Long-range seasonal rainfall forecast for Zimbabwe and its relation with El-Niño/Southern Oscillation (ENSO)

Summary This investigation shows a fairly definite connection between the mean seasonal rainfall in a rainy season and the ground minimum temperature in the preceding two winter seasons in Zimbabwe. The latter is considered to represent the intensity of the over land high over Botswana and the corresponding degree of cooling of the subcontinent during the winter season. This over land high is related to the east-west overturning Walker Circulation. This relationship emphasizes that the rainfall variability over Zimbabwe is strongly linked to the ENSO phenomenon.The study brings out an empirical relationship between these two factors from which the mean seasonal rainfall over Zimbabwe can be predicted three months before the start of the rainy season. These approaches have been examined against independent data covering a period of 20 years and the results were very encouraging.

---

Zusammenfassung Diese Untersuchung zeigt einen ziemlich deutlichen Zusammenhang zwischen dem durchschnittlichen Niederschlag während der Regenzeit und den Bodentemperatur-Minima während der beiden vorhergehenden Winter in Zimbabwe. Letztere Daten sollen die Intensität des Land-Hochs über Botswana repräsentieren und somit das Ausmaß der Abkühlung des Subkontinents während des Winters zeigen. Dieses Land-Hoch steht in Zusammenhang mit der auf Ost—West umschlagenden Walker-Zirkulation. Dies macht deutlich, daß zwischen der Niederschlags-Variabilität über Zimbabwe und dem ENSO-Phänomen ein enger Zusammenhang besteht.Die vorliegende Studie weist einen empirischen Zusammenhang zwischen den beiden Faktoren nach, wodurch eine Vorhersage des durchschnittlichen Niederschlags über Zimbabwe bereits drei Monate vor Beginn der Regenzeit möglich wird. Die genannten Ansätze wurden mit einem unabhängigen Datensatz von 20 Jahren überprüft und durch das Ergebnis in ermutigender Weise bestätigt.

---

---

With 7 Figures     

A contribution to the geology of the Bahariya Oasis,Western Desert,Egypt

Size and mineral analysis of the Upper Cretaceous clastics of the Bahariya Oasis indicate moderately well sorted, coarse skeewed and mesokurtic sediments. These sediments were most probably derived from mixed igneous, metamorphic and sedimentary sources, under conditions of low rainfall and poor drainage interfered by high rainfall periods.The shape of quartz grains and occurrence of stable and less stable minerals prove a short distance, saltation to graded suspension transportation of these sediments.Probably coastal plain, interfered by fresh water conditions had prevailed during the accumulation of these sediments, i.e. fluviomarine environment.     

Ethnoscapes, entertainment and ’eritage in the global city: segmented spaces in Singapore’s Joo Chiat Road

This case study considers the early development and recent changes that have occurred in the vicinity of Joo Chiat Road, Singapore, which can be described as a ‘linear activity corridor’ linking the districts of Geylang, Katong and Marine Parade, immediately east of Singapore’s urban core. Singapore’s Urban Redevelopment Authority (URA) has declared Joo Chiat to be a ‘Conservation Area’, reflecting local-born Peranakan and Eurasian cultures, with similar status to other more central historic sites such as Chinatown, Kampong Glam, Little India and Emerald Hill. But the story of Joo Chiat has evolved along a somewhat different trajectory from the more prominent, tourism-related, heritage areas, with a multiplicity of interactions operating at the margins of the planning process. This has led to the spatial infusion of potentially discordant, globally related, ‘entertainment and recreational’ activities into an area of established urban identity and multiple attachments. When a policy of police containment was found to be inadequate in protecting local residents from undesirable impacts, changes were eventually brought about through a combination of neighbourhood activism and local political initiative. Through detailed land use inspections, press reports and strategic interviews, backed up by secondary sources, the study highlights the impingement of marginalised, potentially disruptive ‘global’ elements into a local heritage conservation area, and the importance of strong neighbourhood identity and community involvement as active components in the process of conflict resolution.     

Groundwater beneath the urban area of Khan Younis City,southern Gaza Strip (Palestine): assessment for multi-domestic purposes

The present study research investigation is aimed to assess the groundwater quality for the urban area in Khan Younis City, southern Gaza Strip, for multi-domestic purposes. The physicochemical analysis of the groundwater wells shows the major ions in the order of Na⁺ > Mg²⁺ > Ca²⁺ > B³⁺ > K⁺ and Cl^? > HCO₃ ^? > SO₄ ^2? > NO₃ ^2? > F^? > PO₄ ^3?. Groundwater quality is classified as very hard-brackish water type. Ninety-five percent of the wells are classified as saline water type with high NO₃ ^2? concentrations. Based on water quality index (WQI), the groundwater falls into one of three categories: fair water (10%), poor water (15%), very poor (45%), and worst (30%). The high WQI values are because of high Na⁺, Cl^?, SO₄ ^2?, and NO₃ ^2? concentrations, while synthetic pollution index (SPI) values indicate that most about 80% of the wells are seriously polluted. Langelier Saturation Index (LSI) indicates that most of data are either slightly scale forming or corrosive water or slightly corrosive but non-scale forming, and 75% of the wells are suitable for construction purposes (have SO₄ ^2? concentrations <300 mg/L). The groundwater reaches alarming situation, where almost chemically unsuitable for drinking purposes and the water to be used after proper treatment such as desalination.     

Ramadan and Bussorah Street: the spirit of place

The presence of ‘seasonal spaces’ such as the Ramadan-related activities associated with Bussorah Street, Singapore, during the holy Muslim month of Ramadan surfaces significant issues on the convergence and management of identity, heritage, space and conservation important to all Singaporeans. Conservation projects to ‘prettify’ or commodify the historic district of Kampong Glam, which contains Bussorah Street had to be revised to include the local tradition of the Ramadan food bazaar but at the adjoining Kandahar Street. Undoubtedly, what is being underlined by this seasonal space is the affirmation of identity, the reclamation of space and the possibility for improved management and economic viability of the Kampong Glam district. However, as stressed in the paper, that while the spirit of Bussorah Street can be construed as forms of spatial or cultural resilience, the new Malay Heritage Centre (Taman Warisan Melayu) located in the district acts as a strong reminder that, ultimately, ‘seasonal spaces’ are still subjected to the calculated considerations of the Singapore urban planners or the governing elite with significant implications for those with strong ethnic and religious connections with the area and its Islamic heritage.

Characteristics of optical emissions and particle precipitation in polar cap arcs

Simultaneous optical and particle data from the ISIS-2 satellite are used to characterize polar cap arcs. Polar cap arcs are identified from two-dimensional geomagnetic transforms of the optical data along with precipitating electron data for the time at which the satellite is on the field line intersecting the arc. No precipitating protons were detected for any of the arc crossings. The pitch angle. distribution of the precipitating electrons is generally isotropic and the differential electron spectra show enhancements in the flux in the 300–750 eV energy range. The average energy of the precipitating electrons for the different arcs ranges from about 300 to 600 eV. A possible explanation of the observed precipitating particle characteristics is that parallel electric fields are accelerating polar rain type spectra at an altitude of several thousand km. For the arc crossings reported here the equivalent 4278 Å emission rate per unit energy deposition rate has a mean value of 162 R/(erg cm^?2 s^?1). Average 3914 Å intensities are about 0.8 kR while 6300 Å intensities range from 0.5 to 3 kR. Model calculations indicate that direct impact excitation is a minor source for the 5577 Å emission rate, but supplies approx. 40% of the 6300 Å emission.     

Coastal failures during the 1999 Kocaeli earthquake in Turkey

During the 1999 Kocaeli earthquake (M_w=7.4) in Turkey, coastal failures and sea inundation were observed and were particularly concentrated along the margins of Izmit Bay and Lake Sapanca, in pull-apart basins created by stepovers in the fault rupture. Geotechnical site characterization, geologic mapping, liquefaction evaluation, and slope stability analysis were carried out to identify the principal contributing factors of the coastal failures. Results from this study indicate that both liquefaction and tectonic subsidence contributed to the failures and sea inundation within the pull-apart basins. Most of the liquefaction sites were situated at the prograding nose of active delta fans, where the presence of steep slopes coupled with the loose sediments found within young active delta fan deposits resulted in liquefaction-induced slope failures and sea inundation. Liquefaction in other coastal deposits outside the actively prograding delta fans caused limited lateral spreading and only minor sea inundation. Outside the delta fans, where soils were not liquefiable, tectonic subsidence associated with normal faulting was the cause of the observed sea inundation. Generally, tectonic subsidence caused the most severe sea inundation. Based on these observations, the identification of regions susceptible to both tectonic subsidence and liquefaction are important when evaluating seismic hazards.     

Groundwater beneath the urban area of Khan Younis City,southern Gaza Strip (Palestine): hydrochemistry and water quality

Arabian Journal of Geosciences - This paper presents the results of a groundwater hydrochemical assessment in the urban area of Khan Younis City in the southern Gaza Strip by measuring its...