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201.
为探明宁东煤田枣泉矿井首采区煤层自然范围及充水性,根据采区内地球物理物征,采用高精度磁法,直流电测深法和激发极化法进行综合勘探。在磁法勘探中结合测区曲线特征,建立数据体模型,正演计算烧变岩边界;电法勘探利用烧变岩含水后电阻率降低的特征确定其含水范围及富水性。 相似文献
202.
203.
Sediment concentration changes in runoff pathways from a forest road network and the resultant spatial pattern of catchment connectivity 总被引:6,自引:0,他引:6
Hydrological connectivity is a term often used to describe the internal linkages between runoff and sediment generation in upper parts of catchments and the receiving waters. In this paper, we identify two types of connectivity: direct connectivity via new channels or gullies, and diffuse connectivity as surface runoff reaches the stream network via overland flow pathways. Using a forest road network as an example of a landscape element with a high runoff source strength, we demonstrate the spatial distribution of these two types of linkages in a 57 km2 catchment in southeastern Australia. Field surveys and empirical modelling indicate that direct connectivity occurs primarily due to gully development at road culverts, where the average sediment transport distance is 89 m below the road outlet. The majority of road outlets were characterised by dispersive flow pathways where the maximum potential sediment transport distance is measured as the available hillslope length below the road outlet. This length has a mean value of 120 m for this catchment. Reductions in sediment concentration in runoff plumes from both pathways are modelled using an exponential decay function and data derived from large rainfall simulator experiments in the catchment. The concept of the volume to breakthrough is used to model the potential delivery of runoff from dispersive pathways. Of the surveyed road drains (n=218), only 11 are predicted to deliver runoff to a stream and the greatest contributor of runoff occurs at a stream crossing where a road segment discharges directly into the stream. The methodology described here can be used to assess the spatial distribution and likely impact of dispersive and gullied pathways on in-stream water quality. 相似文献
204.
Curie-point depth map of Turkey 总被引:3,自引:0,他引:3
205.
This study was carried out in the Cuenca de la Independencia, a semi-arid basin in Central Mexico. The objective is to describe the main features of a groundwater flow regime under natural conditions, based on groundwater discharge manifestations. Information obtained from paleoecological, paleontological, archaeological and historical data suggests that, prior to heavy development (starting in the 1950s), the hydrogeologic regime was characterized by a larger groundwater availability in a more humid and colder climate. Manifestations associated to groundwater discharges are springs, lagoons, wetlands, saline soils, chalcedony deposits, phreatophytes, thermalism, and artesianism. The different types of manifestations and their position in the basin indicate the influence of groundwater flow systems hierarchically nested, forming concentric zones at ground level. The groundwater flow regime corresponds to a classical gravity-induced flow system with generation of local, intermediate and regional patterns. Integrating several types of data to establish the flow geometry and its dynamics has proven a useful tool to increase understanding of the original groundwater regimes. This approach can also be applied in other over-exploited semi-arid basins. 相似文献
206.
A size classification for debris flows 总被引:4,自引:0,他引:4
A 10-fold classification for debris flow size is proposed based on total volume, peak discharge and area inundated by debris. Size classes can be used for regional overview studies where detailed site investigations are either unnecessary, too costly or where the highest hazard and risk creeks need to be identified for further study. They are also useful to compare the regional impact between affected areas and the effects of rainstorms, and they allow lay-people to obtain an understanding of debris flow magnitude and consequences. Finally, different size classes allow the estimation of travel times to points of interest based on empirically derived equations. It is proposed that agencies concerned with debris flows should establish a documentation of debris flow size according to this classification, which serves as a data base for hazard and risk planning. 相似文献
207.
我国公路泥石流病害严重,泥石流淤埋公路构建筑物是一类常见的公路泥石流病害类型。泥石流衰减动力学是防治泥石流淤埋病害的重要关键技术,也是泥石流运动学、动力学研究的核心问题之一。本文作者运用泥沙运动力学及流体力学原理,初步建立了泥石流固相颗粒和液相浆体的能量衰减条件,把泥石流衰减模式概化为两类,即能量抑制衰减和能量自由衰减;通过泥石流沉积模型试验,得到了不同粘度泥石流体的沉积扇变化形态,随着泥石流体粘度的增大,沉积扇边缘变陡、扩展范围变小、纵轴线长度减小等结论与实际情况吻合;初步建立了泥石流能量衰减速率计算方法。研究成果为防治公路泥石流病害奠定了基础。 相似文献
208.
Temporal and spatial variations in water flow and sediment load in Narmada River Basin, India: natural and man-made factors 总被引:1,自引:0,他引:1
The Narmada River flows through the Deccan volcanics and transports water and sediments to the adjacent Arabian Sea. In a
first-ever attempt, spatial and temporal (annual, seasonal, monthly and daily) variations in water discharge and sediment
loads of Narmada River and its tributaries and the probable causes for these variations are discussed. The study has been
carried out with data from twenty-two years of daily water discharge at nineteen locations and sediment concentrations data
at fourteen locations in the entire Narmada River Basin. Water flow in the river is a major factor influencing sediment loads
in the river. The monsoon season, which accounts for 85 to 95% of total annual rainfall in the basin, is the main source of
water flow in the river. Almost 85 to 98% of annual sediment loads in the river are transported during the monsoon season
(June to November). The average annual sediment flux to the Arabian Sea at Garudeshwar (farthest downstream location) is 34.29×106 t year−1 with a water discharge of 23.57 km3 year−1. These numbers are the latest and revised estimates for Narmada River. Water flow in the river is influenced by rainfall,
catchment area and groundwater inputs, whereas rainfall intensity, geology/soil characteristics of the catchment area and
presence of reservoirs/dams play a major role in sediment discharge. The largest dam in the basin, namely Sardar Sarovar Dam,
traps almost 60–80% of sediments carried by the river before it reaches the Arabian Sea. 相似文献
209.
210.
本文通过火铺煤矿矸石场滑坡的调查研究,在对其地质环境条件分析的基础上,论述滑坡的特征,探讨其形成机制,提出了防治措施,可供该矿山地质环境的保护与修复参考。 相似文献