River North Research Articles

The life cycle of the Maghrebian endemic Ecdyonurus rothschildi Navás, 1929 (Ephemeroptera: Heptageniidae) and its potential importance for environmental monitoring

North African streams and rivers face multiple anthropogenic stressors, and their aquatic fauna is rapidly dwindling before comprehensive knowledge of their distribution and ecology has been attained. We investigated the distribution and life cycle of the Maghrebian endemic Ecdyonurus rothschildi Navas, 1929 in northeastern Algeria. The species was recorded both from permanent and intermittent freshwater habitats with stony substrate. It exhibited pronounced sexual dimorphism, with F-0 females being significantly larger than F-0 males. Three generations were completed during an annual multivoltine cycle. The first generation extended from October to February/March, the second spanned the months of March to June, and the third stretched from June to the end of September/October. We argue that monitoring of E. rothschildi could prove useful for assessing the rapid changes affecting North African hydrosystems, which are in need of adequate management.

Homogeneous selection drives antibiotic resistome in two adjacent sub-watersheds, China

Rivers are a significant reservoir of antibiotic resistance genes (ARGs), yet the biogeographic pattern of riverine ARGs and its underlying driving forces remain poorly understood. Here, we used metagenomic approach to investigate the spatio-temporal variation of ARGs in two adjacent sub-watersheds viz. North River (NR) and West River (WR), China. The results demonstrated that Bacitracin (22.8 % of the total ARGs), multidrug (20.7 %), sulfonamide (15.2 %) and tetracycline (10.9 %) were the dominant ARG types. SourceTracker analysis indicated that sewage treatment plants as the main source of ARGs, while animal feces mainly contributed in spreading the ARGs in the upstream of NR. Random forest and network analyses confirmed that NR was under the influence of fecal pollution. PCoA analysis demonstrated that the composition of ARGs changed along with the anthropogenic gradients, while the Raup–Crick null model showed that homogenizing selection mediated by class 1 integron intI1 resulted in stable ARG communities at whole watershed scale. Structural equation models revealed that microbial community, grassland and several non-antibiotic micropollutants may also play certain roles in influencing the distribution of ARGs. Overall, the observed deterministic formation of ARGs in riverine systems calls effective management strategies to mitigate the risks of antibiotic resistance on public health.

Evaluation of heavy metal pollution in the Zayandeh-Rud River as the only permanent river in the central plateau of Iran.

Zayandeh-Rud River is the only permanent river in the central plateau of Iran. This river has been subject to an extensive discharge of wastewater and effluents from several point and nonpoint pollution sources. Accordingly, sediment quality of Zayandeh-Rud River in Varzaneh region, were studied. Algae and the sediment were sampled through 3 replications at 6 stations in the downstream after crossing through the Isfahan city and reaching Gavkhuni international wetland. Chlorophyll content and As, Pb, and Cd concentrations were measured in each sample Cladophora sp. and Oscillatoria sp. were identified using standard identification keys. The mean concentrations of metals in all stations exceeded background levels. Mean concentration of arsenic (162.9mg/kg) in the sediment is about 31 times more than the ISQG standard (5.9mg/kg) and considerably higher than the similar studies in Iran and other regions of the world. The mean concentration of As in algae samples is higher than the most polluted areas of the world. The mean concentration of Pb in the sediment (19.69mg/kg) is lower than the ISQGs standard (35mg/kg) and most of the studied river in north of Iran such as Chalous, Baboul-Rud, Gorgan-Rud (North), Khiav (North West), and Anzali wetland. The mean concentration of Cd in the sediment (2.11mg/kg) is significantly higher than ISQG standard (0.6mg/kg and some north highly polluted wetlands of Iran such as Anzali. There is a significant positive correlation between the mean concentrations of As and Pb in the sediment and Cladophora sp. tissue, and a negative one between the mean concentration of Pb in the sediment and chlorophyll b/a. There are significant negative correlations between the mean concentration of As in the sediment and chlorophyll a, and the total chlorophyll concentration in Oscillatoria sp. The results of Muller index indicate that the concentrations of Pb, Cd, and As in all stations occur in the Unpolluted, Moderate/Heavy, and Heavy/Extreme groups, respectively. Degree of contamination and modified degree of contamination show very high degree of pollution in the studied area. RI in all the stations showed very high ecological risk. The bioaccumulation factor for all metals in both algae is less than one. So, these two species may not be described as heavy metal accumulators. This study is an alarm for the Zayandeh-Rud River as the most important freshwater source for the Iranian Plateau. Graphical abstract.

Topographic Map Analysis of Mountain Passes Crossing the Continental Divide Between Colorado River Headwaters and North and South Platte River Headwaters to Test a New Geomorphology Paradigm, Colorado, USA

Detailed topographic maps are used to identify and briefly describe named (and a few unnamed) mountain passes crossing high elevation east-west continental divide segments encircling south- and southwest-oriented Colorado River headwaters and linking the Colorado River drainage basin (draining to the Pacific Ocean) with the North and South Platte River drainage basins (draining to the Platte, Missouri, and Mississippi Rivers and Gulf of Mexico). Previous researchers following commonly accepted geomorphology paradigm rules have not explained how most, if any of these mountain passes originated. A recently proposed geomorphology paradigm requires all Missouri River drainage basin valleys to have eroded headward across massive south- and southeast-oriented floods, which implies south- and southeast-oriented floods flowed from what are today north-oriented North Platte River headwaters across the continental divide, the present-day south- and southwest-oriented Colorado River headwaters valley, and then across what is now the continental divide a second time to reach east- and southeast-oriented South Platte River headwaters. Paradigms are rules determining how a scientific discipline governs its research and by themselves are neither correct nor incorrect and are judged on their ability to explain observed evidence. From the new paradigm perspective, a stream eroded each of the passes into a rising mountain range until the uplift rate outpaced the erosion rate and forced a flow reversal in what would have been the upstream valley. The passes and the valleys leading in both directions from the continental divide are best explained if diverging and converging south- and southeast-oriented flood flow channels crossed rising mountain ranges. While explaining observed drainage patterns and erosional landforms such an interpretation requires a fundamentally different regional middle and late Cenozoic glacial and geologic history than what previous investigators using the accepted paradigm perspective have described.

Geochemical transfer of cadmium in river sediments near a lead-zinc smelter.

Cadmium (Cd) is a highly toxic element and non-essential to human. Herein, the source and fate of Cd were examined in a typical sediment profile from the North River, South China, which was affected by the massive Pb-Zn smelting activities for decades. An exceptionally high enrichment of Cd, 107-441mg/kg, was observed across the whole profile. Approximately 50-75% of Cd was retained in the weak acid soluble fraction. Risk assessment based on geoaccumulation index (Igeo), potential ecological risk index (Eri), bioavailable metal index (BMI) and toxic risk index (TRI) further indicated an extremely strong degree of potential ecological pollution and high toxic risks. The mineralogical composition of particles from the sediment profile exhibited the presence of pyrite, magnetite, wurtzite and greenockite. This further confirmed that Cd was migrated from smelting slags to the North River basin and enriched in sediment profile. Sediment Cd speciation analysis also implied a possible transformation of Cd from metal oxides in smelting slags to adsorbed phases and carbonates, which enhances the bioavailability of Cd. The findings indicate proper countermeasures or remediation approaches should be promptly taken towards high ecological risks of Cd arising from the depth profile extending nearly 1m, due to lead-zinc smelting related activities.

Spatiotemporal distribution of Oncomelania hupensis snail habitats in Anhui Province

To investigate the spatiotemporal distribution of Oncomelania hupensis snails and infected snails in the endemic areas of schistosomiasis in Anhui Province. Based on the snail survey data in Anhui Province in 2016, the distribution of snails and infected snails were analyzed, and the spatial distribution of snails and spatial cluster patterns of infected snails were investigated in snail habitats in Anhui Province from 1950 to 2016. A total of 22 757 snail habitats and 5 004 infected snail habitats were identified in Anhui Province from 1950 to 2016, which appeared single-peak and double-peak patterns, with an inflection point seen in 1970. There were 141 000 hm2 historically accumulative snail habitats, 88.08% of which were firstly identified from 1950 to 1979, and totally 114 500 hm2 snail habitats were eradicated, 77.17% of which were eradicated from 1970 to 1999. There were 4 830 snail habitats identified until 2016, in which 1 051 were once detected with infected snails. In addition, 78.12% of current snail habitats had been present for over 40 years, and infected snails had been eliminated in 65.75% of the infected snail habitats within 10 years. There was a spatial autocorrelation of the living snail density in current snail habitats in Anhui Province (Moran's I = 0.196, Z = 139.63, P < 0.001), and local hotspot analysis showed spatial clusters of living snails density in snail habitats, with high-value clusters in south of the Yangtze River and low-value clusters in north of the Yangtze River. The 21 high-value clusters of living snail density with statistical significance were distributed along the Yangtze River basin and its branches. Spatiotemporal scan analysis revealed spatiotemporal clusters of infected snails in 4 current snail habitats. The current snail habitats have been present for a long period of time, and snails are difficult to be eliminated by chemical treatment alone, which requires the combination of environment improvements. There are spatial clusters of living snail density in current snail habitats in Anhui Province. The epidemic factors and risk of human and animal infections still remain in some clusters of historical infected snail habitats revealed by spatiotemporal scan analysis, which should be consid- ered as the key target areas for snail control in Anhui Province.

Occurrence, geochemistry and provenance of REE-bearing minerals in marine placers on the West Coast of the South Island, New Zealand

ABSTRACT The occurrence, concentration and geochemistry of REE-bearing minerals in beach sands along the West Coast of the South Island of New Zealand is reported as a proxy for the composition of adjacent uplifted Holocene marine terraces. The strandlines of 13 beaches along this coast contain REE-rich allanite (average: 15% REO), monazite (82% REO) and xenotime (83% REO), with allanite being most common and xenotime having a restricted range. Other REE-rich phases are apatite (average: 2259 ppm), zircon (1756ppm), epidote (761 ppm), titanite (699 ppm) and scheelite. Geographical trends to the distribution of these minerals are not entirely clear, but there is an influx of titanite and allanite north of the Grey River and an increase in apatite, allanite, monazite and epidote north of Little Wanganui River. In-situ trace elements and/or 87Sr/86Sr isotopes indicate allanite, monazite and xenotime to be likely mainly derived from exhumed Paleozoic and Cretaceous granites, with minor amounts from the Alpine Schist metasedimentary rocks. The main source of the analysed apatite is likely also the granitoids, with contributions from the Greenland Group and Alpine Schist. When the REE abundances in the beach sands are compared to the size of the uplifted adjacent Holocene terraces, Waimangaroa terrace may contain the highest concentration of REE, followed by the Little Wanganui and Barrytown terraces.

Recent adjustments of pool-riffle distribution along the channels in the Pearl River Delta, China

The adjustments of pool-riffle distribution along the deltaic channels in the Pearl River Delta (PRD) under the combined effects of human interventions and natural evolution are examined in the three periods, namely 1952–1977 period, 1977–1999 period, and 1999–2014 period, corresponding to the different dominant factors. The residual depths along the channel thalweg and their spatial autocorrelation are introduced to quantify the pool-riffle distribution. The results show that the average pool depths of the deltaic channels increased significantly and the percentages of longitudinal length occupied by riffles decreased significantly by large-scale sand excavation during the 1977–1999 period and by sediment input decrease during the 1999–2014 period. It is highlighted sand excavation has a greater impact on the pool-riffle distribution of the North River channel and sediment input decrease has a greater impact on the pool-riffle distribution of the West River channel. The changes in spatial autocorrelation of pool-riffle sequence reveal a dramatic decrease of the average pool spacing after sand excavation, reflecting a rearrangement in the pattern of pool-riffle sequence. Moreover, the rearrangement process of the North River channel is ahead of that of the West River channel. In addition, the inhomogeneity indexes of deltaic channels are decreasing during the study period, indicating a deterioration of aquatic habitats diversity. It is anticipated that these results are useful for river management and utilization in the PRD and other river deltas worldwide that are subject to large-scale human interventions.

Source Appointment of Heavy Metals in Agricultural Soils of the Jiulong River Basin Based on Positive Matrix Factorization

In order to study the source appointment of heavy metals in agricultural soils of the Jiulong River Basin, Fujian Province, China. 71 agricultural soil samples were collected in July 2017. The concentrations of heavy metals in agricultural soils were determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS). Here, we use a positive matrix factorization (PMF) model for the source appointment of heavy metals in the sampled soils. The results showed that most of the heavy metal concentrations in the sampled agricultural soils were higher than soil background concentrations for the Fujian Province. The concentrations of Cd, Zn, Pb, and Cu in some soil samples were greater than the screening value of the Chinese soil pollution risk levels for agricultural land (GB 15618-2018). The spatial distributions of heavy metals showed a moderate variation across three regions of the study area (i.e., the North River watershed, West River watershed, and the estuary area). The highest concentration of Cr, Ni, Cu, Zn, and Cd were found in Longyan City (North River watershed), the highest concentrations of Pb were found in the West River watershed, and the highest concentrations of Co, Hg, and As were found in the estuary area. The non-negative properties of the source component spectrum and source contribution rate (obtained by the PMF model), as well as the significant correlation between the measured and PMF predicted concentrations, indicated that the results of the PMF model were relatively reasonable and can meet research needs. The source apportionment results of the PMF model showed that natural sources, agricultural sources, coal combustion, and industrial sources were the four major potential sources for heavy metals in the sampled agricultural soils, contributing 37.0%, 26.7%, 17.6%, and 18.7%, respectively.

Monitoring River Basin Development and Variation in Water Resources in Transboundary Imjin River in North and South Korea Using Remote Sensing

This paper presents methods of monitoring river basin development and water variability for the transboundary river in North and South Korea. River basin development, such as dams and water infrastructure in transboundary rivers, can be a potential factor of tensions between upstream and downstream countries since dams constructed upstream can adversely affect downstream riparians. However, because most of the information related to North Korea has been limited to the public, the information about dams constructed and their locations were inaccurate in many previous studies. In addition, water resources in transboundary rivers can be exploited as a political tool. Specifically, due to the unexpected water release from the Hwanggang Dam, upstream of the transboundary Imjin River in North and South Korea, six South Koreans died on 6 September 2009. The Imjin River can be used as a political tool by North Korea, and seven events were reported as water conflicts in the Imjin River from 2001 to 2016. In this paper, firstly, we have updated the information about the dams constructed over the Imjin River in North Korea using multi-temporal images with a high spatial resolution (15–30 cm) obtained from Google Earth. Secondly, we analyzed inter- and intra-water variability over the Hwanggang Reservoir using open-source images obtained from the Global Surface Water Explorer. We found a considerable change in water surface variability before and after 2008, which might result from the construction of the Hwanggang Dam. Thirdly, in order to further investigate intra-annual water variability, we present a method monitoring water storage changes of the Hwanggang Reservoir using the area-elevation curve (AEC), which was derived from multi-sensor Synthetic Aperture Radar (SAR) images (Sentinel-1A and -1B) and the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). Since many previous studies for estimating water storage change have depended on satellite altimetry dataset and optical images for deriving AEC, the method adopted in this study is the only application for such inaccessible areas since no altimetry ground track exists for the Hwanggang Reservoir and because clouds can block the study area for wet seasons. Moreover, this study has newly proven that unexpected water release can occur in dry seasons because the water storage in the Hwanggang Reservoir can be high enough to conduct a release that can be used as a geopolitical tool. Using our method, potential risks can be mitigated, not in response to a water release, but based on pre-event water storage changes in the Hwanggang Reservoir.

Sandhill Crane abundance in Nebraska during spring migration: making sense of multiple data points

The USFWS conducts an annual one-day aerial survey of the North and Central Platte River Valleys, generally on the fourth Tuesday in March, to estimate the abundance of the midcontinent Sandhill Crane population. However, these abundance indices demonstrate unrealistic inter-annual variation as a result of deviations in migration chronology and other factors. Additional research efforts have been undertaken within the region to estimate Sandhill Crane abundance over time and space but these projects generally seek to answer unique questions, employ differing survey methods, and cover overlapping yet distinct survey areas. Despite the wealth of information there remains significant uncertainty regarding the actual abundance of Sandhill Cranes in Nebraska during the peak of migration. We conducted a model-based metadata analysis relying on the distinctive strengths of three databases to assess USFWS data, identify annual abundance estimates that may not be robust, and developed parameter-based and factorbased corrections to USFWS indices from 2000 to 2019. Our analyses suggest that at the peak of spring migration there is likely between 1.1 and 1.4 million Sandhill Cranes in the North and Central Platte River Valleys of Nebraska. Our best performing models indicated the most likely peak estimate was 1.27 million Sandhill Cranes with approximately 220,000 in the North Platte River Valley and 1,050,000 in the Central Platte River Valley in both 2018 and 2019. Our assessment suggests that 25% of USFWS aerial estimates are robust, with the rest representing underestimates as both exogenous and endogenous factors such as migration chronology and survey methodology serve to bias indices downward. Given this downward bias, the three-year running average used by the USFWS actually provides a robust estimate for only 5–15% of the years analyzed. By contrast, we found that a five-year rolling maximum provides a robust estimate for 70–75% of the years analyzed.

AZERBAYCAN'DA KAPİTALİST GELİŞİM SÜRECİNİN POLİTİK EKONOMİSİ (19. YÜZYILIN ORTALARI-20. YÜZYILIN BAŞLARI)

Azerbaijan is a country that went through a number of different phases under the control of many countries for long permanent and short temporary terms. It can be said that states founded by Azerbaijan Turks were active in the states existed in middle ages and modern times and empires that controlled the region during their hegemony periods. The most important breaking point of the political history of Azerbaijan Turkish people corresponds to the beginnings of the nineteenth century. Russian empire, that was rising in this period and started expand to south, interfered to the long term Ottoman-Iran struggle in this period. Russian empire achieved significant gains from the competition that included three great powers. In 1813 Gülistan and 1828 Türkmençay agreements Azerbaijan’s territories north of Aras River were annexed by Russia. Russia developed different formulas in regards of the regional governance after its occupation. But these formulas that are known as administration reform were changed frequently as they were bereft of permanent and problem solving qualifications.The important changes in the socially traditional and economic structures were made possible by the 1861 reform that abolished the serfdom system that existed in the Czardom Russia. These reforms’ results, which started in the Caucasus ten years later, explicitly revealed itself in the development of the petroleum industry in Baku. The capitalist development in Baku simultaneously caused developments in education, press and cultural fields. On the one hand the development of petroleum industry changed Baku’s economic and political features and on the other hand caused serious demographical transformations. Within the scope of this process social and political transformations gained momentum concurrently with economic transformations, Azerbaijan Turkish People’s nation building process broken new grounds.Azerbaijan society, which built on Islamic identity and lived in colonial system, made progressions in enlightenment and nation consciousness, ummah and nation concepts started find distinct meanings in the start of twentieth century. As in the history of other nations, economic and social transformations show up as mutually triggering and concurrent processes in Azerbaijan history. In this regard, examination of economy politic of the colonial system and nation building process is important for demonstrating the social economic side of nationalization process that Azerbaijan Turks went through

Study on midtower longitudinal stiffness of three-tower four-span suspension bridges with steel truss girders

The determination of midtower longitudinal stiffness has become an essential component in the preliminary design of multi-tower suspension bridges. For a specific multi-tower suspension bridge, the midtower longitudinal stiffness must be controlled within a certain range to meet the requirements of sliding resistance coefficient and deflection-to-span ratio. This study presents a numerical method to divide different types of midtower and determine rational range of longitudinal stiffness for rigid midtower. In this method, influence curves of midtower longitudinal stiffness on sliding resistance coefficient and maximum vertical deflection-to-span ratio are first obtained from the finite element analysis. Then, different types of midtower are divided based on the regression analysis of influence curves. Finally, rational range for longitudinal stiffness of rigid midtower is derived. The Oujiang River North Estuary Bridge which is a three-tower four-span suspension bridge with two main spans of 800m under construction in China is selected as the subject of this study. This will be the first three-tower four-span suspension bridge with steel truss girders and concrete midtower in the world. The proposed method provides an effective and feasible tool for engineers to design midtower of multi-tower suspension bridges.

THE PHYSICAL STRUCTURE OF TABRIZ IN SHAH TAHMASP SAFAVID’S ERA BASED ON MATRAKCI MINIATURE

Tabriz city located in the North-west of Iran is one of the most ancient cities of Iran before and after Islam. Up to the middle of governing of King Tahmasb, the second King of Safavid dynasty 962AH/1555AD, this city was the capital and after that up to the end of the government of Qajarid dynasty 1194AH/1780AD has always been the second most important and unique city of Iran considering the religious, political and economic standpoints and consequently the architecture and urbanism. Unfortunately, consecutive earthquakes and wars with the neighbor Ottoman country have destroyed the spatial structure of this historical city. Like, now after three decades the spatial structure of Tabriz during Safavid era, is ambiguous. Only, the documents related to this era is limited to itineraries and some drawings that is recorded by tourists. The miniature drawn by Nasuh known as Matrakci in 944Ah/1537AD is the oldest and most important recorded document from Safavid Tabriz because of political- military reasons that is drawn during the attack of Sultan Suleyman the Ottoman to Iran and the reign of King Tahmasb the First, but none of the architecture and urbanism researchers has attempted to reread this important historical document. Hence, the goal of the present paper is recreating the physical structure of Dar Al-Saltaneh [i] of Tabriz in Safavid dynasty from historic texts based on Matrakci miniature and other historical documents, and for this purpose the recreation was done on the oldest and most complete historical map remained from Tabriz in 1297Ah/1880AD named Qaracadagi Dar Al-Saltaneh, therefore a fairly accurate picture of Tabriz could be presented in this period. Information was gathered using historical-interpretative method or phenomenological approach and data were analyzed and interpreted using analytical-comparative method. Results of pictorial modelling show that structural system of Tabriz was based on two main centralities: governmental center, located at north of river, with aggregation of urban spaces and tombs; and in contrast, the southern center, located at south of river, which was considered city center or aggregation of religious, commercial, services and residential spaces. [i] The word Dar Al-Saltaneh means the capital, which was the nickname of Tabriz, Isfahan and Tehran (Dehkhoda, 1998).

Alkalinity and dissolved inorganic carbon exports from tropical and subtropical river catchments discharging to the Great Barrier Reef, Australia

AbstractDissolved inorganic carbon (DIC) transport by rivers is an important control on the pH and carbonate chemistry of the coastal ocean. Here, we combine DIC and total alkalinity (TAlk) concentrations from four tropical rivers of the Great Barrier Reef region in Australia with daily river discharge to quantify annual river loads and export rates. DIC in the four rivers ranged from 284 to 2,639 μmol kg−1 and TAlk ranged from 220 to 2,612 μmol kg−1. DIC:TAlk ratios were mostly greater than one suggesting elevated exports of free [CO2*]. This was pronounced in the Johnstone and Herbert rivers of the tropical wet north. The largest annual loads were transported in the two large river catchments of the southern Great Barrier Reef region, the Fitzroy and Burdekin rivers. The carbon stable isotopic composition of DIC suggests that carbonate weathering was the dominant source of DIC in the southern rivers, and silicate weathering was likely a source of DIC in the northern Wet Tropics rivers. Annual loads and export rates were strongly driven by precipitation and discharge patterns, the occurrence of tropical cyclones, and associated flooding events, as well as distinct seasonal dry and wet periods. As such, short‐lived hydrological events and long‐term (seasonal and inter‐annual) variation of DIC and TAlk that are pronounced in rivers of the tropical and subtropical wet and dry climate zone should be accounted for when assessing inorganic carbon loads to the coastal ocean and the potential to buffer against or accelerate ocean acidification.

“A river runs through it”: Using small urban rivers as catalysts for revitalization in post-industrial New England cities

Although the revitalization of urban rivers in large cities in the Global North has received much scholarly attention, the role of streams in small cities (with populations less than 100,000 people) has been much less studied. This chapter uses two case studies to examine the potential of streams in small post-industrial cities to serve as catalysts for urban regeneration in the new services-based economy. Faced with an aging infrastructure, decades of disinvestment, competition for scarce financial resources for physical improvements, and often, expensive and time-consuming cleanups of industrial wastes, stakeholders in small cities face unique challenges in making the most of these assets. A study of the dynamics of urban redevelopment in Amesbury, MA (Powwow River) and Peabody, MA (North River), both of which had used their downtown rivers to serve industrial production in the 19th and early 20th centuries, illustrates the diverse opportunities and challenges endemic in re-imagining these rivers. Analysis of the two cases presented here suggests empirically that successful strategies for using small urban rivers as part of an urban revitalization strategy include at least three factors. First, a transformative new vision for river landscapes (often articulated by outsiders rather than endogenously) must be created. This vision may reference historical industrial contexts, but must also find ways to resonate with current inhabitants, who may not be aware of the community’s industrial history. Second, key actors must be committed to the strategies for the long term, and must promote the strategies to their professional networks across multiple scales of government and business. Last, synergistic, creative financial support from multiple scales of government is necessary to move urban revitalization forward.

Trends of hydrograph components in rivers of North of Iberian Peninsula during 1972–2012

An analysis of temporal evolution of discharge components was made in 13 rivers located at the North of Iberian Peninsula over the period 1972–2012. Three hydrograph separation methods (PART, HYSEP-LM and BFI) were used to evaluate the trend of baseflow and quickflow. Baseflow represents more than 50% of streamflow on an annual scale in all rivers, except in one of them (Miera River). All rivers of Northwestern part showed a significant negative trend of monthly baseflow, with a mean decrease of 0.6% per year and in Northeastern part most of rivers (4 out of 7) showed a negative trend representing an annual decrease of 2%. In contrast, quickflow increased significantly in five of the 13 rivers studied. The relation of hydrograph components trend and rainfall trend was significant for baseflow in winter, while quickflow was significant for winter and spring. In autumn and summer, no relationship between these trends was detected.

Responses of Riverine Phosphorus Exports to Land Use and Hydrological Regime in the Jiulong River Watershed

In-situ monitoring, geographic information technology (GIS), watershed model, and statistical techniques were coupled in this study to explore the responses of riverine phosphorus exports to land use pattern and hydrological regime in the Jiulong River Watershed (JRW). We analyzed riverine phosphorus concentrations and exports from March 2015 to February 2017 across a land use gradient spanning 14 monitored sampling sites. Results showed that significantly spatial and seasonal variations of phosphorus concentrations and exports were observed in JRW. Mean phosphorus concentrations and exports were the highest in the agricultural watershed, followed by the urban watershed, whereas the West River reach had higher mean phosphorus concentration and export than the North River reach. Mean concentrations of phosphorus were higher in spring and winter, whereas lower concentrations were observed in autumn and summer. Phosphorus exports were higher in spring and summer, consistent with the seasonal trend of runoff. Phosphorus concentrations and exports had negative correlations with percentages of forest and bare land, and were positively correlated with cropland and orchard. The responses of riverine phosphorus to land use types and hydrological regime varied across seasons, whereas the relationships between phosphorus concentrations/exports and land use or runoff were the strongest in summer, suggesting that non-point source pollution associated with agricultural activities would be the critical source of riverine phosphorus and an increase in forest percentage could be useful for improving water quality. Overall, the spatiotemporal patterns of phosphorus exports were affected by land use pattern, as well as the characteristics of the hydrological regime.

Roosting Habitat Use by Sandhill Cranes and Waterfowl on the North and South Platte Rivers in Nebraska

Abstract Migration ecology and habitat use of spring migrating birds using the Central Platte River is a well-explored topic, yet less is known about use of the North and South Platte rivers (NSPR) in western Nebraska. The efficiency and effectiveness of conservation efforts in the NSPR could be greatly improved with access to information about where and when birds roost and landscape prioritization tools. We used aerial surveys to determine population distribution and migration phenology of sandhill cranes Antigone canadensis, Canada geese Branta canadensis, and ducks using the NSPR for roosting during the mid-February to mid-April spring migration. We used these data and geospatial information to identify important river reaches for these species and habitat covariates that discriminate between those used at lower and higher densities. We found that sandhill cranes and waterfowl generally roosted in different segments of the NSPR and, subsequently, different factors were associated with high densities. Sandhill crane density was positively correlated with distance from obstructions greater than 1 m high and negatively correlated with area of unvegetated sandbar within 1 km. Density of Canada geese and ducks was high in segments positively associated with wetland and sand pit habitats. Human disturbance variables such as roads and bridges in this rural region had little effect on identification of roosting areas used by high densities of all groups. On the basis of our results, habitat conservation efforts that specifically target sandhill cranes will not have similar positive effects on waterfowl use and distribution in the NSPR. Our identification of the most important river segments should allow managers to better target land acquisition or management resources to areas that will have the greatest effect on either waterfowl or sandhill cranes during spring migration.

Diversity, Abundance, and Distribution of Cladocera at the end of the Tigris River North of Basrah – IRAQ

Seasonal variations of the species composition and abundance of Cladocera were studied in two stations at the end of the Tigris River and one station at the confluence of the Tigris with Euphrates area, at the beginning of the Shatt Al-Arab River in Al-Qurnah North of Basrah Province, from October 2015 to August 2016. Samples of zooplankton were collected by plankton net 100-µm. mesh size. The population density of Cladocera ranged between 1 Ind /m³ during summer and 211 Ind./m³ during winter at station 1 (Al-Jewaber Bridge). A total of 16 species of Cladocera belonging to 12 genera were recorded in the study. The average density of Cladocera ranged from 23.2 ind./m3 at Station 2 (Hamayon Bridge) to 53.7 Ind./m3 at Station 1 (Al-Jewaber Bridge). The results showed that the Bosmina meridionalis was dominant at the three stations 47.8%, while the other species were as follow Moina affinis 15.1%, Daphnia lumholtzi 9.3%, Simocephalus (Simocephalus) vetuloides 8.1% and Daphnia exilis 6.6% of the total Cladocera.