Changing rainfall inputs in the Volta basin: implications for water sharing in Ghana

We present evidence from the analysis of gridded annual rainfall data that, increased variability and declining rainfall totals are the main cause of declining lake levels in the Volta basin above the Akosombo Dam. West Africa has undergone a period of diminished rainfall, punctuated by a series of severe droughts and marked by a shift in rainfall regime. As a result, lake levels behind the hydro-electric impoundment have fluctuated so widely at times that, power has had to be rationed. The trends in the spatial and temporal variability of annual rainfall in the riparian nations explain the low impoundment levels frequent in recent decades. The drying of Burkina Faso and Mali is particularly marked and synchronous to an apparent shift in the rainfall regime in Ghana towards a longer dry season and vanishing short dry spell, the effects which tend to negate each other. The various regional and temporal associations between El Niño-Southern Oscillation phenomenon (ENSO) are investigated as a possible cause of variation across the basin. The strengths of these associations and low frequency shifts suggest an unfortunate correspondence between national and climatological boundaries which may serve to heighten regional political tensions resulting from ENSO effects. Lack of re-investment in the Akosombo Dam as a result of management policies, political and pre-construction contractual agreements have all conspired in recent decades to make these hydro-climatological changes more devastating.     

Distribution and speciation of mercury in the Hongfeng Reservoir,Guizhou Province,China

The water, pore water, sediment, and fish samples were collected from the Hongfeng Reservoir in November 2003 and February 2004 in accordance with trace metal protocols. The average concentrations of total mercury （THg）, dissolved mercury （DHg）, reactive mercury, dissolved gaseous mercury, total methylmercury, and dissolved methylmercury in the water columns were 8.00, 5.70, 0.63, 0.05, 0.16, and 0.07 ng/L, respectively. THg and DHg in the water columns, THg in pore water and THg in lake sediments of the Hongfeng Reservoir showed the level of mercury in the Hongfeng Reservoir was higher than in other natural waters in the world due to the loading of a lot of waste water with relatively high concentrations of mercury, whereas methylmercury concentrations in fish （wet weight） varied from 1.73-51.00 ng/g, much lower than in most remote lakes and reservoirs reported in northern Europe and North America. Methylmercury distributions in pore water and sediments showed methylation occurred mainly in the upper several centimeters of sediment cores in the Hongfeng Reservoir. The concentrations of dissolved organic carbon, total suspended particles, total Hg, and methylmercury were higher at Houwu than those at Daba in November 2003. It is suggested that other pollutants such as N and P from fishing farm and other waste water at Houwu, which resulted in deterioration of water quality, affected the concentrations and distributions of mercury species in the reservoir.     

A Grey Fuzzy Comprehensive Model for Evaluation of Geological Structure Complexity

Several structure sets (faults and folds) are characterized by their self-similarity properties. Herein, we discuss the degrees of complexity of fractures by introducing the box-counting fractal dimension of faults as a key criterion to be used in comprehensive fuzzy analysis model for evaluation of the complexity of structures. Totally, eight criteria including density, intensity, length of faults, types and box-counting fractal dimension of faults, the intersection angle between faults and coal beds, gradient coefficients, dip angles of the coal beds, and variation coefficients of dip angles of the coal seams, were used for the evaluation purpose. The grey fuzzy comprehensive assessment model was used to rank the relative importance of these criteria. Scores indicating the complexity of structure were calculated on the base of criteria values and their weights for each sub-area of the study area in the Pansan (潘三) coal mine district in the southern Anhui (安徽) Province, China. The result on the calculated complexity of structure is useful for mining planning in the study area.     

冰碛层工程性质及地基处理方法的研究

以川西某工程为例,采用详实的现场调查、测绘,室内颗粒分析、抗压、抗剪、化学分析试验、室外标贯、动力触探、固体体积率、载荷试验、波速测试、颗粒分析、抽水试验等系统地研究了冰碛层工程性质,并结合工程实践采用强夯、碾压等方法对冰碛层地基进行了处理试验,并对挖方原地面地基和高填方地基进行了变形观测.结果表明,冰碛层总体为一种良好的地基和填料,可作为机场、公路、房屋等建筑地基.     

国企改制中企业真实价值确认审计

国有企业的改制是国家产业结构的调整、国有资产的保值增值等的必然,改制最核心的问题在于企业真实价值确认。而企业真实价值确认审计,是价值确认中的重要一环。分析了帐面价值、无形资产、评估方法等对企业价值评估的影响,总结了价值审计中应重点关注的帐面资产、无形资产以及管理层收购等方面应注意的问题与应采取的措施。     

四分量钻孔应变观测的时间滞后标定

经过四分量钻孔应变观测的实地相对标定[1]以后,将应变观测值与理论值进行拟合,使得观测值与理论值之间的相关性最大,发现观测值与理论值之间存在相位差。通过计算得出了相位差在时间上的表现形式,即时间滞后。我们计算了佘山、江宁、攀枝花、乐都、格尔木、湟源和门源7个台站的滞后时间,发现靠海较近的佘山和江宁台的体应变时间滞后分别为0.37和0.80小时,而其他5个内陆台站的体应变滞后时间大约在1.2～1.5小时以内,这可能说明海洋负荷潮对佘山和江宁的体应变影响较明显。各台站之间的差应变以及同一台站不同方向上的差应变都存在较大差异,个别台站的差应变出现相位超前的现象。     

Possible connection between the East Asian summer monsoon and a swing of the haze-fog-prone area in eastern China

Theoretical and Applied Climatology - The summer monsoon has recently been hypothesized to influence haze-fog events over China, but the detailed processes involved have yet to be determined. In...     

Effect of slow-release iron fertilizer on iron-deficiency chlorosis,yield and quality of Lilium davidii var.unicolor in a two-year field experiment

Iron deficiency chlorosis of Lilium davidii var. unicolor is often the case in practice in alkaline soils of northwest region of China. It is difficult to control iron chlorosis because of high cost and short effective work time of conventional iron fertilizers. In this study, a 2-year field experiment was conducted to evaluate the effects of two slow-release fertilizers on the suppression of iron deficiency chlorosis, soil chemical properties, and the yield and quality of L. davidii var. unicolor. Results show that both coated slow-release iron fertilizers and embedded slow-release iron fertilizer effectively controlled iron-deficiency chlorosis. The application of slow-release iron fertilizers significantly increased plant height and chlorophyll content of L. davidii var. unicolor at different growth stages. Furthermore, coated iron fertilizer application significantly increased starch, protein, soluble sugar and vitamin C content of L. davidii var. unicolor, and it also significantly improved total amino acid content, with increases in essential amino acids(Trp, Leu, Lys, Phe, Val, and Thr contents) and in nonessential amino acids(Asp, Glu, Cit, Ihs, Acc, Ala, Pro, and Cys contents). It was concluded that application of coated slow-release iron fertilizer could be a promising option for suppression of iron deficiency chlorosis and deserves further study.     

城市再开发背景下的社区感知——基于内隐联想测验的研究

以广州市永庆坊为例,研究采用内隐联想测验法、问卷以及质性访谈相结合的方法,探究其改造前后社区相关主体的社区感知,旨在探讨社区空间变化背后相关主体的感知态度差异。研究结果揭示了社区感知的外显态度和内隐态度的分离效应,且外显态度表现的差异性强于内隐态度。参与者对永庆坊改造前后的连贯性和积极性存在外显感知态度的显著差异,在内隐态度结果上,参与者对永庆坊改造前后的连贯性和积极性并未存在显著差异。实验结果表明：物质层面的更新并非引起居民等主体对改造热议的根本原因,社区更新重点应关注利益主体对权利、参与权的诉求,关注其利益分配的合理性。诚然,社区改造规划中不仅应重视公众参与和调查,也应深入挖掘社区公众对于社区改造的内隐感知态度,以提高社区规划的效力。研究采用内隐联想测验的神经科学认知方法对景观感知的探讨,以期开拓人文地理学研究方法神经科学转向的新方向。