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131.
The study was carried out in the Altindere Valley, which is an area appropriate for tourism activities with natural, historical and cultural values through all four seasons, with Yazlik Village in the centre and including the surrounding sites Cosandere village, Altindere village, hamlets (The Hamlets) and plateau areas. In this study, the goal is to set forth the ecological-based tourism potential in line with the concepts of intactness; conservation-use balance; and sustainability at natural, historical and cultural sites through a determined planning approach. In this respect, assessments have been made on the study area on the basis of the ‘Ecological Evaluation Method’, which has been developed for urban areas. Through the determination of quotients, classification and quantitative assessment of unweighted values were found for natural and cultural elements that show percentage (%) dispersion at the area (slope, exposition, soil, forest, vegetation, existing areas use, historical and cultural structure). ‘Weighted values’ were calculated by multiplying the determined factor weights and the unweighted inside grid values of the factors. With the results of grid values obtained, 10.58% Very Good, 48.82% Good, 19.7% Average, 8.82% Weak, and 12.05% Very Weak, ‘Ecological Based Tourism Potential Areas According to Natural, Historical and Cultural Factors’ have been identified.  相似文献   
132.
In Ethiopia, not only farmers but also the public and private sector partners are still hesitant to invest in sustainable land management (SLM). This study focuses on the Central Rift Valley and explores the potential for co-investments in SLM, where public and private sector partners support farmers with material, capital, knowledge, etc. A survey revealed current bottlenecks for co-investments and requirements needed to collaboratively invest in SLM. It covered 165 public sector partners (micro-, meso- and macro-level institutions) and 42 private sector partners (banks, exporters and local traders). Results for the public sector show a gap between macro- and micro-/meso-level actors concerning co-investments in SLM. Macro-level institutions do not acknowledge the bottlenecks identified by micro- and meso-level institutions (e.g. lack of accountability, top-down approaches and lack of good leadership). Similarly, opinions on requirements for co-investments in SLM differ considerably, showing that bridging the institutional micro–macro gap is crucial to co-investments. Most factors are related to the wider governance context and to different perceptions among micro- and macro-level actors as to the critical pre-conditions to co-investment in SLM. Improving governance at all institutional levels, capacity building and enhancing a common understanding on barriers to SLM is required. Results for the private sector reveal that economic bottlenecks limit possibilities to co-invest in SLM, and that enabling policies in the public sphere are required to trigger private investments. Hence, the potential for co-investments in SLM is available in Ethiopia at micro- and meso-level and within the private sector, but profound commitment and fundamental policy changes at the macro-level are required to exploit this potential.  相似文献   
133.
多种干旱监测指标在黄河流域应用的比较   总被引:2,自引:0,他引:2  
利用黄河流域(包括青海、甘肃、宁夏、陕西、山西、河南、山东、内蒙古中西部)145个气象站1961—2010年月降水、气温、蒸发资料,为探讨目前国内常用的干旱监测指标的区域适用性,对比分析了几种干旱监测指数在黄河流域的应用情况,这些指数包括综合气象干旱指数(CI)、标准化降水指数(SPI)、帕默尔干旱指数(PDSI)、降水距平百分率(Pa)和K干旱指数(K)。结果表明,近50 a来,5种干旱指数中,K和CI对干旱的监测结果与实际情况吻合得较好,其次分别为SPI、Pa和PDSI。就CI和K而言,CI监测结果过于偏轻,对研究区内一些较重的干旱过程有遗漏;K对干旱程度的判断在某些区域(如青海、内蒙古中西部)过于偏重,对河南的夏、秋季干旱过程有遗漏。总体来说,在黄河流域,K指数监测的干旱结果与实况最为吻合,使用K的监测结果能最接近地反映实际的干旱状况,但以下情况除外,对于河南的夏、秋季,内蒙古的冬季,建议采用CI的监测结果;内蒙古的夏季,K和CI的监测结果均比较适宜,可结合使用;山东的冬季,K和Pa的监测结果可结合使用;山东的夏季,建议采用Pa的监测结果;而对于青海省,各个季节均建议使用SPI的监测结果。  相似文献   
134.
Surfactant enhanced aquifer remediation (SEAR) had previously been thought to require a capillary barrier below the contaminated zone to prevent the vertical migration of a microemulsion containing solubilized DNAPL. This paper shows the vertical migration of the dense microemulsion is described and predicted by the value of three dimensionless scaling groups. Embedded within these scaling groups are four design parameters. The value of these parameters can be manipulated in order to reduce the amount of vertical migration anticipated for a given remediation design. Plots have been constructed that illustrate the relationship between vertical migration and the value of the scaling groups; such plots can be used to predict vertical migration and to determine appropriate screen intervals of extraction wells to ensure full capture of the contaminants. This predictive capability has been verified in laboratory experiments. Predicted migration of the microemulsion agreed within about 2% of that observed. Development of the scaling groups is presented, remediation design implications are discussed, and laboratory verification is shown. Additional discussion of the laboratory work is given in a companion paper [Kostarelos, K., Pope, G.A., Rouse, B.A., Shook, G.M., 1998. A new concept: the use of neutrally-buoyant microemulsions for DNAPL remediation, J. Contam. Hydro., this edition].  相似文献   
135.
Gu HH  Qiu H  Tian T  Zhan SS  Deng TH  Chaney RL  Wang SZ  Tang YT  Morel JL  Qiu RL 《Chemosphere》2011,83(9):1234-1240
The mechanisms of stabilization by silicon-rich amendments of cadmium, zinc, copper and lead in a multi-metal contaminated acidic soil and the mitigation of metal accumulation in rice were investigated in this study. The results from a pot experiment indicated that the application of fly ash (20 and 40 g kg−1) and steel slag (3 and 6 g kg−1) increased soil pH from 4.0 to 5.0-6.4, decreased the phytoavailability of heavy metals by at least 60%, and further suppressed metal uptake by rice. Diffusion gradient in thin-film measurement showed the heavy metal diffusion fluxes from soil to solution decreased by greater than 84% after remediation. X-ray diffraction analysis indicated the mobile metals were mainly deposited as their silicates, phosphates and hydroxides in amended treatments. Moreover, it was found metal translocation from stem to leaf was dramatically restrained by adding amendments, which might be due to the increase of silicon concentration and co-precipitation with heavy metals in stem. Finally, a field experiment showed the trace element concentrations in polished rice treated with amendments complied with the food safety standards of China. These results demonstrated fly ash and steel slag could be effective in mitigating heavy metal accumulation in rice grown on multi-metal contaminated acidic soils.  相似文献   
136.
选取地处长江三峡河谷(湖北侧)的香溪长江公路大桥桥位区(郭家坝站)附近沿江3个气象站、6个自动站多年的风速、风向资料进行对比分析,讨论了峡谷对河谷内不同区域风速的不同影响。结果表明:在水平方向上,烟墩堡、郭家坝、庙堡等临江3站平均风速偏大、最大风速及极大风速出现大值频次偏高,狭管效应明显,其余非临江站则受局地地形遮蔽影响平均风速偏小、最大风速及极大风速出现大值频率偏低;在垂直方向上,150 m以下风速几乎没有明显的高度变化,实测风廓线指数几乎为0;桥位处阵风性强,阵风系数为1.56。  相似文献   
137.
汉江流域位于黄土高原南侧,属中国南北气候的过渡区域,其重矿物组成对区域沉积物物质来源与演化研究具有重要意义。运用强磁选、重液分离法等技术手段将汉江上游谷地黄土沉积物中的重矿物提取出来,在双目显微镜和偏光显微镜下测定其含量和特征。结果表明:(1)汉江黄土重矿物有22种,其中角闪石、磁铁矿、钛铁矿等矿物为优势矿物,占重矿物总量的60%以上;稳定矿物约占重矿物总量的47.95%,是汉江黄土最主要的矿物组合。(2)典型黄土和古土壤中重矿物种类相同,但含量有一定差异,马兰黄土(L1)相较古土壤(S0)不稳定矿物含量较高,稳定矿物含量较低;(3)汉江黄土与北侧黄土高原黄土相比重矿物种类相似,稳定性组合分布一致,但汉江黄土稳定性矿物含量较高,不稳定性矿物含量较低。这些特征说明:(1)汉江上游地区古土壤和黄土物质来源一致,古土壤S0在物质组成上继承了黄土,是黄土高度风化的产物;(2)汉江谷地黄土和黄土高原风成黄土两者的物源区一致,但汉江地区黄土受到较黄土高原地区强的风化成壤作用。  相似文献   
138.
周蜜  刘国东 《四川环境》2008,27(4):66-69
应用模糊综合评价的方法进行环境质量评价,能较传统方法提供更多信息。本文将模糊数学的方法首次应用于贡嘎山景区燕子沟景群区环境质量综合评价,选择线性模糊分布确定隶属函数,并采用标准加权法计算权重因子,以消除评价因子实测浓度的影响。分别采用两类算子模型进行评价,结果均表明评价区总体环境质量属于清洁型。  相似文献   
139.
利用时空替代原理,选取漓江流域红壤区退化生态系统恢复过程中具有代表性的草丛、灌丛、针叶林、针阔混交林、常绿阔叶林5个阶段作为演替序列,研究自然恢复过程中各演替阶段的植被结构动态和生物量变化。结果表明:随着草丛→灌丛→针叶林→针阔混交林→次生常绿阔叶林正向演替的进行,在未形成成熟而稳定的顶极群落之前,物种丰富度、物种多样性指数、植被生物量及生产力都呈增大趋势。退化群落通过自然恢复总是向着结构更复杂、更完善的方向发展。根据恢复过程中植被的动态变化规律,提出了一些人工促进植被恢复的建议.  相似文献   
140.
聚乙烯醇(PVA)存在下[HgI4]2-与罗丹明B(RHB)形成配合物[HgI4]2--RHB-PVA,在波长610nm处有最大吸收,表观摩尔吸光系数ε = 6.02×105 L/( mol·cm).结合巯基棉(SCF)对汞的选择性吸附,实现了水样中痕量汞的分离、富集与测定.标准样品富集前后测定的相对标准偏差RSD分别为4.25%和7.40%(n=6).本法应用于三峡水域长江和嘉陵江江段中总汞的测定,回收率为90.6%~111.4%,最低检出浓度0.040μg/L,对比国控点原子荧光光谱分析法监测汞数据,结果令人满意.  相似文献   
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