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81.
We studied the quality of water obtained using a new method of tapping underground water seepages by digging shallow water collection chambers in the Almora Hills of the state of Uttar Pradesh, India; quality of this water was compared with that of water obtained using traditional water sources in this region, namely naulas (surface seepages) and springs.Water from both the new and the traditional water sources had an excess of chromium and, in some samples, of iron and lead. Microbiological analysis showed that water from new water sources was safer than that obtained from tradional sources; however, only 40% of the shallow seepages provided water conforming to WHO standards on water quality.We conclude that tapping of underground water seepages may be a useful method of providing potable water to populations living in the hills. However, further improvement is necessary in the maintenance of the clean catchment area and in disposal of waste water from these water sources to ensure water quality.  相似文献   
82.
ABSTRACT: The Soil and Water Assessment Tool (SWAT) model was used to assess the effects of potential future climate change on the hydrology of the Upper Mississippi River Basin (UMRB). Calibration and validation of SWAT were performed using monthly stream flows for 1968–1987 and 1988–1997, respectively. The R2 and Nash‐Sutcliffe simulation efficiency values computed for the monthly comparisons were 0.74 and 0.69 for the calibration period and 0.82 and 0.81 for the validation period. The effects of nine 30‐year (1968 to 1997) sensitivity runs and six climate change scenarios were then analyzed, relative to a scenario baseline. A doubling of atmospheric CO2 to 660 ppmv (while holding other climate variables constant) resulted in a 36 percent increase in average annual streamflow while average annual flow changes of ?49, ?26, 28, and 58 percent were predicted for precipitation change scenarios of ?20, ?10, 10, and 20 percent, respectively. Mean annual streamflow changes of 51,10, 2, ?6, 38, and 27 percent were predicted by SWAT in response to climate change projections generated from the CISRO‐RegCM2, CCC, CCSR, CISRO‐Mk2, GFDL, and HadCMS general circulation model scenarios. High seasonal variability was also predicted within individual climate change scenarios and large variability was indicated between scenarios within specific months. Overall, the climate change scenarios reveal a large degree of uncertainty in current climate change forecasts for the region. The results also indicate that the simulated UMRB hydrology is very sensitive to current forecasted future climate changes.  相似文献   
83.
ABSTRACT: The existence and importance of macro-pores to the containment efficiency of cover clay liners at waste landfills is documented. Macro-pores exist as voids, or cracks, and act to increase the volume and rate of leakage through cover liners. Existing numerical models used to simulate flow through clay liners are shown to neglect the macro-pore aspect of the problem. Current theories of macro-pore flow developed from related areas of research are presented, and applications to the landfill liner problem are considered.  相似文献   
84.
The objective of this study was to use the freshwater food fish, Heteropneustes fossilis, as a model to evaluate the concentration-dependent effects of LAS on the testicular structure through short-term static bioassays. Concentration mediated histopathological leisions were observed in testis of H. fossilis, treated with four different concentrations of LAS for 24, 48, 72 and 96 hr Inference drawn from the study is that the cytotoxic damage is more pronounced in fish exposed to higher concentrations of LAS for shorter durations than lower concentrations of LAS for longer durations. Gross damage of germinal epithelium, inflammatory response, intertubular vacuolations and contraction and condensation in the cells of tubules under all sets of intoxication and exposures are quite suggestive of reproductive impairment leading to delayed gonadal maturity.  相似文献   
85.
Indaziflam is a new preemergence herbicide for the control of annual grass and broadleaf weeds in various cropping systems including pecan orchards. The objectives of this study were to (1) determine the mobility and dissipation of indaziflam and (2) evaluate herbicide efficacy in a flood-irrigated pecan orchard in southern New Mexico, USA. Indaziflam was applied at 0, 36.5, and 73.1 g/ha in areas with (impacted) and without (unimpacted) tree injury symptoms. Soil samples were collected at 0–15, 15–30, and 30–46 cm depths 26, 63, 90, and 126 days after the first herbicide application. Additional soil samples were collected 4, 30, and 56 days after the second application. Indaziflam was detected in soil samples collected at each depth, suggesting movement with irrigation water. Indaziflam concentrations decreased with increasing soil depth and time. Indaziflam mass recoveries were greater in the unimpacted area than in the impacted area after the first and second applications. Dissipation half-lives of indaziflam in the soil ranged from 30 to 86 days for total indaziflam recovered from the entire soil profile after the first and second applications in both areas. The percent weed control was similar in the impacted and unimpacted areas for both rates of indaziflam on 26 and 63 days after application; however, on 90 days after the application, percent weed control was lower in the impacted than unimpacted area.  相似文献   
86.
Journal of Material Cycles and Waste Management - This study characterizes the municipal solid waste (MSW) accumulated for more than 25 years at Bhalswa dumpsite, Delhi, India. 50...  相似文献   
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