Alluvial floodplains (meadows and wetlands) of large riversystems are among the most productive ecosystems on Earth [1– 4], yet floodplains are dynamic landscapes which may function as both a sink or source of nutrients [5,6]. Floodplain fertility is often broadly ascribed to nutrient deposition during flooding events, and the natural productivity of floodplains yields immense production of grasses, sedges and herbs. This makes these floodplain landscapes a foci for grazing ungulates  and the cradle of agrarian culture [8–10]. Similar to their ancient farming predecessors in Euphrates, Tigris and the Nile, farmers settling the sub-arctic regions in the interior of northern Europe selectively exploited floodplains and also constructed intricate water fed meadow systems to increase fodder production . These productive meadows are a dramatic contrast to the surrounding often species poor, slow growing and low productivity coniferous forests. Alluvial floodplains at northern latitudes (Arctic, subarctic and boreal) with their long winter seasons were particularly valuable resources used for cattle farming and for the harvest of winter fodder until the middle of the 20 th Century [11,12]. The unfertilized, seasonally flooded meadows exhibited exceptional productivity resilience in spite of annual harvests over extended periods of time [12,13]. Flooded meadows were the backbone of fodder production until commercial fertilisers were introduced and production switched to ploughed fields on higher ground where
Abstract. Economic and social development has greatly in- creased ecological water demand and modified land use of riversystems worldwide, causing overall degradation of many of these systems. In this study, theoretical and techni- cal frameworks for regionalization on the eco-environmental function of riversystems are formulated and applied to the Luanhe River system. Based on its eco-environmental func- tions, this river can be regionalized into four types of first- class functional areas: ecological preservation areas, habi- tat restoration areas, ecological buffer areas and develop- ment and utilization areas. Considering the overall eco- environmental functions, we assessed the ecological land use of the Luanhe River system. The total area of basic ecological land use is 876.98 km 2 ; the restrictive ecological land use is 1745.52 km 2 ; ecological land use of the river system returned from farmland is 284.25 km 2 ; and that returned from con- struction land is 17.35 km 2 . The average minimum ecologi- cal flow of mainstreams in upper and middle reaches of the Luanhe River is 4.896 m 3 s −1 based on the habitat method. And the recommended minimum and suitable annual eco- logical water demand of channels in the lower reaches are 391 million m 3 and 819.5 million m 3 , respectively. The evap- oration and seepage consumption and vegetation consump- tion in riparian zones of the Luanhe River system are ap- proximately 132.6 million m 3 and 145.3 million m 3 per year, respectively. Our results suggest that is crucial to regulate the instream ecological water use of the Luanhe River’s mainstream starting from the Panjiakou-Daheiting Reser- voir system. We recommend accelerating ecological land-use
Abstract. Riversystems maintain unique biotic resources and provide essential renewable water supplies for humankind. Flood pulses are the key natural drivers of species richness and productivity of the large river-floodplain ecosystems, but traditional water management has sought to reduce the natural variability of river flows to achieve more stable water supplies for socio-economic water needs. The increasing human pressure on riversystems directly threatens the biodiversity of fluvial ecosystems across the world. Ecologically sustainable river management is aimed at maintaining the ecological integrity of the affected ecosystems while meeting the intergenerational human needs and sustaining the full array of other goods and services provided by natural river ecosystems. Several criteria of ecologically sustainable water management are outlined, such as the assessment of the reference status, the documentation of the deficiencies of the baseline conditions, the iden- tification of the causes of ecosystem degradation using the DPSIR framework, the analysis of the compatibility of water needs, the definition of the target vision, etc.
The interpretation of large river deposits from the rock record is hampered by the scarcity of direct observations of active large riversystems. That is particularly true for deep-channel environments, where tens of meters deep flows dominate. These conditions are extremely different from what is found in smaller systems, from which current facies models were derived. MBES and shallow seismic surveys in a selected area of the Upper Amazonas River in Northern Brazil revealed the presence of large compound barchanoid dunes along the channel thalweg. The dunes are characterized by V-shaped, concave-downstream crest lines and convex-up longitudinal proﬁles, hundreds of meters wide, up to 300 m in wavelength and several meters high. Based on the morphology of compound dunes, expected preserved sedimentary structures are broad, large-scale, low-angle, concave up and downstream cross- strata, passing laterally and downstream to inclined cosets. Examples of such structures from large river deposits in the rock record are described in the Silurian Serra Grande Group and the Cretaceous São Sebastião and Marizal formations in Northeastern Brazil, as well as in Triassic Hawkesburry Sandstone in Southeastern Australia and the Plio–Pleistocene Içá Formation in the western Amazon. All these sedimentary structures are found near channel base surfaces and are somewhat coarser than the overlying fluvial deposits, favoring the interpretation of thalweg depositional settings. The recognition of large barchanoid dunes as bedforms restricted to river thalwegs and probably to large riversystems brings the possibility of establishing new criteria for the interpretation of fluvial system scale in the rock record. Sedimentary structures compatible with the morphological characteristics of these bedforms seem to be relatively common in large river deposits, given their initial recognition in ﬁve different fluvial successions in Brazil and Australia, potentially enabling substantial improvements in facies models for large rivers.
Given that riversystems can be characterized by unidirectional water movement seed dis- persal via the water (i.e. hydrochory) will most likely occur downstream. When downstream migration is slightly higher than upstream migration, genetic diversity could accumulate downstream, while populations upstream may gradually lose genetic diversity and in the most extreme case may disappear due to stochastic events . This phenomenon is known as ‘the unidirectional dispersal hypothesis’ [12,17–19]. However, the observation that upstream habi- tats along rivers are not depleted of riparian plant species and populations upstream are gener- ally genetically diverse as well, indicates that species are capable of dispersing seeds, pollen or vegetative structures upstream as well as downstream [11,20,21]. For instance, riparian popula- tions of Sparganium emersum and Populus nigra disperse upstream via birds and wind, while downstream migration might have occurred via riversystems [22,23].
Many Atlantic salmon, Salmo salar, populations are decreasing throughout the species’ distributional range probably due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture. However, most previous research has focused on analyzing single or only a few populations, and quantified isolated effects rather than handling multiple factors in conjunction. By using a multi-river mixed-effects model we estimated the effects of oceanic and river conditions, as well as human impacts, on year-to-year and between-river variability across 60 time series of recreational catch of one-sea-winter salmon (grilse) from Norwegian rivers over 29 years (1979–2007). Warm coastal temperatures at the time of smolt entrance into the sea and increased water discharge during upstream migration of mature fish were associated with higher rod catches of grilse. When hydropower stations were present in the course of the riversystems the strength of the relationship with runoff was reduced. Catches of grilse in the river increased significantly following the reduction of the harvesting of this life-stage at sea. However, an average decreasing temporal trend was still detected and appeared to be stronger in the presence of salmon farms on the migration route of smolts in coastal/fjord areas. These results suggest that both ocean and freshwater conditions in conjunction with various human impacts contribute to shape interannual fluctuations and between-river variability of wild Atlantic salmon in Norwegian rivers. Current global change altering coastal temperature and water flow patterns might have implications for future grilse catches, moreover, positioning of aquaculture facilities as well as the implementation of hydropower schemes or other encroachments should be made with care when implementing management actions and searching for solutions to conserve this species.
Study area. The Eg-Uur watershed area (3.48 million ha) is located in a remote region of northern Mongolia covering territories of 6 soums (administrative units like districts) in Hövsgöl Aimag and 2 soums in Bulgan Aimag (administra- tive units like provinces). The Eg and Uur rivers are relatively pristine, naturally meandering, and oligotrophic steppe riversystems. The Eg river (length = 277 km) originates from Lake Hövsgöl and ﬂ ows south where it meets with the Uur river (length = 152 km), a river fed by groundwater and precipitation run-off from the eastern Sayan Mountains. The combined Eg-Uur, known as the Eg river after the conﬂ uence (length = 281 km), feeds into the Selenge River, the largest tributary of Lake Baikal. The Eg-Uur rivers have an annual period of ice cover that usually spans from late November until early May and often reach peak ﬂ ows in July and August during monsoonal rains. At the time of sampling (May-June, and October 2006), the Uur river had an approximate wetted width of 50–100 m with a variety of habitats (sand banks, rifﬂ es, gravel and cobble runs, and deep
cause the effect of groundwater DIC is transient and is only observed near the im- mediate source at the first order stream, carbon exchange at this interface has been largely unexplored (Johnson et al., 2008; ¨ Oquist et al., 2009). Therefore, a more quan- titative understanding of carbon exchange in headwater systems is essential to derive a reliable carbon budget of riversystems.
The lower genetic variability recorded in the up- per-middle, mid- and downstream populations may reflect their re-colonisation via successive founder events, each with a relatively low Ne value, and by either a single or only few organelle-lineage colonisation (Grant and Bowen, 1998; Wang et al., 2000), in a passive downstream dis- persal-migration route. This downstream migration pattern had already been documented in a study by Halls et al. (1998) of C. striata in Bangladesh. Alternatively, the low variability observed in these three populations could also be the result of a historical bottleneck event that may have almost eradicated these populations. Notwithstanding, ge- netic variation in three downstream populations, viz., the Parit Buntar, Kampung Gajah and Teluk Intan, was higher than in the upper-middle and mid ones. Presumably their downstream location was more propitious for the overlap- ping of colonisation routes, with concomitant admixture of haplotypes or alleles from several separate refugia, or other connected riversystems. This had already been observed in other studies of the same scenario (Nguyen et al., 2006).
Considering the Canonical Correspondence Analysis (CCA), the two first axes were significant (p <0.05) explaining 84% (Figure 6 ). There was a correlation between the first larval stage (D Larvae) with some abiotic factors, such as temperature, PO 4 and phytoplankton density (Figure 6a ). Phytoplankton species were composed primarily by Cholorophyceae and Zygnemaphyceae microphytoplankton (63-500 µm) (Figure 6c) in the environments Baia River in March (BAI-M), Baía River in December (BAI-D), Paraná River in December (PAR-D) and Curutuba Channel in December (CUR-D) (Figure 6b). The other larval stages (Straight-hinged, Umbonated, Pediveliger and Plantigrader) correlated primarily with conductivity, pH, NO 3 and only the Dinophyceae nanoplankton (2-63 µm) (Figures 6a, 6b and 6c ).
Later, during the mid-19th century, the Hungarian hydrological engineer, Pál Vásárhelyi also made plans for the regulation of the River Bodrog. He suggested 12 small cut-offs that were carried out in 1867. In the 1880s the two tributary streams of the River Bodrog, the Ondava and the Tapoly were also regulated. As a consequence their sediment was deposited in the Bodrog. By the end of the 1890s 15 cut-offs were created altogether, 8 of them are in Hungary. In order to controll the inland waters along the Bodrog, canals, locks and sluice valves were built. The flood controll of the Bodrogzug was completed with the building of Tiszalök Dam in 1954 (Ihrig, 1973).
much as 10 pins from the total of 21 pins and fourth observation in total of 8 pins followed by plot 2 which recorded the total of 5 pins, plot 3 as much as 10 pins, plot 4 with 3 pins and finally plot 5 with 4 pins. Relatively, the average of eroded pin is more actively happened under the edge of the river causing the upper part of the river edge collapse because there was no support under the edge of the river. Next, the analysis of width ratio then showed that plot 1 and plot 2 entirely exhibit the total width-depth ratio a decrease from 0.48-0.46. The ratio value that indicates this reduction means these plot experiencing widening process and the erosion deepen the river which actively occurring in this area. For plot 3 until plot 5, its value of width-depth ratio indicates that there is an increasing ratio number at the end of the observation. In plot 3, the initial ratio value is 0.36 and it increased to 0.37 at the end of observation. Plot 4 then recorded a constant ratio number at the beginning of observation that is 0.39 before it’s increased to 0.40 at fourth observation. For plot 5, there is an increase from 0.44 until 0.47 at the end of observation. By the increase of ratio values, it shows that within the plot area there is a river widening process and the river floor becomes shallow because the deposition process taking place.
This article is devoted to analysis and estimation of opportunities of information technologies in formation of marketing decisions. The role of information technologies in marketing activity of the companies is considered. The information systems are classified and the features of each system are described. Advantages of using information technologies in marketing and some recommendation about rise efficacy of inculcation of information technologies in marketing activity of home-grown enterprises are shown. The history of distance learning which providing an opportunity to study in any level not depending on the leaving place or job, age and others are considered in this work. The situation of e-learning in the world, especially in developed countries has been analyzed. The situation in Uzbekistan of distance education and e-learning was considered. The measures of the government and institutions, educational organizations, showed the results of the first experience in the e-learning field were analyzed.
Moreover, in Figure 10 it can be seen an increase in mean concentration of total phosphorus from upstream towards downstream, from P2 to P4 (0.09 to 0.10 mg/L) in the Campo River, and more sharply from P1 to P3 (0.05 to 0.18 mg/L) in the Km 119 River. Approximately 83% of these results were higher than the limit of 0.1 mg/L of the Conama Resolution 357/2005 (Brasil, 2005) for Class 2 in lotic environment. The results indicate points of contamination, probably due to the disposal of effluents of sewage treatment plants, Km 119 and Campo wastewater treatment plants, in the urban area of the municipality of Campo Mourão and fertilizers used in agricultural activities in the rural area of the basin.
Seven species and ten morphospecies of Isoptera and three species of Symphyla were identifi ed. The highest density and diversity were found in secondary forest. One supposes that the low density of mesofauna found in all of the studied systems is being infl uenced by soil structure and composition as well as litter volume. For SUT, the composition of taxonomic groups in the cultivated areas is similar to the one found in primary forest, while the groups found in the agroforestry system are similar to those in the pasture, which may help to decide on land use strategies.
Our results suggest that termite mounds are im- portant resources for significant portions of the her- petofauna of the upper Tocantins River Valley. They support our initial hypothesis that termite mounds would prove herpetologically diverse. Between 30% and 50% of the herpetofauna known from each of our study sites were also found in termite mounds. Future studies may demonstrate termite mounds are critical components to the environment in maintaining her- petological diversity.
Substantially greater increases in river discharge relative to baseline are consistently projected for the semi-arid, River Huangfuchuan catchment in north China compared to the sub-tropical humid, River Xiangxi catchment in south China. There is, however, substantial uncertainty in the magnitude of projected increases in river discharge resulting from cli- mate change. The greatest source of uncertainty in hydrolog- ical projections in both catchments is GCM structure (choice of GCMs). Our results provide an indication of the rela- tive magnitude of uncertainty in current projections of hy- drological change in sub-basins of the Yangtze River and the Yellow River, and highlight the importance of using multi- model (GCM) evaluations of climate change impacts on wa- ter resources. Although the priority subset of senven GCMs was specifically selected to represent the expected range of uncertainty in GCM projections, uncertainty would be ex- pected to increase if a larger number of GCMs had been em- ployed. Similar to other studies in this issue (Arnell, 2010; Kingston and Taylor, 2010; Thorne, 2010), noted differ- ences in projections of mean river discharge and intra-annual (seasonal) flows question the representivity of using mean flows to represent hydrological change to water managers as
Fish is one of the most important food resources of the Amazonian population, which has 30,000 fishermen and more than 70,000 directly related jobs. Little is known regarding Hg bioaccumulation as a function of hydrological cycles in the Amazonian ecosystem (Dorea & Barbosa, 2007). Moreover, previous studies in the Amazon and other areas have determined that fish is the main route of mercury contamination to the population, especially villages along the river, where contaminated fish is the main protein source (Malm et al., 1995; Bastos et al, 2007). The tolerance limit recommended for consumption by the WHO is 0.50mg.kg -1
The abiotic variables mentioned above were used in a Principal Components Analysis (PCA) to reduce the number of predictor variables in the multiple regression model (see below). We used mean values for the hydro- metric levels of the Paraná and Ivinhema rivers measured over a period of 14 days because there was a temporal lag phase in the effect of fluctuating water levels on phyto- plankton (this number was selected by preliminary cor- relation analysis). For precipitation, values correspond- ing to the two days prior to sampling were recorded. For the Baía River analysis we used the hydrometric levels of the Paraná River. Detrended Correspondence Analysis (Jongman et al., 1996) was used to determine the major variation in species composition (presence/absence) data and to reveal patterns in community structure.