Transboundary biodiversity conservation of the Pha Taem Protected Forest Complex: A bioregional approach     

Yongyut Trisurat   《Applied geography (Sevenoaks, England)》2006,26(3-4):260-275

With the financial assistance from the International Tropical Timber Organization (ITTO), the Thailand's Royal Forest Department (RFD) has initiated a strategy for cooperation in transboundary biodiversity conservation with Cambodia and Laos. The Pha Taem Protected Forest Complex (PPFC) in northeastern region was chosen as a pilot project because of the increasing pressure on biodiversity from illegal trade in plants and wildlife across the tri-national borders. The PPFC covers five protected areas in Thailand and adjoins the Phouxeingthong National Biodiversity Conservation Area (NCBA) in Laos and the Cambodia's Protected Forest for Conservation of Genetic Resources of Plants and Wildlife. Two important outputs derived from the project phase I (2001–2004) were a long-term management plan in a framework of transboundary biodiversity conservation and initiative cooperation between the three countries. Cooperation is achieved at certain level and Laos is reluctant to nominate the Phouxeingthong NBCA for inclusion in the project's second phase. In addition, forest cover in buffer zone has been encroached for agricultural practices. The ecological management zones using bioregional approach was developed to provide a framework for transboundary biodiversity conservation in the adjoining protected forests and reducing the conflict of resource uses by local residents in the buffer zone.  相似文献   

Effects of dam operation and land use on stream channel morphology and riparian vegetation     

Eric Gordon  Ross K. Meentemeyer   《Geomorphology》2006,82(3-4):412-429

Dams are well known for influencing channel and vegetation dynamics downstream, but little work has focused on distinguishing effects of land use and channel responses to the impoundment. In this paper, we examined interacting effects of a dam and land use on downstream changes in channel morphology and riparian vegetation along an agricultural stream system in northern California. Measurements of planform channel morphology, vegetation area, and land use were mapped along multiple stream segments based on a chronological sequence of historical aerial photographs over a 34-yr period prior to operation of the dam in 1983 and over a 17-yr period after dam operation, and compared to a nearby, undammed reference stream. A two-factor analysis of covariance (ANCOVA) was used to examine the effect of the dam on changes in bankfull area, stream length, and riparian vegetation area while accounting for the effect of land use and distance downstream. The dammed stream's bankfull area contracted 94% after dam operation. Prior to dam operation, bankfull area decreased when land use area increased, but not after operation of the dam. Stream length varied 64% less after dam operation as a consequence of less frequent episodic channel migration and entrenchment. The area of riparian vegetation was decreasing during the pre-dam period, but then increased 72% after operation of the dam. Across time periods, decreases in the area of riparian vegetation were also associated with increases in land use area in both the dammed and reference stream. After operation of the dam, reduced peak discharges and sediment reduction likely lead to channel incision and constrained channel migration, which allowed vegetation to increase 50% on less accessible, abandoned banks. Rating curve and hydraulic exponent analyses based on stream gauge measurements corroborate statistical analyses of the mapped changes. In conclusion, we found that operation of the dam and land use patterns together influenced spatial and temporal changes in channel morphology and riparian vegetation. Use of a nearby undammed reference stream in conjunction with multivariable analysis of spatially and temporally replicated observations provided an effective framework for unraveling interacting effects of dams and land use activities on stream channel and vegetation dynamics.  相似文献   

东天山成矿带斑岩铜矿和其他类型矿床找矿勘查   总被引：4，自引：0，他引：4  

王庆明  赵仁夫  屈迅  程晓红  袁永江 《西北地质》2006,39(2):57-77

东天山地区横跨哈萨克斯坦与塔里木两大板块,是新疆最重要的有色金属、黑色金属和贵金属矿产地之一。经历了前震旦纪基底形成→震旦-泥盆纪古亚洲洋形成、消亡→石炭纪-早二叠世后碰撞造山→晚二叠世至今的陆内造山等阶段。主要成矿期为晚古生代早期(泥盆纪-二叠纪),成矿作用复杂、类型繁多。其中,北部形成岛弧斑岩型和火山岩型铜、钼、金矿,中部形成拉张火山岩型和矽卡岩型金、铜、镍、银矿,中南部形成前寒武纪结晶基底叠加改造的层控-热液型铅、锌、银矿,南部库鲁克塔格和北山地区形成拉张铜、镍、金矿。通过研究认为,东天山地区尤以铜、镍、钼矿产资源潜力很大,优选出28个矿找矿靶区。  相似文献   

高边坡岩体卸荷带划分的量化研究   总被引：7，自引：0，他引：7  

郑达  黄润秋 《水文地质工程地质》2006,33(5):9-12

边坡卸荷及其卸荷带是西南地区高边坡一种常见的现象，对岩石边坡稳定性及其它岩石工程问题有重要的影响。在分析目前卸荷带划分方法的基础上，根据卸荷带的形成机理及地质表现，提出了用裂隙率、张开裂隙率和“隙宽和”3个量化指标进行卸荷带的划分。结合实际工程，进行了大量的现场裂隙测量，分析结果表明，3个量化指标对卸荷带的强弱有较好的响应关系，作为卸荷带划分的量化指标具有较好的可操作性。进一步，结合卸荷带的地质特点，提出了所研究的具体工程其卸荷带划分的建议方案。  相似文献   

盐沼植被光谱特征的间接排序识别分析   总被引：1，自引：0，他引：1  

高占国  张利权 《国土资源遥感》2006,(2):51-56

运用ASD地物光谱仪,采用12个小型机载成像光谱仪(CASI)默认的植被波段组,以上海崇明东滩自然保护区的盐沼植物群落为对象,应用主成分分析法和相关分析研究了不同群落光谱特征与生态环境因子之间的关系。结果表明:运用PCA间接排序法能够识别盐沼植被中光滩、海三棱藨草群落、芦苇群落和互花米草群落等光谱特征;绝大多数盐沼植物的群落组成与所选波段的光谱特征之间有显著的相关关系;可见光和近红外波段数据可以分别识别低盖度的海三棱藨草群落和高盖度的互花米草和芦苇群落;对光谱反射率影响最大的生态环境因子是植物群落的高度和盖度,而高程和其它环境因子的影响次之。  相似文献   

Impact of hillslope vegetation restoration on gully erosion induced sediment yield   总被引：4，自引：0，他引：4  

CHEN Hao  CAI Qiangguo 《中国科学D辑(英文版)》2006,49(2):176-192

As a result of serious soil erosion on the Loess Pla-teau of China, about 1.6 billion tons of silt discharge into the downstream and 0.4 billion tons deposit on the riverbed every year, causing serious threat to the life and property of the local people on both banks of the lower Yellow River[1]. Since the 1950s, the Chinese government has initiated the work on soil and water conservation and environmental management on the Loess Plateau and formulated the guiding principle of hillslope and …  相似文献   

Ground-water surface-water interactions and long-term change in riverine riparian vegetation in the southwestern United States   总被引：1，自引：0，他引：1  

Robert H. Webb  Stanley A. Leake 《Journal of Hydrology》2006,320(3-4):302-323

Riverine riparian vegetation has changed throughout the southwestern United States, prompting concern about losses of habitat and biodiversity. Woody riparian vegetation grows in a variety of geomorphic settings ranging from bedrock-lined channels to perennial streams crossing deep alluvium and is dependent on interaction between ground-water and surface-water resources. Historically, few reaches in Arizona, southern Utah, or eastern California below 1530 m elevation had closed gallery forests of cottonwood and willow; instead, many alluvial reaches that now support riparian gallery forests once had marshy grasslands and most bedrock canyons were essentially barren. Repeat photography using more than 3000 historical images of rivers indicates that riparian vegetation has increased over much of the region. These increases appear to be related to several factors, notably the reduction in beaver populations by trappers in the 19th century, downcutting of arroyos that drained alluvial aquifers between 1880 and 1910, the frequent recurrence of winter floods during discrete periods of the 20th century, an increased growing season, and stable ground-water levels. Reductions in riparian vegetation result from agricultural clearing, excessive ground-water use, complete flow diversion, and impoundment of reservoirs. Elimination of riparian vegetation occurs either where high ground-water use lowers the water table below the rooting depth of riparian species, where base flow is completely diverted, or both. We illustrate regional changes using case histories of the San Pedro and Santa Cruz Rivers, which are adjacent watersheds in southern Arizona with long histories of water development and different trajectories of change in riparian vegetation.  相似文献   

巴州植被盖度的变化和状况评价     

邢文渊  肖继东  冯志敏  石玉  李聪 《沙漠与绿洲气象(新疆气象)》2006,29(3):22-24

利用2004和2005年4￣9月250×250m分辨率Modis资料,计算了巴州绿洲区域的植被盖度。巴州2005年植被盖度与2004年同期相比,低盖度植被面积变化较大,中、高盖度植被面积相对较稳定。在低盖度植被变化中,1级负变化比较明显,说明低植被覆盖地区生态环境脆弱,植被的生长不稳定,需要加大保护力度。  相似文献   

Structure, geometry and formation of brittle discontinuities in anisotropic crystalline rocks of the Central Gotthard Massif, Switzerland     

Christian Zangerl  Simon Loew  Erik Eberhardt 《Eclogae Geologicae Helvetiae》2006,99(2):271-290

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SLIP4EX – A Program for Routine Slope Stability Analysis to Include the Effects of Vegetation, Reinforcement and Hydrological Changes     

John R. Greenwood 《Geotechnical and Geological Engineering》2006,24(3):449-465

SLIP4EX is a straightforward computer program developed in connection with the EU funded ECOSLOPES project for routine stability analysis and the assessment of the contribution of vegetation to slope stability. The slope section is drawn up and dimensions and parameters are fed in to the Microsoft Excel based program for stability calculations and comparisons of Factors of Safety using different methods of analysis (Bishop, Janbu, Fellenius, Simple, Greenwood). The background and assumptions involved in the derivation of each of the methods is briefly described. The simplicity of the program enables the user to understand the nature of the analysis, explore the parameter assumptions made and compare the different methods of analysis. Soil reinforcement by geosynthetic layers or anchors, and vegetation effects of enhanced cohesion, changed water pressures, mass of vegetation, wind forces and root reinforcement forces are readily included in the analysis. The program is freely available on request from the Author.  相似文献