Current Issue : October - December Volume : 2013 Issue Number : 4 Articles : 7 Articles
Crop growth can be simulated under different water application using simulation models. The main\r\npurpose of deficit irrigation is high water productivity with less application of water to plants. In this\r\nresearch, the potential of AquaCrop to simulate the growth of cabbages in Keiyo Highlands (0?22?45??N\r\nand 35?32?9?, 2586 m.a.s.l) under nine different irrigation treatments in the dry season between\r\nDecember to February was studied. Statistical comparisons of observed and simulated biomass\r\nshowed that R2 = 0.96, Root mean square error (RMSE) = 0.38 tons and coefficient of residuals = -0.17.\r\nThe results showed that the model overestimated the biomass of cabbages. The model also provided\r\nexcellent simulation of canopy and yield. In this study water productivity of 17 g/cm2 and Harvest index\r\nof 76% were found for cabbages....
Geoelectric study of Abule Egba, Igando and Olushosun landfills within Lagos municipality has been\r\nundertaken to determine their hydrogeologic implications. The field technique involved vertical\r\nelectrical soundings utilizing Schlumberger electrode array. At Abule Egba, landfill materials are\r\ndefined by resistivity varying between 1.6 -m at decomposed stage and 144 -m within fresh dump.\r\nThe Igando landfill is defined by resistivity varying between 2.5 -m at decomposed stage and 26.1 -m\r\nat fresh dump. Olushosun landfill is defined by resistivity varying between 2.4 -m at decomposed\r\nstage and 51.5 -m at fresh dump. Interpretation of sounding curves showed that Abule Egba is\r\nunderlain by fairly thick column of clayey sand indicating an unconfined aquifer. Igando landfill is\r\nunderlain by thick clay column indicating a confined aquifer. The northern flank of Olushosun landfill is\r\noverlain by thin refuse dump (4.4 m) while thick refuse dump (22.9 m) overlies the central area. The\r\nhydrogeologic system at Abule Egba is vulnerable to contamination. The impermeable geoelectric\r\ncharacteristics of materials underlying Igando landfill offer the hydrogeologic system some form of\r\nprotection. At Olushosun landfill, materials of impermeable geoelectric characteristics in the northern\r\nflank offer hydrogeologic protection while fairly permeable materials in the south offer limited\r\nhydrogeologic protection....
The study area forms a part of Madurai block and lies in the Dindigul and Karur district of Tamilnadu, India. Madurai block is the largest Granulite block of South India. It is bounded by Palghat Cauvery shear zone in the north and Achankoil shear zone in the south. The study area falls in the survey of India Topographic sheet number 58 J/2 and 58J/6. The Kadavur structural basin is a large-scale structural formation of rock strata formed by tectonic warping of previously flat lying strata. This basins was the result of sediment that filled up a depression or accumulated in the study area and were resulted by tectonic events long after the sedimentary layers were deposited. The structural study of the area reveals three major folding and development. Geomorphology of the study area reveals a dome-basin morphometry with radial drainage patterns. The various geomorphic features such as the structural hills, bajadas, pediments, escarpments and second order relief features such as plains, plateaus, mountains ranges, large dome and basins etc are significance. Geomorphic features like structural hills, linear ridges, escarpments, colluvial fills, bajadas, pediments and buried pediments were identified and their boundaries were demarcated. Bajadas comprises of pebbles, boulders, stones and sand materials made up of quartzites, gabbros and anorthosite. Weathered anorthosite formed maximum part of the pediments. Escarpments and ridges are made up of quartzites and forms the structural hills of the study area. The entire area of the district is a pediplain. The Rangamalai hills and Kadavur hills occurring Eastern Ghats and rise to heights of over 1031 m above MSL. In the present study mainly focussed on the geomorphological features in Kadavur taluk, Karur district, Tamilnadu, India....
An integrated geophysical investigation involving 2D-Wenner profiling, very low frequency\r\nelectromagnetic, vertical electrical sounding (VES) and water quality analysis was conducted around\r\nAule area within Akure the capital city of Ondo state southwestern Nigeria where there have been\r\nreported cases of groundwater contamination. Also hydrochemical analysis was carried out on five\r\nwater samples in the area; two from boreholes and others from hand dug wells. Results of the\r\ninvestigation showed that the groundwater had been contaminated by hydrocarbon arising from a\r\nfilling station in the area. The hydrocarbon contaminant plumes are characterized by relatively high\r\nresistivity values (> 200 -m) and were delineated to a depth of about 10 m. Hydrochemical results\r\nshowed that three of the sampled water have higher total dissolved solids (TDS) (>240 ppm) compared\r\nto the remaining water samples. The major ions identified includes (Na+, K+,Cl-,Mg2+,,Ca2+ and NO3\r\n-). The\r\ntotal dissolved solid (TDS) and electrical conductivity shows values not in agreement with WHO\r\nstandards. Twelve (12) Vertical Electrical Sounding (VES) stations were occupied along three traverse\r\nlines trending NW-SE and Nââ?¬â??S direction. The vertical electrical sounding results indicate maximum of\r\nfour subsurface layers-Top soil, hydrocarbon contaminated clay, weathered layer and the fresh\r\nbasement. The VLF-EM results assist in the delineation of non conductive zones which in most cases\r\ncoincides with the hydrocarbon contaminated plumes delineated by the 2D-pseudo section obtained\r\nfrom modeling the results obtained from Wenner profiling. The contaminant plume has migrated to a\r\nsignificant depth thus posing an inherent danger to the inhabitant of the area....
Dune sand was subjected to varying rainfall intensities in order to generate runoff under laboratory\r\nconditions on slopes of 20 and 30�°. Soil moisture probes were inserted into the soil at varying depths to\r\ninvestigate the movement of water through the profile. Results indicate that in spite of continuous\r\nsimulated rainfall administered for over 4,000 min, no runoff could be generated over the sand surfaces\r\nand across the different slopes. It was deduced that for this to occur, rainfall intensities in excess of\r\n6,000 mmh-1 would be required. The results also indicated that to generate runoff from such sandy\r\nsoils, treatment of the upper 0 to 10 cm of the soil profile would be required to reduce significantly the\r\ninfiltration rate of the soil profile, which then will translate into runoff generation....
Storm water management and road tunnel (SMART) was built to direct water around a major meeting\r\npoint of two major rivers located in a large urban area; in addition, it doubles up as a road tunnel,\r\nthough that section is only used in major storms. Much information has come from the Malaysian\r\nDepartment of Irrigation and Drainage (DID), in the form of data and reports. Pre-project historical water\r\nflow data as well as a simple velocity-area calculation to find the tunnel capacity was used to assess its\r\nefficiency. Water level data from the DID was used to create a graph in order to calculate the minimum\r\namount of water to create flooding. Processing this information has revealed that SMART is in itself an\r\neffective flood deterrent, due to its water capacity and the lag time it creates. Although most storms\r\nshould be easily dealt with, SMART only diverts water around the critical meeting point from one of the\r\ncontributing rivers. It has no effect on the flow from the other river but it caused the sustained water to\r\nflow out. For an example, rainfall from a 100 year average return interval from this river will flood Kuala\r\nLumpur. Although the development of SMART has been considered as successful, however, the\r\ngrowing development in the other part of the city could not ensure no flooding will take place or\r\nthoroughly protect the city centre....
Irrigation development is a gateway to increased agricultural, water and land productivity, increased\r\nhousehold and national food security. However, irrigation development has been a major challenge in\r\nmany developing countries, including Egypt. The overall objective of this study is to detect the\r\ninfluence of different irrigation systems on water-use efficiency, crop and soil salinity in highly soil\r\nsalinity. Two techniques were applied in experiment, the first technique was siphon irrigation, and the\r\nsecond one was gated pipe. The monitored parameters were water table depth, water and soil salinity\r\nand crop yield. The study revealed that the intensive management is a very important aspect for the\r\nsuccess of siphon technique and cotton crop yield was higher by 17% compared to gated pipe\r\nirrigation treatment. The total soil salinity increased in both treatments. The siphon method increases\r\nthe average salinity by 2.7% while the gated pipe increased it by 12.9%; converging the value of the\r\ncrop coefficient in all relations used in most stages of growth, except Penman relationship which gave\r\nthe highest values....
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