نتایج جستجو برای: distance from river
تعداد نتایج: 5759812 فیلتر نتایج به سال:
Patterns of genomic variation in Coho salmon following reintroduction to the interior Columbia River
Coho salmon were extirpated in the mid-20th century from the interior reaches of the Columbia River but were reintroduced with relatively abundant source stocks from the lower Columbia River near the Pacific coast. Reintroduction of Coho salmon to the interior Columbia River (Wenatchee River) using lower river stocks placed selective pressures on the new colonizers due to substantial difference...
Infectious diseases have become a rising challenge to mankind in a globalizing world. Yet, little is known about the inland transmission of infectious diseases in history. In this study, we based on the spatio-temporal information of 5559 plague (Yersinia pestis) outbreaks in Europe and its neighboring regions in AD1347-1760 to statistically examine the connection between navigable rivers and p...
The purpose of this study was to investigate the effect of voltage, salinity and temperature on the performance of electrofishing. Number 850 pcs Capoeta capoeta of Chehel Chay river of Golestan province fishing and transported to the laboratory. Distance from the anode, cathode and anode distance during testing, respectively, 10 cm and the 120 cm. Range of length and weight of the fish test sp...
The generalization operation should first make decision of object importance at geographic level, which relates not only to the geometric properties of independent object but also the other context objects. In the channel selection of river network, besides the length and the distribution density, the order, the angle, the distribution pattern, proportion of left river branch and right river br...
The growing population led to greater human need to use natural resources such as sand and gravel mines. Direct removal of sands from the bed river leads to increase suspended sediment concentrations in downstream of harvested area and creates other problems viz. filling reservoirs, change in hydraulic characteristics of the channel and environmental damages. However, the range of temporal and ...
In this research we aimed to study the sedimentology of Jajrud River, upstream from Latian Dam. Initially, a field review was conducted to ascertain complete familiarity with the geographical and geological conditions of the proposed region. After determining the sampling location, the acquired samples were taken to the laboratory. From morphoscopic studies of the sediments, we have determ...
The contemporary distribution of genetic variation within and among high latitude populations cannot be fully understood without taking into consideration how species responded to the impacts of Pleistocene glaciations. Broad whitefish, Coregonus nasus, a species endemic to northwest North America and the Arctic coast of Russia, was undoubtedly impacted by such events because its geographic dis...
To analyze the changes in the Upper Danube Floodplain, we used aerial photos to quantify the change of landscape pattern from 1963 to 2010. We focused on typical floodplain habitats, i.e., riparian forest and floodplain grassland. We used landscape metrics and transformation matrix to explore changes in land cover structure and composition. The active floodplain experienced increasing fragmenta...
Westslope cutthroat trout (Oncorhynchus clarki lewisi, Salmonidae) are native to the upper Columbia, Missouri, and South Saskatchewan river drainages of western North America and are at the northern periphery of their range in southeastern British Columbia, Canada. We examined geographical variation in allele frequencies at eight microsatellite loci in 36 samples of westslope cutthroat trout fr...
Key-words: particulate organic matter, periphyton, nitrogen stable isotope, subtropical river The stable nitrogen isotope ratios (δ15N) of particulate organic matter (POM) and periphyton were measured at sites along the Dashahe River, a short subtropical watercourse in SE China. δ15N values of both POM and periphyton tended to increase from upstream to downstream, ranging from 1.1‰ to 7.4‰ for ...
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