due to successes of fingerprinting method in producing rapid and low-cost information of sediment sources, in this research this method was used in three sub-cathments of chasht-khoran basin in semnan province: amrovan, atari and ali-abad. samples below 63 μm were separated and 15 fingerprinting propertis was measured. in the first stage comparison of means and differentiation analysis were use...

[1] Recession flows in a basin are controlled by the temporal evolution of its active drainage network (ADN). The geomorphological recession flow model (GRFM) assumes that both the rate of flow generation per unit ADN length (q) and the speed at which ADN heads move downstream (c) remain constant during a recession event. Thereby, it connects the power law exponent of –dQ/dt versus Q (discharge...

We review the trans-Andean species of Ancistrus from Panama, Colombia and Venezuela. Based on analyses of meristic, morphometric and pigmentation pattern data of preserved specimens, eight of sixteen species reported from this region are considered valid and two new species are described. Here we review Ancistrus chagresi Eigenmann & Eigenmann 1889 from both slopes of central Panama; A. centrol...

The watersheds of the Mississippi are some of the most intensively managed agricultural basins in the world. As such, they receive high loadings of nitrogen and export a large amount of nitrate to the drainage networks of the Mississippi River basin and coastal ocean. We find a positive correlation between fertilizer input and stream export of nitrogen. According to the correlation, 34% of appl...

We describe two new species of pebblesnails (Lithoglyphidae: Fluminicola) from southwest Oregon based on morphologic and mitochondrial DNA (COI, cytB) evidence. Fluminicola umpquaensissp. n., which had been traditionally identified as F. virens prior to the recent restriction of the latter to the lower Columbia River drainage, lives in lotic habitats in the Umpqua River basin. This species is r...

The Mobile Basin historically supported one of the most diverse freshwater mussel (Bivalvia: Unionidae) assemblages in North America. More than 65 species of mussels are known from the Basin, but it is difficult to determine how many species were present historically. The drainage's unique physical habitat was largely destroyed between the late 1800s and mid-1900s by impoundment and channel mod...

Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff, soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices and timing of chemical use gre...

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...

We explain that supersymmetric attractors in general have several critical points due to the algebraic nature of the stabilization equations. We show that the critical values of the cosmological constant of the adS5 vacua are given by the topological (moduli-independent) formulae analogous to the entropy of the d = 5 supersymmetric black holes. In one-moduli case critical points with positive d...