西昌市泸山地区典型火后泥石流特征与成因机制研究——以响水沟左岸3^#支沟为例     

铁永波  徐如阁  刘洪  王家柱  巴仁基  向安平  杨剑  欧阳渊  张玙  王宏 《中国地质调查》2020,7(3):82-88

2020年3月30日,四川省凉山州西昌市经久乡发生森林大火,山火燃烧后形成的山火灰和烧焦土体在强降雨作用下极易启动形成泥石流,给西昌市泸山、琼海景区生态环境及当地百姓生命财产安全带来潜在地质灾害风险。以西昌市安哈镇响水沟左岸3^#支沟为例,采用野外调查、无人机航拍、地球物理探测、现场及室内实验等手段,对2020年5月1日该沟发生的火后泥石流流体特征、动力学参数及成因机制等开展研究,系统分析了山火及降雨过程对该次火后泥石流形成的影响机制。该成果可为系统认识西昌泸山“3·30”山火地区火后泥石流的运动特征、物源规模、激发雨量及其发展趋势研判提供科学参考。  相似文献   

Differentiated payments for environmental services schemes: Amethodology proposal     

Carlos R.AGUILAR-GóMEZ  Sergio FRANCO-MAASS  Tizbe T.ARTEAGA-REYES 《山地科学学报》2018,15(8):1693-1710

Payment schemes for environmental services face serious budget constraints in Mexico. Payments are equally distributed among forest owners, and the governmental agencies that make payments to beneficiaries do not evaluate the amount of environmental services produced by forested areas. This lack of evaluation could lead to economic and environmental deficiencies that restrict the possible benefits of such programmes. In general, these programmes do not achieve their conservation objectives, and local beneficiaries are not involved in the design or application of these programmes. Similarly, the Payments for Hydrological Environmental Services (PHES) programme of the State of Mexico, Mexico, makes equal payments to beneficiaries of forested areas considering tree density. The objective of the present work was to create a methodology for determining differentiated payments schemes for hydrological environmental services, prioritising areas that contribute the most to groundwater recharge and promote the participation of society. In the Nevado de Toluca Natural Protected Area, the environmental criteria of forest type, tree density and aquifer overexploitation as well as social participation were considered in a multi-criteria analysis implemented in a Geographic Information System. A methodology was developed to determine differentiated payments based on specific forest characteristics that influence the potential capacity of forests to recharge groundwater reserves in addition to the level of social participation. In particular, social participation is key as it could ensure the viability of PHES programmes as conservation alternatives in forested areas with high groundwater recharge potential.  相似文献   

卡里马塔海峡水体交换的季节变化   总被引：2，自引：0，他引：2  

王研  徐腾飞  李淑江  Susanto R. Dwi  Agustiadi Teguh  Trenggono Mukti  谭伟  魏泽勋 《海洋学报(英文版)》2019,38(4):47-57

Four trawl-resistant bottom mounts, with acoustic Doppler current profilers(ADCPs) embedded, were deployed in the Karimata Strait from November 2008 to June 2015 as part of the South China Sea-Indonesian Seas Transport/Exchange and Impact on Seasonal Fish Migration(SITE) Program, to estimate the volume and property transport between the South China Sea and Indonesian seas via the strait. The observed current data reveal that the volume transport through the Karimata Strait exhibits significant seasonal variation. The winteraveraged(from December to February) transport is –1.99 Sv(1 Sv=1×10~6 m~3/s), while in the boreal summer(from June to August), the average transport is 0.69 Sv. Moreover, the average transport from January 2009 to December2014 is –0.74 Sv(the positive/negative value indicates northward/southward transport). May and September are the transition period. In May, the currents in the Karimata Strait turn northward, consistent with the local monsoon. In September, the southeasterly trade wind is still present over the strait, driving surface water northward, whereas the bottom flow reverses direction, possibly because of the pressure gradient across the strait from north to south.  相似文献   

Morphological and molecular evidence supports the first occurrence of two fishes,Siganus sutor(Valenciennes, 1835)and Seriolina nigrofasciata(Rüppell, 1829)(Actinopterygii:Perciformes), from marine waters of Odisha coast,Bay of Bengal,India     

Barik Tapan K.  Swain Surya N.  Sahu Bijayalaxmi  Tripathy Bibarani  Acharya Usha R. 《海洋学报(英文版)》2020,39(6):26-35

Marine ecosystems provide a wide variety of diverse habitats that frequently promote migration and ecological adaptation. The extent to which the geographic distribution of marine organism has reshaped by human activities remains underappreciated. The limitations intrinsic to morphology-based identification systems have engendered an urgent need for reliable genetic methods that enable the unequivocal recognition of fish species,particularly those that are prone to overexploitation and/or market substitution. In the present study, however, an attempt has been taken to identify two locally adapted fish species, Siganus sutor(Valenciennes, 1835) and Seriolina nigrofasciata(Rüppell, 1829) of order Perciformes, which happens to be the first record in Odisha coast,Bay of Bengal. The diagnostic characteristics of Siganus sutor are: dorsal fin XIII-10, anal fin VII-9, pectoral fin 15,pelvic fin II-3, while that of Seriolina nigrofasciata dorsal fin VI-I-35, anal fin I-17, pectoral fin 16, pelvic fin 5. All COI barcodes generated in this study were matched with reference sequences of expected species, according to morphological identification. Bayesian and likelihood phylogenetic trees were drawn based on DNA barcodes and all the specimens clustered in agreement with their taxonomic classification at the species level. The phylogeographic studies based on haplotype network and migration rates suggest that both the species were not panmitic and the high-frequency population distribution indicates successful migration. The result of this study provides an important validation of the use of DNA barcode sequences for monitoring species diversity and changes within a complex marine ecosystem.  相似文献   

Mantle-earthquake geothermometry of rejuvenated Proterozoic lithosphere, western Saudi Arabia     

Alexander R. Blanchette  Simon L. Klemperer  Walter D. Mooney  Hani M. Zahran 《《地质学报》英文版》2018,92(Z1):102-103

  相似文献   

Geochemistry and Petrogenesis of Intracontinental Basaltic Volcanism on the Northwest Arabian Plate,Gaziantep Basin,Southeast Anatolia,Turkey     

Sevcan KüRüM  Abdurrahman B?LüCü  Melek URAL 《《地质学报》英文版》2018,92(2):519-535

Volcanism along the northwest boundary of the Arabian Plate found in the Gaziantep Basin, southeast Turkey, is of Miocene age and is of alkaline and calc-alkaline basic composition. The rare earth element data for both compositional series indicates spinel–peridotite source areas. The rare earth and trace elements of the alkaline lavas originate from a highly primitive and slightly contaminated asthenospheric mantle; those of the calc-alkaline lavas originate from a highly heterogeneous, asthenospheric, and lithospheric mantle source. Partial melting and magmatic differentiation processes played a role in the formation of the petrological features of these volcanics. These rocks form two groups on the basis of their ~(87) Sr/~(86) Sr and ~(143) Nd/~(144) Nd isotopic compositions in addition to their classifications based on their chemical compositions(alkaline and calc-alkaline). These isotopic differences indicate a dissimilar parental magma. Therefore, high Nd isotope samples imply a previously formed and highly primitive mantle whereas low Nd isotope samples may indicate comparable partial melting of an enriched heterogeneous shallow mantle. Other isotopic changes that do not conform to the chemical features of these lavas are partly related to the various tectonic events of the region, such as the Dead Sea Fault System and the Bitlis Suture Zone.  相似文献   

基于MACD指标的渐变型滑坡临滑预报模型研究          下载免费PDF全文

王家柱  巴仁基  葛华  铁永波  高延超 《水文地质工程地质》2022,49(6):133-140

滑坡的临滑预警预报研究一直以来都是热点也是难点。速度倒数模型是目前广泛使用的临滑预报模型,选择恰当的拟合曲线起始点将提高预报模型的精度。利用经济学上非常成熟的平滑异同平均线指标（MACD）快速寻找速度倒数模型拟合曲线的起始点,也就是滑坡临滑加速变形阶段开始加速（Onset of Acceleration,OOA）点,并以云南省会泽县的区布嘎滑坡为例,使用该指标对滑坡体进行临滑预报,并对该模型准确性进行了评估。结果表明:当变形速度的MACD值在?1~1的区间时,代表滑坡变形速度虽然有所增加,但变形趋势并未整体改变;当MACD值超过?1~1的区间,代表滑坡变形趋势整体发生改变,可将此阶段短期平均线上穿长期平均线的点（同时也是MACD值由负转正的点）,作为滑坡OOA点。利用MACD指标能够快速有效的寻找拟合曲线起始点,利用指数平滑函数（ESF）处理的监测数据,拟合曲线的确定系数最高,误差率最低,误差率低于2%,模型预测结果随着数据的更新,将不断逼近真实结果,具有较高的准确率。  相似文献   

西南山区典型地质灾害链成灾模式研究     

铁永波  张宪政  龚凌枫  高延超  白永健  徐伟  巴仁基  李宗亮  葛华 《地质力学学报》2022,28(6):1071-1080

西南山区是中国地质灾害链最发育、成灾最严重的地区。为深入认识区域地质灾害链成灾模式, 文章在系统收集西南山区历史上19次典型重大灾害事件基础上, 分析了地质灾害链的主控因素及成灾特征, 总结了滑坡型、崩塌型、泥石流型3类灾害链分类模式及5种链式成灾过程, 并选择每一类中的典型地质灾害链成灾过程进行了剖析, 在此基础上对地质灾害链成灾机理研究、数据库构建、技术标准体系建设及跨界流域链式灾害风险防控机制构建等进行了展望, 提出了地质灾害链防范建议, 旨在为区域地质灾害防灾减灾规划、重大工程与城镇建设安全提供参考。   相似文献   

Timing of Proterozoic magmatism in the Sunsas belt,Bolivian Precambrian Shield,SW Amazonian Craton     

Ingrid M.Nedel  Reinhardt A.Fuck  Amarildo S.Ruiz  Gerardo R.Matos-Salinas  Alanielson da C.D.Ferreira 《地学前缘(英文版)》2021,12(6):277-293

We present new U-Pb zircon and monazite ages from the Sunsas belt granitic magmatism in Bolivia,SW Amazonian Craton.The geochronological results revealed four major magmatic events recorded along the Sunsas belt domains.The older igneous event formed a granitic basement coeval to the Rio Apa Terrane(1.95-1.85 Ga)in the southern domain.The second magmatic episode is represented by 1.68 Ga granites associated to the Paraguá Terrane(1.69-1.66 Ga)in the northern domain.The 1.37-1.34 Ga granites related to San Ignacio orogeny represent the third and more pervasive magmatic event,recorded throughout the Sunsas belt.Moreover,magmatic ages of～1.42 Ga revealed that the granitogenesis asso-ciated to the Santa Helena orogeny also affected the Sunsas belt,indicating that it was not restricted to the Jauru Terrane.Lastly,the 1.10-1.04 Ga youngest magmatism was developed during the Sunsas oro-geny and represents the final magmatic evolution related to Rodinia assembly.Likewise,the 1.95-1.85 and 1.68 Ga inherited zircon cores obtained in the～1.3 Ga and 1.0 Ga granite samples suggest strong par-tial melting of the Paleoproterozoic sources.The 1079±14 Ma and 1018±6 Ma monazite crystallization ages can be correlated to the collisional tectono-thermal event of the Sunsas orogeny,associated to reac-tions of medium-to high-grade metamorphism.Thus,the Sunsas belt was built by heterogeneous 1.95-1.85 Ga and 1.68 Ga crustal fragments that were reworked at 1.37-1.34 Ga and 1.10-1.04 Ga related to orogenic collages.Furthermore,the 1.01 Ga monazite age suggests that granites previously dated by zir-con can bear evidence of a younger thermal history.Therefore,the geochronological evolution of the Sunsas belt may have been more complex than previously thought.  相似文献   

Mineralogical and Fluid Characteristics of the Fluorite-rich Monakoff and E1 Cu-Au Deposits, Cloncurry Region, Queensland, Australia: Implications for Regional F-Ba-rich IOCG Mineralization     

David A. HOLWELL  Megan R. WILLIAMS  Richard M. LILLY  Iain MCDONALD 《《地质学报》英文版》2014,88(Z2):350-351

Please?refer?to?the?attachment(s)?for?more?details.  相似文献