排序方式： 共有102条查询结果，搜索用时 0 毫秒
101.
ABSTRACTLow streamflow conditions can have adverse consequences for society and river ecology. The variability and drivers of streamflow drought indicators within the USA were investigated using observed streamflow records from 603 gauges across the USA. The analysis was based on two main approaches: (i) low-flow magnitude indicators, and (ii) streamflow deficit indicators. First, we examined how streamflow drought indicators vary spatially across the USA. Second, we used a data-driven clustering method to identify spatial clusters for each indicator. Finally, we assessed the association with regional climate drivers. The results show that the spatial variability of low-flow magnitude indicators is significantly different from the deficit indicators. Further, our clustering approach identifies regions of spatial homogeneity, which can be linked to the extreme regional climate drivers and land–atmosphere interactions. The influence of regional climate on streamflow drought indicators varies more between clusters than between indicators. 相似文献
102.
Kamini Narain Taiyyaba Yazdani Mohd. Muzamil Bhat Mohmmad Yunus 《Environmental Earth Sciences》2012,66(3):977-984
Molasses-based distilleries are one of the most polluting industries generating large volume of wastewater. Distillery effluent
(DE) on its discharge alters the physical and chemical properties of the soil. This study has been conducted to assess the
distribution of heavy metals and its effect on physiochemical and structural changes of soil which has been treated with diluted
and undiluted effluents. The soil has been assayed both before and after crop plantation. Out of the crop plants studied,
Cicer
arietinum was least effected and more effective than Pisum
sativum in diminishing the heavy metals from soil. However, only at higher concentration DE has some adverse impact on the nutrient
contents of the soil. Fourier transform infrared spectrum (FTIR) study of the soil indicated the presence of –OH, –NH, –COOH
groups. It was also noted that the soil amended with different concentration of DE and on which Cicer and Pisum were grown has varied IR spectrum. These variations show the presence of different functional groups of soil before and after
plants were grown. The presence of inorganic carbonate was found in soil planted with Cicer from 10 to 50% of DE, whereas aliphatic primary amides were observed up to 25 and 100% concentrations of DE in soil planted
with Pisum. The appearance of inorganic nitrates, carbonates, aliphatic hydrocarbons and aliphatic primary amides at various concentrations
of DE showed a change in functional groups probably because of the differential breakdown of parent component present in the
effluent. Besides our main finding that Cicer is a very useful crop species in remediating the soil which has inflicted with even undiluted DE, it is also validated through
FTIR spectra that IR technique is an efficient tool in studying the structural changes of soil and with some degree of caution
may be summed up that FTIR may be used to correlate the relative efficacy of plants to transform organic contaminants. 相似文献