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  • very good indeed ,using

    very good indeed ,using natural materials and mud especially is what should be more used for buildings ...

    Posted by: Anonymous | 6 years ago | Reply
  • Such sensible designs. I

    Such sensible designs. I shiver with horror when I see the mushrooming apartment complexes in Calcutta, low ceilings, tiny rooms, large glass windows, no verandahs and one brick thin walls - effectively turning them into tiny ovens in the 10 month long summer. No wonder people use more ACs, and no wonder the entire country is suffering a power-shortage!

    Posted by: Anonymous | 6 years ago | Reply
  • I loved this one..I want to

    I loved this one..I want to know how his ideas play out within dense urban metropolis where all you can build are high rises..any 2nd part to follow?

    Posted by: Anonymous | 6 years ago | Reply
  • And most people cannot

    And most people cannot breathe in modern buildings!

    Posted by: Anonymous | 6 years ago | Reply
  • Terrific story. For the first

    Terrific story. For the first time, I understood why
    buildings consume about half of electricity and how can that be prevented.

    I have wondered why buildings over here are different since I came to London. Buildings should be built differently in different climatic conditions. But unfortunately, most architects want to copy the western model. Those horrible glass and concrete monsters in Gurgaon always made me angry.

    Posted by: Anonymous | 6 years ago | Reply
  • Good Luck to Fournier but

    Good Luck to Fournier but historical/ground reality does not suggest that he will be able to see his dream come true in the consumption oriented society.

    Incidentally I was born in Raipur and obtained my matriculation Certificate from Government High School Raipur.

    The consumption oriented society does not look mud-ward or bamboo-ward; it looks upward because that is how the black money gets whitened.

    Consumption oriented socity is a mess of social pollution; it believes in wasteful investments which by definition is not sustainable.

    I am attaching a copy of my paper:CLIMATE CHANGE & SOCIOECONOMIC PROBLEMS, A CASE OF PAKISTAN
    whose section on Socioeconomic Problems is particularly related to the issue we are talking about and whose concluding para reads as follows:
    "Based on the above analysis, it is possible to conclude that poverty per se is not a problem of the people of Pakistan and for that matter all developing countries. It is the impoverishment of resources at the hands of the get-rich-quickly Syndrome that has induced poverty. The poor have otherwise learnt to live within their means and hence poverty irks them only when they find that the get-rich-quickly syndrome has left him far behind his neighbor.



    CLIMATE CHANGE & SOCIOECONOMIC PROBLEMS:
    A CASE OF PAKISTAN

    MIRZA ARSHAD ALI BEG
    136 C, Rafahe Aam Housing Society
    Karachi 75210

    Introduction
    Climate change may be defined as abnormal variations in atmospheric and terrestrial conditions that are the result of changes caused by natural and man-made intervention in an ecosystem and may have persisted in the microenvironment and macro environment during the lifetime of the planned or unplanned intervention.

    The situation current since the mid-1980s indicate unequivocally that Pakistan is faced with extremes of climate variations resulting from natural as well as manmade modifications. The aftermath of Cyclone 02A, which landed on the low lying coastal area of Badin in May 1999 and the floods in the same area in 2003, were a preview of the impending disaster in 2010 and 2011, all due to man-made interventions to attain rapid economic growth. This has resulted in rapid impoverishment as well as degradation of resources, including water, soil and vegetative cover on the one hand and climate change on the other.

    It will be seen in a later section that it is the lust for rapid growth that has induced impoverishment of resources and is responsible for incidence of poverty. Poverty is otherwise not a problem, since people in developing and least developed countries have been living amicably with poverty.

    Climatic change is viewed as an abnormality in Pakistan resulting from
    (i) Increase as well as decrease in the mean maximum and minimum temperature,
    (ii) Deforestation: extensive loss of vegetative/forest cover, and desertification
    (iii) Abrupt variations in rainfall and/or snowfall, cloud cover, and receipt of solar energy,
    (iv) Decreased availability of water from surface run off and groundwater extraction, and reduction in the water level of the aquifer,
    (v) Production of greenhouse gases, including water vapour, nitrogen oxides and methane,
    (vi) Land loss to the sea due to subsidence,
    (vii) Rise in sea level,

    The Abnormalities
    1. Temperatures
    Many of the abnormalities just mentioned have appeared after the mid-1980s in the form of failure of the monsoon system in completing the western segment of its cycle and widespread precipitation of moisture in its eastern segment with heavy rains causing devastating floods each time. The Abnormalities being noticed are in the magnitude and intensity of heat wave but not in the range in the mean maximum and mean minimum temperature and in the erratic nature of precipitation, snowmelt and river flow since early 1990s1.

    The Earth's surface temperature, according to data provided by satellites, indicates little if any warming of the low-to mid- troposphere. The disparity between the surface temperature and upper-air temperature has nevertheless been noted.

    Table: Mean Monthly Maximum Temperature oC
    Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
    2001 27.2 29.6 33.1 34.6 35.1 34.9 32.2 32.3 33.1 36.0 33.5 30.4 32.7
    2002 27.0 28.2 33.3 35.4 35.6 35.1 32.2 31.6 31.4 36.5 32.7 28.1 32.3
    2003 27.6 28.5 32.4 36.6 35.7 34.9 34.1 32.6 32.5 37.0 32.2 28.3 32.7
    2004 26.6 29.9 36.2 35.4 36.8 35.6 33.8 32.7 32.8 33.7 33.1 29.4 33.0
    2005 24.9 26.3 31.5 35.3 35.4 36.0 33.2 32.2 34.2 35.2 33.1 28.4 32.1
    2006 26.0 31.3 31.8 34.0 34.6 35.3 33.8 31.0 34.2 35.0 33.4 26.3 32.2
    2007 26.9 29.4 31.4 37.7 36.0 36.4 N/A N/A N/A N/A N/A N/A 33.0
    2008 24.4 26.9 34.3 34.4 33.9 35.1 33.5 31.9 34.7 35.5 32.5 27.2 32.0
    2009 26.2 29.8 33.0 36.0 36.8 35.7 34.5 33.0 32.8 35.9 33.0 28.6 32.9
    Source: Pakistan Meteorological Department


    Table: Mean Monthly Minimum Temperature oC
    Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
    2001 11.5 14.9 19.6 23.8 28.1 29.0 27.1 26.5 25.9 24.4 18.6 15.8 22.1
    2002 12.8 13.8 19.5 23.9 27.0 28.2 29.6 25.6 24.8 22.5 17.7 14.9 21.7
    2003 12.7 16.9 19.8 24.2 26.5 28.2 23.6 27.0 25.3 20.9 15.2 12.0 21.0
    2004 12.9 14.5 19.1 24.8 27.3 28.8 27.5 26.3 25.3 22.4 18.0 15.4 21.9
    2005 12.3 11.3 20.3 23.0 26.4 28.3 27.2 26.6 26.6 22.9 18.9 13.0 21.4
    2006 11.7 18.1 19.6 24.5 27.5 28.5 28.3 26.3 26.8 25.7 19.4 14.0 22.5
    2007 13.0 17.3 19.7 24.7 27.6 28.6 N/A N/A N/A N/A N/A N/A 21.8
    2008 10.1 11.1 19.6 24.0 27.3 29.1 27.9 26.8 26.6 23.8 17.6 14.9 21.6
    2009 14.7 16.5 20.8 23.8 27.6 28.7 28.1 27.5 26.5 22.6 17.0 13.9 22.3
    Source: Pakistan Meteorological Department

    The maximum temperatures recorded by PMD have remained at the same level during the last 30 years but the minimum average has increased by 1.5oC to 2.0oC. Analysis of data on the mean monthly maximum and minimum temperatures recorded during the nine years (2001 ÔÇô 2009) at Karachi Airport Meteorological Station of Pakistan Meteorological Department, given in the above Tables, indicate:
    ÔÇó The mean monthly maximum temperature in Karachi ranged between 32.0oC and 33.0oC during the 2001-2009 period, while the mean monthly minimum temperature ranged between 21.0oC and 22.5oC.
    ÔÇó The mean maximum and mean minimum temperature during 1991-99 were 32.2oC and 20.9oC, respectively. This indicates that there has been a slight but significant rise in the mean minimum temperature during the last 30 years.

    This is in conformity with the surface warming trend that exists and has become more pronounced after the 1980s. The ten warmest years of the 20th century occurred after 1980, and the three hottest years occurred after 1990, with 1998 being the warmest year of all, and the year 2004 was the fourth warmest year on record, following 1998, 2002 and 2003, which were the first, second and third warmest years respectively. A study published by Nature in February 2005, found that, based upon indirect temperature records found in tree rings and other natural phenomena, the global warming trend since 1990 has not been matched for at least 2,000 years.

    The low cloud cover and increased sunshine has resulted in rise in temperature of landmass in the hinterland of the Arabian Sea. High temperatures such as 55oC recorded at Moenjo Daro on May 25 setting the fourth world record, have (i) since turned large territory of Pakistan into an extensive heat zone, and (ii) raised the temperature of the North Arabian Sea by 1oC to 1.5oC.


    Deposition of material around vegetation is evidence of wind transport of sediment

    The heat zone serving as the main heat engine for the monsoon system, while the significant rise in temperature of the Arabian Sea has led to high evaporation rates over the sea surface. This has led to higher salinity and hence to higher heat content of the Arabian Sea. These are sufficient conditions to create salinity steep gradient in addition to thermal gradients and trigger cyclones in the high seas, and the Arabian Sea was no exception.

    Higher temperature of the Arabian Sea and its high heat capacity makes more water vapor available over the sea surface which in turn produces more rain bearing clouds and more than usual rainfall and snowfall.

    Rise in temperature of the sea indicates onset and persistence of low-pressure zone on land and temperatures higher than the critical 26oC that may induce thermal gradient at the sea. High salinity will induce steep gradient on the sea. The former parameter i.e. heat zone can attract rain bearing winds in case they are around, while the latter can nucleate cyclones/storms. Such attraction of moisture laden winds did cause severe storms, the latest August and September 2011 and June 6, 2010; and the earlier one on June 5, 2007; on August 21, 2007; and August 17, 2006, and brought sudden heavy rains of as much as 50 to 100 mm in two to three hours.
    Over the past three decades, the pertinent findings on climate change indicate that:
    The abnormal changes have occurred because of i) the typical geographical location of the country in the arid region at the head of the Arabian Sea that has a surplus heat budget, and ii) manmade interventions are largely responsible for a number of these events. Because of the surplus heat budget, the high temperatures on land have:
    a. induced high evaporation rates all over including the seas; on land it has increased the aridity of soil and on seas it has increased the vapour content over the sea surface,
    b. caused increase in heat capacity of the land and the seas, which allows retention of thermal energy in the two systems, and thus
    c. raised the temperature of the Arabian Sea by at least 1oC to 1.5oC and higher near the shoreline.

    The high heat content of the Arabian Sea and its hinterland as well as formation of extensive heat zone over Pakistan have disturbed the heat balance and water-balance of the region, and have at least partly modified the monsoon cycle.

    Higher temperature of the Arabian Sea and its high heat capacity makes more water vapor available over the sea surface which in turn produces more rain bearing clouds and more than usual rainfall and snowfall.

    2. Air-Glacier Interaction
    More water vapor in the atmosphere also means increased condensation of water saturated air at greater heights leading to increased snowfall. Since latent heat of vaporization is the same as the latent heat of condensation, snowfall will induce melting of snow and formation of ice. This may be the reason for increase in the formation of glacial lakes and increase in ice cover in the glacier areas.

    The March 2011 maximum ice coverage value was 14.64 million square kilometres; this is down 7.7 percent from the 1979 to 2000 average. The September 2011 minimum ice coverage value was 4.33 million square kilometres, the second lowest on record after 2007 and 31 percent lower than the 1979 to 2000 average. The five summers between 2007 and 2011 have seen five of the lowest ice coverage values and the 10 summers between 2002 and 2011 have seen nine of the ten lowest values. The following is a graph showing the gradual percentage decrease in both maximum and minimum ice extent values since 1979 (http://3.bp.blogspot.com/-KrL-HQlBjs/TtlcWc9VD5I/AAAAAAAABpg/rRLWdmCIPB8/s1600/Screen+shot+2011-12-02+at+7.07.07+PM.png):

    Impact of Air Glacier interaction was reported in a Seminar on Glacier Behaviour under Climate Change & its impact on Agriculture in Pakistan, June 4, 2008, where different Organizations reported their observations. The Pakistan Meteorological Department reported the following:
    ´éº Kabul river melt flow (during 15th to 30th June) has increased from 30,000 cusecs in 2001 to 160,000 cusecs in 2005
    ´éº Indus river melt flow (during 15th to 30th June) has increased from 150,000 cusecs in 2001 to 375,000 cusecs in 2005
    ´éº Total Himalaya glaciers are 5024 in 10 river basins of Pakistan
    ´éº There are 2419 glacial lakes, with 25 potentially dangerous for GLOF
    ´éº Gangotri glacier is retreating 3 times more at the end 20th century than the previous average
    ´éº Liligo glacier is surged 2114 meters in last 24 years
    ´éº Siachin glacier retreated about 1.8 km in last 17 years
    ´éº The snow cover in Pakistan increases from Jan to March, decreases from March to September and again increases from September to March (2007-08)
    ´éº Average snow cover in 2007 was 60,000 sq. km.

    Fresh Snow (A), Glacier Ice (B), and Glacier Ice Covered with Debris (C) in the Gangotri Glacier

    SUPARCO reported that
    ´éº Batura glacier is 7500 m.a.s.l, feeding Hunza River, which flows from west to East and fall into Indus. Snow / ice and ice free areas were observed as 98 and 25 sq.km in 1992 while in 2000 it accounted for 81 and 42 sq.km respectively
    ´éº Biofo glacier lies in Karakuram range in Baltistan. It feeds Barldu river which falls in to Shigar River and ultimately in to the Indus river. Snow/ ice and ice free areas were observed as 93.137 and 21.959 sq.km in 1992 while in 2000 it accounted for 84.622 and 30.474 sq.km respectively.
    ´éº Yazghil glacier lies in Hipar Muztagh Karakuram range at 7324 m.a.s.l. Temporal analysis indicate 1.18 sq.km decrease in area during 1992 and 2007
    ´éº Jutmau glacier lies in north of Hispar glacier in Karakuram range. It lost 6 sq.km area during the period 1992-2007
    ´éº Snow covered area in Northern Pakistan on 10th May 2004, 2005, 2006 and 2007 was observed as 57066, 68420, 59731 and 34820 sq.km respectively.

    Asianics Agro Dev Pakistan have reported that:
    ´éº Rise in mean temperature of 0.6-1oC in arid coastal, arid mountains and hyper arid plains.
    ´éº 30 to 40 % decline is projected in precipitation with rising intensity in monsoon
    ´éº 0.5 -0.7 % increase in solar radiation over southern half of the country
    ´éº 5 % increase in Net Irrigation Water Requirements
    ´éº The time frame for glaciers melt is 45 years
    ´éº 40 to 50 % less water was available this year
    ´éº 62 % (74) districts are food deficit in terms of net availability

    A report in the Daily Times of April 14, 2012 confirms this AuthorÔÇÖs view that the Karakorum Glaciers have gained a small amount of mass between 1999 and 2008 Nature Geoscience, April 2012). The Karakoram mountain range in the Himalayas has contributed less to sea level rise than previously thought. The study estimates that the Karakoram glaciers have gained around 0.11 to 0.22 metres per year between 1999 and 2008, and concludes that Karakoram glaciers had a small mass gain at the beginning of the 21st century indicating that the central/eastern glaciers are not representative of the whole (Himalayas). The Karakoram mountain range spans the borders between India, China and Pakistan and is covered by 19,950 square kilometres of glaciers. It is home to the second highest mountain in the world, K2 (http://www.dailytimes.com.pk/default.asp?page=2012%5C04%5C16%5Cstory_16-4-2012_pg7_3).

    3. Man Made Interventions
    3.1 Development Activities
    Deforestation has been held largely responsible for inducing modifications in the climatic norms [(G.P. Kalinin and V.D. Bykov, The World Water resources, Present and Future, in Ecology of Man: An Ecosystem Approach, ed. R. L. Smith, Harper & Row Publishers, New York, 1972), Mirza Arshad Ali Beg (1977) Environmental Problems of Pakistan, Working Paper for the International Seminar on Environmental Risk Assessment in an International Context, Tihanyi, Hungary, pp. 30]. This author had in the late 1990s argued that the precipitation across the Himalayas in Tibet and over the catchment area of the Brahamputra was much higher than over the Indus perhaps because of extensive deforestation in the eastern Himalayas prompted the monsoon winds to cross over unrestrained by the high mountains.

    Anthropogenic activity has, through increased oxidative dehydration of land, burning of biomass and other combustibles, increased the concentration of the GHGs, warmed the microenvironment and left the CO2 and other acidic gases unabsorbed. The warmth can be reduced by reductive rehydration of the CO2, and other acidic gases. The latter process is in operation among the plants and vegetation on land and by phytoplankton in the sea. Removal of vegetative cover through indiscriminate cutting of trees for lumber or clearing land for agricultural activities has deforested extensive land area and produced excessive GHGs. This has restrained the natural process of reductive rehydration by photosynthesis and thus the heat generated has increased the warmth of the environment, and the unabsorbed GHGs have been left free to selectively acidify the microenvironment. GHGs in appropriate concentration in the atmosphere are needed nevertheless to maintain the heat balance. Life forms on Earth rely on maintenance of the Oxidative Dehydration-Reductive Rehydration (OD-RR) balance, without which, the planet would be colder by at least 33oC, and ice would cover the Earth from pole to pole. Contrarily, a growing excess of these gases would, as it does now, threaten to tip the balance towards continual warming.

    3.2 Air Emissions
    The pollution due to these emissions is set to grow in coming decades, because in case of reduced availability of fossil fuel, much more than the present seven billion tons of biomass will be burned. Likewise forest fires, which are mostly triggered by lightning and are responsible for an estimated 20 per cent of CanadaÔÇÖs carbon dioxide emissions, will further reduce the forest cover.

    Another factor that is contributing to the observed climate change is the sulphate aerosol induced fog that is observed during winter over the area from Multan to Islamabad, and the ÔÇÿBrown HazeÔÇÖ observed over South Asia There is an annual slow down of economic activity for at least five weeks due to the fog that has its origin in the south of the Himalayas in India. The Brown haze observed over South Asia reduces solar radiation over the concerned areas and thus reduces availability of moisture in the air. This has aggravated the impact of climate change. The root cause of the brown fog is sulphur dioxide, nitrogen oxides and particulate matter emitted by foundries and other industrial units using coal as fuel in the region extending from Bengal and Bihar to Uttar Pradesh and Gujrat in India. These emissions are likely to multiply with increasing use of coal for intensification of industrial activity in India.

    Particulate matter in high proportion causes cooling of air and is cause for creation of high pressure zones that can push moisture laden winds away from the area. The particles being small in size tend to suppress rainfall because the water droplets that condense on them are light enough to remain upward. High pressure zones, such as the one that develops over the northern areas of Pakistan and Afghanistan, are formed when the concentration of particulate matter in air over land is high. Carpet bombing was overwhelmingly intense in Afghanistan during the critical period when the winter storms cross over into Pakistan. Accordingly the air over the entire territory must have had the level of particulate matter beyond critical limits. As such the high pressure zone so formed did not allow the winter storms to reach Pakistan. It might be interesting to note that climate change of similar nature was also noted when Hiroshima and Nagasaki were destroyed by atomic bombs. Temperature of the macroenvironment recorded a rise and the macroclimatic conditions had changed.

    Crutzen, of the Max Planck Institute for Chemistry in Mainz, Germany, however attributes the brown fog created over the Tropics to biomass burning in the tropics and. Emissions from biomass burning and other anthropogenic activities have the potential to cause a cooling effect by blocking the warmth of the sun, which according to his calculations is almost ten times greater than the warming from greenhouse gases. The reason that the region on the north, south and east of the Himalayas does not show cooling is that much of the pollution is due to black soot, which absorbs the sunlight and then itself radiates heat towards the ground. According to Crutzen the tropical smog could have major consequences for the atmosphere, since for one thing they could upset the hydrological cycle that maintains the monsoons. They might also use up large amounts of the atmosphere's main cleansing agent, the hydroxyl radical, thus damaging the ability of the atmosphere to cleanse itself.

    This argument is supported by the observation that the brisk activity initiated in the mid-1990s on both sides of the Tibet Plateau in China and India has had to use coal for fueling the economy and to achieve a growth rate of their GDP of over 8 percent. The natural outcome of this race to achieve high growth rate in the name of improvement of quality of the people and thus to gain supremacy in the Region is impoverishment of resources and the consequent degradation of the environment.

    4. Irrigation System
    The other Manmade intervention that has spanned over at least half a century as a non-sustainable development activity is the irrigation system that has outlived its age have resulted in warming of the Arabian Sea and thus caused an irreversible damage to the ecosystem of this part of the earth. It has impoverished the entire delta area comprising the Thatta and Badin Districts of its only resource: Freshwater!

    The irrigation system has diverted the freshwater into the agricultural fields and very little freshwater flows into the Arabian Sea. This is not all; no freshwater flows into the Arabian Sea from any river on the coast of East Africa, the Gulf Countries, Tigris and Euphrates, the small rivers of Balochistan, the Indus delta in Pakistan, and the Tapti and Narbada on the western coast of India. It goes without saying that having dammed the rivers the Arabian Sea has been damned by making its coastline hyper-saline.

    The hyper-salinity at the coastline is nearly 4 percent compared with 3.5 percent salinity of the seawater. The hyper-salinity is the result of high rate of evaporation caused by the high temperatures on land which forms the heat zone that drives the heat engine of the monsoon system.

    The development activities with respect to irrigation system have deprived the Indus delta of the 8.2 MAF water flow that it used to get in the 1950s i.e. before construction of the Kotri Barrage. This activity reduced the flow of freshwater downstream Kotri. Consequent upon the reduced flow, the Indus delta instead of protruding started receding and is now allowing seawater to intrude up to Kotri Barrage. This then is yet another irreversible damage done to the ecosystem of the Indus Delta (Mirza Arshad Ali Beg, Ecological Imbalances in the coastal areas of Pakistan and Karachi harbour, Pakistan Journal of Marine Sciences, 4(2), 159-74, 1995), (H.T. Sorley (1964) The Gazetteer of West Pakistan: The Former Province of Sind, Government of West Pakistan, Lahore, pp-11,).

    4.1 Seawater-Coastal Land Interaction
    Salinity values recorded recently are in conformity with the change in ecology of floodplains and delta area after the mid-1960s, and the adverse and irreversible impacts it has had in
    i) depriving the delta area of its share of freshwater on which the traditional rice crop was harvested, and ii) inducing seawater intrusion by extensively harvesting the groundwater.

    The changes brought about by construction of embankments from Kashmore to the sea and reduced flow or no flow downstream Kotri have reduced the aquifer discharge and increased its salinity besides inducing major changes in the deltaic ecosystem. The earlier volume of normal flow into the channels and creeks has been drastically reduced, while the pattern of water flow has been completely altered during the last fifty years. The large delta with an intricate network of rivulets and creeks had shrunk after the construction of embankments and was restricted to two small channels Turshian and Khobar. The freshwater flow into the creeks has been restrained to periods of massive flood flow. This was, for example, the observed situation in December 1992 and January 1993, 1997, 2006, 2010 and 2011.

    Surveys conducted in 1993-94 noted that freshwater was available in the coastal areas and that kept the salinity level within optimum limits. The electrical conductivity of the samples of seawater collected from the root zone of a few mangrove trees in Keti Bunder had indicated that the salinity in the region was in the range of 33 to 35 ppt. Similar range of values was noted for the seawter at the Hajamro Creek near the high water line about 15 km to the Southwest of Keti Bunder. These values were found lower than those observed for the creeks near Karachi viz. 38 to 40. The observed salinity range of 35 ppt suggests that adequate interaction of the seawater with freshwater was taking place to effect the much needed dilution. In the past, however, the water would flow through the creeks during the floods; and would inundate the deltaic zone; it would thereafter be restricted to streamflow during the winter months.

    The inflow-outflow balance that was, until the mid-1950s, being maintained by river flow and flood flow is, since the mid-1990s replaced by seepage from canals and distributaries. This has caused the reversal in the flow of groundwater from the canals instead of the stream flow from the Indus. The seepage of the order of 0.3 MAF out of the 3.0 MAF received from Kalri Baghar Feeder was, in the 1990s seen flowing into old river basins, creeks and depressions (Mirza Arshad Ali Beg, Ecological Imbalances in the coastal areas of Pakistan and Karachi harbour, Pakistan Journal of Marine Sciences, 4(2), 159-74, 1995). Because of the failure of the system, the seepage flow into the creeks has increased to 0.6 MAF. The creeks are, as noted above, no longer hypersaline, with salinity ranging above 35 ppt; they are hyposaline with salinity in the 23 to 29 ppt range, the dilution having been effected by the seepage which has, according to the above estimates exceeded the normal 10% and is rated at 15 to 25% as a result of cultivation of the water intensive rice crop that by the traditional system also requires puddling the fields.

    Salinity Intrusion: Reduction in streamflow is responsible for salinity intrusion in the sense that with reduced flow or no flow of water downstream Kotri reversed the outflow-inflow system and outflow of freshwater had to yield to inflow of saline water from the sea. Intrusion of seawater into the Indus River has been noted by the findings on increase in total salt content in and along the Indus River stream. The total salt content has been found to increase from 120 to 145 mg/l at upstream Kotri Barrage to 190 to 220 mg/l at Kotri Bridge (Railway), 650 to 810 mg/l at Talib Dal Goth; 750 to 1040 mg/l at Sonda; 1050 to 1570 mg/l at Sujawal; 2000 to 7800 mg/l at Odero Lal; 28,000 to 39,000 mg/l at Jange Sir; 32,000 to 44,000 mg/lat Kharo Chann and 37,000 to 44,000 mg/l at Keti Bunder (Mirza Arshad Ali Beg, Lead Author of Higher Education Commission Project: Ecosystem Research on Water Resources in Sindh West December 2010).

    The tidal channels in Indus Delta are generally hyper saline with the salinity range of 38 to 45 ppt over the period when there is no water flowing from the river and irrigated fields. It is hypo-saline from June to September when the rains and the runoff from Indus River reduce the sea water Salinity to 26 to 30 ppt (Harrison et al., 1994). The more recent surveys conducted in the year 2010 have noted the values recorded in the following Table (Mirza Arshad Ali Beg, Lead Author of Higher Education Commission Project: Ecosystem Research on Water Resources in Sindh West December 2010):

    Table: Temperature, Dissloved Oxygen & Total Dissolved Solids in Seawater of Creeks
    Location Date Temperature DO Total Dissolved Solids
    Manora Channel 11-01-2010 21.3 1.18 35800
    Manora Channel 05-08-2010 34.5 1.79 36400
    Ziarat hasan Shah Creeks 21-12 2009 18.9 - 19.1 3.92 ÔÇô 4.12 36300 -39900
    Ziarat hasan Shah Creeks 30-07 2009 20.1 4.9 21000
    Ziarat hasan Shah Creeks 26-05 2008 31.9 4.76 42600
    Gharo Creek 30-07-2009 19.5 5.11 31400
    Gharo Creek 19-12-2009 18.7 2.16 19380
    Kharo Chann 06-03-2010 24.1 5.11 36500
    Kharo Chann 06-06-2010 32.2 4.35 25500
    Kharo Chann 06-02-2010 31.8 & 32.9 2.24 3.18 44800 & 47800
    (Cyclone expected)
    Hajamro Creek 10-03-2010 29.6 5.22 38400
    Umbra Creek 06-03-2010 26.5 1.92 17100
    Jange Sir 10-03-2010 27.1 5.29 25200
    Jange Sir 02-06-2010 30.4 3.94 39300
    Jange Sir 02-06-2010 31.2 3.36 40900
    Keti Bunder 02-06-2010 31.1 4.08 42,800

    It has been found during the surveys that salinity of seawater has increased though only slightly. Seawater on sea front generally has TDS ~ 38200 -38800 ppm and DO 4.0 ÔÇô 4.4 mg/L at 30.1oC; while seawater in sheltered channels generally has TDS in excess of 40,000 and DO ~ 3.0 at 30.4 oC. It was also found that the salinity given by total dissolved solids was in excess of 44000 ppm in the days preceding the cyclonic activity in early June 2010 (Mirza Arshad Ali Beg, Lead Author of Higher Education Commission Project: Ecosystem Research on Water Resources in Sindh West December 2010).

    4.2 Reduction in Silt Load
    Diversion of water into dams and barrages has reduced the availability of silt load in the streamflow downstream Kotri. The Indus and its tributeries carry detritus in suspended material and bed loads varying from 0.5 to 500 million tons. It has been estimated that some 675 MT of sediment was being discharged by the Indus prior to the construction of the dams and barrages, 60% of which used to be deposited in the river channels and approximately 250 MT reached the estuary where there was a 9 m accretion in the flood plain during the past 5000 years and a seaward growth of 80 km in the delta during the last 2000 years(J.D. Milliman, G.S. Quraishee and Mirza Arshad Ali Beg (1984) Sediment Discharge from the Indus River to the Ocean: Past, Present and Future, Marine Geology and Oceanography of Arabian Sea and Coast¬al Pakistan ed. B.U. Haq and J.D. Milliman, Van Nostrand Reinhold Company, New York, pp 65-70). The construction of barrages has provided the obstacles in the flow of water and has led to selective settlement of detritus there and/or to their diversion into canals and onwards into the farms. As such the sediment load now reaches the sea only during flood flow and does not constitute even 5% of what was brought in the 1980s. Accordingly sediment flow into the Indus Canyon and the deltaic system may have been seriously reduced.

    Suspended matter: The suspended matter in the creek areas has an annual range of 25-170 ppm. The higher values were observed during the southwest monsoon period (usually May-August) and also during the period preceding the 2010 cyclone: Phet. The average suspended load during June-July was between 80-115 ppm. However, higher values (115-170 ppm) were also recorded at some places in the Gharo/Korangi Creek system. Lower suspended matter (25-50 ppm) was recorded during March and the September-November period. The suspended load in these creeks also exhibits variations with the degree of turbulence during a tidal cycle. During the flood season in the Indus River (September) the suspended load rises to about 4000 ppm in Khobar Creek and to about 1500 to 2000ppm in the adjacent creeks.

    5. Land Subsidence
    Reduced water flow downstream Kotri has also resulted in land erosion and land submergence. Erosion downstream Kotri barrage has exposed the bedrock which is now only about 3 meter level, which is within the high tide range.

    The seawater current pattern has apparently assumed adequate potential energy to erode the Indus river estuary and surfaces of the land over the creeks and this is the reason that many of the islands between Keti Bunder and Mirpur Sakro have lost their identity, Lakha Island in Union Council Boharo in Taluka Mirpur Sakro, being an example.

    This leads to the conclusion that erosion of the coastline is responsible for the observed intrusion of seawater and sea level rise is not apparent yet.

    6. The Cyclones
    Increase in sunshine period, high temperatures over the extensive heat zone, windstorms and low rainfall all appear to fit into the general monsoon pattern. These are also the ideal conditions for Tropical Cyclones, which occur primarily during summer in the Northern Hemisphere and during autumn in the Southern Hemisphere. The necessary conditions for development of cyclones are warm ocean waters with temperatures of at least 26┬░C, a tropical atmosphere that can quite easily kick off convection causing thunderstorms, low vertical shear in the troposphere, and a substantial amount of large-scale spin available, either through the monsoon trough or easterly waves.

    In the North Arabian Sea the ocean reaches its warmest temperatures in the month of May and thus the conditions for peaking of the cyclones are obtained much earlier than late June which is the time for maximum solar radiation in the tropical Northern Hemisphere. The atmospheric circulation in the tropics is also favorable for tropical cyclones.

    One of the indicators of intensity of monsoon activity is upwelling that comes along with the Mozambique current. In the years 2007 and 2010 there was reason for upwelling to intensify because
    i) input of sunshine over the land area of Pakistan had increased, and ii) salinity gradient was created at the mid-tropical region of the Arabian Sea where the cool hyposaline layers of seawater from the Antarctica were creating deep gradients with the hypersaline layers from the heated up coastline along the Arabian Sea.

    The thunderstorm that struck the Northern Areas and Azad Kashmir from the start of second week of May in 2007 and also in 2010 was part of the western system and its incidence was not unusual. Its intensity and the damage done were severe in each case.
    In the month of July 2011 Pakistan received below normal monsoon rains; however in August and September a strong weather system entered the areas of Sindh from the Indian States of Rajasthan and Gujrat in August and gained strength with the passage of time. That was responsible for the heavy downpours in the southern part of the country where above normal monsoon rains were recorded. The four weeks of continuous rain created an unprecedented flood situation in Sindh.
    District Badin received record breaking rainfall of 615.3 millimeters during the monsoon spell breaking earlier records of 121 millimeters in Badin in 1936. The area of Mithi received record rainfall of 1,290 millimeters during the spell, where maximum rainfall recorded was 114 millimeters in 2004. The heavy cloudburst on August 10, 2011 induced continuous rainfall for 46 hours in Badin District where 350 millimetres of rain was recorded. According to estimates the total volume of water fallen over Sindh during the four weeks was above 37 million acre feet. (Pakmet.com.pk. Retrieved on 19 September 2011).

    7. SOCIOECONOMIC PROBLEMS
    Climate variability and change profoundly influence social and natural environments throughout the world, and Pakistan is no exception. The consequent impacts on natural resources, agriculture, energy and industry are large and far-reaching. The seasonal to inter-annual climate fluctuations have singled out the criticality of the agricultural production system, and of the limitations on availability of key resources, and the demand for energy, while long-term climate change has appeared in the form of alterations in landscapes, recreational activities, agricultural productivity, and the services that ecosystems supply.

    The impact of climate change on the economy, particularly agricultural activity, will nevertheless be highly disturbing since per capita water availability will be reduced to below 900m3 and Pakistan will remain a water stressed country. Availability from tube wells will go down each year since the groundwater sources will not be adequately charged.

    Rising sea levels, water shortages, melting Arctic ice, and extreme weather events, are indicators of the direct and indirect impact climate change. The impact is leading to degradation of the environment and to impoverishment of resources which in turn is cause for poverty all over. Poverty is the consequence of impoverishment of resources, which acts as an accelerant of instability and conflict. It is perhaps in order to remove the deficiencies caused by the conflicts that places a burden on civil society to act. When compared with other national security challenges, climate change is considered by the rulers of the Industrialized countries as representing a great or a greater threat. In Pakistan, unprecedented floods have killed several hundred people and displaced a few millions, global warming is a myth as well as a reality.

    When floods swept through the country in late July 2010 and again in 2011, there was extensive loss of the already impoverished resources. The same phenomena occurred in each episode starting from the cyclone events of 1999, 2007 and 2010, the rainstorm of 2003 and 2011, the 2005 earthquake and the landslide at Atta Abad in 2009. Each time there was displacement of people and stress on public and private resources.

    Instead of alleviation of poverty and redressing the stresses created by impoverishment of resources the get-rich-quickly and enjoying the richness syndrome countries found such incidents as opportunity to link them with threats to security and stress on weak and fragile states, and the creation of conditions that stimulate extremism and terrorism.

    The floods, as well as the heat wave in Russia, have been attributed by some meteorologists to a dome of high atmospheric pressure which has diverted the jet stream further south than usual. Instead of dropping the rain where it normally would in Russia the jet stream came down to Pakistan. Combined with the rainfall from the seasonal monsoon in south Asia, this meant too much rain for Pakistan and too little for Russia.

    The connections between climate change-induced events and security issues are considered real in view of the disruption of supply routes for NATO forces in Afghanistan by the floods.

    The above analysis paints a gloomy picture and presents a worst-case scenario, which deserves serious consideration. Pakistan has already lost time in adopting conservation practices. In terms of wastage it is ranked among the countries that are at the advanced stage of development but in terms of GDP growth versus growth of population it is among the failed states. This shows that economic progress in Pakistan has since been halted and now it is on the path to collapse. It is now time only for crash programmes to save our resources and to live within our means, with a limited budget of less than 90 maf (Mirza Arshad Ali Beg http://www.dawn.com/2002/09/09/ebr14.htm).

    Child malnutrition was already a serious problem in Pakistan long before the floods. Pre-flood data revealed 77 million of PakistanÔÇÖs 175 million people suffered from hunger and 45 million were malnourished. In the province of Balochistan, 27 percent of children under the age of five were malnourished. In Punjab, the province that is home to the majority of Pakistanis, 17 percent of children under five were malnourished, and in KP, 13 percent.

    Floods and other climate related disasters cause rise in food prices in a region which is home to half of the world poor. India, Pakistan, Bangladesh and other countries have witnessed sky rocketing hike in the prices of daily essentials in recent years. Floods, droughts, bad governance and environmental changes have been held responsible for escalation of price because most of agriculture zones are hit by floods and droughts.

    Environmental Degradation, Desertification & Poverty Nexus
    Pakistan is located in high heat zone area where the intense heat and high aridity has caused widespread degradation of the ecosystem. The area presents a picture of social pollution playing a dominant role in impoverishment of the meager resources of the land to fulfill the demand for urban and industrial development.

    Over exploitation of the meager resources has given rise to degradation of soil, water and vegetation. These three elements of the natural ecosystem serve as the natural foundation for human existence. The fragile ecosystem in Pakistan, has lost the productivity of soil through an irrigation system that has outlived its age, impoverishment of plant, animal, soil and water resources has become irreversible, and has permanently reduced its capacity to support human life.

    Impoverishment of resources leading to environmental degradation is both a cause and a consequence of poverty. Therefore, impoverishment of resources leads to desertification which in turn leads to poverty, and the vicious circle completes when poverty leads to further desertification. Operation of the vicious circle is very much apparent from the poverty induced desertification that is rampant all over the rural areas. Shortage of liquid and gaseous fuel created huge demand for firewood. The rural and coastal area is where some small trees are still around and that has prompted the relevant facilitator to go all out for cutting the trees by the root and supplying it to the charcoal kilns owned by him. Hundreds of charcoal kilns have been built just to fulfill this urban and industrial demand and thus the already impoverished rural area has been impoverished further while the short term gain has pushed the wood cutter to absolute poverty.

    Level of poverty is increasing further in this arid zone of the world due to ruthless exploitation of the meager resources compounded by frequent droughts, floods and loss of land due to erosion by the sea. The trend, of uprooting shrubs, cutting trees for fuel wood, over grazing due to over stocking, and sand /gravel removal from the river beds, is spreading from the plains to the interior and towards the hills and mountains. If the current trend continues, the already exhausted rangelands will not be in a position to support the existing level of livestock population of the arid region. The economic impact of such a situation has had direct effect on the population and is likely to increase the level of poverty amongst the herders of the area.

    Such continuous and uninterrupted degradation of natural resources is pushing the ever growing population for its livelihood to migration to urban centres, which are not prepared to absorb it. The migration of the rural population to the urban areas has amassed the urban areas with social problems by increasing slums around the cities. This situation has created law and order problem in the cities. Because of increasing poverty and lack of basic amenities the most vulnerable sections of population like the children and women are being affected and will be badly affected in the next few years.

    Although formal area poverty profile has not been prepared for Thatta and Badin, the secondary data generated by the project preparatory technical assistance (PPTA) shows that 54% are among the ÔÇ£poorestÔÇØ category and 79% may be characterized as poor. In a 2004 national survey PakistanÔÇÖs poorest district was Thatta, and Badin was not far behind. Family income of Rs 5 to7 thousand, arrived at by this Author, already suggests that almost 90% of the families live below the poverty line. All members of the family have to contribute to sustain their subsistence living.

    Based on the above analysis, it is possible to conclude that poverty per se is not a problem of the people of Pakistan; it is the impoverishment of resources at the hands of the get-rich-quickly Syndrome that has induced poverty. The poor have otherwise learnt to live within their means and hence poverty irks them only when they find that the get-rich-quickly syndrome has left him far behind his neighbor.

    Posted by: Anonymous | 6 years ago | Reply
  • Very Happy to see such

    Very Happy to see such creative ideas mushrooming among architects which are indeed eco friendly. I greatly admire Laurent Fournier's idea and passion.
    Wishing him for venturing more and more into this field.

    Posted by: Anonymous | 6 years ago | Reply
  • Excellent article. Yes.

    Excellent article. Yes. Traditional methods of construction offers promise for adoption even now as they are eco-friendly.
    As a construction material, bamboo is as strong as steel and sturdier than concrete. Moreover, in tropical areas bamboo is a much less expensive construction material than either steel or concrete and is always readily available. In tropical areas, therefore, building with bamboo makes better economic sense than building with steel or concrete, except where land values are high.
    Bamboo has a long and well-established tradition as a building material through out the worldÔÇÖs tropical and sub-tropical regions. It is widely used for many forms of construction, in particular for housing in rural areas. Bamboo is a renewable and versatile resource, characterized by high strength and low weight, and is easily worked using simple tools. It is widely recognized as one of the most important non-timber forest resources due to the high socio-economic benefits from bamboo based products. It is estimated that there are 1200 species growing in about 14.5 million hectares area. Most of them grow in Asia, Africa and Latin America.
    Bamboo is the worldÔÇÖs fastest growing woody plant. It grows approximately 7.5 to 40cm a day, with world record being 1.2m in 24 hours in Japan. Bamboo grows three times faster than most other species. Commercially important species of bamboo usually mature in four or five years time, after which multiple harvests are possible every second year, for upto 120 years in some species and indefinitely in others. Bamboo also excels in biomass production, giving 40 tons or more per hectare annually in managed stands. It accounts for around one-quarter of biomass produced in tropical regions and one-fifth in subtropical regions.
    It has been used successfully to rehabilitate soil ravage by brick making in India, and abandoned tin-mine sites in Malaysia. It shelters top soil from the onslaught of tropical downpours, preserves many exposed areas, providing micro-climate for forest regeneration and watershed protection It is often introduced into the banks or streams or in other vulnerable areas, for rapid control of soil erosion; one bamboo plants closely matted roots can bind upto six cubic meters of soil.
    GENERAL USES
    a) Soil stabilization, wind break, urban waste water treatment and reduction of nitrates contamination
    b) Creating a fire line in traditional forests-due to the high content of silica.
    c) Removing atmospheric carbon- bamboo can capture 17 metric tons of carbon per hectare per year, i.e., effectively than any other species.
    d) The shoots are edible.
    e) Building and construction.
    f) Small scale and cottage industries, for handicrafts and other products.
    g) New generation products as wood substitutes
    h) Industrial products
    i) Transportation industry- truck bodies, railway carriages etc.
    j) Boards and furniture
    k) Medicine
    l) Paper and pulp industry
    m) Long time source of biomass for industry
    n) Fuel source- capable of generating 1000-6000 cal/g- for households and small industries is an age-old, continuing practice.

    PROPERTIES
    TENSILE STRENGTH
    Bamboo is able to resist more tension than compression. The fibres of bamboo run axial. In the outer zone are highly elastic vascular bundle, that have a high tensile strenght. The tensile strenght of these fibres is higher than that of steel, but itÔÇÖs not possible to construct connections that can transfer this tensile strength. Slimmer tubes are superior in this aspect too. Inside the silicated outer skin, axial parallel elastical fibers with a tensile strength upto 400 N/mm2 can be found. As a comparison, extremely strong wood fibers can resist a tension upto 50 N /mm2.
    COMPRESSIVE STRENGTH
    Compared to the bigger tubes, slimmer ones have got, in relation to their cross-section, a higher compressive strength value. The slimmer tubes possess better material properties due to the fact that bigger tubes have got a minor part of the outer skin, which is very resistant in tension. The portion of lignin inside the culms affects compressive strength, whereas the high portion of cellulose influences the buckling and the tensile strength as it represents the building substance of the bamboo fibers.
    ELASTIC MODULUS.
    The accumulation of highly strong fibers in the outer parts of the tube wall also work positive in connection with the elastic modulus like it does for the tension, shear and bending strength. The higher the elastic modulus, the higher is the quality of the bamboo. Enormous elasticity makes it a very useful building material in areas with very high risks of earthquakes.
    ANISOTROPIC PROPERTIES.
    Bamboo is an anisotropic material. Properties in the longitudinal direction are completely different from those in the transversal direction. There are cellulose fibers in the longitudinal direction, which is strong and stiff and in the transverse direction there is lignin, which is soft and brittle.
    SHRINKAGE.
    Bamboo shrinks more than wood when it loses water. The canes can tear apart at the nodes. Bamboo shrinks in a cross section of 10-16 % and a wall thickness of 15-17 %. Therefore it is necessary to take necessary measures to prevent water loss when used as a building material.
    FIRE RESISTANCE.
    The fire resistance is very good because of the high content of silicate acid. Filled up with water, it can stand a temperature of 400┬░ C while the water cooks inside.
    THE WORKING OF BAMBOO
    METHODS
    1) Splitting
    The cane is split in halves and quarters and then driven apart by a wedge. It can also be split with a knife frame into four or eight segments as shown in (Fig 2(a) and 2(b)). By means of splitting you get halved canes, strips and battens. To get planks, all the nodes are smashed and the wall of the pole is split over its entire length and forced open until the wall of the pole lies flat. Up to the age of 18 months, the canes can be peeled. The strips can be used as ties or be woven to make strings and ropes.
    2) Shaping
    Bamboo available in nature is usually circular in cross section. But if bamboo is made to grow in a box of square shape it attains the shape of that box, so that it can be better used for making connections
    3) Bending
    Freshly cut, bamboo can be bent by heating and will keep this shape after drying. When heated above 150┬░ C, bamboo starts changing its shape and remains as such after it goes cold.

    PRESERVATION OF BAMBOO
    Bamboo is subject to attack by microorganisms and insects in almost any construction applications. The decay and biodegradation of bamboo culms during outdoor storage can be checked to a great extend by adopting a good storage yard practices. Culms should be stacked horizontally over raised wall to facilitate water drainage and air circulation. For reed bamboos, vertical stacking results in a small gain in pulp yield over horizontal stacking because the former suffers less fungal damage. The service life of bamboo is therefore, mainly determined by the rate of attack. A variety of methods to improve the durability of bamboo have however, been developed. Basically, there are two methods for increasing the durability of bamboo.
    NON CHEMICAL METHODS OR TRADITIONAL METHOD
    Non-chemical methods are otherwise known as traditional methods of preservation are widely used by villagers and is usually done on bamboos used for structural purposes. However, the treatment cost is almost nothing and thus can be carried out at village level without special equipment. This method includes curing, smoking, whitewashing and soaking.
    a) Smoking
    Traditionally, bamboo culms are placed above fireplaces inside the house so that the smoke and heat rises up and both dries and blackens the culms. It is possible that the process produces some toxic agents that provide a degree o protection. Alternatively, the heat generated by the fire could possibly destroy or reduce the starch content of the parenchyma cells by pyrolysis. This is considered an effective treatment against insects and fungi.
    b) White washing
    Bamboo culms and bamboo mats for housing construction are often painted with slaked lime. This is carried out mainly to enhance the appearance, but there is also an expectation that the process will prolong the life of the bamboo structure by preventing moisture entering the culms. It is possible that the water or moisture absorption is delayed or in some cases prevented which will provide a higher resistance to fungal attack.In Indonesia, bamboo mats are tarred and later sprinkled with a layer of sand. When this is dry, upto 4 coats of whitewash are applied. Plastering is also a common practice using cow dung mixed with either lime or mortar.
    c) Curing
    Bamboo culms are treated during or immediately after extraction and before stacking in the storage yard. Curing involves harvested culms, with branches and leaves intact, in open air. The leaves continue to transpire causing the starch content of the culms to fail.
    d) Soaking
    The culms are submerged in either stagnant or running water, or mud for several weeks. This is one of the best methods to preserve bamboo against the attack of microorganisms and insects.
    CHEMICAL METHODS
    Methods that use preservative chemicals are generally more effective than non-chemical methods in the protection of bamboo under storage, but they are not always economical or feasible. The penetration of liquids into the culms takes place through the vessels in the actual direction from end to end. The vessels account for only 5-10% the bamboo cross-section. Thus even when the vessels are filled to saturated point, the bamboo can still be vulnerable to fungal insect attack if the preservative does not diffuse sufficiently into the main tissue of the culms. The chemical treatment techniques are as follows:
    a) Butt treatment
    The butt ends of the freshly cut culms with the branches and leaves intact are placed in a drum containing the preservative. The continued transpiration of the leaves draws the chemical solution into the vessels of the culms. This process is very slow and often the vessels do not take up enough of the liquid to preserve by diffusion, the surrounding fibers and parenchyma cells. The preservative in the barrel must be replenished regularly in order to maintain the desired level. When the treatment has been completed, care should be taken in the disposal of the contaminated foliage. Butt treatment is usually adopted to bamboo posts.
    b) Open tank method for cold soaking
    This method is economical simple and provides good effective protection for bamboo. Culms, which have been prepared to size, are submerged in a solution of water-soluble preservative for a period of several days. The solution enters the culms through the ends and sides by means of diffusion.
    c) Boucherie method
    This method requires the culms to be in green condition. Best results are obtained when the bamboo is used during or shortly after the rainy season. The water transporting part of the culm can be penetrated completely and the treatment itself is applied by an inexpensive installation. Preservative is fed by gravity from a container placed at a higher level than the culms through pipes into the base ends. The treatment is terminated when the solution at the dripping end shows a sufficiently high concentration of chemicals. Allowing the bamboo to dry slowly in the shade for a period of at least two weeks after treatment ensures that the solution diffuses into all of the tissues surrounding the vessels.
    d) Pressure treatment
    Pressure treatment, using either creosote or water borne preservatives offers the best method of preservation for bamboo culms. The applied pressure ranges from around 0.5-1.5N/mm2 and as such requires special plants and equipment. Costs are high, but a service life upto 15 years can be expected from adequately treated bamboo when used in the open and in contact with the ground.
    e) Hot and cold bath process
    The bamboo is submerged in a tank of preservative, which is then heated, either directly over a fire or indirectly by means of steel coils in the tank. The bath temperature is raised to 90o C and maintained as such for 30 minutes and then allowed to cool. The bamboo should be allowed to dry slowly to provide further diffusion of the preservative to take place.
    f) Glue line treatment
    This is specific to bamboo mat board and involves adding preservatives to the glue during manufacture. Additives that have been shown to provide effective preservation treatment without impairing the bond strength of the mat include 1% chlordane or 1% sodium octaborate tetra hydrate with a 1:2 diluted pH solution containing 17% solid content.
    BAMBOO HOUSING
    The majority of bamboo construction relates to the rural community needs in developing countries. As such domestic housing predominates and in accordance with their rural origins, these buildings are often simple in design and construction relying on a living tradition of local skills and methods. Other common types of construction include farm and school building s and bridges. Further applications of bamboo relevant to construction include its use as scaffolding, water piping and as shuttering and reinforcement for concrete. In addition, the potential number of construction applications has been increased by the recent development of a variety of bamboo-based panels.
    DOMESTIC HOUSING AND SMALL BUILDINGS
    There is a long-standing tradition of bamboo construction, dating back to many hundreds of years. Different cultures have found in this material an economical system of building, offering sound yet light and easily replaceable forms of shelter. The methods, activities and tools are often simple, straightforward, accessible even to the young and unskilled. Despite human exploitation and unfavorable treatment, trees maintain its contributively role towards the dwelling of mankind. Man has for centuries enjoyed the benefits of the free gift of nature.

    Housing is one of the priority items and sensing the current shortage of the dwelling units, the present administrative leaders around the world find tough to hit upon a solution for. The search for an efficient economical and replicable housing solution based on the contextual needs is the need of the hour. Apart from the other substances already in practice, bamboo appears to be the most promising material. Bamboo building construction is characterized by a structural frame approach similar to that applied in traditional timber frame design and construction. In this case, the floor, the wall, the roof elements are all interconnected and often one dependent on the other for overall stability.
    Bamboo culms are used in building. The thicker culms or strands made up of several culms are employed for load bearing materials such as girder, purlin, post or rafter. Bamboo based materials are widely used too. In its natural condition as solid culms, halved culms or as longitudinally split strips, bamboo has been used in almost all parts of house construction except for the fireplace and the chimneys. These are described in detail below:
    Foundation
    The use of bamboo for foundation is rather restricted. This is mainly due to the fact that like timber when in contact with damp ground, they deteriorate and decay very quickly unless treated with some very effective preservatives. However, in spite of their short life considerable use of bamboos is made as foundation or supporting posts in case of houses built on raised platforms. The types of bamboo foundations identified are:
    (a) Bamboo in direct ground contact: Bamboo is placed either on the surface or buried. For strength and stability, large diameter and thick walled sections of bamboo with closely spaced nodes should be used. Where these are not available, smaller sections can be tied together. It can decay within six months to two years, and hence preservative treatment is recommended.
    (b) Bamboo on rock or preformed concrete footings: where bamboo is being used for bearings, it should be placed out of ground contact on footings of either rock or preformed concrete. The largest and stiffest sections of bamboo should be used.
    (c) Bamboo incorporated in to concrete footings: the poles are directly fit into concrete footing. It can take the forms of single posts or strip footings.
    (d) Composite bamboo/concrete columns: a concrete extension is given to a bamboo post using a plastic tube of the same diameter. The result is a bamboo post with an integral durable foundation.
    (e) Bamboo piles: it is used to stabilize soft soils and reduce building settlement. The treated split bamboo piles were filled with coconut coir strands wrapped with jute. The sections were then tied with wire. After installation of the piles the area was covered with a sandy material.
    Flooring
    The floors may be at ground level, and therefore consists only of compacted earth, with or without a covering of bamboo matting. The preferred solution is to raise the floor above the ground creating a stilt type of construction. This improves comfort and hygiene and can provide a covered storage area below the floor. The surface of earth floor is sometimes made more stable by paving it with crude bamboo boards made by opening and flattening whole culms. The various types used are:
    (a) Small bamboo culms: they are directly tied and nailed together.
    (b) Split bamboo: culms are split along their length into strips, several centimeters wide.
    (c) Flattened bamboo: formed by splitting green bamboo culms removing the diaphragms, then rolling and flattening them. The resulting board is laid across the joists and fixed by nailing or tying. They are screeded with cement mortar for reasons of hygiene and comfort as they are uneven and difficult to clean.
    (d) Bamboo mats: thin strips varying in size from 5-6mm or 10-15mm and thickness of 0.6-1.2mm. These slivers are then woven into mats of different sizes according to the available hot-press plates and userÔÇÖs demands. After drying the mats to 6-10% moisture content, sufficient glue is applied to ensure enough bonding between the overlapped areas. In construction using bamboo mats, phenolic resins are employed.
    (e) Bamboo plastic composites: it is an innovative technology in which bamboo fiber is the raw material and compounded with plastic as the core material of the flooring. This has higher water resistance and dimensional stability properties than those of normal floorings.
    The ratio of plastic should be over 30% for higher water resistance and dimensional stability. Polypropylene is recommended, and if recycled plastic is used it is ideal to reduce the cost of production. The density of substrate should be higher than 1gm/cm3 to ensure best mechanical properties. It prevents the floor from swelling and cracking, which is the disadvantage of other timber based flooring materials.
    Walls
    The most extensive use of bamboo in construction is for the walls and partitions. The major elements, the posts and beams, generally constitute part or structural framework. They are to carry the self-weight of building and loads imposed by the occupants and the weather. An infill between framing members is required to complete the wall. The purpose of the infill is to protect against rain, wind and animals, to offer privacy and to provide in plane bracing to ensure the overall stability of the overall structure when subjected to horizontal forces.
    Roofing
    The roof offers protection against extremes of weather including rain, sun and wind, and to provide shelter, clear and usable space beneath the canopy. Above all it must be strong enough to resist the considerable forces generated by wind and roof coverings. In this respect, bamboo is ideal as a roofing material- it is strong, resilient and light weighted. The bamboo structure of a roof can comprise of purlins, rafters and trusses.
    (a) The simplest form consists of a bamboo purlin and beams, supported on perimeter posts. Halved culms are then laid convex side down, edge-to-edge, spanning from the ridge to the eaves. A second layer, convex side up, is then laid to cover the joints.
    (b) Corrugated sheets made out of bamboo are also used commonly as roof covering. The bamboo mats are dipped in resin, dried and heat pressed under pressure in a specially made platen, to give strong, reliable sheets of bamboo, which is lightweight. It has good insulation properties too.
    (c) A layer of bitumen is sandwiched between two mats of bamboo forming a semi rigid panel. The mats can be fixed to rafters at 200-250mm center to center. A bituminous or rubberized weatherproof coating is then applied to the finished roof.
    (d) Plastered bamboo: A cement plaster, with or without the addition of organic fibres, is traditionally applied to bamboo roofs, to get stronger roof coverings. Various forms of trusses are also adopted using bamboo culms of diameter ranging from 40mm-100mm. The king post trusses are the most common and the simplest.
    Scaffolding
    Because of the favourable relationship between load-bearing capacity and weight, bamboo can be used for the construction of save scaffoldings even for very tall buildings. Even at their connections the canes are not treated in any way. Only lashed joints are used. The cane extension is carried out by lashing the cane ends together with several ties. The ties are arranged in such a way that a force acting vertically downwards wedges the nodes in the lashing. With larger cane diameters the friction can be increased by tightening the rope between the canes. The vertical and horizontal canes used for scaffolding are almost exclusively joined using soft lashing. This technique has the great advantage that the joints can be re-tensioned to the right degree without difficulty and also quickly released again.
    ADVANTAGES OF BAMBOO
    The various advantages of bamboo are mentioned below.
    1) Light, strong and versatile.
    2) Light, strong, versatile.
    3) Environment friendly.
    4) Accessible to the poor.
    5) Self renewing resource
    6) Fast growing.
    7) Highly productive.
    (Source: Civil Engineering)
    Dr.A.Jagadeesh Nellore(AP),India

    Posted by: Anonymous | 5 years ago | Reply
  • hii...this is one excellent

    hii...this is one excellent article. i am doing my final semester b.arch in andhrapradesh. i've chosen my thesis topic as "flood and cyclone resistant fisherman village." can you please give me more info about the location and type of the houses built in sunder bans after cyclone aila?? i want to go there for a case study.

    Posted by: Anonymous | 3 years ago | Reply
  • He's challenging the prevailing thought processes that lead to the decision of using concrete and other conventional materials. It will be a great achievement if this takes the form of another green revolution. Fournier came to our college PMCA to conduct a workshop and even though we could not interact with him as it was for the fourth years, whatever I've heard of him makes me want to join this movement of his. I hope the government cooperates because this is a common solution for so many problems.

    Posted by: Durjoy Biswas | one year ago | Reply
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