Partitioning of rainfall in a eucalypt forest and pine plantation in southeastern australia: I throughfall measurement in a eucalypt forest: Effect of method and species composition     

R. H. Crockford  D. P. Richardson 《水文研究》1990,4(2):131-144

A seven year event-based study partitioning of rainfall into throughfall, stemflow, and interception was conducted in a dry sclerophyll eucalypt forest and a Pinus radiata plantation. Resulting information will be of use for process modelling. Stemflow was influenced by event type, rain angle having a major effect; and the yields of the different species are compared. Tree characteristics that influenced stemflow yields are outlined and discussed. The canopy storage capacity of the eucalypt forest was determined and the influence of species composition is shown. The likely influence of climate variations is discussed. The canopy storage capacity is compared to the interception values estimated for continuous events of various sizes. The interception of the eucalypt forest and the pine plantation are compared on event basis for event size classes and on an annual basis. The comparative interceptions for continuous events are also discussed, while the effect of thinning the pine plantation on throughfall, stemflow, and interception is shown. The hydrological consequences of this study are: more informed judgment can be made about techniques for measurement of throughfall, tree structural characteristics (species related) can more adequately be considered when selecting trees for measurement of stemflow, and the stemflow yields can in some cases be better understood from the information about effect of event type. This paper deals with the influence of measurement method, species composition, and tree characteristics on the estimation of throughfall in the eucalypt forest. The site is near Canberra, lat. 35°S, 145°E, with annual rainfall about 650 mm. Two methods of measuring throughfall are compared: randomly placed, 200 mm cylindrical gauges (standard) and 50 mm square opening wedge type gauges (plastic), and randomly placed 5 × 0–22 m troughs. Despite the high placement density (150 to 225 ha^?1), throughfall estimates from gauges has high variance and consistently underestimated those of the troughs, which had a total opening equivalent to 2325 raingauges (200 mm diameter) per hectare. Local concentration of stemflow into drip points provided by detaching bark pieces of one smooth barked species, Eucalyptus mannifera, is believed to be the principal cause of the lower collection and greater variance of the gauges. The low leaf area index (1–3) and large wood area of the forest together with a pendulous vertical habit of the leaves also contributed. The presence of E. mannifera is shown to substantially affect the relative values of throughfall as measured by troughs and gauges. The plastic receivers were found to underestimate rainfall or throughfall relative to the standard gauges, particularly for fine drop rainfall in multiperiod events.  相似文献   

Water repellency in a dry sclerophyll eucalypt forest — measurements and processes     

H. Crockford  S. Topalidis  D. P. Richardson 《水文研究》1991,5(4):405-420

The magnitude of soil water repellency in a dry sclerophyll eucalypt forest was measured periodically over four years. The varying responses from a range of sites within the forest are discussed and the effect of amount and frequency of rainfall is shown. It was found that some weeks of consistently wet weather were required for water repellency breakdown, and a frequency of rainfall much greater than normal in the study area for it to remain broken down. Even after an extended period of breakdown, it was found that repellency can be reestablished after one week of hot dry weather. Laboratory tests were used to examine the major repellency processes; three were identified and the relative importance of each considered in the context of the field study. The relative influence of each depended on the physical and chemical characteristics of the sites. The repellent soil samples were more repellent to water of throughfall origin, and even more repellent to stemflow than to distilled water. The repellency response also varied with the type of vegetative cover present. The influence of these phenomena on the preservation of water repellency and the relevance of repellency in macropore infiltration processes are discussed.  相似文献   

Heat refraction and heat production in and around granite plutons in north-east England     

P. C. England  E. R. Oxburgh  S. W. Richardson 《Geophysical Journal International》1980,62(2):439-455

Summary. Existing surface heat flow determinations in north-east England indicate a difference in thermal structure between the Alston block of the North Pennines and the coastal regions. New heat flow determinations in the Askrigg block and on the coast support the original indications of higher heat flow in the positive blocks, which are underlain by 400 Myr old granites, than in their marginal sedimentary troughs along the present coastline. Although the two blocks are geophysically and geologically similar, surface heat flow in the Alston block is 30mW m^-2 higher than it is in the Askrigg block 50km to its south. Heat flow refraction around high conductivity plutons with high heat production may significantly affect the interpretation of heat flow measurements made on a regional scale but in the present case its effect, if any, is to emphasize the heat flow difference between the two otherwise similar blocks. The chemical differences between the Wensleydale and the Weardale granites – cupolas of the granites underlying the Askrigg and Alston may be representative of the granites as a whole and the blocks respectively – difference in surface heat flows may result from a contrast in radiogenic heat production between the two granites extending to mid-crustal depths.  相似文献   

A third-order intermediate orbit for planetary theory     

David L. Richardson 《Celestial Mechanics and Dynamical Astronomy》1982,26(2):187-195

By use of a new canonical transformation procedure, a third-order intermediary for planetary motion is developed. The intermediary contains all contributions that arise from the assumption of circular, coplanar orbits for the disturbing masses. The results are expressible in terms of elliptic integrals of the first, second, and third kinds.Proceedings of the Conference on Analytical Methods and Ephemerides: Theory and Observations of the Moon and Planets. Facultés universitaires Notre Dame de la Paix, Namur, Belgium, 28–31 July, 1980.  相似文献   

Crustal structure beneath the Faroe Islands and the Faroe–Iceland Ridge     

K. R. Richardson  J. R. Smallwood  R. S. White  D. B. Snyder  P. K. H. Maguire 《Tectonophysics》1998,300(1-4):159-180

We have mapped the transition from the continental Faroe block (the Faroe Islands and surrounding shelf) to the thickened oceanic crust of the Faroe–Iceland Ridge in the North Atlantic using the results of a detailed sea-to-land seismic profile with wide-angle to normal-incidence recordings of explosive and airgun shots fired at sea along the Faroe–Iceland Ridge. Interpretation of all available seismic and gravity data indicates that this aseismic ridge is composed of 30±3-km-thick oceanic crust, with a gradual transition to ancient continental crust from 100 to 40 km northwest of the Faroe Islands, close to the shelf edge. This confirms that the crust beneath the Faroe Islands, which may be up to 46 km thick, comprises continental material in agreement with previous seismic and geochemical results. Results suggest that the upper 5.2±0.7 km of the Faroe crust consists of Tertiary basalts generated during continental breakup, overlying the continental crust beneath. The lower crust, where seismic constraint is poor, may exhibit high seismic velocities (7.1–7.6 km s⁻¹) which we attribute to underplating or intrusion by mafic melts during continental breakup in the early Tertiary.  相似文献   

SPATIAL DETERMINANTS OF RURAL LIVELIHOOD IN COSTAL GUYANA*     

Bonham C. Richardson 《The Professional geographer》1973,25(4):363-368

  相似文献   

Petroleum hydrocarbons, polycyclic aromatic hydrocarbons, organochlorine pesticides and polychlorinated biphenyls in tissues of Indo-Pacific humpback dolphins from south China waters     

Leung CC  Jefferson TA  Hung SK  Zheng GJ  Yeung LW  Richardson BJ  Lam PK 《Marine pollution bulletin》2005,50(12):33-1719

  相似文献   

Polybrominated diphenyl ethers (PBDEs) in sediments and mussel tissues from Hong Kong marine waters   总被引：17，自引：0，他引：17  

Liu Y  Zheng GJ  Yu H  Martin M  Richardson BJ  Lam MH  Lam PK 《Marine pollution bulletin》2005,50(11):1173-1184

Sediments and green-lipped mussels, Perna viridis, were used to investigate concentrations of polybrominated diphenyl ethers (PBDEs) in Hong Kong's marine environment. PBDEs have been used extensively over the past two decades as flame retardants in polymer additives for a variety of plastics, computers, furniture, building materials, and fabrics. Many measurements of PBDEs in various environmental matrices have been reported from Belgium, Holland, Japan, Europe and North America, but few measurements are available for the southeast Asian region and Hong Kong. PBDE congeners (n=15) were measured in 13 sediments and nine mussel samples, taken from Hong Kong marine waters. The Sigma15PBDEs in sediments ranged between 1.7 and 53.6 ng g(-1) dry wt, with the highest concentrations located around the most heavily populated areas of Victoria Harbour and Sai Kung, while the lowest concentrations of Sigma15PBDEs were found at more remote locations of Sha Tau Kok, Wong Chuk Bay, Castle Peak Bay, and Gold Coast. Sigma15PBDEs ranged from 27.0 to 83.7 ng g(-1) dry wt of mussel tissues. Although not identical, most of the congeners in sediments were found in mussel tissues, with BDE-47, BDE-99, BDE-153 and BDE-183 being the most prominent in both matrices. On the basis of a literature survey, the concentrations of PBDEs reported in Hong Kong sediments and mussel tissues are amongst the highest in the world.  相似文献   

Emerging chemicals of concern: pharmaceuticals and personal care products (PPCPs) in Asia, with particular reference to Southern China   总被引：40，自引：0，他引：40  

Richardson BJ  Lam PK  Martin M 《Marine pollution bulletin》2005,50(9):913-920

  相似文献   

Certain jurassic (Aalenian-Vesulian) strata of Southern Northamptonshire     

Linsdall Richardson 《Proceedings of the Geologists' Association. Geologists' Association》1923,34(2):97-IN2

  相似文献