Physico-chemical indices of breeding sites of Simulium damnosum in the lower Cross River Basin, Nigeria

To determine the factor influencing the abundance development and distribution of Simulium damnosum(S.I) immature stages in the lower Cross River Basin, Nigeria, the physico-chemical characteristics of water at breeding sites were analysed longitudinally over a 12 month period. Analysis of the water samples showed that water current correlated positively and significantly(p<0.05), with dissolved oxygen(r = 0.95 vs 0.10); conductivity(r = 0.95 vs 0.81); hydrogen ion concentration(r = 0.03 vs 0.46); and biochemical oxygen demand(r = 0.80 vs 0.64); from Agbokim Waterfalls and Afi River respectively. The result indicates that these parameters and low ionic concentration are the most essential requirement for the development of S. damnosum pre-imaginal stages. Amplitudes of annual variability as measured by co-efficient of variation varied between the parameters. From the trends in hydrological variables it was deduced that the integrated impact of precipitation, input of surface runoff and municipal effluents played an overriding role in determining the absolute levels and temporal pattern in the water quality attributes. Of the 3578 pre-imaginal stages of S. damnosum collected, 52.52% and 47.4% were collected from Agbokim Waterfall and Afi River respectively. There was a significant difference(p<0.05) in the number of pre-imaginal stages collected from both sites. The highest number of pre_imaginal stages of S. damnosum collected were at the peak of rain(July—September) indicating that S. damnosum in the River Basin is a wet season breeder. The need for long term laboratory colonization of blackfly immature stages becomes imperative especially how these parameters could be exploited in control programme through the testing of larvicides without adverse ecological damage to the aquatic habitat.

Species Composition and Gear Characteristics of the Macrobrachium Fishery of the Cross River Estuary,Nigeria

The Cross River Estuary,Nigeria,is an important shrimping area for artisanal fishermen of the coastal communities.The multi-species Macrobrachium fishery is exploited with three main gears,namely beach seine,push net and trap.Studies on species composition of this fishery recorded thirteen shrimp species,one swimming crab (Callinectes amnicola) and two fish species (Eleotris sp.and Pellonula leonensis).The shrimp species identified included Macrobrachium macrobrachion (83.39% and 55.69% by number and weight,respectively),M.vollenhovenii (9.66% and 37.18%),M.equidens (3.8% and 2.87%),juveniles-sub-adults of Penaeus notialis (1.11% and 1.3%),M.dux,M.felicinum,Palaemonetes africanus,Palaemon maculatus,Palaemon elegans,Desmocaris sp.,Leander sp.,Nematopalaemon hastatus and Alpheus pontederiae.While the selectivity index for trap was 0.25,beach seine and push net had a lower index of 0.063.The results present the first comprehensive and representative report for the Estuary shrimp fishery and will assist in the management of the biodiversity of this ecosystem.

Cross River Watershed Hydrologic Adjustment： Pre- and Post-June 2012 Mega-storm

The Cross River watershed was disturbed by historic logging activity during the past century, but under the management of the USDA （United States Department of Agriculture） Forest Service, the area has mostly recovered from ecological disturbance. Today a new threat is being imposed by climate change; changes affect not only the temperature but also more extreme wind and rain In 2012, a mega-storm event passed through the north shore region of Lake Superior overwhelming many watersheds with excessive rain and runoff. As part of a Cross River study for the Forest Service, pre- and post-event hydrologic adjustment of the Cross River watershed were captured. Samples were collected for δD and δ18O during April, July, and September to estimate HRT （hydraulic residence time） using the stable isotopes of hydrogen and oxygen, The results showed that water collected throughout the watershed shifted toward the signature of the mega-event precipitation signature, then slowly diffused with new precipitation and fractionation processes that resumed into the summer and fall.

Survey of Medicinal Plants Used in the Treatment of “Ailments of Utmost Native Importance” in Cross River State, Nigeria

Regardless of the high value of medicinal plants to residents of Cross River State in health maintenance especially for the treatment of “ailments of utmost native importance”, the major constraint is the uncertainty of the availability of the herbs and knowledge of traditional medicine still being passed by word of mouth. For better reliance on the plant species as medicine, this research seeks to identify and infer on the population and distribution of the species used in their treatment and documents them. Data were collected using field work and oral interviews. The survey team comprised of Taxonomists, survey assistants, five trado-medical herbal practitioners and the Authors. The status and geographical distribution of the identified medicinal plant species was appalling, 59 percent of the medicinal plant species were distributed in 3 out of 15 sampled plots. Causal factors included over misuse of therapeutic plant species, habitats destruction and absence of proper conservation education of the masses. Recommendations are that Communities should set up therapeutic plants farms, enrichment planting be made in agricultural fields and sustainable harvesting methods used.

Re-examination of Hydrochemistry and Groundwater Potentials of Cross River and Imo-Kwa-Ibo Intersecting Tropical Basins of South-South Nigeria

This review attempted a detailed description of geological and hydrogeological configurations of Cross River and Imo-Akwa Ibo basins.It presented a synthesis of hydrochemistry and a description of the hydrogeological configurations of the two basins.Hydrogeologically,most areas under Cross River and Imo-Kwa-Ibo are poor in terms of groundwater potentials.Based on the hydrochemistry,the basins hold water of excellent quality.Groundwater sources fall in soft to moderately hard classes.The entire sources groundwater has a TDS concentration of less than 500 mg/l.Groundwater classification based on electrical conductivity(EC)showed EC levels were less than 500μS/cm.Most of the examined cations and anions are within WHO reference guidelines for drinking water quality.However,no broad analysis of water quality based on water quality indices.Also,studies modeling pollution or the impact of land use changes on groundwater quality are wanting.Thus,further analysis of the hydrochemistry of groundwater aquifers is recommended.

Habitat fragmentation and the population status of rodents in Abayum forest, Ikom, Cross River State, Nigeria

The threat to wildlife population is attributed to various anthropogenic activities. The main objective of this study was to identify the influence of fragment size on the population density of rodents in the study area. Fourteen (14) out of forty (40) fragments existing in the area were randomly sampled. The parameters used for the study were number, size of fragments and the corresponding population distribution of rodents in the study area. Fifty hunters in the area were also interviewed. The fragments were stratified into first, second and third order fragments on the basis of their sizes and randomly selected for the study. Indirect method of wildlife census was carried out through the observation of droppings, trail or tract, burrows, eating habits and noise. Fragment growth rate was 18 to 40 (87.5%) in 7 years. Anthropogenic perturbations in the form of cultivation of permanent cropland, settlement expansion, bush burning, timber exploitation and new settlements in areas previously thinly settled or not accessible to outsiders have resulted in disjointed ecosystems. The population density of rodents correlated with fragment size was highly significant ((P < 0.05) r = 0.9). It was then concluded that fragment size greatly influenced the population and diversity of rodent species. It was recommended that the remaining large fragments in the study area should be protected by law from further fragmentation.

Ecosystems Services of the Tropical Rain Forest Environment: Lessons from the Cross River National Park, Nigeria

This paper essayed to examine ecosystem functions with a case study of the tropical rainforest environment of the Cross River National Park, Nigeria. The paper highlighted the important functions of the ecosystems to include Purification of air and water mitigation of floods and droughts, detoxification and decomposition of wastes, generation and renewal of soil and natural vegetation, pollination of crops and natural vegetation, control of the vast majority of potential agricultural pests, dispersal of seeds and translocation of nutrients, maintenance of biodiversity, protection from the sun’s harmful ultraviolet rays among others. Problems associated with the rainforest ecosystems among which are logging, traditional methods of farming, poaching, excessive noise and encroachment were identified. The paper concluded by highlighting the way forward among others that, awareness creation should be stepped-up in Support Zone Communities;indigenes should be educated periodically on the benefits of the ecosystem services to not just humans but the forest resources and biodiversity themselves.

Evaluation of the Anti-Poaching Programme of the Cross River National Park Okwango Division, Nigeria 2002 to 2013

Poaching of wildlife has continued to be the major problem confronting national parks managers in Nigeria in spite of effort being made to curb the ugly trend. This paper examined the anti-poaching programme of the Cross River National Park Okwango Division Nigeria from 2002 to 2013, with a view to making recommendations for the improvement of the programme. Focused group discussions, personal interviews, review of official records and structured questionnaires were used to collect data. Analysis of variance using randomized complete block design and student’s t-test were used to analyse data. Result showed that 1 - 5 arrests of poachers per month per patrol station was significantly (P 0.05) in the number of poachers arrested and fined between 2002 to 2006 and 2007 to 2011. The low performance of the anti-poaching programme was attributed to poorly equipped rangers’ posts as well as well the absence of alternative livelihood options in the enclave and surrounding communities. It was recommended that more rangers should be employed, and the rangers should be adequately kitted, well equipped patrol stations be constructed and the enclave and surrounding communities be involved in the management of the National Park in addition to providing them with alternative livelihood options.

Discussion on the Construction of Negotiation Mechanism of Cross-bounder Water Pollution Treatment in Changjiang River

In order to construct cooperation platform for the treatment of water pollution in Changjiang River,thoughts and revolution were performed from both central government and regional area two aspects.From the national level,Changjiang region water resources management cooperation counsel committee was constructed as the national cooperation platform;from the regional level,Changjiang region water resources management cooperation counsel committee was constructed as the platform of Changjiang cooperation platform.The two platforms built fine interaction mechanism to deal with the national water management and Changjiang regional water management.

Estimation of Stature from Percutaneous Tibia Length of Indigenes of Bekwara Ethnic Group of Cross River State, Nigeria

Estimating stature by developing linear regression equations which incorporate the features of fragmented body parts or human skeletal remains has been employed by many forensic anthropologists to establish the identity of victims of mass disaster although all formulas are ethnic,age,and gender specific.The study is aimed at using the percutaneous tibia length(PCTL)to deriving a specific regression equation formula which could be used to estimate the stature of adult indigenes of Bekwara ethnic group in Cross River State.A total number of 600 subjects within the age range of 21–45 years were recruited randomly for this research(300 males and 300 females).Observed height and PCTL were measured using the standard anthropometric technique,respectively.Stature was estimated from PCTL using simple regression analysis.On analysis of the data,the mean PCTL for male was found to be 43.60±2.31 cm while that of female was 42.55±2.83 cm.The observed height was 165.80±6.88 cm and 156.70±6.06 cm for male and female,respectively.Statistical analysis showed that the male values of the measured parameters were significantly higher than the corresponding female values.The linear regression equations derived for male and female for the estimation of height using the PCTL was found to be 5.289(PCTL)+(−64.78)and 4.230(TL)+(−23.28),respectively.It was concluded that stature can be estimated using the length of an intact mutilated leg.Thus,the data of this study are recommended in anthropological studies for stature estimation among the ethnic group under study.

Geometric properties of river cross sections and associated hydrodynamic implications in Wuhan-Jiujiang river reach,the Yangtze River

Based on measured hydrological data by using ship-mounted Acoustic Doppler Current Profiler （ADCP） instrument, we analyzed shapes of river cross sections of the middle Yangtze River basin （mainly focusing on Makou and Tianjiazhen river reach）. Hydrodynamic properties of river channels were also discussed. The research results indicate that nonlinear relationships can be identified between river-width/river-depth ratio （W/D ratio）, sizes of cross section and mean flow velocity. Positive relations are detected between W/D ratio and mean flow velocity when W/D〈1; and negative relations are observed when W/D〉1. Adverse relationships can be obtained between W/D ratio and cross-section area. Geomorphologic and geologic survey indicates different components of river banks in the wider and narrower river reaches respectively. These may be the main driving factors causing unique hydrological properties of river channels in the middle Yangtze River basin. Narrower river cross sections tend to raise water level in the upstream river reach near narrower river channel, giving rise to backwater effects. River knots can cause serious backwater effects, which is harmful for flood mitigation. However river knots will also stabilize river channel and this will be beneficial for river channel management. The results of this paper may be helpful for flood mitigation and river channel management in the middle Yangtze River basin.

Effect of insufficient tunnel crown thickness on the post-tensioned concrete lining of the Yellow River Crossing Tunnel and its strengthening schemes

The effect of deficiency in tunnel crown thickness on the Yellow River Crossing Tunnel with post-tensioned concrete inner lining was investigated by the elasto-plastic finite element method. Changes in the deformations and circumferential stresses of the post-tensioned concrete inner lining with the gradual decrease of the tunnel crown thickness were compared, and the potential bearing risk of insufficient tunnel crown thickness for the Yellow River Crossing Tunnel was revealed. Based on the finite element calculation results of circumferential stresses under different defective cases, the corresponding reinforcement schemes were proposed. The calculation results show that the inner lining can still maintain a satisfactory stress state when the tunnel crown thickness is equal to or greater than 0. 28 m. When the tunnel crown thickness decreases below 0.28 m, the external surface of the crown and internal surface of the crown＇s adjacent areas may be under tension. The tension stresses will incrementally increase and ultimately exceed the tensile strength of the inner lining concrete as the tunnel crown thickness further decreases gradually. Then, the Yellow River Crossing Tunnel cannot operate normally, and severe cracking, leaking or even failure may occur. When the tunnel crown thickness is equal to or greater than 0.28 m, the reinforcement suggestions are that the void spaces between the inner lining and the outer lining should be back-filled with concrete. When the tunnel crown thickness is less than 0. 28 m, the inner lining should be reinforced by steel plates after concrete back-filling.

On the National Symptoms of Boar Crossing the River:One Hundred Years of Solitude in a Malaysian Chinese Village

After the famous“Rainforest Trilogy”such as Monkey Cup and Elephants,Zhang Guixing,a Malaysian Chinese writer in Taiwan,recently published another Nanyang story Boar Crossing the River,in the background of anti-Japanese War,focusing on the massacres and resistance of the Chinese in Krokop,a Malaysian Chinese village in Borneo from 1941 to 1945 according to a list of“Committee for the Relief of Refugees of the Motherland”.In this novel,Zhang Guixing changes the accustomed narrative mode of individual family history,expands the description to the group images of the Chinese in Krokop,highlights their patriotic sacrifice,and saves the reality of the slaughter of the compatriots by magic means such as the myths and legends of Borneo and masks in children’s imagination.It is also noteworthy that the novel talks about the relationship between individual freedom and national identity in depth,and describes the tragic fate of cross-national love in the period of national opposition.These nation-state discourses in Boar Crossing the River are Zhang Guixing’s biggest transitions when missing in the literary world for 17 years,which indicate a landmark progress in his spiritual history.

Vegetation Formation in Estuarine Tidal Flats: Influences of Basin Scale and River-Crossing Structures of the Eight Rivers of Ise Bay in Mie and Aichi Prefectures, Japan

In this study, we examined the influences of the differences in basin scale and river-crossing structures of 8 rivers of Ise Bay in Mie and Aichi Prefectures, Japan on the vegetation in the estuarine tidal flats of these rivers. The dominant plant communities of the estuarine tidal flats formed from rivers of large-scale river basins (exceeding 300 km2) were determined. In the Miya River, the dominant plant community was the Suaeda maritima and Artemisia fukudo community. In the Kushida River, the dominant plant community was composed of Phacelurus latifolius, Artemisia fukudo, Phragmites australis, and bamboo. In the Kumozu River, the dominant community was composed of the coastal plants Calystegia soldanella, Lathyrus japonicus, and Carex pumila and the exotic plant of Lolium multiflorum. The plant community of Suzuka River was dominated by the exotic plant of Eragrostis curvula. Among the estuarine tidal flats influenced by a small-scale river basin (50 km2 or less), the plant community of Shinbori River (Fukue tidal flat) was dominated by Suaeda maritima, and the plant communities of the Shio and Harai Rivers were dominated by Phragmites australis. The plant community of Tanaka River was dominated by Phragmites australis and coastal plants. Regarding the relationship between the vegetation and the river environment for each study site, we hypothesised that in a large basin area with few structures crossing the river, the river water catchment in the estuary after heavy rains caused large areas of disturbance and formed bare land, providing suitable habitat for an annual salt marsh plant community. In contrast, in cases with many structures crossing the river, a stable channel, an excavated riverbed and the suppression of runoff and the resulting disturbance of the estuary, flooding did not occur during high tide. Moreover, we hypothesised that in a small basin with many structures crossing the river, disturbance to the estuary was not likely, and the perennial salt marsh plant community of Phragmites australis would be widely distributed, except for a river type such as the Shinbori River, in which tide and river flow were managed by a final closure.

水下穿越管道外腐蚀检测评价系统River-ROV的应用性研究

长输油气管道的江河水下穿越管道由于施工和和环境等问题使得管道面临严峻的腐蚀损伤风险,由于缺乏对应的技术手段,绝大多数穿越管段未能开展相关的检测。在全国长输油气管道大力度提升管道安全管理的背景下,迫切地需要先进的检测手段,本文采用江河水下River-ROV检测技术进行应用性研究和试验,选取两处大开挖穿越管段的管道为代表,验证了其技术的适用性和可靠性,实现水下穿越管道的外腐蚀状况检测和评价,为水下穿越管道的维护维修项目提供全面准确有效的数据支持,运营安全管理形成操作性强的技术支持。

Horizontal freezing study for cross passage of river-crossing tunnel

To determine the appropriate soft foundation treatment for a river-crossing tunnel, freezing reinforcement design and technology were introduced based on the channel tunnel design and construction practice. Through finite element analysis and engineering practices, two rows of horizontal perforated freezing pipes were designed and installed on both sides of a passage for tunnel rein- forcement, which produced the thickness and strength of frozen crust that satisfied the design requirements. These information are valuable for guiding the design and construction of river-crossing tunnels in coastal areas.

问诊天堑:基于多源数据的城市跨江城区数字体检与优化策略研究——以南京浦口中心城区为例

城市体检是识别诊断“城市病”的有效途径,数字技术为城市体检提供了方法基础,针对不同的区域对象需提出特色的诊断指标。本文以城市跨江城区为研究对象,跨江发展是滨江城市突破拓张城市规模的重要措施,由于江河的自然地理条件限制,跨江城区易出现空间发展不协调、服务设施不匹配、城市活力不足等问综合问题,需要通过数字化体检评估加以应对。在南京浦口中心城区的实例研究中,基于多源大数据从交通便捷、风貌特色、城区活力等维度进行数字体检,发现其交通组织“潮汐交通”、风貌特色“屏风遮廊”、生活圈“跨域割裂”等问题,并从空间形态、设施布局、景观风貌等方面提出针对性的优化策略。

广州城市快捷路二期过江通道总体设计

广州城市快捷路二期是广州中心城区内外环之间的辅助环形连续交通道路,同时也是白鹅潭地区“三环七射”道路骨架系统的三环之一,过江通道两岸具有接线路网复杂、沿线城中村及建设地块密集等特点,总体设计难度大。详述了过江通道建设的意义,综合考虑总体规划、城中村改造计划、征地拆迁、环境效应和江中通航要求等因素,先进行线位比选,然后进行过江桥隧方案比选,最后通过隧道工法比选,对过江通道总体设计做了细致的分析比对,最终选取了过江沉管隧道作为实施方案。该项目对缓解城市交通压力和加速项目沿线经济快速发展具有重要意义,同时也为沉管隧道建设进一步积累经验。

新时期运河战略及平陆运河规划建设实践

中国在世界的运河开凿利用和运河经济文化交流中发挥着引领性和示范性作用。综述我国运河的开发历史、世界十大运河的基本情况和功能价值、我国近代百年运河梦想和谋划。进入新时代,内河航运开发向全面考虑国民经济、产业布局、社会环境等各方面综合效益转变。阐述新时期跨水系连通运河规划背景和重大意义,重点介绍平陆运河这一世纪运河工程的规划历程、研究工作的重难点和工程技术创新点,可为相关工程的规划咨询提供借鉴。

中哈跨界河流合作:进程、机遇与深化路径

中哈跨界河流合作机制以联合委员会为平台,在水文信息交换、水质保护、水量分配、水利工程合作等方面取得突出成果,中哈两国政治关系的提升、环委会的积极配合及“一带一路”倡议相关政策的支持是推进中哈跨界河流合作的主要因素;同时,中哈跨界河流合作机制也面临一系列挑战;制定切实有效的水资源分配规则,深化跨界河流环保合作,重视跨界含水层条约的签订,构建系统的跨界水合作制度以及多元化的水争端解决方法体系,并提升国际话语权引导国际舆论等是应对挑战,实现中哈跨界水资源可持续利用的关键。