A hydrogeological study was completed within a sub-catchment of the Zerka River drainage basin, in western Jordan. The system
is characterized by anticlinal bending with an axis trending SSW–NNE and plunging a few degrees in the SSW direction. The
anticlinal structure diverts groundwater flow towards the SSW while the strike-slipe faults cause the groundwater to diverge
where the fault is perpendicular to the groundwater flow lines, and to converge where the fault is parallel to the groundwater
flow lines. A direct relationship was found between the location of springs and the type of groundwater flow with regard to
the amount of discharge wherein large spring discharges are located in zones of converging groundwater flow lines. In areas
where faults are not abundant, the groundwater retention time in the aquifers is long and a zonation of the electrical conductivity
was detected due to mineral dissolution. By controlling groundwater flow, the anticlinal setting produces three genetic groups
of groundwater flow systems: (1) alkaline–earth alkaline water which is predominately a bicarbonate-type composition, (2)
alkaline–earth alkaline water which is predominately bicarbonate–sulfate, and (3) alkaline–earth alkaline water with a high
alkaline component. 相似文献
This research is conducted as part of a Spanish International Cooperation Agency project with the aim to investigate the sustainable protection of Tunisian coastal zones, as in the case of Beni Khiar and Dar Chaabane coasts (Hammamet Gulf) separated by Oued El Kebir river. The sedimentary dynamic of these beaches is studied in order to identify the main causes responsible for their erosion by the use of different approaches of in situ measurements and numerical methods. Geophysical surveys and sedimentary analyses have demonstrated that sediments are finer and less carbonated from Beni Khiar to Dar Chaabane. Then, the shoreline mapping of several missions of aerial photos has illustrated a mean shoreline retreat between 3 and 4 m/year. In terms of sand volume, a sediment loss more than 30,000 m3/year at Dar Chaabane has been observed since the hill lake structures were built within Oued El Kebir river in 1996. Finally, modelled hydrodynamic and sedimentary patterns have illustrated the refraction of waves in deep water close to shoals and a high-energy concentration along Dar Chaabane coast. The sediment transport direction is mainly of NE-SW induced by ESE-SE wave-driven alongshore current. Results provided by these approaches have shown the importance of Oued El Kebir sediment yield in supplying the neighbouring beaches. Changes in sedimentary dynamics are affected by the modification of hydrodynamic patters caused by the presence of hydrological dams and the implementations of hotels close to the shoreline. This finding underlines the key role of Oued El Kebir fluvial activity in controlling the equilibrium of beaches and their sensitivity to coastal managements induced by man activities, as in the case of the most Mediterranean beaches. 相似文献
At present, lightning is one of the 10 natural disasters, and it is also the top environmental factor of power interruption. It often causes huge losses to the electric system. The Wuhan High Voltage Institute of the State Grid Corporation of China and Huazhong University of Science and Technology have been researching and developing lightning location systems (LLSs) since the late 1980s. In the mid-1990s, a lightning detection network was created in 29 provinces and cities in China. It is primarily applied to rapidly find lightning accidents, which greatly reduces power interruption. Also, it ensures high efficiency and safe operation of the electricity system. Remarkable benefit is achieved. China's LLS went through an "orientation positioning - time difference positioning - integrated positioning" development process. The positioning precision, detection efficiency, degree of automation, practicability and applied range are improved. Also, a lightning information system plan of the national network has been implemented, which services the whole society. 相似文献
Remarkable progress has been made in electromagnetic (EM) techniques as applied to the petroleum industry in instruments,
data acquisition, and processing and interpretation in China. Included here is equipment, such as high-power Controlled Source
EM (CSEM) acquisition systems, acquisition methods, such as the three dimensional small-bin Continuous Electromagnetic Array
acquisition method, Time and Frequency Domain Controlled Source Electromagnetic, Borehole-to-surface Electromagnetic technique
and marine magnetotelluric method. Data processing methods, such as fast three dimensional inversion using nonlinear conjugate
gradients, and data interpretation methods, like Induced Polarization and Resistivity anomalies for hydrocarbon detection,
are also included. These new techniques have been applied in petroleum survey and many cases are in complicated areas. They
have successfully served the investigation of deep igneous rock reservoirs, and prediction of potential hydrocarbon targets.
The cases indicate that electromagnetic techniques can help seismic survey to effectively detect hydrocarbon reservoir and
remarkably improve drilling successes. 相似文献
The effects of four microalgae,Chlorella vulgaris,Platymonas helgolandicavar,Isochrysis galbana,and Nitzschia closterium on the grazing and filtering rates of the marine rotifer,Brachionus plicatilis,were evaluated under laboratory conditions.The grazing rates in separate cultures of the four microalga were as follows:C.vulgaris > P.helgolandicavar > I.galbana > N.closterium.However,the filtering rates occurred in the following order:P.helgolandicavar > N.closterium > C.vulgaris > I.galbana.A mixed diets ex... 相似文献