Overview of Ecological Restoration Technologies and Evaluation Systems     

ZHEN Lin  YAN Huimin  HU Yunfeng  XUE Zhichao  XIAO Yu  XIE Gaodi  MA Jianxia  WANG Jijun 《资源与生态学报(英文版)》2017,8(4):315-324

Ecological degradation is a global problem, and ecological restoration technologies have played and will continue to play an important role in its mitigation. However, the lack of systematic research and evaluations of ecological technologies has thus far affected their effective application in vulnerable ecological regions. This study therefore provides an overview of the main technologies for remediating soil and water erosion, desertification, and rock desertification in China and throughout the world. It addresses key issues and recommends approaches for evaluating ecological restoration technologies. Restoration technology emerged as early as 1800. Over the years such technology has changed from single objective applications to multi-purpose, multi-objective applications employing strategies that take into account ecosystem rehabilitation and integrated ecological and socioeconomic development. Along with this technological evolution, different countries have taken pertinent actions as part of their restoration initiatives. However, key issues remain, including the lack of location-specific restoration technologies and a methodological strategy to assess and prioritize existing technologies. This study proposes a four-level analytical hierarchical framework in conjunction with an indicator system that highlights the establishment and adaptation of associative indicators, while also recommending a three-phase evaluation method (TheMert), targeting TheMert to qualitative (quick and extensive) and quantitative (detailed) evaluations in order to select the most appropriate restoration technologies available. This study can also be used as a basis for understanding the evaluation and prioritization of restoration technologies, while increasing the awareness of decision makers and the public on the role of technology in restoring degraded ecosystems.  相似文献   

邯郸娄里金矿床金元素赋存状态及其找矿意义     

赵书梅  李玉成  曹铌涛 《地质与资源》2017,26(6):552

对娄里金矿中金元素的赋存状态、产出特征进行的分析研究显示,娄里金矿床中金主要以细粒（5~20 μm）自然金为主分散浸染于蚀变较强的凝灰岩和粗面岩裂隙中.金在石英脉和褐铁矿中赋存比例仅为12.5%,远低于片理发育的蚀变凝灰岩.因此娄里金矿的找矿标志有其特殊性.结合野外已知金矿体周边岩性分布特征,提出在岩石片理化及层间裂隙发育处,且出现含霓辉石细粒正长斑岩地段应是下一步找矿重点区域.  相似文献   

Establishing a predictive performance indicator for real‐time hybrid simulation          下载免费PDF全文

Amin Maghareh  Shirley J. Dyke  Arun Prakash  Gregory B. Bunting 《地震工程与结构动力学》2014,43(15):2299-2318

Real‐time hybrid simulation (RTHS) is increasingly being recognized as a powerful cyber‐physical technique that offers the opportunity for system evaluation of civil structures subject to extreme dynamic loading. Advances in this field are enabling researchers to evaluate new structural components/systems in cost‐effective and efficient ways, under more realistic conditions. For RTHS, performance metric clearly needs to be developed to predict and evaluate the accuracy of various partitioning choices while incorporating the dynamics of the transfer system, and computational/communication delays. In addition, because of the dynamics of the transfer system, communication delays, and computation delays, the RTHS equilibrium force at the interface between numerical and physical substructures is subject to phase discrepancy. Thus, the transfer system dynamics must be accommodated by appropriate actuator controllers. In this paper, a new performance indicator, predictive performance indicator (PPI), is proposed to assess the sensitivity of an RTHS configuration to any phase discrepancy resulting from transfer system dynamics and computational/communication delays. The predictive performance indicator provides a structural engineer with two sets of information as follows: (i) in the absence of a reference response, what is the level of fidelity of the RTHS response? and (ii) if needed, what partitioning adjustments can be made to effectively enhance the fidelity of the response? Moreover, along with the RTHS stability switch criterion, this performance metric may be used as an acceptance criteria for conducting single‐degree‐of‐freedom RTHS. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Effects of fabric anisotropy on elastic shear modulus of granular soils   总被引：1，自引：1，他引：0  

Bo Li  Xiangwu Zeng 《地震工程与工程振动(英文版)》2014,13(2):269-278

The fabric anisotropy of a granular soil deposit can strongly infl uence its engineering properties and behavior. This paper presents the results of a novel experimental study designed to examine the effects of fabric anisotropy on smallstrain stiffness and its evolution with loading on the elastic shear modulus of granular materials under a K0 condition. Two primary categories of fabric anisotropy, i.e., deposition-induced and particle shape-induced, are investigated. Toyoura sand deposits with relative densities of 40% and 80% were prepared using deposition angles oriented at 0o and 90o. Piezoelectric transducers were used to obtain the elastic shear modulus in the vertical and horizontal directions(Gvh and Ghh). The measurements indicate distinct differences in the values of G with respect to the different deposition angles. Particle shapeinduced fabric anisotropy was examined using four selected sands. It was concluded that sphericity is a controlling factor dominating the small-strain stiffness of granular materials. The degree of fabric anisotropy proves to be a good indicatorin the characterization of stress-induced fabric evolution during loading and unloading stress cycles. The experimental data were used to calibrate an existing micromechanical model, which was able to represent the behavior of the granular material and the degree of fabric anisotropy reasonably well.  相似文献   

基于指示和普通克里金的不连续地层厚度估计方法     

李晓军  张振远 《岩土力学》2014,35(10):2881-2887

因为克里金插值方法考虑了样本的空间统计特征而被广泛应用于地层建模。但对于地层尖灭、缺失等不连续地层情况,常用的克里金方法（如普通克里金方法）通常给出较为平滑的地层厚度估计结果,在地层分布边缘的局部范围内与实际情况相差较大。针对不连续地层,提出一种采用指示克里金和普通克里金相结合的地层厚度估计方法。该方法首先采用指示克里金方法估计地层分布范围,然后采用普通克里金方法估计分布范围内的地层厚度,并根据估计标准差来评价地层厚度的不确定性。将提出的方法应用于上海长江隧道的地层建模,通过交叉验证,证明了该方法在地层分布边缘的局部范围内能明显改善地厚度估计结果,标准差降低了15%～18%,得到了比普通克里金和线性插值方法更接近真实情况的地层厚度估计值。  相似文献   

辽宁本溪大台沟铁矿地质特征及找矿标志   总被引：1，自引：0，他引：1  

张璟  邵军  鲍庆中  王宏博  周永恒 《地质与资源》2014,23(4):343-351

辽宁本溪大台沟铁矿为鞍山-本溪铁矿成矿带内发现的首个位于标高-1000 m以下的特大型“鞍山式”铁矿床,含矿岩系为近直立展布的鞍山群樱桃园岩组,包含其内的铁矿体为隐伏的厚板状陡倾斜矿体,矿体埋深1100~1200 m,控制矿体延长2000 m.矿体自上向下可划分3种自然矿石类型,分别为赤铁矿石、赤铁磁铁复合矿石及磁铁矿石.大台沟铁矿床属典型“鞍山式”铁矿床,矿物成分较简单,含铁矿物以磁铁矿和赤铁矿（镜铁矿）为主;矿石结构类型有镶嵌粒状变晶结构、鳞片粒状变晶结构、柱状粒状变晶结构等;矿石构造类型以条带状为主.铁矿石TFe品位平均为29.34%;mFe品位平均为14.63%;矿石中其他元素含量除SiO₂较高外,均甚微,SiO₂平均含量46.08%.笔者在阐述大台沟铁矿地质特征基础上,总结出大台沟铁矿找矿标志,对于区域内潜在的“大台沟式”（埋藏较深、存在高大磁异常）铁矿床的找寻具有一定借鉴意义.  相似文献   

重特大自然灾害综合评估     

史培军  袁艺 《地理科学进展》2014,33(9):1145-1151

基于作者近年对多次重特大自然灾害综合评估的实践,就重特大自然灾害的影响范围、破坏程度、直接经济损失的综合评估予以阐述。重特大自然灾害快速评估结果是制定应急救援、转移安置方案和恢复重建规划的科学依据。综合现场调查、遥感监测、模型评估和地方上报数据于一体,是提高重特大自然灾害评估结果准确度和精度的关键。制定科学合理的重特大自然灾害评估指标体系,仍然需要在大量综合评估的实践中完善。  相似文献   

某污染场地土壤苯并(a)芘含量的三维估值及不确定性分析   总被引：3，自引：0，他引：3  

陶欢  廖晓勇  阎秀兰  赵丹  马栋  李鹏 《地理研究》2014,33(10):1857-1865

污染场地修复前的准确评估是开展场地修复行动的基础和前提。建立了一套评估污染场地中污染土方量的三维插值方法,采用该方法模拟了某污染场地土壤苯并(a)芘(BaP)含量的空间分布并分析其不确定性。结果表明：场地地下环境中BaP含量数据服从对数正态分布,土壤中污染严重区域分别位于研究区的西南部和北部。通过普通克里格插值得到的BaP浓度超过0.4 mg·kg^-1的污染羽体积为14134 m³,对应的累积概率为0.585。依据给定变差范围值计算,得出现有收集数据对整个场地的描述程度为65%。基于该三维插值方法能准确地反映场地污染物空间分布特征,其不确定性分析可为补充采样布点及精准评估提供参考。  相似文献   

辽宁本溪小阳沟铁矿深部找矿成果及其意义     

张亚楠 《地质与资源》2014,23(3):251-255

通过钻探等手段发现小阳沟铁矿为埋藏较深、厚度较大、层位较多、倾斜中等的层状矿体,探获（332）+（333）磁铁矿及低品位矿量1.4×10⁸ t.矿体埋深标高-100~+838 m,平均垂厚86 m,呈单斜层状产出,厚度变化稳定,矿化连续,品位均匀.矿石成分简单,矿石矿物主要为磁铁矿,脉石矿物主要是石英、长石.矿物粒度呈中细粒-微细粒不均匀嵌布.矿石结构为粒状变晶结构、氧化交代结构.矿石构造为细条带状构造、柔皱状构造或角砾状构造.矿床类型为火山沉积变质型铁矿.根据研究分析,总结出深部找矿标志.  相似文献   

黑龙江省萝北县杜家河金矿地质特征与找矿标志     

张朋  邢丽萍  聂喜涛  彭明生  崔培龙 《地质与资源》2014,23(5):424-428

杜家河金矿产于中元古界黑龙江群联营岩组中,并受背形构造控制.在详细的野外地质调查基础上,系统研究了矿床的地质特征、矿石结构构造、金矿物学特征等.研究表明,矿石具有结晶结构、自形粒状结构,致密块状构造、浸染状构造,围岩蚀变有绢云母化、硅化、黄铁矿化等,矿床成因类型属于与韧性剪切带有关的金矿,并指出矿床在地层、构造、蚀变等找矿标志,为该地区找矿提供理论基础.  相似文献