Relationship between the variation of water quality in rivers and the characteristics of watershed at Miyun,Beijing, China

Based on the characteristics of land use and drainage network of the upper watershed of the Miyun Res-ervoir, Beijing, 26 monitoring and sampling sites were selected in different sub-catchments. Temporal and spatial variations in nutrient loss were dealt with in this paper in terms of the monitoring data on the water quality of the main tributaries flowing into the Miyun Reservoir. In combination with the monitoring data on water quality, the impacts of watershed characteristics including land-use type, landscape pattern, and drainage density were assessed, The concentrations of nutrients in the rainy season are higher than those in other seasons, and the concentrations of NO3--N are linearly related to those of total N which is the main form of nitrogen present in the fiver water. The concentrations of nitrogen become higher toward the reservoir along the main rivers. The seasonal variation of ni-trogen in the watershed affected by intensive human activities is very obvious; in the watershed with steady or low water flow, the seasonal variation of nitrogen is less obvious. Forest land and grassland can trap and filter nitrogen effectively. Land-use pattern also has important impacts on the loss of nitrogen. The concentrations of nitrogen and phosphorus in the water bodies show great temporal and spatial variations. On a temporal scale, the concentrations of TN and TP in the rainy reason are higher than those in other seasons. On a spatial scale, the concentrations of TN and NO3--N in the Qingshui River and Chaohe River are highest all the time. The spatial variation of TP is distinct, being obvious at sampling sites near villages. The form of nitrogen and phosphorus loss varies in different hydrological seasons. Dissolved nitrogen and phosphorus are the main forms in streams in non-rainy seasons, the dissolved nitro-gen and total nitrogen decrease in percentage in the rainy season. Particulate nitrogen and phosphorus are the main forms in some rivers. The concentrations of TN and NO3--N from orchards and villages are high whereas those from forest land are lowest. Land-use pattern has impacts on TN and NO3--N losses, at the sampling sites near the source landscape, the concentrations are higher than those at the sampling sites near the sink landscape. Water quality of the rivers which flow into the Miyuan Reservior is influenced by the composition of adjacent soils.     

莺—琼盆地1号断裂带含烃热流体活动初探

１号断裂带是莺－琼盆地油气勘探的重点地区之一,有机包裹体研究有助于追踪油气及热流体活动的痕迹,为油气运聚成藏提供地球化学依据,通过包裹体薄片镜下观察,均一温度和盐度测试,认为工区内发育五种类型的有机包裹体：（１）液态烃包裹体;（２）气流态烃包裹体;（３）气态烃包裹体;（４）含烃ＣＯ２包裹体;（５）烃子矿物包裹体,含烃ＣＯ２包裹体一般与气态烃共生,含烃子矿物包裹体既无液态烃共生又与气态烃共生,包裹体     

区域性热带气旋暴雨短期预报系统在MICAPS系统上的移植

利用MICAPS系统上的实时报文资料,以物理量场诊断为动力相似的主要依据,综合热带气旋移动路径及登陆范围来订正,以人机结合方式完成梧州及贺州地区的热带气旋暴雨24h落区预报工具在MICAPS系统上的移植,直观形象地显示预报结果。该工具利用1979～1980年7～9月、1995年7～9月3a的热带气旋实例进行试报,1997～1998年7～9月试运行,均取得较好的预报效果,目前已可以在后汛期台风季节中投入准业务试用。     

萨拉乌苏河流域萨拉乌苏组砂丘砂沉积特征

The Salawusu Formation of Milanggouwan section in Salawusu River Valley includes 7 layers of paleo-mobile dune sands, and 4 layers of paleo-fixed and semi-fixed dune sands. Their structures have been observed and their grain size, surface textural features and several main chemical elements have been analyzed. The results showed that： 1） Some of the aeolian structural characteristics of these dune sands are similar to that of the recent dune sands. 2） They are also similar to the recent dune sands in grain size components, and parameters of Mz,σ, Sk and Kg, as well as in several main chemical components. 3） The scattergrams of Mz-σ and SiO2-Al2O3＋TOFE and the probability curves of grain size showed that these paleo-dune sands are different from paleosols and fluvio-lacustrine facies, but are consistency with recent dune sands. 4） Quartz sands have well roundness and surface textural features such as dish-shaped pits, crescent-shaped pits, pockmarked pits, upturned cleavage plates, siliceous precipitates and siliceous crevasses, indicating that they had been carried for a long time by the wind. As the 11 layers of paleo-dune sands possess the aeolian characteristics in structure, grain size, surface textural features and chemical elements, the origin of their formation should be attributed to eolation.     

湖南省岳家桥典型岩溶发育区电性特征及构造格架研究

为探讨湖南省益阳市岳家桥地质灾害现状,以区内典型岩溶发育区为研究对象,通过长剖面高密度电法、视电阻率联合剖面法等地球物理方法,研究了地层电性响应特点,利用钻孔数据和综合电法勘探数据建立了三维地层结构模型,揭示了典型区域近地表电性结构形态,构建了区内三维地层构造格架,圈定了岩溶发育范围,并评价了地质灾害程度。研究表明: 因地制宜地利用综合电法勘探,有助于在我国南方含水较多的岩溶发育区快速、有效地进行灾害范围的圈定和评价。     

24万年来西昆仑山甜水海湖岩芯碳酸盐含量变化与气候环境演化

青藏高原现代气候与环境存在着明显的区域差异。高原西北部的西昆仑山甜水 海地区是高原上气候最干旱的区域。作者于１９９５年６月在该区海拔４８４０ｍ的湖盆首次打钻取芯（ＴＳ９５孔）,获得５７ｍ湖泊岩芯,经对样品的实验室测年和多项环境指标分析,表明,ＴＳ９５孔岩芯覆盖了距今２４０－１７ｋａ间的时间尺度。期间,经历了倒数第二次冰期,末次间冰期,末次冰期早期,末次冰期间冰阶和末次冰盛期几个气候变化阶段。岩芯中     

Cases-97: Late-Morning Warming And Moistening Of The Convective Boundary Layer Over The Walnut River Watershed

Aircraft, radiosonde, surface-flux, and boundary-layer windprofiler data from the Cooperative Atmosphere Surface Exchange Study's 1997 field project, CASES-97, are combined with synoptic data to study the evolution of the vertically-averaged mixed-layerpotential temperature []and mixing-ratio [Q] onthree nearly-cloudless days from 1000 CST to 1200CST (local noon is approximately 1230 CST). This was achieved through examination of the terms in the time-tendency (`budget')equations for []and [Q]. We estimate three of the terms –local time rate of change, vertical flux divergence, andhorizontal advection. For the [Q]-budget, vertical flux divergence usually dominates, buthorizontal advection is significant on one of the three days. The [Q]-budget balances for two of the three days to within the large experimental error. For the -budget,vertical flux divergence accounts for most of the morningwarming, with horizontal advection of secondary importance.The residual in the -budget has the same sign for all three days, indicating that not all the heating is accounted for. We can balance the []-budgets to within experimental error on two of the three days by correcting the vertical-flux divergence for apparent low biases in the flux measurements of one of the aircraft and in the surface fluxes, and accounting for direct heating of the mixed layer by radiative flux divergence allowing for the effects of carbonaceous aerosols. The [];-budget with these corrections also balances on the third day if horizontal gradients from synoptic maps are used to estimate the horizontal advection. However, the corrected budget for this day does not balance if the horizontal gradient in the advection term is estimated using CASES-97aircraft and radiosondes; we suggest that persistent mesoscale circulations led to an overestimate of the horizontal gradient andhence horizontal advection.     

残余和现今应力场重迭法预测强震危险时区

以红河断裂带测区为例，用Ｘ射线法测量了测区的古构造残余应力场及其应变能密度场，用有限单元法计算了测区在两种边界条件下的水平最大剪应力场，用实验和理论证明了古构造残余主压应力大小和方向对岩石破坏、破裂扩展和震级的影响。用上述方法预测，松平—南涧、玉溪—开远、普洱为测区内强震危险区段。结合地球自转角速度相对变率的天文观测曲线在时间轴上的外延，预测得１９８９－１９９６、１９９９－２００４、２００７－２０１３、２０１６－２０１８年为测区内强震危险时段。     

Climate change implications for irrigation and groundwater in the Republican River Basin,USA

This study investigates the influence of climate change on groundwater availability, and thereby, irrigation across political boundaries within the US High Plains aquifer. A regression model is developed to predict changes in irrigation according to predicted changes in precipitation and temperature from a downscaled dataset of 32 general circulation models (GCMs). Precipitation recharge changes are calculated with precipitation-recharge curves developed for prognostic representations of precipitation across the Nebraska-Colorado-Kansas area and within the Republican River Basin focal landscape. Irrigation-recharge changes are scaled with changes in irrigation. The groundwater responses to climate forcings are then simulated under new pumping and recharge rates using a MODFLOW groundwater flow model. Results show that groundwater pumping and recharge both will increase and that the effects of groundwater pumping will overshadow those from natural fluctuations. Groundwater levels will decline more in areas with irrigation-driven decreasing trends in the baseline. The methodologies and predictions of this study can inform long-term water planning and the design of management strategies that help avoid and resolve water-related conflicts, enabling irrigation sustainability.     

The geochemical characteristics and origin of crude oils in the Kekeya Oilfield,Xinjiang, China

GC/MS and GC/MS/MS techniques were employed to describe the characteristics of biomarker assemblages in two sets of hydrocarbon source rocks, Jurassic and Permian, in southwestern Tarim, and the parameters for the classification of the two sets of hydrocarbon source rocks have been established. It is found that diahopane and C30-unknown terpane are abundant in Permian samples, the contents of diahopane in Jurassic samples are relatively low, and terpenoids have been detected in Jurassic samples but not in Permian source rock samples. Kekeya crude oils are abundant in diahopane and C30-unknown terpane. The results of fine oil-rock correlation indicated that Kekeya crude oils were derived mainly from the Permian hydrocarbon source rocks. However, a small amount of diterpenoid was detected in the crude oils, indicating that the Jurassic hydrocarbon source rocks also made a certain contribution to Kekeya crude oils.