detection of subsurface structures by means of gravity method can be used to determine mass distribution and density contrast of rock units. this distribution could be detected by different geophysical methods, especially gravity method. however, gravity techniques have some drawbacks and can't be always successful in distinguishing subsurface structures. performance of the gravity technique co...

ِdfferent drip (surface and subsurface) and furrow irrigation methods effects on grain, oil and water use efficiency based on grain black cumin(nigella sativa l.) as medicinal plants was investigated. for this purpose, experiment over the past two years (2009 and 2010) in a randomized complete block was designed in three replications. treatments in this research were consisting of 50, 75 and 100...

An analysis of channel head locations provides insight into controls on drainage density, the response of landscapes to climatic change, and the delineation of source areas for channel network simulations. Channel heads and colluvial deposits were mapped in a roughly 2 km 2 area near San Francisco, California, and, although channel heads are located within colluvial deposits in hollows, many su...

[1] Unsaturated zone chloride profiles in semiarid regions provide a decadalto century-scale record of past environmental changes, similar to climate change records provided by tree rings and ice cores. Impacts of conversions from natural ecosystems to rain-fed agriculture on water resources are recorded in chloride profiles in semiarid regions, as typified by the southern High Plains (SHP), Te...

Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological s...

In Asia, there are two distinct types of chum salmon (Oncorhynchus keta Walbaum). The early-maturing or “summer” chum salmon generally returns to spawn from June through August in streams bordering Kamchatka, the Sea of Okhotsk, the east coast of Sakhalin Island, and the Amur River. Later-maturing or “autumn” chum salmon generally return to spawn from September through November in streams in Ja...

A taxonomic review of Copella is presented based on the analysis of the type material of all nominal species and extensive material from South American drainages. Six out of ten nominal species are recognized as valid: Copella arnoldi, C. callolepis, C. compta, C. eigenmanni, C. nattereri, and C. vilmae. Copella carsevennensis is a junior synonym of C. arnoldi, C. nigrofasciata and 'Nannostomus...

Magnetotelluric (MT) method is an electromagnetic technique that uses the earth natural field to map the electrical resistivity changes in subsurface structures. Because of the high penetration depth of the electromagnetic fields in this method (tens of meters to tens of kilometers), the MT data is used to investigate the shallow to deep subsurface geoelectrical structures and their dimensions....