乡级自动雨量站与自动气象站雨量资料的融合

分析了乡级自动雨量站与自动气象站雨量资料融合的必要性,介绍了资料融合的思路与方法。通过这种方法,实现了商丘市两种雨量资料的完全共享。     

Mobility and retention of trace elements in hardpan-cemented cassiterite tailings, north Queensland, Australia

This study reports on the mobility and retention of trace elements in cassiterite tailings at the inactive Jumna mill, tropical north Queensland. Since the 1980s, the uncapped tailings have developed laterally discontinuous Fe-rich hardpans, which are located in the higher parts of gently sloping tailings masses and at the top (<50 cm) of the tailings piles. Hardpan-cemented tailings comprise thin layers (typically ∼0.2–2 mm thick) of HFO (hydrous ferric oxides) and sulfate efflorescences cementing tailings grains. In comparison to the tailings, the hardpan-cemented tailings contain significantly higher median As, Ca, Cd, Co, Cu, Fe, In, Mn, Mo, S_total, Th, U, Y and Zn values. Partial leaching studies of tailings and pond water analyses indicate that wetting and acidification of Fe-cemented tailings removes significant proportions of trace elements into pore and surface waters. Tin shows no mobility due to the presence of weathering-resistant cassiterite (SnO₂) and, As and Pb display limited mobility possibly due to their coprecipitation with jarosite-type phases and HFO materials at the top of the tailings profile. By contrast, the trace elements Cd, Ce, Cu, La, Ni, Pb, U and Zn display the greatest mobility, possibly due to their incorporation in soluble sulfate efflorescences and sorption onto mineral and HFO surfaces. Hence, the Fe-rich hardpans do not protect the sulfidic tailings from further oxidation nor do they cause permanent sequestration of trace elements.     

Groundwater Inflow Controls Acidity Fluxes in an Iron Rich and Acidic Lake

To ascertain the influence of hydrological boundary conditions on acidity fluxes in lakes influenced by acid mine drainage, acidity budgets were developed for two sediments in areas of differential groundwater inflow (approx. 1 L m^?2 d^?1 and 10 L m^?2 d^?1). In both sediments iron was deposited as schwertmannite leading to iron(III) enriched sediments (3.9…6.2 mmol g^?1, referred to dry weight). Compared to the surface water, the inflowing groundwater had higher pH (4.5 vs. 3), ferrous iron (6…20 mmol L^?1 vs. 0.8…2.0 mmol L^?1), and sulfate (5…60 mmol L^?1 vs. 8…13 mmol L^?1) concentrations. The inflow changed the sediment pore water chemistry and triggered a further increase in pH to above 5.5. In both sediments acidity generation in the surface water (10…30 mol m^?2 a^?1) strongly prevailed over acidity consumption in the sediments (> ?0.6 mol m^?2 a^?1). With advective groundwater inflow, however, more acidity was consumed due to TRIS formation (?0.12 mol m^?2 a^?1 vs. ?0.017 mol m^?2 a^?1), iron carbonate burial (upper estimate: ?0.14 mol m^?2 a^?1 vs. ?0.022 mol m^?2 a^?1), and unspecific ferrous iron retention (?0.39 mol m^?2 a^?1 vs. ?0.08 mol m^?2 a^?1). Also, less acidity was generated due to schwertmannite transformation (?2.4 mol m^?2 a^?1 vs. ?0.11 mol m^?2 a^?1). The acidity balance of internal processes in the sediment with groundwater inflow was negative, whereas it was positive in the other sediment. The study demonstrates that in acidic and iron rich lakes the hydrological boundary conditions strongly affect geochemical processes as subsumed in acidity fluxes.     

The 6 h climatology of thunderstorms and rainfalls in the Friuli Venezia Giulia Plain

Friuli Venezia Giulia is a region located in the North-Eastern part of Italy. It has the Adriatic Sea (Gulf of Trieste) on the South and the Julian and Carnic Alps surrounding it on the North. For these geographical properties thunderstorms and precipitations are common events in the plain of this region.The climatology of thunderstorms and rainfalls, considering 6 h interval periods, is studied in this work. It is shown how the thunderstorm frequency, based on the recording of at least three lightning strikes during the 6 h period, is 16%. The occurrence frequency of at least 1 mm of rain accumulated in 6 h is 24%, while that of at least 5 mm in 6 h is 14%.The daily and monthly distributions of these events are then stratified in three classes, based on their “intensity” (weak, medium and strong), and the different behaviors are analysed. Finally, an explanation for the main monthly rain frequency is sought by looking at only two sounding-derived indices and in particular at their annual cycles. The two indices (related to the potential instability and to the water vapour flux) attempt to summarize the “convective” and “flux” mechanisms for producing rain. It is found that in some particular periods of the year the rain-originating process seems well identifiable, while in many others the two processes seem to be concomitant.     

The impact of landslides and salt weathering on Roman structures at high latitudes—Conway Castle, Great Britain: a case study

Conway Castle is an immense historical structure, dating back to 1289 AC. It was built on highly dipping thickbeds of indurated shale (argillite) and sandstone. It is surrounded by Conway Bay, railway lines, and tall dense forests indicating high relative humidity and rainfall in this coastal area. The castle suffers from weathering noted as honeycomb, black crust, exfoliation, and discoloration with white salt efflorescence at some parts; these are diagnostic features for salt weathering as confirmed by the laboratory investigations using scanning electron microscopy, X-ray diffraction (XRD), point XRD, and hydrochemical analysis. The salt is found to be from three sources, namely, water spray from Conway Bay that is part of the Irish Sea, chemical alteration of the mortars carbonate content into sulfate salts by acid rain, and wet deposition of air pollutants on the surface of the stone. The cracks noted in the southwestern tower of this castle are a result of landslides in this area that resulted from three factors: (a) high dip angle of the indurated sandstone and shale thickbeds (about 60–65° to the south) under this castle, (b) undercutting of these beds in the dip direction by the surface water of Conway Bay, and (c) seismic waves generated by the trains passing close to this castle. All these factors result in land sliding even at a low rate; however, the net result is cracks in the tower close to these factors.     

2000-09-24郑州暴雨过程物理量演变特征

利用郑州实时探空资料 ,分析了 2 0 0 0年 9月 2 4日本区暴雨发生前郑州站物理量演变特征 ,为秋季暴雨预报提供了思路和线索     

贵阳市SO2雨水清除系数的研究

提出了一种利用SO2 空中和雨水采样资料和气象资料、云物理探测资料等计算云下SO2 降水清除系数的方法 ,计算了贵阳市冬、夏季不同雨强下的SO2 降水清除系数kw,并将所得结果实际用于城市SO2 浓度的数值计算。结果表明 ,这一方法所得结果与实际情况相当一致     

Ion fluxes from fog and rain to an agricultural and a forest ecosystem in Europe

The deposition fluxes of inorganic compounds dissolved in fog and rain were quantified for two different ecosystems in Europe. The fogwater deposition fluxes were measured by employing the eddy covariance method. The site in Switzerland that lies within an agricultural area surrounded by the Jura mountains and the Alps is often exposed to radiation fog. At the German mountain forest ecosystem, on the other hand, advection fog occurs most frequently. At the Swiss site, fogwater deposition fluxes of the dominant components SO₄²⁻ (0.027 mg S m⁻² day⁻¹), NO₃⁻ (0.030 mg N m⁻² day⁻¹) and NH₄⁺ (0.060 mg N m⁻² day⁻¹) were estimated to be <5% of the measured wet deposition (0.85, 0.70 and 1.34 mg m⁻² day⁻¹, respectively). The corresponding fluxes at the forest site (0.62, 0.82 and 1.16 mg m⁻² day⁻¹, respectively) were of the same order of magnitude as wet deposition (1.04, 1.01 and 1.36 mg m⁻² day⁻¹), illustrating the importance of fog (or occult) deposition. Trajectory analyses at the forest site indicate significantly higher fogwater concentrations of all major ions if air originated from the east (i.e. the Czech Republic), which is in close agreement with earlier studies.     

松辽高平原地下水年龄：公主岭附近同位素水文地质剖面研究

本文运用稳定同位素δD、δ~(13)O阐述了公主岭一带地下水成因,并根据水文地质条件和稳定同位素混合模型,采用放射性同位素~3H、~(14)C计算出地下水在含水层中平均滞留年龄。通过分析,对天然状态下和长期开采条件下地下水循环周期也提出了新认识。因此,公主岭一带地下水同位素年龄的研究,对山前高平原各城镇开辟供水水源地具有重要的生产实践意义。     

昭通“7.12”暴雨滑坡泥石流灾害初步研究

昭通“7.12”暴雨过程诱发了区域性滑坡泥石流的强烈活动,造成严重的灾害。本文通过对灾害现场考察,剖析了暴雨成因、时空分布,并阐明了“7.12”暴雨滑坡泥石流区域分布和成灾特征,并以彝良县为例,探讨了暴雨与滑坡泥石流形成关系。根据昭通地区暴雨滑坡泥石流发生规律和发展趋势,提出了减灾对策。