Characterization of complex fluvial systems using remote sensing of spatial and temporal water level variations in the Amazon,Congo, and Brahmaputra Rivers

The Surface Water and Ocean Topography (SWOT) satellite mission will provide global, space‐based estimates of water elevation, its temporal change, and its spatial slope in fluvial environments, as well as across lakes, reservoirs, wetlands, and floodplains. This paper illustrates the utility of existing remote sensing measurements of water temporal changes and spatial slope to characterize two complex fluvial environments. First, repeat‐pass interferometric SAR measurements from the Japanese Earth Resources Satellite are used to compare and contrast floodplain processes in the Amazon and Congo River basins. Measurements of temporal water level changes over the two areas reveal clearly different hydraulic processes at work. The Amazon is highly interconnected by floodplain channels, resulting in complex flow patterns. In contrast, the Congo does not show similar floodplain channels and the flow patterns are not well defined and have diffuse boundaries. During inundation, the Amazon floodplain often shows sharp hydraulic changes across floodplain channels. The Congo, however, does not show similar sharp changes during either infilling or evacuation. Second, Shuttle Radar Topography Mission measurements of water elevation are used to derive water slope over the braided Brahmaputra river system. In combination with in situ bathymetry measurements, water elevation and slope allow one to calculate discharge estimates within 2.3% accuracy. These two studies illustrate the utility of satellite‐based measurements of water elevation for characterizing complex fluvial environments, and highlight the potential of SWOT measurements for fluvial hydrology. Copyright © 2010 John Wiley & Sons, Ltd.     

Insights into the phylogeny of sporadotrichid ciliates (Protozoa, Ciliophora: Hypotricha) based on genealogical analyses of multiple molecular markers

The sporadotrichid ciliates are an especially diverse group. A number of investigators have studied the morphological, morphogenetic, and molecular relationships among members of this group. Despite this, a consistent classification is still lacking and several important questions about the phylogenetic relationships within this group remain unsolved. To improve our understanding of these relationships, we constructed phylogenetic trees using the nucleotide sequences of the small-subunit rRNA (SSrRNA) gene and amino acid sequences of actin I and α-tubulin. Analyses of SSrRNA gene sequences indicated that: 1) the Sporadotrichida sensu Lynn (2008) and the Oxytrichidae are polyphyletic; 2) the Uroleptus species, which are classified to urostylids, formed a sister group with the oxytrichids; 3) Halteria grandinella, which is grouped morphologically with oligotrich species, clustered within the oxytrichids. These results are congruent with previous studies based on SSrRNA gene sequences. However, the amino acid sequences of actin I and α-tubulin yielded different topologies. The main results are: 1) in all phylogenetic trees, the genus Oxytricha was paraphyletic; 2) Uroleptus was sister to a subset of Urostyla and Holosticha, albeit with low supporting values; 3) Halteria grandinella was separated distantly from the Oxytrichidae in trees inferred from actin I amino acid sequences but clustered with oligotrichids in the α-tubulin analysis. The inconsistency among the trees inferred from these different molecular markers may be caused by rapidly accumulated genetic characterizations of ciliates. Further studies with additional molecular markers and sampling of more taxa are expected to better address the relationships among sporadotrichids.     

Projected impacts of land use and road network changes on increasing flood hazards using a 4D GIS: A case study in Makkah metropolitan area,Saudi Arabia

Makkah City, west of the Kingdom of Saudi Arabia, is considered the third main highly populated metropolitan area in the Kingdom of Saudi Arabia. It exhibits two unique features that increase the hazardous flood consequences: (1) its topography is very complex and (2) about three million Muslims are gathered annually in Makkah to perform Hajj over a 2-week period. Floods are natural returning hydrological phenomena that have been affecting human lives. The objectives of the current study are: (1) identification of land use types and road networks in Makkah, (2) hydrological modeling of flood characteristics in Makkah based on precise up-to-date databases, (3) examination of the relationship between land use, land cover changes, transportation network expansion, and the floods' prosperities and hazards, and (4) development of digital hydrological maps for present and near future flood hazards in Makkah. The attained results show that the mean runoff depth and the total flood volume are significantly increased from 2010 to 2030. Additionally, it has been found that a great part of the road network in Makkah City is subjected to high dangerous flood impacts. The overall length of flood danger-factor roads is increased from 481 km (with almost 37 %) to 1,398 km (with 74 % approximately) between 2010 and 2030. Thus, it is concluded that urbanization has a direct strong relationship with flood hazards. Consequently, it is recommended that the attained results should be taken into account by decision makers in implementing new development planning of the Makkah metropolitan area.     

Taxonomic description of a new marine ciliate,Euplotes qingdaoensis n. sp. (Ciliophora: Euplotida)

The characteristics and infraciliature of a new euplotid ciliate,Euplotes qingdaoensis n.sp.,discovered from the coastal waters of Jiaozhou Bay,northern China,were studied using live observation and silver impregnation.The new marine species is characterized by a slightly fl attened body(90–110 μm×70–80 μm,in vivo),an adoral zone of 26–29 membranelles,10 strong frontoventral and fi ve transverse cirri,two caudal cirri,a single left marginal cirrus,seven dorsal kineties,a middle kinety with about 15 pairs of basal bodies,a silverline system of the double-eurystomus type,and a C-shaped macronucleus.     

Divisional morphogenesis in the marine ciliate Anteholosticha manca (Kahl, 1932) Berger, 2003 (Ciliophora: Urostylida)

The cortical development and macronuclear evolution of the marine hypotrichous ciliate Anteholosticha manca, collected from the coastal waters near Qingdao, China, were investigated using the protargol impregnation method. The morphogenesis of A. manca is generally typical for the genus, and can be characterized as the following features ： （ 1 ） in the proter, a new oral primordium is formed on the bottom （beneath the pellicle） of the buccal cavity, disorganization of the parental undulating membranes do not contribute to the formation of this primordium ; （2） FVT-cirral anlagen in both dividers develop independently, and very likely only a few midventral cirri join in the formation of these primordia; （ 3 ） both marginal row and dorsal kinety anlagen develop intrakinetally within the parental structure; （4） at the middle stage, macronuclear segments fuse together to form a single mass as observed in most of its related forms.     

Planktic foraminiferal biostratigraphy of the Maastrichtian-Paleocene succession at the north Farafra Oasis,Western Desert,Egypt

Seven planktic foraminiferal zones are distinguished in the Maastrichtian-Paleocene succession at the north Farafra Oasis. These are the Rugoglobigerina hexacamerata (CF8b), Gansserina gansseri, and Contusotruncana contusa zones in the Maastrichtian topped by a well-known unconformity across the Cretaceous/Paleogene (K/Pg) boundary. The Danian is subdivided into two biozones: Globanomalina compressa/Praemurica inconstans-Praemurica uncinata Subzone (P1c) and Praemurica uncinata–Morozovella angulata (P2) Zone. The Late Paleocene is divided into two zones: Morozovella angulata-Globanomalina pseudomenardii (P3) and Globanomalina pseudomenardii (P4). A minor hiatus between the Danian/Selandian and Selandian/Thanetian boundaries are also recorded. These time gaps across the stage boundaries may be related to the tectonic events that affected the sedimentation regime throughout the Upper Cretaceous–Lower Paleogene interval in the Farafra Oasis.     

Comparison of DRASTIC and DC resistivity modeling for assessing aquifer vulnerability in the central Nile Delta,Egypt

DRASTIC indexing and integrated electrical conductivity (IEC) modeling are approaches for assessing aquifer vulnerability to surface pollution. DRASTIC indexing is more common, but IEC modeling is faster and more cost-effective because it requires less data and fewer processing steps. This study aimed to compare DRASTIC indexing with IEC modeling to determine whether the latter is sufficient on its own. Both approaches are utilized to determine zones vulnerable to groundwater pollution in the Nile Delta. Hence, assessing the nature and degree of risk are important for realizing effective measures toward damage minimization. For DRASTIC indexing, hydrogeological factors such as depth to aquifer, recharge rate, aquifer media, soil permeability, topography, impact of the vadose zone, and hydraulic conductivity were combined in a geographical information system environment for assessing the aquifer vulnerability. For IEC modeling, DC resistivity data were collected from 36 surface sounding points to cover the entire area and used to estimate the IEC index. Additionally, the vulnerable zones identified by both approaches were tested using a local-scale resistivity survey in the form of 1D and 2D resistivity imaging to determine the permeable pathways in the vadose zone. A correlation of 0.82 was obtained between the DRASTIC indexing and IEC modeling results. For additional benefit, the obtained DRASTIC and IEC models were used together to develop a vulnerability map. This map showed a very high vulnerability zone, a high-vulnerability zone, and moderate- and low-vulnerability zones constituting 19.89, 41, 27, and 12%, respectively, of the study area. Identifying where groundwater is more vulnerable to pollution enables more effective protection and management of groundwater resources in vulnerable areas.     

Discussion of “Experimental study on the hydraulic conductivity of calcareous sand in South China Sea”

Hydraulic conductivity of the granular soils depends on many factors including the soil density and the particle size distribution. For internally unstable soils, the hydraulic conductivity could be changed beyond a critical value of hydraulic gradient. This discussion calls attention to the effect of the internal stability on the hydraulic conductivity, where the internal stability of the soils is assessed and the critical hydraulic gradient is computed using some theoretical methods, and such calculations could be used to plan the experimental tests.     

Discussion of (anisotropic hydraulic conductivity and critical hydraulic gradient of a crushed sandstone–mudstone particle mixture)

A discussion is presented here to the work of Wang and Qiu including some notes about the analysis and the correlations of the results. First, we show that there is no clear relationship between the critical hydraulic gradient and the uniformity coefficient. Also we show that the internal erosion mechanism of soils with bimodal structure is different from that for soils with no bimodal structure. Finally, we emphasis that the anisotropy in the hydraulic conductivity is not related to the uneven compaction only but also to the particle arrangements and connectivity between pores.     

Bedouin farms in the Saint Katherine mountainous area(South Sinai,Egypt)

This study aims to assess the natural and cultivated plant species in 26 Bedouin farms in Saint Katherine Protectorate(SKP),identify their soil and water characteristics,and assess the suitability of these farms for the cultivation of some wild medicinal plants.The farms were selected to represent wide wadis with deep sand and clay deposits,gorge-like wadis covered with rock fragments of different sizes,spot-like oases,and the Al Q'aa Plain.Using TWINSPAN(two-way indicator species analysis)and DCA(detrended correspondence analysis)techniques,the 26 farms were classified into 5 groups(Ⅰ-Ⅴ)based on their floristic composition of wild plants.These groups reflect an elevation gradient among the farms above sea level from a mean of 119 m to a mean of1,865m.A total of 73 wild species were recorded,with47 in groupⅡ(500-1,000 m)and 25 in group V(1,700 m).The common target species were Artemisia judaica,Acacia tortilis subsp.raddiana,Origanum syriacum subsp.sinaicum and Varthemia montana(34.6%-26.9%).The cultivated speciesnumbered 25,with 17 in groupⅡ(500-1,000 m) andⅡin groupⅣ(1,500-1,700 m).The common fruit trees were olive,grape,fig,apple,palm,almond,apricot and pomegranate(73.0%-42.3%).Based on the soil characteristics,13 farms belong to soil class 2that describes good soils with moderate limitations,and 12 belong to soil class 3 that describes moderately good soils,which can be used regularly for crops after proper treatment.