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121.
The remotely sensed data provides synoptic viewing and repetitive coverage for thematic mapping of natural resources. In the
present study hydrogeomorphological mapping has been carried out in Kakund watershed, Eastern Rajasthan for delineating groundwater
potential zones. IRS-1D LISS III Geocoded FCC data in conjunction with Survey of India toposheet (1:50000 scale) and field
inputs were used for thematic mapping. Geomorphic units identified through visual interpretation of FCC include: alluvial
plain, plateau, valley fills, intermontane valleys, burried pediment, residual hills, and linear ridges. In addition, lineaments
were mapped since they act as conduit for groundwater recharge. Majority of the lineaments trends NE-SW and a few along NW-SE
directions and are confined to the southern and southeastern parts of the watershed. Based on hydrogeomorphological, geological
and lineament mapping the Kakund watershed has qualitatively been categorized into four groundwater potential zones, viz.
good to very good, moderate to good, poor to moderate and very poor to poor. The study reveals that only 10.97% of the area
has good to very good, 35.41% area with moderate to good, 49.04 % of the area has poor to moderatel, while remaining 4.57%
has poor to very poor groundwater potential. 相似文献
122.
The Wajid Sandstone of southeastern Saudi Arabia is a prolific aquifer and a recent target for hydrocarbon exploration, but a sedimentologic model and the stratigraphic architecture of the sediments have only recently been presented for the type area of the Wajid Group around Wadi Dawasir. Farther to the west, the Wajid Sandstone was also recognized, but stratigraphic architecture and sedimentology are poorly known. This paper presents the preliminary results of investigations targeted at the outcrops west and south of the type area, covering the area between Wadi Dawasir, Najran in the south, and Abha in the west. Two successions are recognized, a lower red one and an upper beige one. Although the lower one sedimentologically shares several features with the lowermost unit in the type area, the marine Dibsiyah Formation, a correlation remains doubtful. The red succession lacks the Skolithos fauna of the Dibsiyah Formation, and its facies associations point to a fluvial depositional environment. From its stratigraphic position and from its lithology, the red succession is similar to the Siq Formation of the northern Kingdom and it will be discussed whether the red succession might be a yet unrecognized equivalent of the Siq Formation. The lower red unit is bounded by a major unconformity, separating it from the underlying basement. This pan-African unconformity developed during a latest Neoproterozoic–Cambrian episode of intensive weathering and peneplanation. It is characterized by a thick weathering zone and an overlying coarse but thin quartz pebble breccia to conglomerate, which together represent a regolith. The beige succession is definitely correlated to the Khusayyayn Formation. Both successions are characterized by macro-scale to giant 2D and 3D submarine dunes and share many other phenomena. The basal unconformity also shows regolith development with a quartz pebble conglomerate, whose clasts seem to have been reworked from the pan-African regolith. 相似文献
123.
Summary The differential heating between land and sea is incorporated into the theory of atmospheric tides. This involves the representation of the land and sea distribution by a set of Fourier series.The theory postulates the existence of waves of angular speeds different from the angular velocity of the earth with some of the waves travelling from West to East instead of the usual East to West.By considering the diurnal variation of eddy diffusion of heat energy absorbed close to the surface, the semidiurnal standing waves at the poles was calculated by the application of this theory. The order of magnitude of the calculated tides agreed well with observation, though, contrary to observation, the calculated amplitude at the South pole is larger than that at the North pole.It is also shown that the polar standing oscillation is caused mainly by the land and sea distribution between 75°N and 45°S. 相似文献
124.
D. P. Agrawal P. S. Datta Zahid Hussain R. V. Krishnamurthy V. N. Misra S. N. Rajaguru P. K. Thomas 《Journal of Earth System Science》1980,89(1):51-66
Quaternary formations in western Rajasthan are of fluvial, locustrinal and aeolian origins. Fossil gravel ridge of Jayal in
Nagaur District is one of the earliest quaternary formations so far recorded in the region. A rich lower palaeolithic habitation-cum-workshop
site has been discovered in association with the gravel ridge. Multiple evidence for climatic change in the area during the
quaternary period is discussed. 相似文献
125.
126.
S. Mahmood A. Hussain Z. Saeed M. Athar 《International Journal of Environmental Science and Technology》2005,2(3):269-274
The heavy metal tolerance in corn (Zea mays L.) var. ‘Neelum’ was assessed at germination and seedling growth after having subjected it to different concentrations of CuSO4 and ZnSO4. Germination was not affected by any of the metal tested, whereas initial growth was strongly inhibited by increasing concentrations of ZnSO4. Seedlings developed toxicity symptoms in the presence of both metals but more chlorotic and necrotic regions were observed at varying levels of ZnSO4 than CuSO4. The metal accumulation was concentration dependent. Z. mays seedlings accumulated more copper in roots but greater contents of zinc in their shoots. On the basis of results presented here, it can be concluded that the cultivar of the species tested has shown a marked sensitivity to the presence of small amounts of metals present in the growth medium. The data support the assumption that metal sensitivity is probably due to strong tendency of the species to accumulate them. This justifies that the corn variety ‘Neelum’ is not suitable for the cultivation under situations where water and soil suffer from occasional and/ or transitory metal pollution. 相似文献
127.
The groundwater reserves in Kharga Oases have been studied for the long-term socioeconomic development in the area. The Nubian Sandstone, which consists of a thick sequence of coarse clastic sediments of sandstone, sandy clay interbedded with shale, and clay beds, forms a complex aquifer system. The Nubian Aquifer has been providing water to artesian wells and springs in the Kharga Oases for several thousand years. Groundwater in the Kharga Oases is withdrawn from springs and shallow and deep artesian wells Nearly all the wells originally flowed, but with the exploitation of ground-water from deep wells for irrigation beginning about 1959. the natural flows declined as more and more closely spaced deep wells were drilled By 1975 many deep wells had ceased to flow The water demand in the area has been met by pumping both shallow and deep wells The total annual extraction from deep wells has fluctuated over the year, however, the annual withdrawal from deep wells has exceeded extraction from shallow wells About 17 billion m3 of water was withdrawn from the combination of shallow and deep wells during the period 1960–1980 The Nubian complex aquifer in the Kharga Oases has a very large groundwater potential that could be exploited and beneficially used for a long-term agricultural development in the area, provided proper well spacing and management are implemented Other major environmental considerations for which precise hydrogeologic data are needed include
- Determination of the long-term yield available from properly constructed and producing artesian wells that will support a planned migration of population from the overcrowded Nile delta and flood plain areas
- Development of an effective management program and adequate staff to maintain groundwater production over an extended period of years
- The impact on climate caused by extensive irrigation in the oases of the Western Desert of Egypt
- Protection against water logging of soils from irrigation practices
- Protection against salinization of soils from irrigation practices
- Development of effective surface and subsurface drainage practices
- The impact of farming and pest control practices on the shallow groundwater of the oases
- Determination of the long-term development of the artesian water on the quality of the water from the aquiter systems in the Western Desert
128.
Quaternary alluvium, ranging in thickness from a few to 100 meters underlain by Precambrian rocks of metamor-phic and igneous origin, constitutes an important source of ground water in Wadi Al-Yammaniyah, Saudi Arabia. The purpose of this report is to assess the hydraulic properties, quality of water, and estimated change in storage in waterbearing rocks in the area. The results of eight pumping tests carried out in hand-dug, large-diameter wells, indicate that the hydraulic conductivity of the alluvial aquifer ranges from 5.6 × 10−5 to 1.85 × 10−3 cm/second (3.36 × 10−5 to 1.11 × 10−3 m/minute) and that its storativity varies from 8.23 × 10−2 to 1.17 × 10−1. The aquifer is replenished by sporadic but intensive rainfall of short duration. The present withdrawal is only about 10 percent of the annual recharge which is estimated at 52 × 106 m3. It is shown that there is a substantial potential for the future development of potable ground water which would be required for the development of the area. 相似文献
129.
Y. Ali G. Sarwar Z. Aslam F. Hussain 《International Journal of Environmental Science and Technology》2006,3(2):191-195
Sixteen genotypes developed through hybridization and mutation breeding techniques were evaluated during the year 2003–04 on nine locations covering most of the area of Punjab province including Faisalabad, Toba Tek Singh and Jhang. NIAB-IRRI-9, Jhona-379 salt tolerant genotypes and super Basmati, a salt sensitive variety were included as standard checks. The tested material (six genotypes) was generated by crossing fine varieties of rice viz. Basmati-370 and Basmati-385 with three coarse varieties of rice viz. NIAB-IRRI-9, Jhona-349 and NIAB-Rice-1. The mutants (seven mutants) were derived by gamma irradiation of rice varieties, Basmati-370 and Basmati-385. The nine sets of experiments were conducted in the naturally high saline sodic soils having EC range of 9.2–18.13 d/Sm pH=8.65–9.50, and SAR=20.7–37.15. The seed yield data collected at maturity and stability parameters were computed to know genotypic x environment interaction and varietals performance. The combined analysis of variance showed highly significant variance in case of varieties, locations and varieties x locations interaction. Varieties and varieties x Environment (Lin) also showed highly significant differences. It means that genotypes exhibited different behavior in different locations / environments which is due to their different genetic make up. The behavior may be cross over (in which significant change in ranking occurs from one environment to another) or cross over nature (in which case the ranking of genotype remains constant across environments and the interaction is significant because of change in the magnitude of response) depending upon the ranking order of genotypes performance under different environment. In our study, only super Basmati behavior was of almost non cross over nature, while others had cross over type of interaction. Based on overall mean seed performance, mutant NIAB-Rice-4 and DM-38/88 produced significantly the highest grain yield (5.6 t/ha) followed by mutant line NIAB-Rice-5 (5.4 t/ha) and NIAB-rice-2 (5.3 t/ha). The lowest performing genotype was super Basmati (3.0 t/ha). The coarse variety Jhona-349 produced (4.8 t/ha) grain yield. Mutant line DM-38/88 showed significant regression co-efficient differences from unity while mutant line NIAB-Rice-4 showed non significant difference of regression co-efficient from unity. Mutant line, NIAB-Rice-4 also showed non significant difference of standard deviation to regression co-efficient from zero. All the three parameters of stability i.e. overall mean seed yield, regression co-efficient and standard deviation to regression, provided clear evidence that mutant line NIAB-Rice-4 produced maximum stable yield compared to super Basmati. 相似文献
130.
S. Hussain J. van Leeuwen R. Aryal B. Sarkar C. W. K. Chow S. Beecham 《International Journal of Environmental Science and Technology》2018,15(4):847-862
One of the key challenges in water treatment industry is the removal of organic compounds by cost-effective methods. This study evaluated the adsorptive removal of dissolved organic carbon (DOC) from reservoir water using fuller’s earth (FE) in comparison with natural (SQ) and modified quartz (MSQ) sands. The removal capacities of FE at different contact times, pH levels, adsorbent dosages and initial DOC concentrations were compared with both the quartz sands. The optimum DOC removals by FE and SQs were achieved at contact time of 60 and 30 min, pH level of 6 and 4, and at adsorbent dose of 1.5 g/150 mL and 10 g/100 mL, respectively. The adsorption capacity of FE (1.05 mg/g) was much higher compared to the MSQ (0.04 mg/g) and SQ (0.01 mg/g). Adsorption equilibrium data better fitted to the Freundlich model than to the Langmuir model, suggesting that adsorption occurred primarily through multilayer formation onto the surfaces of FE and SQ. The pseudo-second-order model described the uptake kinetics more effectively than the pseudo-first-order and intra-particle diffusion models, indicating that the mechanism was primarily governed by chemisorption. These observations were well supported by the physiochemical characteristics and charge behaviour of the adsorbents. In mass-transfer study, the results of liquid film diffusion model showed that the adsorption of DOC on FE was not controlled by film diffusion, but other mechanisms also played an essential role. This study demonstrates that FE is an effective adsorbent for the removal of DOC in surface water treatment. 相似文献