action provides an enabling framework and guiding principles for coordinated action among governments and organizations.

“Sustainable management of groundwater is key to maintaining ecosystems and adapting to climate change,” said Naoko Ishii, CEO and Chairperson of the Global Environment Facility (GEF). “We can no longer take this invisible but vital source for granted; urgent action is needed to ensure its long term availability. We look forward to joining hands with partner agencies and countries to ensure water for drinking, food, cities, energy and industrial uses is available for generations to come.”

In response to the urgency of the situation and a product of four years of consultations with stakeholders from more than 100 countries, these principles focus on legal and institutional frameworks, policies, and plans as well as information and incentive structures for sound and effective groundwater management.

This process signals strengthened collaboration across the international community to understand the barriers to better groundwater governance and address key regional challenges.

Read the full article: FAO

A major water crisis in South Asia

Photo credit: Google

India’s thirst for groundwater is threatening a major water crisis, and adding to global sea level rise, says a report.

(http://www.impactlab.net/2009/10/04/indias-thirst-for-groundwater-raising-global-sea-levels/)

South Asia running out of groundwater

[NEW DELHI] India, Nepal, Bangladesh and Pakistan along with China account for nearly half of the world’s total groundwater use and these regions are expected to  experience serious deficits, says the UN World Water Development Report (WWDR 2015), Water for a Sustainable World 2015 released ahead of  World Water Day on 22 March.

WWDR 2015 explains the complex relationship between access to water and economic development using India as an example.  Between 1960 and 2000 India’s mechanised tube wells increased from one million to 19 million.

India has 26 million groundwater structures; Bangladesh and Pakistan each have around 5 million.

Read the full article: SciDevNet