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981.
982.
Barbara Ntombi Ngwenya Ketlhatlogile Keta Mosepele Lapologang Magole 《Natural resources forum》2012,36(2):109-122
Fish is a major source of livelihood for the majority of people living around the Okavango Delta in northwestern Botswana. Gender dynamics and governance regimes determine differential access to, and control of, resources between women and men in the area. The purpose of this case study is to critically assess the embeddedness of gendered inequities in the governance of Okavango Delta fishery. Primary data was collected through focus group discussions and face‐to‐face interviews of 96 basket fishers from five villages along the Panhandle area of the Okavango River. The study found that past and present Okavango Delta fishery policy and programme interventions tended to entrench rather than minimize gendered disparities between women and men fishers' access to and control over fish resources, asset accumulation and employment opportunities. Basket fishers have intimate knowledge of flood variability, fish migration and habitat and use this knowledge to make decisions about when and where to harvest what fish species. Women fishers' ecological knowledge, interests and concerns however, have been excluded from current zoning and closed season regulations and co‐management structures. The paper concludes that past and current development interventions as well as the regulatory framework continue to entrench pre‐existing gender relations in the fishery sector which excludes, disempowers and marginalizes women fishers. We recommend innovative co‐management and local based structures which recognize the diversity of interests and interest groups. 相似文献
983.
Precision agricultural fertilization technique at small scale is the key for regional cultivated land protection and management. Taking Dingzhuang Town (located in Guangrao County, Shandong Province) as a case study, this article explores the precision agricultural fertilization technique at small scale. First, three main cropping systems are identified via field investigation, namely wheat–maize–soybean, garlic–maize and cotton. Then, application amount of fertilizer N, P and K under the three cropping sys... 相似文献
984.
徐学哲 《中国环境管理干部学院学报》2009,19(2):112-115
摄影本体语言是其传递视觉信息的方式,融入照相机、镜头以及成像系统最前沿的科学技术。摄影本体语言包含摄影的纪实性、瞬间性、时间与空间的拓展、镜头透视关系变化、清晰与模糊的运用等。这些视觉语言是最具摄影性质的语言,也是摄影区分其他平面艺术的要素和本质。而构图、用光、影调和色彩的表现是摄影与绘画相互交融的造型语言,是摄影视觉表达的技术与技巧。摄影本体语言和造型语言相互交融,创造影像视觉表达与表现的价值。 相似文献
985.
Kenneth J. Tobin Marvin E. Bennett 《Journal of the American Water Resources Association》2009,45(1):253-271
Abstract: Both ground rain gauge and remotely sensed precipitation (Next Generation Weather Radar – NEXRAD Stage III) data have been used to support spatially distributed hydrological modeling. This study is unique in that it utilizes and compares the performance of National Weather Service (NWS) rain gauge, NEXRAD Stage III, and Tropical Rainfall Measurement Mission (TRMM) 3B42 (Version 6) data for the hydrological modeling of the Middle Nueces River Watershed in South Texas and Middle Rio Grande Watershed in South Texas and northern Mexico. The hydrologic model chosen for this study is the Soil and Water Assessment Tool (SWAT), which is a comprehensive, physical‐based tool that models watershed hydrology and water quality within stream reaches. Minor adjustments to selected model parameters were applied to make parameter values more realistic based on results from previous studies. In both watersheds, NEXRAD Stage III data yields results with low mass balance error between simulated and actual streamflow (±13%) and high monthly Nash‐Sutcliffe efficiency coefficients (NS > 0.60) for both calibration (July 1, 2003 to December 31, 2006) and validation (2007) periods. In the Middle Rio Grande Watershed NEXRAD Stage III data also yield robust daily results (time averaged over a three‐day period) with NS values of (0.60‐0.88). TRMM 3B42 data generate simulations for the Middle Rio Grande Watershed of variable qualtiy (MBE = +13 to ?16%; NS = 0.38‐0.94; RMSE = 0.07‐0.65), but greatly overestimates streamflow during the calibration period in the Middle Nueces Watershed. During the calibration period use of NWS rain gauge data does not generate acceptable simulations in both watersheds. Significantly, our study is the first to successfully demonstrate the utility of satellite‐estimated precipitation (TRMM 3B42) in supporting hydrologic modeling with SWAT; thereby, potentially extending the realm (between 50°N and 50°S) where remotely sensed precipitation data can support hydrologic modeling outside of regions that have modern, ground‐based radar networks (i.e., much of the third world). 相似文献
986.
Vestergaard Peter 《Journal of Coastal Conservation》2001,7(2):117-128
The initial recovery of vegetation after a wildfire in a coastal dune area in NW Jutland, Denmark, was studied over a 5-yr
period by means of permanent plots representing various dune communities along a topographical gradient.
The impact of the fire varied with the position of the plots. Fens and south-facing dunes were little affected while dune
heath plots were severely affected including loss of the O-horizon. Post-fire conditions included presence of remaining soil
organic matter, a soil seed bank and surviving below-ground plant parts. The soil surface remained stable during the study
period.
The initial five years of recovery comprised of an initial three-year recruitment phase during which cover and number of species
increased and the quantitative species composition changed markedly, followed by two years of a declining rate of change.
38 species of vascular plants were recorded, 35 are regular components in dune, dune heath and heath fen and were recruited
from the seed bank, from locally dispersed seeds and/or by sprouting from surviving vegetative parts. The remaining three
species were ‘aliens’, dispersed from sources outside the area. Crustose lichens had an important role in the initial recovery
by stabilizing the surface and probably inhibiting seed germination, whereas mosses mostly had a subordinate role.
The seral position of the plots, as well as the expected time needed for full recovery of pre-fire vegetation, vary with topography
and initial soil conditions. Five years after the fire the fen and the south-facing dune probably need less than a decade
for full recovery. The remaining plots are judged to be relatively early seral; their full recovery into mature dry or moist
dune heath vegetation and O-horizon is expected to need several centuries. 相似文献
987.
全二维气相色谱/飞行时间质谱联用监测环境空气中VOCs 总被引:2,自引:0,他引:2
采用全采样系统-全二维气相色谱/飞行时间质谱联用技术监测环境空气中的VOCs,优化了调制周期、升温程序、进样体积等分析条件.39种目标化合物在0 μg/m3~10.0 μg/m3范围内线性良好,检出限范围为0.03 μg/m3~0.09 μg/m3,标准气体平行测定的RSD为1.1% ~5.3%.应用于化工园区环境空气样品测定,与热脱附-气相色谱/质谱法相比,目标物的分离效果更佳. 相似文献
988.
Mohamed Aqiel Dalvie Ina Naik Kalavati Channa Leslie London 《Journal of environmental science and health. Part. B》2013,48(2):163-172
The study investigated urinary levels of dialkyl phosphates resulting from pesticide exposure amongst 40 farm workers. Workers were tested (urinary dialkyl phosphate levels, anthropometry, short exposure questionnaire) before and after the first day of seasonal chlorpyrifos spraying. Median baseline urinary dialkyl phosphates was high amongst both non-applicators (1587.5 μg/g creatinine, n = 8) and applicators (365.6 μg/g creatinine, n = 9). There was not much evidence of an increase in post-spray dialkyl phosphates levels from pre-spray levels amongst both applicators and non-applicators. Hours mixing, spraying, driving a tractor and hours worked by non-applicators were not significantly associated with an increase in post-spray dialkyl phosphate levels, adjusting for age, height, weight, gender, use of empty pesticide containers and self-reported kidney problems. Past applicator status was weakly positively associated with pre-spray dialkyl phosphate levels adjusting for age, height, weight, and gender, self-reported kidney problems, smoking and alcohol (β= 1019.5, p = 0.307, R2= 0.28). The high dialkyl phosphate levels call for an epidemiological investigation into the health effects of organophosphorous pesticides. 相似文献
989.
Hao Cui Shu-Ping Wang Shu-Gang Jia Na Zhang Zhi-Qiang Zhou 《Journal of environmental science and health. Part. B》2013,48(10):869-877
In this study, the effect of ciprofloxacin (CIP) on the catabolic diversity of soil microbial communities was evaluated. Soil samples were spiked with ciprofloxacin (0, 1, 5 and 50 mg?kg?1) and were incubated for 1, 3, 9, 22 and 40 days. Untreated controls received only water. The functional diversity of the microbial community studied was characterized using a catabolic response profile (CRP). Six substrate groups were tested: carbohydrates, amino acids, carboxylic acids, aromatic chemicals, alcohols and polymers. After 40 days, the CIP concentrations in the soil samples ranged from 25% to 58% of the initial concentrations. Soil respiratory responses to the individual substrates D-glucose, lactose, D-mannose, L-glutamic, Na-citrate, malic acid and inosine were inhibited at the high CIP concentrations (5 and 50 mg·kg?1) in the soils and were increased at the lowest CIP concentration (1 mg·kg?1). Soil respiration was inhibited at all of the CIP concentrations after the addition of D-galactose and glycerol. The CIP concentration and incubation time explained 45.3% of the variance of the catabolic responses. The CRP analysis clearly discriminated among the different CIP concentrations. The results suggest that CIP strongly affects the catabolic diversities of soil microbial communities and that its effect is more significant than that of incubation time. 相似文献
990.