I am rereading a couple of chapters from Simon Winchester's book The Map That Changed The World. It is the story of William Smith a canal digger by profession who embarked in the late 1700's and early 1800's on a pioneering and ultimately heroic effort to map the geology of England. In the chapter entitled A Jurassic Interlude I came across the following passage:
The general line of their outcrop, which extends all the way north from Dorset to the Humber in Yorkshire, some two hundred miles, is one of the great dividing lines of world geology, once seen, never forgotten. Around Bath, close to where a northbound traveler like me today, Smith two centuries before me, first came across it, it is stupendously memorable.
On the western side of the line are the timid, milquetoast clays and weakling shales of the Lias, of the Lower Jurassic; on the eastern side are the tough, thick oolitic limestones of the Middle Jurassic. On the western side the consequential scenery all is valley and marsh, river course and water meadow, lowing cattle and in high summer, a sticky, sultry heat. On the eastern side, underpinned by the limestones, everything has changed: there is upland plain and moor, high hills, high wind and flocks of sheep, and in winter fine white snows blowing on what can seem an endless and treeless expanse.
And on the very line itself, at the point where England has tipped itself up gracefully to expose the limestones at its core and to reveal the huge physical contrast between the hardness and the silky softness of the Lias clays below, is a long, high range of hills and cliffs. The line is, for the most part, an escarpment edge that rolls far to the horizon, separating vales and downlands, from high plains and uplands.
It is a wonderful piece of writing and not just because it invokes images of a bucolic England. Here is yet another example of the pervasive influence of geology and geological processes on livelihoods and human economies.
In the Jurassic depositional basins of England there was a lateral facies variation from clays being deposited to the west changing to carbonate sediments to the east. As these sediments turned into rock they acquired different physical properties. The carbonates i.e. the Jurassic oolite became hardened through the precipitation of copious amounts of calcite cement in its abundant pore spaces. That cement bound the initially loose oolite particles together and transformed the sediment into hard rock. The clays which were very fine grained were not cemented into toughness. Instead they were compressed into rock but remained relatively soft.
Over time these two different rocks types got exposed to the elements and were weathered and eroded at different rates. The clay bearing rocks were softer and formed valleys and lowlands with moist organic rich soils, the hard limestones formed hills, escarpments and highlands with poorer soils. An agricultural diary economy developed on the serene clay lowlands, while a pastoral sheep economy developed on the harsher windier limestone highlands.
In my previous post I wrote about the effect of aquifer yield in basalt provinces and their control on farmer poverty. That post was the first of a thread that I have continued here and plan to write on from time to time. Geology and livelihoods. I like making this connection. It is an under appreciated theme. People always nod in agreement when oil and gas and the mining industry is mentioned. It is not hard to make that connection between geology and economy. But facies change, diagenesis, weathering and rural economies? That usually takes a while to sink in.
Tuesday, November 4, 2008
Friday, October 31, 2008
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.
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.
Monday, October 27, 2008
Landslides Trace Kashmir Earthquake Fault
Via Geology.com an article on the NASA Earth Observatory website on the use of satellite imagery for mapping the 2005 Kashmir earthquake fault trace.
This earthquake was unusual for the Himalayan region as it occurred along a shallow fault and caused a surface rupture. i.e the cracks and deformation was visible at the surface. Deformation due to earthquakes is usually mapped by spotting offsets in artificial and natural linear features like walls and fences or gulley's and streams. That is incredibly hard to do in remote steep terrains like the Kashmir Himalayas. So the researchers used before and after earthquake images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard the NASA Terra satellite to try and spot this rupture. A team of geologists had mapped this fault using ground surveys but this is a time consuming process and so a complimentary image analysis was done to evaluate whether imagery can provide a reliable way to quickly identify zones of deformation to aid rescue efforts after an earthquake.
The images below are ASTER false color composites which clearly show the fault trace highlighted by a linear zone of white color. These are landslides that occurred along the hanging wall of the fault. Only a small section of the trace is seen in the images.
Source: NASA Earth Observatory
False Color Composites are prepared by assigning the three primary colors red, green and blue to the three wavelength bands which analysts feel contain the maximum information about surface features. This arbitrary assignment of colors to bands results in features appearing in colors unnatural to the human eye. Hence the term False Color Composite. Depending upon sensor design a range of wavelengths from the visible part of the wavelength spectrum (reflected energy) to the thermal part of the spectrum (emitted energy) can be collected for study. ASTER the sensor used in this study as the name implies senses energy in both the thermal and reflected part of the spectrum. Only the reflected portion of the spectrum was used to process the images in this study.
Satellite sensors break up the reflected or emitted energy coming from the earth's surface into discrete regions or bands to allow better discrimination of surface features. This works because different surface features reflect or emit efficiently in different wavelengths. A judicious selection of bands can then be used to create maximum contrast between different surface features.
When using reflected energy, usually this wavelength combination as is in this image is near infrared, red and green. The wavelength range is from about 0.5 microns (green) to about 1 microns for near infrared. In this case red color has been assigned to the near infrared band since healthy vegetation reflects a lot of near infrared. Water appears blue and built up areas and landslides which are zones where vegetation has been stripped off and fresh rock and soil exposed appear gray and white respectively, indicating a very high reflectance in the smaller wavelengths.
The surface rupture of the Kashmir earthquake extends over 75 km. Another paper which studied the tectonics of this earthquake has concluded that the rupture has occurred along some subsidiary faults and not along the major boundary fault where strain is apparently still accumulating.
This does not bode well for the Kashmir region.
Update: Robert Simmon a NASA researcher in an email to me points out an error in my post. I gave the impression that the fault trace was mapped using landslides as a guide. This is not so. The fault trace was delineated by mapping the ground deformation i.e the offsets caused by the slip along the fault were mapped by correlating the before and after images. Landslides in fact obscure the fault trace such that the before and after images can't be correlated along such patches.
This earthquake was unusual for the Himalayan region as it occurred along a shallow fault and caused a surface rupture. i.e the cracks and deformation was visible at the surface. Deformation due to earthquakes is usually mapped by spotting offsets in artificial and natural linear features like walls and fences or gulley's and streams. That is incredibly hard to do in remote steep terrains like the Kashmir Himalayas. So the researchers used before and after earthquake images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard the NASA Terra satellite to try and spot this rupture. A team of geologists had mapped this fault using ground surveys but this is a time consuming process and so a complimentary image analysis was done to evaluate whether imagery can provide a reliable way to quickly identify zones of deformation to aid rescue efforts after an earthquake.
The images below are ASTER false color composites which clearly show the fault trace highlighted by a linear zone of white color. These are landslides that occurred along the hanging wall of the fault. Only a small section of the trace is seen in the images.
Source: NASA Earth Observatory
False Color Composites are prepared by assigning the three primary colors red, green and blue to the three wavelength bands which analysts feel contain the maximum information about surface features. This arbitrary assignment of colors to bands results in features appearing in colors unnatural to the human eye. Hence the term False Color Composite. Depending upon sensor design a range of wavelengths from the visible part of the wavelength spectrum (reflected energy) to the thermal part of the spectrum (emitted energy) can be collected for study. ASTER the sensor used in this study as the name implies senses energy in both the thermal and reflected part of the spectrum. Only the reflected portion of the spectrum was used to process the images in this study.
Satellite sensors break up the reflected or emitted energy coming from the earth's surface into discrete regions or bands to allow better discrimination of surface features. This works because different surface features reflect or emit efficiently in different wavelengths. A judicious selection of bands can then be used to create maximum contrast between different surface features.
When using reflected energy, usually this wavelength combination as is in this image is near infrared, red and green. The wavelength range is from about 0.5 microns (green) to about 1 microns for near infrared. In this case red color has been assigned to the near infrared band since healthy vegetation reflects a lot of near infrared. Water appears blue and built up areas and landslides which are zones where vegetation has been stripped off and fresh rock and soil exposed appear gray and white respectively, indicating a very high reflectance in the smaller wavelengths.
The surface rupture of the Kashmir earthquake extends over 75 km. Another paper which studied the tectonics of this earthquake has concluded that the rupture has occurred along some subsidiary faults and not along the major boundary fault where strain is apparently still accumulating.
This does not bode well for the Kashmir region.
Update: Robert Simmon a NASA researcher in an email to me points out an error in my post. I gave the impression that the fault trace was mapped using landslides as a guide. This is not so. The fault trace was delineated by mapping the ground deformation i.e the offsets caused by the slip along the fault were mapped by correlating the before and after images. Landslides in fact obscure the fault trace such that the before and after images can't be correlated along such patches.
Wednesday, October 22, 2008
The Beginnings of India
Last week I caught a Discovery Channel special on India called The Story Of India. The first episode was The Beginnings. It was presented by the British historian Michael Wood who has also written a book about this topic. I settled down to watch expecting the story of India to begin with agricultural societies represented by the Indus valley civilization.
To my pleasant surprise Michael Wood took the story way back to Africa and the late- Pleistocene migration of Homo sapiens from Africa around 80,000 years ago. These humans migrated into India soon thereafter taking most likely the coastal route from Arabia into India. There are still relict populations in India which have believed to be descendants of these early settlers. I wrote a post about this some time back. These include the mainland tribals like the Korku and the Kuruba and those in the Andaman chain of islands like the Sentinelese. Mitochondrial genetic analysis supports this contention as the Korku and the Kuruba have one of the oldest mitochondrial genetic markers outside of Africa. The figure below shows migration routes of Homo sapiens reconstructed from genetic analysis.
Source: Univ. of Texas
Wood meet some of these tribal communities and discussed rituals that may be holdovers from very early times. There were some silly moments like when he asked one of the tribals "how does it feel to be the first human in India", but he did highlight the genetic work that is being done to unravel the history of early human presence.
From early Pleistocene settlers the show moved on to the Holocene and the enigmatic Indus valley civilization which lasted from around 3500 B.C to 1800 B.C. Wood talked a lot of town planning and trade between the Indus valley people and centers of civilization in what is now Iran and parts of the Middle East and then talked a little about the demise of this civilization caused most likely due to an increased aridification of the western Indian continent beginning around 2500 B.C. The show then moved on to the arrival of people starting 1500 B.C., speaking an Indo-European language, proto-Sanskrit. The locus of Indian civilization migrated eastward to the Gangetic plain but Wood emphasizes that there is a continuity in the cultural transition from the Indus valley to the Gangetic plains. The focus was on how these Sanskrit speaking people developed the Vedic culture and complex societies around the Gangetic plain. Using linguistic and archaeological evidence he traced the origin of these Sanskrit speaking people to central Asia.
What was left out from this rather predictable but decently presented sequence was any mention of where and when did Dravidian speaking people originate. This is the other big language family in India today, spoken mainly in the south of the country. Dravidian is considered by many linguists as part of the Dravidian-Elamite family of languages that once were spoken all over the northwestern part of Indian subcontinent extending into Iran. Exactly where the center of origin of this language family was is still uncertain but geneticist Luigi Luca Cavalli-Sforva suggests that it could have been the northwestern part of India or it could be farther west towards Iran and the Caspian region.
What is clear is that Dravidian or proto-Dravidian speakers were in India before the arrival of proto-Sanskrit speakers. Linguists like Colin Renfrew suggest that it is likely that the entry and spread of Dravidian languages in India coincided with the farming dispersal and agricultural expansion that began in the Middle East and which expanded into north western parts of the Indian subcontinent around 8,000 years ago. Dravidian languages entered India through demic diffusion of agriculturists and Dravidian speaking people were the first Neolithic farmers of India. This extended history of Dravidian language origin and dispersal was given no attention in the show. These people are the likely candidates who built the Indus valley civilization and Wood missed out on exploring this thesis further. I've noticed this in many documentaries about India. The attention is always on the arrival of the "Aryans" a term used to describe people speaking Indo-European languages. They in fact arrived much later than Dravidian speakers. Today Dravidian is spoken mostly in the south, an example of language displacement by latter arrivals. There is however a northern enclave in Pakistan where Brahui, a Dravidian language is still spoken.
This is not really a rant on Dravidian vs Indo-European languages. I mentioned that Indo-European speaking people displaced Dravidian languages to the south, but Dravidian speaking farmers too must have displaced or made extinct Austro-Asiatic languages or other unclassified languages spoken by the earlier hunter-gatherer settlers of the continent. The history of India is one of immigration and emigration and superimposition of layer upon layer of language, culture and ethnicity.
I particularly liked one sentence Michael Wood said about India:
India is a country where all the pasts of the human species are still living.
That is a very evocative description of the country and its people. It makes you imagine the great antiquity of human habitation in this part of the world.
To my pleasant surprise Michael Wood took the story way back to Africa and the late- Pleistocene migration of Homo sapiens from Africa around 80,000 years ago. These humans migrated into India soon thereafter taking most likely the coastal route from Arabia into India. There are still relict populations in India which have believed to be descendants of these early settlers. I wrote a post about this some time back. These include the mainland tribals like the Korku and the Kuruba and those in the Andaman chain of islands like the Sentinelese. Mitochondrial genetic analysis supports this contention as the Korku and the Kuruba have one of the oldest mitochondrial genetic markers outside of Africa. The figure below shows migration routes of Homo sapiens reconstructed from genetic analysis.
Source: Univ. of Texas
Wood meet some of these tribal communities and discussed rituals that may be holdovers from very early times. There were some silly moments like when he asked one of the tribals "how does it feel to be the first human in India", but he did highlight the genetic work that is being done to unravel the history of early human presence.
From early Pleistocene settlers the show moved on to the Holocene and the enigmatic Indus valley civilization which lasted from around 3500 B.C to 1800 B.C. Wood talked a lot of town planning and trade between the Indus valley people and centers of civilization in what is now Iran and parts of the Middle East and then talked a little about the demise of this civilization caused most likely due to an increased aridification of the western Indian continent beginning around 2500 B.C. The show then moved on to the arrival of people starting 1500 B.C., speaking an Indo-European language, proto-Sanskrit. The locus of Indian civilization migrated eastward to the Gangetic plain but Wood emphasizes that there is a continuity in the cultural transition from the Indus valley to the Gangetic plains. The focus was on how these Sanskrit speaking people developed the Vedic culture and complex societies around the Gangetic plain. Using linguistic and archaeological evidence he traced the origin of these Sanskrit speaking people to central Asia.
What was left out from this rather predictable but decently presented sequence was any mention of where and when did Dravidian speaking people originate. This is the other big language family in India today, spoken mainly in the south of the country. Dravidian is considered by many linguists as part of the Dravidian-Elamite family of languages that once were spoken all over the northwestern part of Indian subcontinent extending into Iran. Exactly where the center of origin of this language family was is still uncertain but geneticist Luigi Luca Cavalli-Sforva suggests that it could have been the northwestern part of India or it could be farther west towards Iran and the Caspian region.
What is clear is that Dravidian or proto-Dravidian speakers were in India before the arrival of proto-Sanskrit speakers. Linguists like Colin Renfrew suggest that it is likely that the entry and spread of Dravidian languages in India coincided with the farming dispersal and agricultural expansion that began in the Middle East and which expanded into north western parts of the Indian subcontinent around 8,000 years ago. Dravidian languages entered India through demic diffusion of agriculturists and Dravidian speaking people were the first Neolithic farmers of India. This extended history of Dravidian language origin and dispersal was given no attention in the show. These people are the likely candidates who built the Indus valley civilization and Wood missed out on exploring this thesis further. I've noticed this in many documentaries about India. The attention is always on the arrival of the "Aryans" a term used to describe people speaking Indo-European languages. They in fact arrived much later than Dravidian speakers. Today Dravidian is spoken mostly in the south, an example of language displacement by latter arrivals. There is however a northern enclave in Pakistan where Brahui, a Dravidian language is still spoken.
This is not really a rant on Dravidian vs Indo-European languages. I mentioned that Indo-European speaking people displaced Dravidian languages to the south, but Dravidian speaking farmers too must have displaced or made extinct Austro-Asiatic languages or other unclassified languages spoken by the earlier hunter-gatherer settlers of the continent. The history of India is one of immigration and emigration and superimposition of layer upon layer of language, culture and ethnicity.
I particularly liked one sentence Michael Wood said about India:
India is a country where all the pasts of the human species are still living.
That is a very evocative description of the country and its people. It makes you imagine the great antiquity of human habitation in this part of the world.
Tuesday, October 21, 2008
NPR Steals My Line on Climate, Well Almost
A while ago I wrote a post on coffee shop conversations about global warming and how to convince friends that it is better to have more faith in peer reviewed science than random self appointed experts who pop up on the Internet and pronounce that an entire field of study with a history of thousands of publications is wrong because that one paper in that hard to find journal says so.
NPR no doubt taking my cue has a similar "How To Be Conversant About Climate" conversation with Michael Oppenheimer, faculty in geosciences Princeton University, about how to convince Uncle Sal at the dinner table that global warming is not only real but is primarily caused by human activity. Oppenheimer is of the view that while the debate about whether warming is taking place is over and settled, there are differences which are quite genuine and not as easily dismissed on how to deal with this problem. That problem has economic, political and cultural roots and needs to be confronted without taking a "I am right and you are wrong" stance.
There is a second good talk on the show. This explores the broader question of why people find it hard to believe in science and scientists. Uncertainty in interpreting data and the results of an experiment, dissent and debate is built into the scientific process. It is the nature of the beast. But it is often bewildering to people that even after say 2-3 decades of work, there is no certain answer from scientists on a problem. People take that as a weakness of the system, a signal that science may not give them ready answers. Maybe we want that certainty, maybe we need closure on a problem, maybe we need to be reassured that yes this is the one correct answer, that we all too readily succumb into believing a confidently told but scientifically unsupported story.
And again how easily available information on the Internet can be at once a boon but also a hindrance and sometimes has dangerous consequences when people in responsible positions choose to believe wild assertions. Harry Collins of Cardiff University gives the example of parents refusing to vaccinate children with the MMR vaccine because they fear that it may cause autism in their child, something that has been refuted by solid scientific work.
Then there is the case of Thabo Mbeki, ex-President of South Africa, who after reading articles on the Internet announced publicly that retro-viral drugs to combat AIDS don't have any helpful effect. The media too bears some responsibility of spreading disinformation through their insistence on giving both sides on the story equal weight even though one side is just illogical and is not supported by any body of evidence and simply does not warrant such attention.
Both a good listen.
NPR no doubt taking my cue has a similar "How To Be Conversant About Climate" conversation with Michael Oppenheimer, faculty in geosciences Princeton University, about how to convince Uncle Sal at the dinner table that global warming is not only real but is primarily caused by human activity. Oppenheimer is of the view that while the debate about whether warming is taking place is over and settled, there are differences which are quite genuine and not as easily dismissed on how to deal with this problem. That problem has economic, political and cultural roots and needs to be confronted without taking a "I am right and you are wrong" stance.
There is a second good talk on the show. This explores the broader question of why people find it hard to believe in science and scientists. Uncertainty in interpreting data and the results of an experiment, dissent and debate is built into the scientific process. It is the nature of the beast. But it is often bewildering to people that even after say 2-3 decades of work, there is no certain answer from scientists on a problem. People take that as a weakness of the system, a signal that science may not give them ready answers. Maybe we want that certainty, maybe we need closure on a problem, maybe we need to be reassured that yes this is the one correct answer, that we all too readily succumb into believing a confidently told but scientifically unsupported story.
And again how easily available information on the Internet can be at once a boon but also a hindrance and sometimes has dangerous consequences when people in responsible positions choose to believe wild assertions. Harry Collins of Cardiff University gives the example of parents refusing to vaccinate children with the MMR vaccine because they fear that it may cause autism in their child, something that has been refuted by solid scientific work.
Then there is the case of Thabo Mbeki, ex-President of South Africa, who after reading articles on the Internet announced publicly that retro-viral drugs to combat AIDS don't have any helpful effect. The media too bears some responsibility of spreading disinformation through their insistence on giving both sides on the story equal weight even though one side is just illogical and is not supported by any body of evidence and simply does not warrant such attention.
Both a good listen.
Subscribe to:
Posts (Atom)