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241.
Ecology of Karez irrigation: a case of Pakistan 总被引:2,自引:0,他引:2
M. Rahman Dr. 《GeoJournal》1981,5(1):7-15
Though hard to construct, difficult to maintain, and yet limited in scope, the karez irrigation system has been an integral part of agricultural landscape in Baluchistan province of Pakistan for the last 2500 years, if not earlier. The irrigation system is well adjusted with the social and political institutions in Baluchistan and synchronizes with the local economies.Archaeology indicates that the idea of karez irrigation originated in the Indus Valley Civilization of Pakistan, while philology, method of construction, migration of karez technocrats support the view that the technology was introduced from Afghanistan and not from Iran as is generally accepted. An attempt has been made in this paper to examine the ecology of karez irrigation in Pakistan in terms of its nature, origin, diffusion and persistence including the recent changes in the system wherein tunnels are being replaced by cement pipes and Delay Action Dams.. The delay action dams are being introduced to augment the subsurface water supply. The tube-wells and modern electric-powered pumps are impinging on the karezes and may ultimately destroy the fragile ecosystem of Baluchistan, including the age-old karez irrigation system. 相似文献
242.
243.
Theoretical and Applied Climatology - Bangladesh is one of the countries in the north-eastern part of South Asia, and it covers an area of about one hundred forty-eight thousand (1.48 × 105)... 相似文献
244.
Azad Md. Abul Kalam Islam Abu Reza Md. Towfiqul Ayen Kurratul Rahman Md. Siddiqur Shahid Shamsuddin Mallick Javed 《Theoretical and Applied Climatology》2022,148(3-4):1261-1278
Theoretical and Applied Climatology - Understanding changes in monsoon precipitation patterns is crucial as it determines the occurrence, intensity, and duration of floods and droughts in... 相似文献
245.
ATM Sakiur Rahman Md. Kamruzzama Chowdhury Sarwar Jahan Quamrul Hasan Mazumder 《Journal of the Geological Society of India》2016,87(2):179-193
In Bangladesh, agriculture plays a major role in the national economy. In the drought prone Barind area in NW Bangladesh, cropping intensity has increased almost double since late eighties of last century (from 1985) because of the introduction of groundwater irrigation. Long-term behavior of groundwater table (GWT) in the drought prone Barind area has been studied using MAKESENS model in the wake of massive installation of tube-wells. The study reveals that the maximum and minimum depths to GWT during 1991-2010 show on average declining trend of 4.51 m and 4.73 m. The long-term prediction for the period of 2020-50 assuming the current rate of groundwater withdrawal is that the declining trend will be 1.16 to 1.59 and 1.07 to 1.82 times more for maximum and minimum groundwater depths respectively in comparison to the present. The rigorous exploitation of groundwater for irrigation, decreasing rainfall and surface geological attributes lead towards declining trend of GWT. This will hamper the country’s food security and ultimately threaten its socio-economic sustainability. So the appropriate strategies for the management of groundwater resource on a sustainable basis should be the priority for maintaining agricultural productivity. 相似文献
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248.
The geographic location of Bangladesh at the confluence of the three mighty river systems of the world renders her one of
the most vulnerable places to natural disasters. Human-induced climate change exacerbates the problem. This study shows that
the Government of Bangladesh has already established a multi-layered institutional mechanism for disaster management, with
formal recognition of the role of various stakeholders. Historically, NGOs and other informal support mechanisms in the country
also have made significant contributions during and after disaster recovery. Despite the presence of some strengths, such
as long experience in disaster response and recovery, the people’s resilience, and donor support, the current management strategies
suffer from a host of policy and institutional weaknesses. Most prominent is the absence of a functioning partnership among the stakeholders within these formal set-ups. What is lacking is the development and embodiment of a culture of collective decision-making in planning, in resource sharing, and in implementing disaster management policies and programs in an integrated and transparent
way. The paper suggests a partnership framework to implement prevention, preparedness, response, and recovery phases of disaster
management. 相似文献
249.
Umar Hamzah Rahman Yaacup Abdul Rahim Samsudin Mohd Shahid Ayub 《Environmental Geology》2006,49(8):1156-1162
A geophysical study was carried out in the Banting area of Malaysia to delineate groundwater aquifer and marine clay layer
of the alluvial Quaternary deposits of Beruas and Gula Formations. The Beruas Formation is formed by peat and clayey materials
as well as silt and sands, whereas the Gula Formation consists of clay, silt, sand and gravels. Both Formations were deposited
on top of the Carboniferous shale of the Kenny Hill Formation. A 2-D geoelectrical resistivity technique was used. Resistivity
measurement was carried out using an ABEM SAS 4000 Terrameter. The 2-D resistivity data of subsurface material for each survey
line was calculated through inverse modelling and then compared with borehole data. The resistivity images of all the subsurface
material below the survey lines show similar pattern of continuous structure of layering or layers with some lenses with resistivity
ranging from 0.1 to 50 Ωm. The upper layer shows resistivity values ranging from 0.1 to 10 Ωm, representing a clay horizon
with a thickness up to 45 m. The second layer with depth varies from 45 to 70 m below surface and has resistivity values ranging
from 10 to 30 Ωm. Borehole data indicate coarse sand with some gravels for this layer, which is also the groundwater aquifer
in the study area. The lowermost layer at a depth of 70 m below ground level shows resistivity values ranging from 30–50 Ωm
and can be correlated with metasedimentary rocks consisting of shale and metaquartzite. 相似文献
250.
The time evolution of atmospheric parameters on intraseasonal time scale in the eastern Arabian Sea (EAS) is studied during
the summer monsoon seasons of 1998–2003 using Tropical Rainfall Measuring Mission Microwave Imager (TMI) data. This is done
using the spectral and wavelet analysis. Analysis shows that over EAS, total precipitable water vapour (TWV) and sea surface
wind speed (SWS) have a periodicity of 8–15 days, 15–30 days and 30–60 days during the monsoon season. Significant power is
seen in the 8–15-day time scale in TWV during onset and retreat of the summer monsoon. Analysis indicates that the timings
of the intensification of 8–15, 15–30, and 30–60 days oscillations have a profound effect on the evolution of the daily rainfall
over west coast of India. The positive and negative phases of these oscillations are directly related to the active and dry
spells of rainfall along the west coast of India. The spectral analysis shows interannual variation of TWV and SWS. Heavy
rainfall events generally occur over the west coast of India when positive phases of both 30–60 days and 15–30 days modes
of TWV and SWS are simultaneously present. 相似文献