Readings: Earth's Ice, Neanderthal Women, Indian Monsoons

Some good stuff from the past few weeks.

1) How much of the Earth's Ice is Melting? Sid Perkins writes about the variety of methods of estimating ice loss from the high latitudes. These methods are showing where and how much melting is taking place, in turn, helping scientists make predictions of future sea level rise. The overall scenario is rather gloomy. 

2) The Lives of Neanderthal Women. "Archaeology is no exception to biases against women’s interests across science and the humanities". Archaeologist Rebecca Wragg Skykes expertly constructs a picture of what the lives of Neanderthal women might have been like.

3) Indian Monsoon Across Millennia. Stalagmites from a cave in Meghalaya, NE India are giving paleoclimatologists information about monsoon variability over a thousand years. Their geochemistry points to periodic deadly droughts that coincide with phases of major social and political turmoil in India. Paper authors Gayatri Kathayat and Ashish Sinha describe their research. 

 

Groundwater Must Be The Focus Of India National Water Policy

India's Water Management Crisis

A piercingly clear essay by Himanshu Thakkar on why India must realign its water resources priorities from big dams and river linking projects to protecting, managing, and regulating ground water.

Just take a look at the numbers:

"Most of the water that India uses today comes from over 30 million wells and tubewells. Irrigation is India’s biggest user of water and over two thirds of irrigated area gets water from groundwater. 85% of rural domestic supply, over 55% of Urban and Industrial water supply comes from groundwater. The graph of % of water in each sub sector coming from groundwater has been going up for at least four decades. In fact, some estimates show that over 90% of additional water India used in last four decades have come from groundwater. It sounds like an immitigable blessing. That’s not how blessings work, unfortunately.

Central Ground Water Board’s data shows that in about 70% of areas, groundwater is depleting and at many places it has exhausted or is on verge of exhaustion. The quality is deteriorating. Warnings have been available for decades now, but the government has done little to address the emerging crisis.

In fact, India’s water resources establishment, lead by the Big dam ideologues at Central Water Commission have ensured that the government do not even acknowledge that groundwater is India’s water lifeline"....

Scary.

Some States have taken initiatives to manage ground water. Maharashtra recently passed the Maharashtra Ground Water Act which provides a framework for management and regulation of ground water. How much diligent enforcement of the rules actually takes place remains to be seen.

Additional Reading:

The Maharashtra Groundwater (Development and Management) Act 2009 - Shashank Deshpande, Deputy Director GSDA.

A Decade Of The Maharashtra Ground Water Legislation: Analysis Of The Implementation Process - Sanjiv Phansalkar and Vivek Kher.

The Aquifer Underneath My House

... is very prolific.

The photo above taken in March 2012 is of an excavation for a building about half a kilometer away from my home in Pune, India. The developer struck water at around 20 feet below the surface. Water began gushing out of sheet cracks in the basalt rock. Within a couple of days the water level had risen to just a few feet below the surface and then stabilized.

The water level you see in the picture is not the water table but the potentiometric surface. The developer had punctured a confined aquifer. Water in this type of aquifer is under hydrostatic pressure. The puncture or hole is this case creates a pressure gradient and water flowed from the aquifer (high pressure) into the hole (low pressure). It rose until the water pressure at the bottom of the hole equaled the water pressure in the aquifer at which point water stopped flowing out of the aquifer and hence stopped rising in the well /excavation.

In the picture below the red arrows point to the sheet cracks from which groundwater is seeping out.

Every Pot Of Coffee You Make Is Dinosaur Pee

I wouldn't have come up with a post title that weird...

but I quote from Charles Fishman's interview with Terry Gross on Fresh Air. Mr Fishman is the author of The Big Thirst: The Secret Life and Turbulent Future of Water and he reminds us about the origin, nature and the journey of water on earth -

Mr. FISHMAN: And all the water on Earth was actually formed in space, in interstellar gas clouds. And it was delivered here when the Earth was formed, or shortly thereafter, in exactly the form it's in.

So all the water on Earth - the water in your Evian bottle, the water in your glass of water, the water you use to boil a pot of spaghetti - all that water is 4.3 or 4.4 billion years old. No water's being created on Earth. No water's being destroyed on Earth. And what that means is the whole debate about reusing wastewater is kind of silly, because all the water we've got right now has been used over and over again. Every drink of water you take, every pot of coffee you make is dinosaur pee, because it's all been through the kidneys of a Tyrannosaurus Rex or an Apatosaurus many, many times, because all the water we have is all the water we have ever had.

And to me, that's actually good news. Water is incredibly resilient. It's unlike fuel or other natural resources. It can be used over and over and over again, and it emerges - except for needing to be cleaned, ready to use again - exactly as water.

That's thinking of recycling well beyond the usual discussions of wash-basin to your lawn. He talks about that too and a lot more in a quite informative talk.

Did you know why the launch pad of the space shuttle is covered in a cascade of water during launch?

And you would naturally think that that has something to do with the heat and the flame. In fact, the water on the launch pad of a space shuttle launch is a sound-dampening mechanism for the space shuttle. The space shuttle is so loud that the sound would ricochet off the concrete and metal launch pad and tear the space shuttle apart, literally destroy it, before it cleared the pad without the water.

Listen / Transcript.

Indian Groundwater Extraction May Be Contributing To Sea Level Rise

I don't know what to make of this calculation which I picked up in a New Scientist story. A few weeks ago there was a study using NASA's Grace satellite measurements that showed an increase in groundwater extraction from North Indian aquifers.

A second study on these satellite measurements asserts that the groundwater loss amounts to about 54 cubic km per year over a time period of 2002 and 2008. A lot of this extracted groundwater ends up in the sea and could be contributing to raising sea-levels by 0.16 millimeters every year, about 5% of the total sea level rise. That is about the same as contributed by runoff from melting Alaskan glaciers the authors conclude.

I don't have access to the full paper so I don't know the details of the calculation but here is what the scientists have to take into account:

Part of the groundwater extracted will be taken up by plants and remain there over the life of the plant and make its way into the food chain.
Part of it will be lost through the plants through evapo-transpiration.
Part of the water will remain in soil adhering to clay and sand particles.
Part of it will make its way back to the aquifer.
Part of it will make its way through the soil to local streams and eventually to the sea.
Part of it will be lost by direct evaporation. That evaporated water (and the water lost by evapo-transpiration) will fall as rain and part of it will infiltrate as groundwater and part of it will be surficial runoff into streams and eventually into the sea.

Just giving you  something to think about what happens to extracted groundwater.

Imagining An Underground Venice In The American Southwest

From BldgBlog post Hexagonal Hydropolis I went to the source Matsys where Andrew Kudless has created a futuristic and imaginative vision of a subterranean urban landscape in a dessicated American southwest.

The concept and architecture is stunning. Vast underground water reservoirs are connected to the cityscape via canals which also are the means of transport.

Image; Sietch Nevada / renderings by Nenad Katic

This is a grand and impressive outlook and I keep thinking on another track when I come across the many futuristic adaptive scenarios that are being proposed as responses to changing climate and resulting changes to our living space. The problems are varied, deep underground water storage, deep underground CO2 storage, coastal erosion, understanding changing river dynamics in the north Indian plains as glaciers shrink, exploring for uranium to boost nuclear energy....geology and geologists will play an increasingly important role as we explore and implement solutions to meet this challenge.

North India Facing Groundwater Calamity

Nature magazine has a great video of North India heading towards a water calamity. Groundwater is dropping more than 1 foot per year on average and over the last 6 years about 109 cubic km of water has been pulled out of aquifers underlying northwestern plains of India.

Recent measurements of water loss were done by twin satellites called GRACE – NASA's Gravity Recovery and Climate Experiment. These satellite orbit the earth at a set distance from each other and instead of taking measurements of objects directly below, they look at each other and measure changes in orbit due to variations in the pull of gravity.

The result is summarized below. Red areas depict areas of groundwater loss and blue areas of groundwater gain.

Although striking, the measurements of the Punjab area should not come as a big surprise. Depletion of the groundwater table has been known to be taking place for many years but presenting the results in such a pictorial form and as volumes does make one sit up.

My attention however was drawn to the blue areas in the central parts of the country. They show a groundwater gain. This has been interpreted as due to above average rainfall for the last several years. No doubt that has played a role, but that hides a more general pattern.

I've written about this region before and the link between groundwater accessibility, use and farmer poverty.

Population densities of this dry interior region are less than the northern plains. Even so, groundwater is an underexploited resource per capita as compared with the northern plains of the country. Geology does play a big part in it. The terrain is all hard rock aquifers which are heterogeneous and compartmentalized and finding groundwater is not easy. Its also very expensive to dig a dug well or drill a bore well so many poor farmers end up relying on rains for their water needs. Vast tracts of this region are not supplied by surface irrigation canals and groundwater must be made more accessible if the widespread problem of reliable water supply to farmers is to be solved.

I want to put up this figure again to emphasize how important groundwater is to the Indian agricultural economy.

Source: The Socio-Ecology of Groundwater in India

More than a decade on the importance of groundwater in agriculture holds and is growing. But till now groundwater has been seen as a resource to be extracted without giving any thought to the long term viability of such an approach. We need to change that mindset and steer it towards one that recognizes that just finding groundwater is not going to be enough. The sensible scientific management of the resource is just as crucial.

Maybe we still don't get it. Sadanand who blogs at Chintan has a post that highlights how we think about water and the solutions to scarcity. Irrigation canals and dams serve only 15% of arable land in India but that's what the apparent solution is in the minds of government and media alike. Groundwater which serves the rest and which will become even more important in the context of climate change is still being neglected.

Water Harvesting: Legal At Last In Colorado

This piece about water harvesting and conservation in NYTimes caught my eye:

“I was so willing to go to jail for catching water on my roof and watering my garden,” said Tom Bartels, a video producer here in southwestern Colorado, who has been illegally watering his vegetables and fruit trees from tanks attached to his gutters. “But now I’m not a criminal.”

I remember reading Marc Reisner's epic book Cadillac Desert which described the complex water regulations of the U.S. southwest. Every drop is owned by some state or water district or the other before it falls to the ground. But water allocation was apparently done during an unusual wet period and without anticipating the massive growth of population in the deserts. Climate change which is making the southwest drier and population pressures have increasingly made these allocations look unfair. At some point if there is just no more water then no matter how you try divvy up the pie someone is going to come up empty.

In India too damming streams and diverting water that would inhibit natural flow as defined by the local government agency used to be frowned upon and the law has always been unclear about the ownership of water harvesting structures and water. Indeed the state reserved the right to send you notice if it felt that the structures being built were unsafe or that blocking too much water would lead to a shortfall in the government canal and dam system allocations. But water harvesting is done at every level ( see this article) from recharging a well in the backyard to community efforts that have rejuvenated landscapes. The local water authorities don't always like it but don't prosecute because they really can't provide an alternative. Village communities and NGO's get massive grants for water harvesting from funding agencies for an activity that the government is finally realizing is the need of the hour. Many state governments are modifying their Command Area and Irrigation Acts to give farmers and local communities more rights to own and manage local water resources.

It usually takes a long time to change laws and regulations. Sometimes people's behavior and actions may act as a signal that times have changed and the rules must change along with it.

Articles On The Groundwater Situation In India

Just a follow up on last week's post on geology, groundwater and climate change. I've been reading a couple of interesting articles on the groundwater situation in India.

The Socio-Ecology of Groundwater in India- International Water Management Institute- Tata Water Policy Program

Energy–Irrigation Nexus in South Asia: Improving Groundwater Conservation and Power Sector Viability - International Water Management Institute- Tata Water Policy Program

My posts on groundwater have a predictable angle of how geology influences the availability and use of groundwater. But if you are interested in going more in depth about the socio-economic and political angle and understanding the role of groundwater in Indian agriculture, farmer livelihoods and the real and potential damage to groundwater resources from rampant mismanagement of the resource then read these articles. The articles also point to the needed policy initiatives for sustainable management of groundwater.

The figure below encapsulates the importance of groundwater to the agricultural economy of India

Change in the contribution of groundwater and surface-water irrigation to agricultural GDP in India

Source: The Socio-Ecology of Groundwater in India

Groundwater Flow in Basalts, Caught on Video

The volcanic rock basalt underlies the city of Pune and much of the state of Maharashtra. Its rock mass is made up of an interlocking fabric of crystals and it doesn't have interconnected pore spaces through which water could be transmitted. The permeability of the rock mass is negligible. But basalts can be prolific aquifers. The reason is the various kinds of fractures and joints that serve to store and transmit water.

I came across a construction site near my house the other day and saw that they had dug a pretty deep hole for a foundation. I could see a thick rock profile consisting of two basalt flows. The upper flow was an amygdaloidal vesicular basalt. The lower one was a compact basalt. These are field terms used to categorize flow units with different physical characteristics. At the junction of the two flows was a fractured zone. The fractures were horizontal giving the basalt a sheeted appearance. And water was flowing out of these fractures at a fair pace. Take a look.

Groundwater flow in Basalt

This narrow flow zone which is a few feet thick is really the aquifer in this case. The compact basalt below forms the base of the system. Above this water seep you can see that the amygdaloidal basalt is bone dry. I wrote before about the enormous influence basalt hydrology has on the lives of Maharashtra farmers. You can get an idea why that is so. Finding water in basalts can be tough work because of such narrow permeability zones. Farmers often have the misfortune of farming tiny plots of land over basalts with no or very deep permeability zones. Digging wells into basalts is expensive and risky. Without proper geological guidance many poor farmers remain without access to groundwater.

So far this shallow groundwater system is not being exploited as a resource within the city of Pune. But that might change. Looking twenty years ahead, an expanding population and more water intensive life styles as people become prosperous might strain the surface water supply, which currently is sufficient to give citizens of Pune one of urban India's highest per day per capita allowance of around 200 liters.

Add to that are the vagaries of the monsoons. Even without global warming induced perturbations to rainfall, Indian monsoons are characterized by a decadal scale natural variability. Pune over the last 3-4 years has experienced higher than average rains but extended periods of lower than average rainfall is also a likely scenario in the future. A combination of lower rainfall and higher population might mean that the surface water reservoirs fall short of supplying enough water. The aquifer underneath Pune might gain importance in this context.

Unfortunately hydrologists don't really know how much water is present in the aquifers underneath Pune. The state ground water board periodically issues completely useless statements about the level of groundwater either going up or going down by said amounts. These are based on a few observation wells in areas where the aquifer is not being exploited. But there is practically no quantitative assessment of what will happen to the groundwater system if people suddenly start sucking water out of it. The system has not been studied under stress.

There is an opportunity to do that. On the outskirts of the city private water suppliers have sunk dug wells and bore wells. Year after year they are pumping water out of the shallow and deep aquifers. The water balance is not understood. How much should be taken out so that natural recharge will balance extraction? But I don't see government scientists rushing with their measuring tools to take advantage of these potential data points. Scientific progress relies as much on opportunism as on any other attribute. But state hydrologists lack the flexibility to deviate from their 2 year or 3 year of 5 year plans and schemes they are directed to follow.

Pune must have a science backed plan if and when the time comes to start exploiting the underlying aquifers. The time to start a serious research program is now.

Groundwater Map of India and Farmer Suicides

At Cryology and Co. David Bressan has a post on world wide groundwater resources maps produced by the "World-wide Hydrological Mapping and Assessment Programme" (WHYMAP). Following the link he provided I found a groundwater map of India on that site. The map below is actually from the web mapping application and attempts to give a very broad overview of the groundwater resources in the subcontinent.


The Himalayas are categorized as having local and shallow aquifers, the Indus-Gangetic plains belong to one homogeneous groundwater basin and the southern peninsular region is a complex hydrogeological province. These are somewhat misleading categories in that they are not mutually exclusive. For example local and shallow aquifers are found all over India. And the Himalayas have plenty of regions of complex hydrogeological structures. But combined with recharge potential the map gives on a broad scale the likely patterns of aquifer yield across the country.

Looking at Maharashtra I could not help noticing that areas of complex hydrogeological structure and medium to low recharge potential spatially coincided with the vast majority of cases of farmer suicides in the state. This is the region north of Hyderabad and east north east of Bombay. Over the last 6-8 years more than 2000 farmers have committed suicide. The immediate explanation for most of these cases is indebtedness. Farmers borrow money to meet high farming input costs or for other personal reasons and fall into a debt trap if crops fail or give a low yield. The Maharashtra government compiled the results of several studies of farmer suicides and identified conditions that made farmers in these regions particularly vulnerable. These were:

Disruption in regular rainfall cycle since 2001. Long dry spells, deficient monsoon.
Single crop a year, and Cotton the dominant crop. About 70% of farmers who committed suicide had planted cotton.
93 percent of land rain fed. 98 percent of the farmers who committed suicide had no irrigation.
Yield limited by rain, but regular rise in cost of input lowered margin of profit.
Volatility in market price further lowered return.
Commitment to money lender did not leave anything with the farmer.

Farmers are heavily dependent on monsoon rains to water crops. But how does complex hydrogeology figure in this? This agricultural region sits on top of the Deccan basalts. Aquifers are local, shallow, deep, all sorts, and show lateral and vertical heterogeneity in their water storage capacity and transmissivity. I have seen this in the field. The situation can change from high yield to bone dry over a distance of tens of meters. So a farmer with a small landholding of a hectare or so - and there are plenty of them in this region- may just have the bad luck of farming on top of an unyielding basalt. He then has to rely entirely on the rains or get into a groundwater sharing agreement with a neighboring farmer who might have a yielding aquifer under his farm. But during times of water stress there is too little water to go around resulting in crop failure or low yields.

Another problem is that not enough attention has been paid to managing the available groundwater resource. Farmers use dug wells as a primary water extraction method but using the dug well to replenish the aquifer during times of good rain is not practiced widely. This has led to aquifer overdraft and a steady diminishing over the years of the groundwater resource. Not all cases of farmer suicide can be linked to water problems. Crops can get wiped out by pests, yields could have been low due to soil degradation, some instances where Bt Cotton seeds failed and then there are probably cases where despite decent yields farmers simply made irresponsible financial commitments. But the link of low yields to ready availability of water is real.

Tushaar Shah a groundwater expert with the International Water Management Institute has made a strong case that focusing on groundwater replenishment will go a long way in preventing crop failure and improving yields. He gives an example:

Over 86 million hectare of India’s rain-fed areas, mid-season or terminal droughts regularly take a toll on the kharif crop. At such times, using around 1000 cubic metres per hectare of water from wells just-in-time to water a wilting crop just once can raise crop yields by 30-230 percent over rain-fed yield levels.

Off course if the wells themselves are dry then there is no backup for failed rains. A Tata Institute of Social Sciences report on farmer suicides found that farmers had little or no groundwater available to them during times of rain failure. A combination of complex hydrogeology and poor management of groundwater resources has exerted a powerful influence on the lives and livelihoods of Maharashtra farmers.

Mr. Shah makes the following recommendation for complex hydrogeological terrains:

What hard-rock India needs is a new mindset of managing dug wells as dual-purpose structures, for taking out water when needed and putting water into the aquifers when the surplus is running off. Recharging aquifers needs to get the first charge on monsoon run off. Unfortunately, government planners give it the last priority.

Water available for recharge is estimated after allowing for the requirements of existing and planned surface reservoirs. This is absurd in a country where 70 percent of irrigated areas and 90 percent of drinking water needs are met from groundwater.

Is the government listening? The Prime Minister of India's special relief package for Maharashtra farmers wants to attack the problem on a broad front which includes tinkering with the economics of cotton farming, encouraging a diverse array of crops and reducing dependence on pesticides and fertilizers. But water underlies any successful agricultural strategy. In terms of water it lists irrigation development as the only long term solution to the water problems faced by farmers and doles almost 10 times more money to irrigation development than to watershed development. Irrigation development in the language of the government of India means canal irrigation (read mega infrastructure projects) and not local groundwater irrigation.

This, despite the revealing statistic that even though thousands of crores of Rupees have been spent on canals, they irrigate just about 15% of arable areas over the landmass of India and marginal farmers and farmers with small landholding benefit most not from canal networks but through groundwater irrigation.

Kosi Breaches Embankment, More Water Refugees In Bihar

I wrote sometime back that although there are been much focus in the media and also concerns raised in the National Action Plan on Climate Change (15 mb) about sea-level rise and coastal populations being displaced, the interior of the country will also see its share of water refugees as climate and environments change. A couple of months ago, a prolonged drought in the Bundelkhand region whose effect was amplified by decades of neglect of water conservation measures lead to a massive dislocation of people in the affected areas. Now, Bihar is witness to another wave of people fleeing a water crises, this time a near catastrophic flood of the Kosi river.

Nearly 2.5 million people living in the Kosi flood plains have lost everything, as the river broke through its constraining embankments near Kusaha village in Nepal on August 18 and flooded several districts in Bihar. See map below for a synoptic view.


As you can see the Kosi forms an alluvial mega-fan, a massive triangle shaped body of sediment which you can distinguish from adjacent environments due to the closely spaced meandering network of channels between the present day Kosi river and Basantpur to the east. Such sedimentary deposits form when rivers suddenly change gradients as the Kosi does when it flows out of the Himalayas into the Indo-Gangetic plains. This fan is enormous, about 180 kms long and 150 km wide. Westward tectonic tilting of the entire area has been the major controlling factor for the river shifting its course about 120 km from east to west over the last 250 years. I have labelled the various paleo-channels using this study as a rough guide.

About 10-15 million years ago rivers bringing sediment from the rising higher Himalayas formed similar alluvial fans in a depression where today the Siwalik mountains stand. The Siwaliks are made up of sediments of such ancient alluvial fans that - as the Indian plate pushed against the Asian plate - have been consolidated, hardened, compressed, deformed and uplifted to form undulating mountains. The locus of sedimentation has now shifted in front of the Siwaliks. The Himalayas are growing southwards. There is nothing more awesome than the geological forces that give shape to this dynamic planet.

The Kosi has breached the embankments before but they have been downstream of the barrages and canals that are used as safety valves. Engineers have been able to control floods by diverting water to the canals. But this breach occurred upstream of the barrage and canal system giving engineers no way of controlling the excess flow. The river has occupied one of the abandoned channels to the east of the present day channel as seen in the image below taken on August 24 2008.


Source: NASA Earth Observatory

I couldn't make out exactly which paleochannel from the image but the district of Madhipura has experienced the worst flooding, so could be one of the channel close to that village. It will be months before the embankment is plugged and the river returns to its original course. Meanwhile hundreds of thousand of people have become water refugees. I don't know how many will go back. It is possible that the topography and recognizable landforms will change significantly to make identifying the tiny plot of land that is farmed a messy process. In short the future looks bleak for large number of people especially those with no clear titles to land and there are plenty of those in Bihar.

The Kosi is such a dynamic system that people living along its flood plains will always face this risk. Embankments don't offer a permanent solution to flood control. The danger is that global warming might make the monsoons more erratic at the same time resulting in more concentrated periods of rains. Coupled with increased summer melting due to the accelerated decline of Himalayan glaciers, the situation will strain the capacity of embankments to hold the river back. It is a question of when not if till the next embankment failure.

High dams in Nepal have been proposed as a "permanent" solution. This experts say will result in better flood control. The worry is the extremely high sediment load carried by Himalayan streams. For example the life span of the Tehri Dam in the Gharwal Himalayas is now being reassessed to being only about 30-40 years as against the older estimate of a 100 years. Dams on the Kosi river will no doubt also be short lived. What will we do after the dam fills up with silt?

But then what can be done? I don't know. The problem really appears intractable for the near future. India simply does not have enough excess arable land to relocate people living in high risk areas like the Kosi flood plain. I mean where can these people go? In developed countries like the U.S. high risk areas seem to be serving as a magnet for people to settle in large numbers. Katrina has not stopped people from returning to New Orleans, and people still seem willing to relocate to Florida in the path of hurricanes and California in earthquake prone zones.

Over here people do return to areas of disaster but because they have little choice. It's either farm these plots or live in slums in big cities. Livelihoods, land use and habitation patterns will change slowly but until then the best we can do is set up better early warning and disaster management systems. This will hopefully save lives, but the problem of loss of property and livelihood remains.