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441.
旅游地的形象塑造是当今旅游地发展中的重要问题之一,兴文石海的形象塑造应以地貌景观特点为基础,按其塑造原理和技术要求,形成特色突出、符合市场需要的形象,以更好地吸引游客,促进旅游地的持续发展。依据RIS框架理念,兴文石海地质公园的旅游形象应从横向、纵向两维进行重塑。其旅游形象总体可以定位为"三绝喀斯特—僰苗风情绝"。为改变当前兴文石海旅游不景气的局面,应通过精心组织旅游线路,制定鲜明的旅游宣传口号,创新营销理念及方式,做好旅游形象的维护和拓展管理,把兴文石海优美的旅游形象根植于广大旅游者心里。 相似文献
442.
Chinese scholars Zhu xuewen put forward Tiankeng and defined it as a collapse feature which was diffe rent from the ordinary doline and developed in large-scale underground river channel.This paper analyzed the sasic conditions of Xiaoyanwan Tiankeng formation,such as sedimentary environment,climatic and hydrological conditions and so on;and deeply discussed the development course of Xiaoyanwan Tiankeng on this basis.The research result showed that Xiaoyanwan Tiankeng was completely accord with Tiankeng’ definition,and was a well-developed and especially big Tiankeng in the maturation stages. 相似文献
443.
Evidence for herbivorous cave bears (Ursus spelaeus) in Goyet Cave,Belgium: implications for palaeodietary reconstruction of fossil bears using amino acid δ15N approaches
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444.
Ung San Ahn Dong-Chan Koh Joonghyeok Heo Byong-Wook Cho Taehee Kim Byoung-Woo Yum 《水文研究》2021,35(8):e14316
Volcanic aquifers supply a substantial portion of water resources in many parts of the world, including islands, and their productivity depends strongly on volcanic stratigraphy, which exhibits considerable heterogeneity. We investigated water inflow to lava tube caves formed from numerous basaltic lava flows in the northeastern coastal area of Jeju Island after storm events and monitored relative inflow rates monthly over 1 year to characterize groundwater flow processes in the upper parts of volcanic aquifers, and to evaluate the applicability of the previous hydrogeological models proposed for the island. Considerable water inflow arose shortly after storms from exposed palaeosol layers on the walls of the caves. The monthly monitoring results showed that wall inflow associated with these palaeosol layers is substantial. In both cases, discharge from ceiling drips was much less and more temporally variable compared to wall inflow discharge. Water flowing into the caves was rapidly drained through the floor at all monitoring sites. The lateral extent of the palaeosol layers was identified using drill core logs near the cave and outcrops in the coastal area. Based on these results, we inferred that multiple perched aquifers are formed by low-permeability palaeosol layers between lava flows, which are connected by vertical flows at discontinuities in the palaeosol layer, eventually reaching the basal aquifer. This study revealed the water inflow processes observed in lava tube caves constrained by palaeosol layers, and established a hydrogeological conceptual model incorporating multiple perched aquifers in both coastal and mountainous areas associated with extensive palaeosol layers formed during volcanic hiatuses. This finding would help elucidate recharge, groundwater flow, and contaminant transport processes in many volcanic aquifers that are not adequately represented by the previous models, and contribute to better management of groundwater in those areas. 相似文献
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通过建立平面问题和空间问题两种计算模型,对黑河工程引水洞进口段高边坡稳定性进行了分析计算,并对比分析了稳定性评价结构,即空间计算模型比二维平面模型更符合实际,具有更高可靠性。 相似文献
447.
南京汤山猿人洞穴的形成及发展过程 总被引:1,自引:0,他引:1
从岩性、构造、洞穴特征等方面对汤山猿人洞穴的成因,发展过程进行了分析,揭示了洞穴形成的主要控制因素和多期复合成因的形成特点,并对洞内沉积物、南京人化石的形成及保存条件进行了初步的探讨。 相似文献
448.
试论我国地洼区喀斯特洞穴的发育与演化 总被引:3,自引:1,他引:3
本文论述了地洼区喀斯特洞穴的发育,成矿和演化规律。比较了地槽、地台和地洼三个大地构造单元区喀斯特洞穴之差异,揭示洞穴发育与大地构造之间的内在联系。根据地洼区洞穴发展,划分了五个成洞期。并对地洼区洞穴溶蚀堆积特征及矿床特征和分类做了讨论。又从地洼区地壳运动特点、古地貌演化、岩性条件以及古水文、古气候变迁,论述了地洼区洞穴时空发展不平衡的发育规律。最后指出了地洼区洞穴研究在科学和生产上的实际意义。 相似文献
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The Bahama Islands contain many abandoned dissolution caves at elevations between two and seven metres above current sea level. The development of dissolution caves in tropical carbonate islands is dependent on the position and nature of the freshwater lens. Lens position is controlled by sea level, which in stable carbonate platforms like the Bahamas is a function of glacioeustatic sea level still stands. Caves in the Bahamas that are currently subaerial must have developed during past higher sea levels. During the Late Quaternary, sea levels higher than present have been relatively short-lived, and that limits the amount of time that a freshwater lens could be situated at the elevation required for the cave formation. The Bahama Islands are low-lying landforms where only aeolian ridges extend to elevations higher than six metres above current sea level. Past high sea level events greatly reduced the exposed land area of the Bahama Islands, thus also limiting both the catchment for and size of freshwater lenses. Caves must be younger than the rock in which they are developed; most subaerial Bahamian caves are found in limestones that are less than 150000 years old. Development of large dissolution caves under these limitations of time and lens size requires a powerful dissolutional mechanism. The mixing of discharging freshwater with tide-pulsed incoming marine water under the flanks of emergent dune ridges may have produced the conditions necessary. Bahamian caves formed by this process are phreatic chambers with complex interconnections and blind tubes. Their presence demonstrates that significant dissolution can occur rapidly as a result of the mixing of fresh and marine waters beneath small carbonate islands. 相似文献