杭州桐庐江南地区浅埋砂性土的工程性质分析

本文分析了浅埋砂性土层在杭州桐庐江南地区的分布规律，综合了地质成因、年代、厚度、土的物理力学性质指标、原位测试成果及建（构）筑物基础设置、工程应用等因素，初步提出了该区的工程地质分区。有利于该区投资者对建设项目的规划选址，方案比较及中小型工程项目的初步设计。     

Simulation of Seawater Intrusion Range in Coastal Aquifer Using the FEMWATER Model for Disaster Information

The FEMWATER model is a three-dimensional finite element model that can simulate both groundwater flow and mass transport at the same time, and so by using this FEMWATER model seawater intrusion was simulated and the results were compared to observation data. By using the observation data, a conceptual model was made of 3 layers based on the type of soil, and the hydrogeological parameter was selected. There are two types of dispersivities: longitudinal dispersivity and transverse dispersivity. Longitudinal dispersivity was calculated by Xu and Eckstein's method (1995 Xu , M. and Y. Eckstein . 1995 . Use of weighted least-squares method in evaluation of the relationship between dispersivity and field scale . Ground Water 33 ( 6 ): 905 – 908 .[Crossref], [Web of Science ®] , [Google Scholar]) and the transverse dispersivity was put at 3/10 of the longitudinal dispersivity for the simulation. The electrical conductivity suggested by Freeze and Cherry (1979 Freeze , R. A. and J. A. Cherry , J. A. 1979 . Groundwater . Eaglewood Cliffs , NJ : Prentice-Hall . [Google Scholar]) and the correlation with total dissolved solids, TDS, was used to classify the state of the water. Upon analyzing the depths at 15 m, 30 m, 60 m, and 90 m, occurrence of seawater intrusion near the ground surface was limited to the vicinity of the coastline, but as the depths became deeper, seawater intrusion expanded inland. From these results we can come to the conclusion that in order to prevent seawater intrusion there needs to be sufficient preliminary examination.     

Growth,feed conversion and faecal discharge of yellowtail kingfish (Seriola lalandi) fed three commercial diets

Abstract

A study was undertaken to provide data on growth, feed conversion ratio (FCR) and faecal discharge of yellowtail kingfish (Seriola lalandi) fed three commercial diets used previously to culture this species in New Zealand. Fish were raised in tanks from 0.4 to 1.2 kg over the spring (water temperature 14–17°C) and summer (17–22°C) periods. There were considerable differences in volumetric and mass‐specific feed intake, and energy intake amongst diets. Daily crude protein intake was similar amongst diets, although it increased from the cold (4.05–4.50 g protein kg^?1 day^?1) to warm period (6.48–7.67 g protein kg^?1 day^?1). The biological and economical FCR varied with diet (BFCR 1.22–2.17, EFCR 1.30–2.62), as did the cost of feed per unit biomass produced (NZ$38–3.78 kg^?1). Growth rates were broadly similar amongst diets, and the warmer summer temperature period greatly improved both growth (increase from 0.51–0.64% to 1.18–1.23% mass gain day^?1) and BFCR (decrease from 1.37–2.17 to 1.22–1.46). The Salmofood ESF diet resulted in only half of the faecal setüeable solids and settleable total nitrogen (T N) and total phosphorus (T P) output compared with Skretting NME, which was in turn only half or less of that of Reliance SF     

Effects of turbidity on the migration of juvenile banded kokopu (Galaxias fasciatus) in a natural stream

Laboratory experiments have shown that the juvenile migratory stage of banded kokopu (Galaxias fasciatus (Gray 1842)) is more sensitive to turbidity than other native fish species and avoids turbidity levels of >25 nephelometric turbidity units (NTU). Field trials using juvenile fish collected from the Tarawera River and Hays Stream, New Zealand, were used to test the results from these laboratory experiments by measuring the effects of turbidity on the migration direction and rate for banded kokopu in a natural stream setting. In the stream setting, neither the migration rate nor the migration direction were affected at turbidity <25 NTU. At higher turbidity levels, significantly fewer fish migrated up stream within a given time period. Because there was rarely any downstream movement, this suggests the fish either halted or slowed their upstream movement. A slower rate of migration could result in fewer juveniles reaching adult habitat, and would account for the reduced abundance of adult banded kokopu in rivers that are turbid during the migration season. Achieving turbidity levels of <25 NTU in rivers and streams during the migration season would therefore help maintain upstream migrations and populations of banded kokopu, and hence other native fish species.     

Choosing methods for estimating dissolved and particulate riverine fluxes from monthly sampling

Abstract

In discrete water quality surveys, riverine fluxes are associated with unknown uncertainties (biases and imprecisions). Annual flux errors have been determined from the generation of discrete surveys by Monte Carlo sorting for monthly sampling, from 10 years of daily records (120 records). Eight calculation methods were tested for suspended particulate matter, dissolved solids and dissolved and total nutrients in medium to large basins (10³ to 10⁶ km²) covering a wide range of hydrological conditions and riverine biogeochemistry. The performance of each method was analysed first by type of riverine material, which appeared to be much less pertinent than the flux variability matrix. The latter combines the river flow duration in two percent of time (W_2%) and the truncated exponent (b_50sup) defining the relationship of concentration vs discharge (C–Q) at higher flows (C = aQ^b50sup). As flux variability increases (high W_2% and/or high b_50sup), averaging and rating curve methods become less efficient compared to hydrograph separation methods. Flux biases and imprecisions were plotted in the [W_2%, b_50sup] matrix for discrete monthly surveys.

Editor Z. W. Kundzewicz

Citation Raymond, S., Moatar, F., Meybeck, M., and Bustillo, V., 2013. Choosing methods for estimating dissolved and particulate riverine fluxes from monthly sampling. Hydrological Sciences Journal, 58 (6), 1326–1339.     

矿井水文地质类型划分的理性思考

为了更好地理解和认识矿井水文地质类型划分标准,提升矿井防治水技术水平,依据矿井水文地质类型划分标准并结合一些矿井实际开采情况,分析讨论划分过程中存在的一些模糊问题,并针对这些模糊问题引出对矿井水文地质类型划分的理性思考,对于未来矿井水文地质类型划分具有一定的借鉴意义。     

Artificial tracers for geothermal reservoir studies

Safe disposal of thermally spent geothermal brines that contain environmentally hazardous constituents is commonly obtained by reinjection. The reinjection process also serves to maintain reservoir pressure, enhance thermal recovery, and eliminate possible compactional subsidence. To avoid premature thermal breakthrough of reinjected fluids, tracer tests are employed for detection and evaluation of preferential path networks. In this paper some promising tracers that have not received much attention in geothermal reservoir studies are discussed, and a comprehensive tabulation of field sites of artificial tracer utilization is presented. Chemical and transport processes responsible for tracer retention by the formation of reservoir solids, as well as available tracer detection techniques, are emphasized.     

The vertical attenuation of light in Charlotte Harbor, a shallow, subtropical estuary, south-western Florida

The relative contribution of different components to the attenuation of photosynthetically active radiation was determined in the Charlotte Harbor estuarine system based on laboratory and in situ measurements. Agreement between laboratory and in situ measurements of the attenuation coefficient (k_t) was good (r² = 0·92). For all in situ measurements (n = 100), suspended, non-chlorophyll matter accounted for an average of 72% of k_t, dissolved matter accounted for 21%, suspended chlorophyll for 4%, and water for the remaining 3%.For individual determinations, suspended non-chlorophyll matter, dissolved matter, suspended chlorophyll, and water, each accounted for as much as 99%, 79%, 21%, and 18% of k_t. Attenuation by suspended matter was greatest near the mouth of the northern tidal rivers and was variable over the rest of the estuarine system. Attenuation by dissolved matter was greatest in the brackish tidal rivers and decreased with increasing salinity. Attenuation due to dissolved matter was positively correlated with water color. The source of the color was basin runoff. Wavelength transmittance changed along the salinity gradient. Maximum transmittance shifted from 500 to 600 nm in gulf waters to 650 to 700 nm in colored, brackish waters. Dissolved matter was primarily responsible for the large attenuation at short wavelengths (400–500 nm).     

珠江口悬浮泥沙迁移数值模拟

建立了珠江口海域三维悬浮泥沙的非饱和输沙数学模型,并与珠江口三维水动力斜压模型耦合,对悬沙迁移分布进行了模拟。模型由4个点的逐时实测含沙量过程进行了验证。各点模拟含沙量与实测含沙量吻合较好,表层分布与同期珠江口悬沙分布遥感图像基本一致.模拟结果表明,珠江口海域悬沙分布分层明显,河口附近水域大多为底层含沙量大于表层,但在盐淡水交汇处出现中层含沙量最小的情况总体上,自各个口门输出的泥沙受沿岸流作用向西南万向输送明显。大多数河口落潮时相对涨潮时含沙量等值线外移,反映珠江口水域悬浮泥沙主要来自河流。