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991.
992.
通过卫片地质解译,从遥感角度对该区的构造特征及规律进行了初步的总结,同时,紧密结合生产性的物探、井探及钻探工作,以半隐伏含煤复向斜为找煤影像模式,在本区中、新生界盖层下或断裂构造下圈出含煤预测区7个,预估含煤面积12.8 km~2,预测煤炭储量5473万吨。 相似文献
993.
Geometry and growth of an inner rift fault pattern: the Kino Sogo Fault Belt, Turkana Rift (North Kenya) 总被引:1,自引:0,他引:1
A quantitative analysis is presented of the scaling properties of faults within the exceptionally well-exposed Kino Sogo Fault Belt (KSFB) from the eastern part of the 200-km-wide Turkana rift, Northern Kenya. The KSFB comprises a series of horsts and grabens within an arcuate 40-km-wide zone that dissects Miocene–Pliocene lavas overlying an earlier asymmetric fault block. The fault belt is 150 km long and is bounded to the north and south by transverse (N50°E and N140°E) fault zones. An unusual feature of the fault system is that it accommodates very low strains (<1%) and since it is no older than 3 Ma, it could be characterised by extension rates and strain rates that are as low as 0.1 mm/yr and 10−16 s−1, respectively. Despite its immaturity, the fault system comprises segmented fault arrays with lengths of up to 40 km, with individual fault segments ranging up to 9 km in length. Fault length distributions subscribe to a negative exponential scaling law, as opposed to the power law scaling typical of other fault systems. The relatively long faults and segments are, however, characterised by maximum throws of no more than 100 m, providing displacement/length ratios that are significantly below those of other fault systems. The under-displaced nature of the fault system is attributed to early stage rapid fault propagation possibly arising from reactivation of earlier underlying basement fabrics/faults or magmatic-related fractures. Combined with the structural control exercised by pre-existing transverse structures, the KSFB demonstrates the strong influence of older structures on rift fault system growth and the relatively rapid development of under-displaced fault geometries at low strains. 相似文献
994.
利用MODIS卫星遥感资料的亮温异常变化信息应用于地震预测研究,虽然目前还处于探索研究阶段,但根据该资料在台湾地区几次中强地震前的异常信息分析认为,其亮温异常信息可作为台湾地区中强地震前的一种较可靠、有效的短临预测方法。其基本原理是构造块体在破裂或错动前,因地壳岩石受挤压时应力应变的增强而引起了震源区及其周边区域的异常增温现象。 相似文献
995.
996.
Kristina?B.?KatsarosEmail author Alexander?V.?Soloviev Robert?H.?Weisberg Mark?E.?Luther 《Boundary-Layer Meteorology》2005,116(2):175-185
Consideration of the dependence of various components of the sea-surface heat and momentum fluxes on sea surface temperature
(SST) leads to an explanation for the observed reduction in the horizontal temperature gradients in the uppermost layer of
the ocean (a few to 10 m in depth). Horizontal temperature gradients within the mixed layer can be masked by a near-surface
layer of warm water. This camouflage of horizontal temperature gradients has importance for the remote sensing of SST used
by the fishing industry, for the estimation of acoustic transmission, and for the forecasting of hurricane development, among
many uses of SST data. Diurnal warming conditions in the Straits of Florida are examined by a simulation calculation and by
analysis of observations obtained on moorings deployed on the south-east Florida shelf. When there is net heating (i.e., the
solar input is stronger than the combined latent, sensible and longwave radiative heat losses) the originally warmer water
experiences less heating than the colder water, leading to a weakening of the horizontal SST gradients as seen by surface
buoys or satellites. The warmer water also experiences more mixing and therefore less increase in temperature. The strongest
effect of the diurnal heating on wind stress occurs when the SST starts out cooler than the air temperature and the atmosphere
is stably stratified. Diurnal warming can then rapidly increase the SST above the air temperature because of reduced wind
stress and reduced upper-ocean mixing. After that the wind stress increases as convectively driven turbulence contributes
to the atmospheric exchange. 相似文献
997.
998.
Mobin-ud-Din Ahmad Wim G. M. Bastiaanssen Reinder A. Feddes 《Hydrogeology Journal》2005,13(5-6):653-664
Over-exploitation of groundwater resources threatens the future of irrigated agriculture, especially in the arid and semi-arid regions of the world. In order to reverse this trend, and to ensure future food security, the achievement of sustainable groundwater use is ranking high on the agenda of water policy makers. Spatio-temporally distributed information on net groundwater use—i.e. the difference between tubewell withdrawals for irrigation and net recharge—is often unknown at the river basin scale. Conventionally, groundwater use is estimated from tubewell inventories or phreatic surface fluctuations. There are shortcomings related to the application of these approaches. An alternative methodology for computing the various water balance components of the unsaturated zone by using geo-information techniques is provided in this paper. With this approach, groundwater recharge will not be quantified explicitly, but is part of net groundwater use, and the spatial variation can be quantitatively described. Records of routine climatic data, canal discharges at major offtakes, phreatic surface depth fluctuations, and simplified information on soil textural properties are required as input data into this new Geographic Information System and Remote Sensing tool. The Rechna Doab region (approximately 2.97 million ha), located in the Indus basin irrigation system of Pakistan, has been used as a case study. On an annual basis, an areal average net groundwater use of 82 mm year–1 was estimated. The current result deviates 65% from the specific yield method. The deviation from estimates using tubewell withdrawal related data is even higher.
Resumen La sobre-explotación de recursos de agua subterránea amenaza el futuro de la agricultura de riego, especialmente en las regiones áridas y semi-áridas del mundo. Para revertir esta tendencia, y para garantizar seguridad alimentaria futura, la meta del uso sostenible del agua subterránea se encuentra alto en la agenda de los políticos. Información espacial y temporal en cuanto al uso neto de agua subterránea- i.e. la diferencia entre las extracciones de agua de pozos entubados para riego y recarga neta- se desconoce frecuentemente a la escala de cuenca hidrográfica. Generalmente, el uso de agua subterránea se estima a partir de inventarios de pozos o fluctuaciones de superficies freáticas. Existen deficiencias en relación con las aplicaciones de estos enfoques. En este artículo se aporta una metodología alternativa para calcular los diferentes componentes del balance hídrico de la zona no saturada utilizando técnicas geoinformativas. Aunque con este enfoque no se cuantifica de manera explícita la recarga de agua subterránea, la cual es parte del uso neto de agua subterránea, puede describirse cuantitativamente la variación espacial. Para esta nueva herramienta de Sistemas de Información Geográfica y Sensores Remotos se requieren datos de entrada como registros rutinarios de datos climáticos, descargas de canales en salidas principales, fluctuaciones de profundidades de superficies freáticas, e información simplificada de las propiedades texturales de los suelos. Se ha utilizado como estudio de caso la región Rechna Doab (aproximadamente 2.97 millones ha), localizada en el sistema de riego de la cuenca Indus de Pakistán. Se ha estimado un uso promedio areal anual de agua subterránea de 82 mm año–1. El resultado obtenido difiere en un 65% del método de productividad específica. La diferencia en relación a estimados provenientes de extracciones en pozos entubados es aún mucho más alta.
Résumé La surexploitation des ressources en eau souterraine menace le futur de lagriculture irrigué, spécialement dans les zones arides et semi-arides du monde. De manière à renverser la tendance, et dassurer la sécurité alimentaire, lutilisation durable des eaux souterraines est devenue une priorité dans lagenda des politiques de leau. La distribution spatio-temporelle de lusage net de leau souterraine (la différence entre l ‹eau pompée et la recharge nette) est rarement connue à léchelle dun bassin versant. Conventionnellement, lutilisation des eaux souterraines est estimée à partir des données de rabattement ou les données de fluctuation du niveau de la nappe phréatique. Il y a des défauts dans ces approches. Une méthodologie alternative pour calculer les différents composants de la balance hydrologique est présentée dans cet article. Avec cette approche, la recharge des eaux souterraines ne sera pas quantifiée de manière explicite, mais sera considérée comme une part de lutilisation nette en eau souterraine, et la variation spatiale peut être décrite quantitativement. Les chroniques des données climatiques, les débits du réseau hydrographique majeur, les fluctuations de la surface de la nappe phréatique, et des données basiques sur la texture du sol sont nécessaires et sont rentrées dans un nouveau Système dInformation Géographique et outil de télédétection. La région de Rechna Doab au Pakistan, environ 2.97 millions dhectare, localisée dans le bassin irrigué de lIndus, a été utilisé comme cas détude. Sur base annuelle, lutilisation nette de leau souterraine est estimée à 82 mm. en moyenne. Le résultat obtenu diffère de 65% du résultat de la méthode du débit spécifique. La différence avec le résultat obtenu en observant le rabattement des puits est encore plus élevée.相似文献
999.
Ola Hall Geoffrey J. Hay 《International Journal of Applied Earth Observation and Geoinformation》2003,4(4):311-327
Landscape spatial pattern is dependent not only on interacting physiographic and physiological processes, but also on the temporal and spatial scales at which the resulting patterns are assessed. To detect significant spatial changes occurring through space and time three fundamental components are required. First, a multiscale dataset must be generated. Second, a change detection framework must be applied to the multiscale dataset. Third, a procedure must be developed to delineate individual image-objects and identify them as they change through scale. In this paper, we introduce an object-specific multiscale digital change detection approach. This approach incorporates multitemporal SPOT Panchromatic (Pan) data, object-specific analysis (OSA), object-specific up-scaling (OSU), marker-controlled watershed segmentation (MCS) and image differencing change detection. By applying this framework to SPOT Pan data, image-objects that have changed between registration dates can be identified and delineated at their characteristic scale of expression. Results illustrate that this approach has the ability to automatically detect changes at multiple scales as well as suppress sensor related noise. This study was conducted in the forest region of the Örebro Administrative Province, Sweden. 相似文献
1000.