Comparative Evaluation of Infiltration Models under Different Land Covers

Water Resources - Quantification of infiltration characteristics of soil is a complex problem because of its variability, selection of suitable infiltration model, and determination of infiltration...     

Reservoir characterization of basal sand zone of lower Goru Formation by petrophysical studies of geophysical logs

The lower Indus basin is one of the largest hydrocarbon producing sedimentary basins in Pakistan. It is characterized by the presence of many hydrocarbon-bearing fields including clastic and carbonates proven reservoirs from the Cretaceous to the Eocene age. This study has been carried out in the Sanghar oil field to evaluate the hydrocarbon prospects of basal sand zone of lower Goru Formation of Cretaceous by using complete suite of geophysical logs of different wells. The analytical formation evaluation by using petrophysical studies and neutron-density crossplots unveils that litho-facies mainly comprising of sandstone. The hydrocarbons potentialities of the formation zone have been characterized through various isoparameteric maps such as gross reservoir and net pay thickness, net-to-gross ratio, total and effective porosity, shaliness, and water and hydrocarbons saturation. The evaluated petrophysical studies show that the reservoir has net pay zone of thickness range 5 to 10 m, net-togross ratio range of 0.17 to 0.75, effective porosity range of 07 to 12 %, shaliness range of 27 to 40 % and hydrocarbon saturation range of 12 to 31 %. However, in the net pay zone hydrocarbon saturation reaches up to 95%. The isoparametric charts of petrophysically derived parameters reveal the aerial distribution of hydrocarbons accumulation in basal sand unit of the lower Goru Formation which may be helpful for further exploration.     

Isotope fingerprinting of precipitation associated with western disturbances and Indian summer monsoons across the Himalayas

Precipitation samples were collected across the Himalayas from Kashmir (western Himalaya) to Assam (eastern Himalaya) to understand the variation of the stable isotopic content (\(\updelta ^{18}\)O and \(\updelta \)D) in precipitation associated with two dominant weather systems of the region: western disturbances (WDs) and Indian summer monsoon (ISM). Large spatial and temporal variations in isotopic values were noted with \(\updelta ^{18}\)O and \(\updelta \)D values ranging from \(-30.3\) to Open image in new window and \(-228\) to Open image in new window , respectively. The d-excess values also exhibit a large range of variation from \(-30\) to Open image in new window . In general, heavier isotopic values are observed in most of the samples in Jammu, whereas lighter values are observed in majority of the samples in Uttarakhand. Precipitation at Jammu seems to have undergone intense evaporation while that from Uttarakhand suggest normal Rayleigh fractionation/distillation of the air mass as it moves from the source region to the precipitation site and/or orographic lifting. The d-excess of rainfall in Kashmir has a distinctly higher median value of Open image in new window compared to other precipitation sites with a median of Open image in new window . Using distinct isotopic signatures, the regions receiving precipitation from two different weather systems have been identified.     

Factors affecting technical efficiency of small-scale apple farms in Balochistan Plateau,Pakistan

In Balochistan, Agriculture is dominated by small-scale farmers and the apple production sector is confronted with the chronic constraint of low output per unit of input. Although some agricultural policies have been implemented in this province, studies on effectiveness and impacts of such policies over apple production and farmers’ performance are still limited. This study is an effort to bridge the research gap on this potential crop in the plateau by investigating technical and scale efficiency of 181 officially designated small-scale apple farmers in mountainous district Mastung in Balochistan; then explored factors that underlie differences in production inefficiency. A two-stage input-oriented Data Envelopment Analysis (DEA) methodology was employed to evaluate technical and scale efficiency followed by truncated bootstrapped regression framework to analyze the correlative determinants to efficiency. Average technical and scale efficiencies of larger landholders were higher than medium and small landholders. Analysis indicated that there is still ample scope for inefficient sample farmers to reduce the input use by 33% without compromising the given yield level. Maximum contributions to the total input savings were from the use of urea, farm yard manure (FYM) and labor-use. Farmer’s experience, farm ownership, irrigation constraints, and farmer’s access to trainings, credit and extension services significantly affected apple farmers’ technical efficiency. Based on the findings of this study, strategies are suggested to enhancing efficiencies by farmers’ capacity development through effective extension services and trainings and provision of adequate credit.     

Macrophytes’ Performance in Floating Treatment Wetlands for the Remediation of Ciprofloxacin-Contaminated Water

The presence of trace antibiotics in domestic and industrial effluents poses a risk of toxicity to fauna and flora. The application of floating treatment wetlands (FTWs) is a low-cost and sustainable approach to remediate wastewater. In this study, the performance of different macrophytes vegetated in FTWs for the remediation of ciprofloxacin (CIP)-contaminated water is investigated. Six macrophytes, Brachia mutica, Typha domingensis, Phragmites australis, Canna indica, Cyperus laevigatus, and Leptochloa fusca, are vegetated in FTWs for the removal of CIP (50 mg L⁻¹) from water. The FTWs show the potential to remove 30–43.58 mg L⁻¹ CIP from water in 28 days. They also reduce the chemical oxygen demand (118–138 mg L⁻¹) and biochemical oxygen demand (35–45 mg L⁻¹) of water. Among the macrophytes, C. indica removes maximum (43.58 mg L⁻¹) and T. domingensis minimum (30 mg L⁻¹) CIP. Canna indica and T. domingensis exhibit the maximum and minimum increase (30% and 12% of dry biomass) in growth, respectively. This study reveals that the FTWs vegetated with different plant species exhibit varying performances in removing CIP from water. This investigation is a step forward toward sustainable bioremediation of water contaminated with antibiotics.     

Multiyear hindcast simulations of summer monsoon over South Asia using a nested regional climate model��BCC_RegCM1.0

Multiyear (1983?C2006) hindcast simulation of summer monsoon over South Asia has been carried out using the regional climate model of the Beijing Climate Centre (BCC_RegCM1.0). The regional climate model (hereafter BCC RCM) is nested into the global climate model of the Beijing Climate Centre BCC_CGCM1.0 (here after CGCM). The regional climate model is initialized on 01 May and integrated up to the end of the September for 24?years. Compared to the driving CGCM the BCC RCM reproduces reasonably well the intensity and magnitude of the large-scale features associated with the South Asia summer monsoon such as the upper level anticyclone at 200?hPa, the mid-tropospheric warming over the Tibetan plateau, the surface heat low and the 850?hPa moisture transport from ocean to the land. Both models, i.e., BCC RCM and the driving CGCM overestimates (underestimates) the 850?hPa southwesterly flow over the northern (southern) Arabian Sea. Moreover, both models overestimate the seasonal mean precipitation over much of the South Asia region compared to the observations. However, the precipitation biases are significantly reduced in the BCC RCM simulations. Furthermore, both models simulate reasonably the interannual variability of the summer monsoon over India. The precipitation index simulated by BCC RCM shows significant correlation (0.62) with the observed one. The BCC RCM simulates reasonably well the spatial and temporal variation of the precipitation and surface air temperature compared to the driving CGCM. Further, the temperature biases are significantly reduced (1?C4°C) in the BCC RCM simulations. The simulated vertical structure of the atmosphere show biases above the four sub-regions, however, these biases are significantly reduced in the BCC RCM simulations compared to the driving CGCM. Compared to the driving CGCM, the evolution processes of the onset of summer monsoon, e.g., the meridional temperature gradient and the vertical wind shear are well simulated by the BCC RCM. The 24-year simulations also show that with a little exception the BCC RCM is capable to reproduce the monsoon active and break phases and the intraseasonal precipitation variation over the Indian subcontinent.     

Designing of the perpendicular drought index

In this paper, a simple, effective drought monitoring method is developed using two dimensional spectral space obtained from reflectance of near-infrared (NIR) and Red wavelengths. First, NIR–Red reflectance space is established using atmospheric and geometric corrected ETM+ data, which is manifested by a triangle shape and in which different surface targets possess certain spatial distribution rules. Second, perpendicular drought index (PDI) is developed on the basis of spatial characteristics of moisture distribution in NIR–Red space, as well as the relationships between PDI and soil moisture is examined. Validation work includes: comparison of PDI with in-situ drought index obtained from field measured data in the study area which includes bulk soil moisture content at different soil depths, field moisture capacity and wilting coefficient, etc.; and comparison of PDI with other recognized drought monitoring methods such as LST/NDVI and vegetation temperature condition index (VTCI). It is evident from the results that graph of PDI of field measured plots demonstrates very similar trends with ground truth drought data, LST/NDVI and VTCI. PDI is highly correlated with in-situ drought values calculated from 0 to 20 cm mean soil moisture with correlation coefficients of R ² = 0.49 (r = 0.75). This paper concludes that PDI has a potential in remote estimation of drought phenomenon as a simple, effective drought monitoring index.     

Radar investigations of cloud merger

Presented are the results of radar investigations of cloud merger during their natural cycle of development and after the seeding. The observations were carried out in the southwest of the Kingdom of Saudi Arabia in 2008. It is revealed that the merging was observed under conditions of very unstable atmosphere, when the convective available potential energy exceeded 3000 J/kg. The cloud merger impacts significantly their development. The most considerable changes due to the cloud merging were observed for the cloud mass and precipitation flow increased as a result of this process by two or three times. It is discovered that the impact of the merger of clouds on their characteristics exceeds significantly the effect of seeding carried out for the feeder clouds.     

A Diagnostic Study of Record Heavy Rain in Twin Cities Islāmābad-Rāwalpindi

Using surface and NCEP reanalysis data along with radar and satellite images, diagnosis has been July 2001. It has been revealed that the sudden evolution of this meso-scale severe weather system was the direct result of strong surface convection in moist and unstable lower layers of the atmosphere. The subsequent rapid development was the combined effect of the presence of the mid latitude westerly's trough in the north and moisture feeding through monsoon flow along the Himalayas and also the direct southwesterly current from the Arabian Sea. After the westward shifting of the Sub-Tropical High (STH) from the north of India, the strong divergence zone on its eastern edge contributed positively to the development of upward motion. Initially the convective systems moved towards the south and then southeastward following the steering current in the middle troposphere. Based on these analyses, the physical model of the sudden record heavy rainfall has been proposed and a comparison between the heavy rainfall in this case and one in China has been conducted.