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191.
As the population of California grows, the discharge of domestic and industrial waste water and power-plant cooling water into coastal waters continuously increases. About 0.75 × 106 m3 of industrial waste water, 3.75 × 106 m3 of domestic waste water, and 26.5 × 106 m3 of thermal effluent are discharged daily into California's nearshore waters. These waters do not have an infinite capacity to break down and disperse the pollutants. Waste water discharged near shore may remain there for considerable time and have a significant effect on water quality and marine life. The low population and wet climate of the northern coastal region have led to small discharges of waste water but very large inputs of fresh water to the ocean. Southward along the Pacific Coast the climate becomes more arid, and population increases. This combination leads to a large excess of waste-water over fresh-water discharge. Many individual waste-water discharges exceed the average daily discharge of most of the rivers which enter the coastal waters.  相似文献   
192.
The course of the active North Anatolian Fault system from Lake Abant to Lake Sapanca was traced by its high micro-earthquake activity. If approaching from the east this section includes a broad south to north overstep (fault offset) of the main fault. Local seismicity has been recorded in this area by a semi-permanent network of 8 stations since 1985 within the frame of the Turkish–German Joint Project for Earthquake Research. The effect of the overstep and its complex fracture kinematics are reflected by the seismicity distribution, the variations of composite fault-plane solutions, and by the spatial coda-Q distribution. Areas of different stress orientation can be distinguished and assigned to different groups of faults. The stresses and the tectonic pattern only in part correspond to a simple model of an extensional overstep and its correlative pull-apart basin. Other types of deformation involved are characterized by normal faulting on faults parallel to the general course of the main strike-slip fault and by synthetic strike-slip faults oriented similar to Riedel shears. Shear deformation by this fault group widely distributed in an area north and east of the main fault line may play an important role in the evolution of the overstep. The development of a pull-apart basin is inhibited along the eastern half of the overstep and compatibility of both strands of the main fault (Bolu–Lake Abant and Lake Sapanca– Izmit–Marmara Sea) seems to be achieved with the aid of the fault systems mentioned. The extension of the missing part of the pull-apart basin seems to be displaced to positions remote from the Lake Abant–Lake Sapanca main fault line, i.e. to the Akyaz?–Düzce basin tract. Highest Q-values (lowest attenuation of seismic waves) were found in the zone of highest seismicity north and west of the overstep which is the zone of strongest horizontal tension. If high coda-Q is an indicator for strong scattering of seismic waves it might be related to extensional opening of fractures.  相似文献   
193.
194.
This paper presents the results of seismic measurements along the Baltic Sea-Black Sea profile. The basic wave groups recorded up to distances of 900 km are characterized. The main elements of a lithospheric model of the southwestern part of the Precambrian East European Platform are given. The thickness of the Earth's crust is about 45 km and the mean velocity of the crust is about 6.3 km/s. At a depth of 65 km, the velocity increases from 8.2 to 8.5 km/s. In the depth interval 110 to 135 km, there is a series of layers with low and high velocities. The lower boundary of the lithosphere is probably defined by the boundary at a depth of 110 km.  相似文献   
195.
Dry-bulb temperature, dew-point, wind speed, and wind direction were measured in and around an isolated vegetative canopy in Davis CA from 12 to 25 October 1986. These meteorological variables were measured 1.5 m above ground along a transect of 7 weather stations set up across the canopy and the upwind/downwind open fields. These variables were averaged every 15 minutes for a period of two weeks so we could analyze their diurnal cycles as well as their spatial variability. The results indicate significant nocturnal heat islands and daytime oases within the vegetation stand, especially in clear weather. Inside the canopy within 5 m of its upwind edge, daytime temperature fell by as much as 4.5 °C, whereas the nighttime temperature rose by 1 °C. Deeper into the canopy and downwind, the daytime drop in temperature reached 6 °C, and the nighttime increase reached 2 °C. Wind speed was reduced by ~ 2 ms–1 in mild conditions and by as much as 6.7 ms–1 during cyclonic weather when open-field wind speed was in the neighborhood of 8 ms–1. Data from this project were used to construct correlations between temperature and wind speed within the canopy and their corresponding ambient, open-field values.With 10 Figures  相似文献   
196.
An analysis of P travel-times from the Nevada Test Site is carried out using data from 23 explosions between 1966 and 1976. Results show a scatter of travel times which may partly arise in the lower mantle. P travel-times over the distance range 25–100° are 2.0–2.5 s faster than the Jeffreys-Bullen travel times.  相似文献   
197.
An attempt has been made in Chinnar sub basin of Dharmapuri district, South India to isolate the geochemistry of uranium occurrences in groundwater. The geology of the area is mainly of charnockite and granite gneiss. Groundwater samples were collected for two different seasons post and pre monsoon in two different litho units (granite gneiss and charnockite) and analysed for major, minor and uranium concentrations. Higher uranium (18.45 μg L?1) has been recorded during pre monsoon season in granite gneiss with increasing pH. The saturation index calculation for the groundwater isolated minerals like uaraninite, coffinite, haiweeite and soddyite to be precipitating and uranium oxides like UO2.25, UO2.25beta, UO2.33beta as oversaturated. The Eh-pH diagram attempted represents solubility of uraninite within the pH range of 6.0 to 8.0. The study isolate uranium in groundwater of the study area is controlled by the presence of (U4O9) uranium oxide.  相似文献   
198.
Contamination of surface water and groundwater by organic pollutants is a serious problem due to their persistence, bioaccumulation and biomagnification through food webs. Since the removal of dyes from wastewater is considered an environmental challenge and government legislation requires textile wastewater to be treated, therefore there is a constant need to have an effective process that can efficiently remove these dyes. The aim of the present study is to evaluate the potentiality of dried Carpobrotus edulis plant as low-cost adsorbent for the removal of the industrial acid blue 113 dye from aqueous solutions using the batch equilibration technique. The effects of different physicochemical parameters such as adsorbent dose, contact time, initial dye concentration, solution pH and temperature on adsorption rate of anionic AB113 dye on microparticles of dried C. edulis plant were investigated. The experimental data were analyzed by using mathematical models to determine the thermodynamic parameters. The negative values of free energy change indicated the spontaneous nature of the adsorption and negative value of enthalpy change suggested the exothermic nature of the adsorption process. These results indicate that dried C. edulis plant as an environmentally friendly adsorbent could be potentially used for the removal of anionic dyes from aqueous solutions.  相似文献   
199.
Judith A. Rees 《Geoforum》1982,13(4):289-300
Without denying the physical relaity of water shortages during the 1982 Australia drought, it is argued that some of the difficulties arise not from climatic factors but from the way the water resource is managed. An attempt is made to explain why metropolitan Australia can continue to make profligate use of water, while rural Australia suffers scarcity. The system of administration is considered and the capacity planning and pricing policies of supply authorities analysed. Finally, a call is made for the introduction of an effective integrated management system.  相似文献   
200.
In the urban environment, surface temperatures and conductive heat fluxes through solid media (roofs, walls, roads and vegetated surfaces) are of paramount importance for the comfort of residents (indoors) and for microclimatic conditions (outdoors). Fully discrete numerical methods are currently used to model heat transfer in these solid media in parametrisations of built surfaces commonly used in weather prediction models. These discrete methods usually use finite difference schemes in both space and time. We propose a spatially-analytical scheme where the temperature field and conductive heat fluxes are solved analytically in space. Spurious numerical oscillations due to temperature discontinuities at the sublayer interfaces can be avoided since the method does not involve spatial discretisation. The proposed method is compared to the fully discrete method for a test case of one-dimensional heat conduction with sinusoidal forcing. Subsequently, the analytical scheme is incorporated into the offline version of the current urban canopy model (UCM) used in the Weather Research and Forecasting model and the new UCM is validated against field measurements using a wireless sensor network and other supporting measurements over a suburban area under real-world conditions. Results of the comparison clearly show the advantage of the proposed scheme over the fully discrete model, particularly for more complicated cases.  相似文献   
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