Resident action groups in Sydney: people power or rat‐bags?

This paper presents an analysis of a neglected area of study by geographers; that of resident action groups. During the 1980s there has been a significant increase in the number of resident action groups throughout Sydney. Resident activism has influenced local planning processes, the location of noxious facilities and subsequent urban form. This has initiated important reactions by government at both the local and State levels. Urban collective activisms have been hypothesised as single‐issue, self‐serving nimby groups. However, RAGs are also empowering forces, in which women and men are introduced to the political structures and become engaged in protest and resistance that can challenge the social and spatial order. RAGs can, either singularly or cumulatively, force a re‐aligning of existing power relations, and they can necessitate changed modes of governance (or govern‐mentality).     

Some factors affecting water yield from mountain ash (Eucalyptus regnans) dominated forests in south-east Australia

An experiment in mountain ash forests in Melbourne's water supply catchments in south-east Australia investigated the impact on long-term water yield of reducing forest density. Fifty-four per cent of basal area was removed from a 17 ha catchment (Black Spur 1) by patch cutting, and the patches were regenerated with mountain ash. A 50% reduction was implemented in Black Spur 3, an 8 ha catchment, through uniform thinning. Uniform thinning was shown to be more effective in enhancing streamflow than patch cutting. A streamflow increase of 25–30% (130–150 mm year⁻¹) was observed after treatment in both catchments. Eleven years later, a treatment effect of 15% was still evident in the selectively thinned catchment (Black Spur 3), but the effect had completely decayed in the patch cut catchment (Black Spur 1).

Research by Melbourne Water has established that streamflow is significantly influenced by forest age. It is hypothesised that this relationship, and the observed decay after patch cutting in Black Spur 1, is largely the result of variation in transpiration. To study the relationship between forest age and transpiration in detail, sap velocity was measured over two summers in four mountain ash plots using the heat-pulse method. The trees on these plots were 50, 90, 150 and 230 years old. On days when measurements were made, the mean sap velocity was not significantly different in the 50-, 90- 230-year-old stands, but was significantly smaller by 14% in the 150-year-old stand. Overstorey sapwood area gradually decreased with plot age, and was 57% lower in the 230-year-old plot than in the 50-year-old plot. When combined with the sap velocity measurements, these data indicated that over the six warmest months of the year, transpiration in the 50-year-old plot was 190 mm more than in the 230-year-old plot. These results support a hypothesis that differences in streamflow between 50-year-old and 230-year-old mountain ash forest can largely be accounted for by differences in transpiration. Further heat-pulse studies in young regrowth and in thinned and unthinned 1939 regrowth will be needed if the streamflow changes in Black Spur 1 and Black Spur 3 are to be fully explained.     

Metasomatic alteration of coarse-grained igneous calcium-aluminum-rich inclusions from CK3 carbonaceous chondrites

We report on the primary and secondary mineralogies of three coarse-grained igneous calcium-aluminum-rich inclusions (CAIs) (Compact Type A [CTA], Type B [B], and forsterite-bearing type B [FoB]) from the Northwest Africa (NWA) 5343 (CK3.7) and NWA 4964 (CK3.8) carbonaceous chondrites, compare them with the mineralogy of igneous CAIs from the Allende (CV3.6) chondrite, and discuss the nature of the alteration processes that affected the CK and CV CAIs. The primary mineralogy and mineral chemistry of the CK3 CAIs studied are similar to those from Allende; however, primary melilite and anorthite are nearly completely absent. Although the secondary minerals identified in CK CAIs (Al-diopside, andradite, Cl-apatite, clintonite, forsterite, ferroan olivine, Fe,Ni-sulfides, grossular, ilmenite, magnetite, plagioclase, spinel, titanite, and wadalite) occur also in the Allende CAIs, there are several important differences: (i) In addition to melilite and anorthite, which are nearly completely replaced by secondary minerals, the alteration of CK CAIs also affected high-Ti pyroxenes (fassaite and grossmanite) characterized by high Ti³⁺/Ti⁴⁺ ratio and spinel. These pyroxenes are corroded and crosscut by veins of Fe- and Ti-bearing grossular, Fe-bearing Al,Ti-diopside, titanite, and ilmenite. Spinel is corroded by Fe-bearing Al-diopside and grossular. (ii) The secondary mineral assemblages of grossular + monticellite and grossular + wollastonite, commonly observed in the Allende CAIs, are absent; the Fe-bearing grossular + Fe-bearing Al-diopside ± Fe,Mg-spinel, Fe-bearing grossular + Fe,Mg-olivine ± Fe,Mg-spinel, and Ca,Na-plagioclase + Fe-bearing Al-diopside + Fe-bearing grossular assemblages are present instead. These mineral assemblages are often crosscut by veins of Fe-bearing Al-diopside, Fe,Mg-olivine, Fe,Mg-spinel, and Ca,Na-plagioclase. The coarse-grained secondary grossular and Al-diopside often show multilayered chemical zoning with distinct compositional boundaries between the layers; the abundances of Fe and Ti typically increase toward the grain edges. (iv) Sodium-rich secondary minerals, nepheline and sodalite, commonly observed in the peripheral portions of the Allende CAIs, are absent; Ca,Na-plagioclase is present instead. We conclude that coarse-grained igneous CAIs from CK3.7–3.8 s and Allende experienced an open-system multistage metasomatic alteration in the presence of an aqueous solution–infiltration metasomatism. This process resulted in localized mobilization of all major rock-forming elements: Si, Ca, Al, Ti, Mg, Fe, Mn, Na, K, and Cl. The metasomatic alteration of CK CAIs is more advanced and occurred under higher temperature and higher oxygen fugacity than that of the Allende CAIs.     

核磁共振测井孔隙度观测模式与处理方法研究

核磁共振（NMR）测井是确定地层孔隙度的有效方法,已经得到广泛应用.但是,在我国部分油田的应用中发现核磁测井孔隙度与常规孔隙度之间存在明显差异.本文对NMR测井孔隙度观测模式和处理方法进行研究,分析了NMR孔隙度误差的来源.针对富含蒙脱石、伊利石和伊/蒙混层粘土矿物的陆相沉积砂泥岩地层,根据这些粘土矿物的NMR横向弛豫时间T2值特征以及孔隙度处理结果得到的40 ms附近孔隙度分配量不合适,提出了新的观测模式和处理方法,并用实验验证了新方法的可行性.     

Natural hazards,disaster management and simulation: a bibliometric analysis of keyword searches

Natural Hazards - Disasters affect millions of people annually, causing large numbers of fatalities, detrimental economic impact and the displacement of communities. Policy-makers, researchers and...     

Changes in zooplankton abundance and diversity after ballast water exchange in regional seas

A study of the efficiency of ballast water exchange (BWE) in regional seas was carried out to assess this management method in reducing the risk of introducing non-native species. Zooplankton samples were taken before and after exchange on ten voyages where BWE took place (North Sea, English Channel, Irish Sea and Bay of Biscay). Zooplankton abundance was always reduced after exchange, but diversity increased on eight occasions. The greatest changes occurred when the source port water was of low salinity and when exchange took place in deeper waters further from land. However, it was clear that BWE did not remove all the source port taxa and this method is unlikely to provide a consistent and effective method of managing ballast water in regional seas.     

Attitudes to Diversity: new perspectives on the ethnic geography of Brisbane,Australia

As a consequence of changing immigration policy over the past 50 years, contemporary Australia has a culturally diverse population. Focusing on Brisbane, one of Australia's smaller immigrant-receiving cities but where some 19 per cent of the population is born overseas, this study examines attitudes to and perceptions of culturally different ethnic (non-Anglo) immigrant groups. Emphasis is placed on patterns of tolerance and intolerance for the city as a whole, both in areas of contact and in areas of minimal contact. Findings show that variations in attitudes vary somewhat from commonly accepted socio-economic and age-based correlations (the lower the status or the older people are the less tolerant), depending on the particular mix of ethnic birthplace groups present. They also show levels of intolerance in areas of minimal contact, which is implicitly attributed to mass media influences. In light of these findings, a concluding plea is made for anti-intolerance strategies to be developed for cities that pay regard to the geography of attitude-forming contexts.     

Relative depletion of niobium in some arc magmas and the continental crust: partitioning of K, Nb, La and Ce during melt/rock reaction in the upper mantle

Depletion of Nb relative to K and La is characteristic of lavas in subduction-related magmatic arcs, as distinct from mid-ocean ridge basalts. Nb depletion is also characteristic of the continental crust. This and other geochemical similarities between the continental crust and high-Mg# andesite magmas found in arcs suggests that the continental crust may have formed by accretion of andesites. Previous studies have shown that the major element characteristics of high-Mg# andesites may be produced by melt/rock reaction in the upper mantle. In this paper, new data on partitioning of K, Nb, La and Ce between garnet, orthopyroxene and clinopyroxene in mantle xenoliths, and on partitioning of Nb and La between orthopyroxene and liquid, show that garnet and orthopyroxene have Nb crystal/liquid distribution coefficients which are much larger than those of K and La. Similar fractionations of Nb from K and La are expected in spinel and olivine. For this reason, reactions between migrating melt and large masses of mantle peridotite can produce substantial depletion of Nb in derivative liquids. Modeling shows that reaction between ascending, mantle-derived melts and mantle peridotite is a viable mechanism for producing the trace element characteristics of high-Mg# andesite magmas and the continental crust.

Alternatively, small-degree melts of metabasalt and/or metasediment in the subducting slab may leave rutile in their residue, and will thus have large Nb depletions relative to K and La [1]. Slab melts are too rich in light rare earth elements and other incompatible elements, and too poor in compatible elements, to be parental to arc magmas. However, ascending slab melts may be modified by reaction with the mantle. Our new data permit modeling of the trace element effects of reaction between small-degree melts of the slab and mantle peridotite. Modeling shows that this type of reaction is also a viable mechanism for producing the trace element characteristics of high-Mg# andesites and the continental crust. These findings, in combination with previous results, suggest that melt/rock reaction in the upper mantle has been an important process in forming the continental crust and mantle lithosphere.     

Quantifying hydrological budgets and pathways in a small upland catchment using a combined modelling and tracer approach

Hydrological budgets and flow pathways have been quantified for a small upland catchment (1.76 km²) in the northeast of Scotland. Water balance calculations for four subcatchments identified spatial variability within the catchment, with an estimated runoff enhancement of up to 25% for the upper western area, compared with the rest of the catchment. Data from spatial hydrochemical sampling, over a range of flow conditions, were used to identify the principal hillslope runoff mechanisms within the catchment. A hydrochemical mixing analysis revealed that runoff emerging from springs in various locations of the hillslope accounted for a significant proportion of flow in the streams, even during storm events. A hydrological model of the catchment was calibrated using the calculated stream flows for four locations, together with results from the mixing analysis for different time points. The calibrated model was used to predict the temporal variability in contributions to stream flow from the hillslope springs and soil water flows. The overall split ranged from 57%:43% spring water:soil water in the upper eastern subcatchment, to 76%:24% in the upper western subcatchment. Copyright © 2006 John Wiley & Sons, Ltd.