Modeling urban leaf area index with AISA+ hyperspectral data     

Ryan R. Jensen  Perry J. Hardin  Matthew Bekker  Derek S. Farnes  Vijay Lulla  Andrew Hardin 《Applied geography (Sevenoaks, England)》2009,29(3):320-332

This study used simple multiple regression to model urban leaf area index (LAI) in Terre Haute, Indiana, USA as a function of AISA+ hyperspectral radiance and its derivative features. Regression R² values ranging from 0.27 to 0.73 were obtained from the various models. Features appearing most frequently in the models included radiance at 0.727, 0.753, 0.848, 0.870, 0.900 and 0.917 μm. The best single predictor of LAI was the absolute difference in radiance between 0.777 and 0.673 μm. The best models performed well at low and intermediate LAI levels, but were less accurate with LAI values between 5.0 and 8.0.  相似文献   

Improving groundwater resource accounting in irrigated areas : a prerequisite for promoting sustainable use     

S. S. D. Foster  C. J. Perry 《Hydrogeology Journal》2010,18(2):291-294

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Seasonal fluxes and sediment routing in tropical catchments affected by nickel mining     

Justine Perry T. Domingo  Mikaël Attal  Simon M. Mudd  Bryne T. Ngwenya  Carlos Primo C. David 《地球表面变化过程与地形》2021,46(13):2632-2655

An important gap in the management of land erosion in mining-affected areas is the understanding of the entire sediment routing system and the links between sources and storage at the catchment scale. In this study, we examine sediment delivery and its seasonality in the nickel mining-affected Santa Cruz and Pamalabawan catchments in the Philippines. We monitored discharge, suspended sediment concentrations and suspended sediment loads across 13 sub-catchments with contrasting degrees of mining influence from June 2018 to July 2019. First, we show the importance of the size of the area that has been physically disturbed within our sub-catchments, with as little as 10–22% of relative disturbance area being enough to generate four-fold to eight-fold increase in the sediment yield relative to less disturbed and pristine areas. We found that sub-catchments with > 10% disturbance exhibit the highest sediment yields (15.5 ± 44.7 t km⁻² d⁻¹) compared with sub-catchments with < 10% disturbance (3.6 ± 17.7 t km⁻² d⁻¹) and undisturbed catchments (2.0 ± 5.7 t km⁻² d⁻¹). We also show that sediment flushing predominantly occurs in the most disturbed sub-catchments at the onset of the wet season. A small number of flood events transports the bulk of the sediment, with hysteresis effects being most pronounced in disturbed areas. Lastly, we show that floodplain sediment recycling exerts a key control on sediment delivery at both reach and catchment scales, with the relative contribution of floodplain sources to the sediment budget becoming dominant in the latter stages of the wet season- up to 89% of the total sediment export per storm event. This study highlights the importance of both degree of disturbance and sediment pathways in controlling sediment transport in mining-disturbed areas, and that considering the entire sediment routing system including intermediate stores is crucial to optimizing existing and future measures against siltation and potential contamination of trace metals and metalloids downstream of mining areas.  相似文献   

Reply to comments on defining biominerals and organominerals: Direct and indirect indicators of life [Perry et al., Sedimentary Geology, 201, 157–179]     

Randall S. Perry  Mark A. Sephton 《Sedimentary Geology》2009,213(3-4):156

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Corporate Greening of Foreign Transnationals in Singapore     

Martin Perry  Sanjeev Singh 《Singapore journal of tropical geography》2001,22(1):52-73

The environmental performance of transnational corporations (TNCs) may need to be updated to include evidence of increased corporate environmental responsibility. This is a challenge to geographical perspectives that have been critical of the environmental performance of TNCs. The paper reports the findings of a survey of TNCs with branches in Singapore. Using the survey evidence, TNCs are classified according to their degree of participation in a range of voluntary environmental initiatives. According to the classification, there is a similar proportion of low and high performers but a dominance of medium level activity that can involve little organisational change. A significant association between organisational size and environmental activity is found. Respondents most frequently report that corporate environmental standards motivate environmental action in Singapore. Overall the survey evidence indicates that few TNCs are significantly changing their environmental behaviour. The absence of citizen, NGO and government pressure on TNCs is reducing the extent of voluntary environmental action in Singapore and expectations of widespread corporate greening overlook organisational differences in their opportunity to benefit from investment in environmental management. It is concluded that voluntary corporate environmentalism does not reduce the need for government regulation.  相似文献   

Mg,Ca and $\text{O}{}^{18}\text{O}{}^{16}$ exchange in the sediment-pore water system,hole 149, DSDP     

Edward A. Perry  J.M. Gieskes  J.R. Lawrence 《Geochimica et cosmochimica acta》1976,40(4):413-423

The diagenesis and geochemical evolution of deep-sea sediments are controlled by the interaction between sediments and their associated pore waters. With increasing depth, the pore water of Hole 149 (DSDP) exhibits a strong depletion in Mg and a corresponding enrichment in Ca, while the alkalinity remains relatively constant. Dissolved SiO₂ is nearly constant in the upper 100 m of sediment, but is highly enriched in the deepest pore waters. The pore waters exhibit a depletion in K with increasing depth, and $\text{O}{}^{18}\text{O}{}^{16}$ pore water ratios also decrease.The sediment section has three zones of sedimentary regimes with increasing depth in the drill hole: an upper 100 m section of detrital clays, a middle section enriched in calc-akalic volcanics which have undergone submarine weathering to a smectite phase, and a lower section of siliceous ooze which still has a diagenetic smectite phase. The quartz-feldspar ratios and $\text{O}{}^{18}\text{O}{}^{16}$ composition of the silicate phases are in agreement with these interpretations.The submarine weathering of volcanics to a smectite can account for the observed pore water gradients. Volcanics release Ca and Mg to the pore waters causing the alkalinity values to increase. Smectite is formed, depletes the pore waters in Mg and O¹⁸ and causes the alkalinity to decrease. The net reaction allows for the observed relationship between pore water Ca and Mg gradients with little net change in alkalinity. Given the abundance of volcanics in many deep-sea sediments, especially in lower sections which often form near ridge crests, the submarine formation of smectite may be an additional oceanic Mg sink which has not yet been fully considered.  相似文献   

Amenability of nitrilotriacetic acid to biodegradation in a marine simulation     

P.W.W Kirk  J.N Lester  R Perry 《Marine pollution bulletin》1983,14(3):88-93

The behaviour of the detergent builder nitrilotriacetic acid (NTA) has been studied in the presence of a marine bacterial population potentially associated with a sewage discharge to coastal waters. Additions of 500 μg l^?1 NTA were made over a period of 80 days and 7500 μg l^?1 NTA over 40 days in both aerobic and anoxic environments. It was concluded that NTA was not degraded at either concentration under aerobic or anoxic conditions, despite the presence of a significant bacterial population under aerobic conditions. Possible effects of NTA recalcitrance and its accumulation in coastal marine waters are discussed.  相似文献   

Asiatic clam (Corbicula manilensis) and other foods used by waterfowl in the James River,Virginia     

Matthew C. Perry  Francis M. Uhler 《Estuaries and Coasts》1981,4(3):229-233

Corbicula manilensis was found in the gizzards of 24 ducks of 5 species taken from the James River, Virginia, between 1973 and 1976. Percent average volume in these species ranged from trace to 6%. This is the first known occurrence of this exotic clam in the food of duck in Chesapeake Bay. A total of 135 other food items was identified from the 116 gizzards of 9 species that were examined. Food that predominated includedCyperus spp.,Leersia oryzoides, Polygonum spp., andZea mays. The great diversity of food consumed in this fresh tidal section of the James River indicates the high value of these wetlands to waterfowl. *** DIRECT SUPPORT *** A01BY015 00008  相似文献   

Oxygen and carbon isotope geochemistry of the Krivoy rog iron formation,Ukranian SSR     

E.C. Perry  S.N. Ahmad 《Lithos》1981,14(2):83-92

Oxygen and carbon isotope analyses of samples from three mines in the Krivoy Rog iron formation, Ukranian SSR, are reported here. Maximum and minimum quartz-magnetite fractionation values ($\text{Δ}{}_{\mathrm{<mtext>QM</mtext>}}$) and inferred temperature range in degrees centrigrade for each mine are: