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101.
Traditional crop diversity and landraces in agricultural land use in Himalaya have great significant for long-term sustainability of agroecosystems, together with conservation and management of the surrounding landscape. Traditional crop varieties and races, which evolved over time through trial and error, not only provide basic nutritional requirements, but also food security. Loss of crop biodiversity has taken place over recent years, principally and inadvertently related to changing lifestyle, growing demand for cash crops in regional markets and burgeoning apple farming, whose acreage has increased with a concomitant decline in area under traditional crops. For sustainable landscape development, on-farm conservation of traditional crop diversity is urgently needed. An empirical study was done to understand the causes and consequences of declines in crop biodiversity and production, effect of apple farming on traditional crops and changing lifestyles of traditional people.  相似文献   
102.
This paper presents evidence that water restrictions in suburbanizing eastern Massachusetts towns are becoming more common, controlling for climate. We then assess the relationship between these suburban droughts and residential development. Focusing on the suburbs of Boston, seven towns independent of the Boston water supply system were selected to represent differing levels of sprawl-style growth. Water restrictions are becoming more frequent in all of the towns studied, and models demonstrate that restrictions are increasing in duration, independent of climate. Interviews suggest that residential development is playing a central role in this increasing sensitivity to suburban drought, though other factors are also important. Long-term planning and integration of land-use planning and water management emerged as two key paths for attenuating the impacts of development.  相似文献   
103.
李善评  马相如  苏保龄  姜艳艳  许洁  郭亮 《环境化学》2012,31(10):1611-1618
为改善普通石墨电极的电催化性能,将以溶胶-凝胶法合成的钙钛矿氧化物LaNiO3混合其它原料做成气体扩散电极,用于电化学降解活性艳红X-3B,以脱色率来考核催化剂的氧还原活性.采用星点设计-效应面曲线法对催化剂制备工艺进行了优化,得出最佳工艺参数为:柠檬酸含量为金属离子物质的量的1.54倍,pH值为9.94,焙烧温度为824.39℃.采用X射线衍射(XRD)、动电位扫描等检测分析方法对所制备的催化剂进行表征和分析.结果表明,制备的催化剂晶相纯净、晶型完整、衍射峰强度较高,是较完整的钙钛矿结构;相比于普通石墨电极,掺杂催化剂的气体扩散电极极化阻力高,氧还原性能良好,有利于有机物的降解.  相似文献   
104.
中亚地区气候生产潜力时空变化特征   总被引:9,自引:4,他引:5  
根据中亚5 国100 个气象站1901-2000 年月平均温度和降水资料,运用Miami、Thornthwaite Memorial 模型对中亚地区气候生产潜力进行了计算,用气候倾向率、Mann-Kendall 法、并结合ArcGIS 和SPSS 对其时空变化特征及驱动力进行了分析。结果表明:①中亚地区100 a 降水气候生产潜力(Yr)和蒸散气候生产潜力(Ye)均呈逐渐增加的趋势,温度气候生产潜力(Yt)趋势相反,Yr 和Ye 均发生了4 次突变,Yt 没有发生突变;②气候生产潜力区域差异明显,其中,Yt 呈从西南向东北减少的趋势,Yr 和Ye 变化比较复杂,大致具有东部大于西部的规律;③增温增湿的气候变化趋势有利于中亚气候生产潜力的提高,中亚气候生产潜力对增湿的响应更敏感。  相似文献   
105.
矿产资源开发生态环境保护与恢复治理是山水林田湖草生态保护修复的重要组成部分,也是区域/流域生态安全屏障建设的重要内容。本文面向长江保护修复的环境管理需求,梳理了第一批中央生态环境保护督察的长江经济带涉矿问题,探讨了矿产资源开发生态环境问题,提出了协同治理对策。结果表明:(1)长江经济带有8个省份发现涉矿生态环境问题,涉及石英砂矿、稀土矿、磷矿、锡矿、石灰石矿和石煤矿;有3个省份出现保护地采矿生态破坏严重问题,涉及自然保护区内违规设置的采矿权、探矿权和违法生产,以及国家级风景名胜区内以治理地质灾害之名开采磷矿。(2)11个省市中均发现了涉保护地违规管理问题,包括饮用水水源保护区、湖滨湿地、长江岸线和重要湿地、海洋保护区、风景名胜区。矿山生态环境协同治理对策包括:(1)科学制定矿山生态修复目标;(2)定期开展矿山生态保护修复成效评估;(3)提高矿山生态环境监管执行力。  相似文献   
106.
This paper analyzes institutional dynamics surrounding common-pool resources in postsocialist Central and Eastern Europe. It is conceived in close conjunction with the case studies by Penov, Schleyer, and Wasilewski and Krukowski (this issue). The purpose of this paper is to frame the individual case inquiries, compare their findings, and relate those to broader agrarian and environmental changes in the region.The case studies report a broad shift in resource governance from the previously dominant legal and administrative state hierarchies towards markets. In addition, state power has moved from central towards local authorities. The waning and decentralization of state power has caused the emergence of significant gaps between property legislation and rights-in-practice, which have been particularly stark in fragmented political systems. The discrepancy between legal texts and rights-in-practice leads to the exclusion of wider interests in favor of individual interests in the management of common-pool resources, resulting in resource deterioration and dwindling resource stocks. Thus, the comparative assessment suggests a tentative framework for understanding the effects of postsocialist transformations on governance of the commons and environmental change in Central and Eastern Europe. Its findings indicate an additional dimension to the diversity and distributive conflicts characterizing postsocialist privatization: the distribution of various rights to a resource among different actors. The findings also suggest the need for postsocialist states to take an active role in the governance of common-pool resources, particularly in the enforcement of legal rights. Note: This version was published online in June 2005 with the cover date of August 2004.  相似文献   
107.
The amount of water Bulgaria uses for irrigation sharply declined during the transition. Large sections of the existing irrigation systems were abandoned, and those still in use are hardly maintained. Crops such as wheat and barley have replaced more water-intensive crops, such as vegetables, rice, and maize. This problem has an impact on the future development of agriculture and the allocation of the countrys water resources. The central argument is that land fragmentation in the wake of decollectivization and restitution contributes to the irrigation systems abandonment. This article focuses on the institutional factors involved, but also considers additional factors that might have influenced the process. Further, it examines the causes driving these changes and analyzes their effect on irrigation. It is based on a review of the relevant legislation as well as fieldwork in 17 villages located in the Plovdiv region of Bulgaria. The article concludes that institutional settings, in addition to changes in large-scale market forces and the state enforcement mechanism, have contributed to the irrigation decline in Bulgaria.Published online Note: This version was published online in June 2005 with the cover date of August 2004.  相似文献   
108.
失地农民在征地过程中没有得到合理补偿和妥善安置,影响农村经济发展和社会稳定.妥善安置失地农民,解决失地农民的后顾之忧,除控制征地规模,对现行征地制度、利益分配机制进行改革外,为失地农民的长远生计设计更合理的制度性保障已迫在眉睫.  相似文献   
109.
光春云  郭星全 《灾害学》1997,12(4):49-53
通过对山西中部地区历史地震灾害资料的研究,得出该区地震高烈度区的分布特点,估算了历史震灾的震亡人数和经济损失,分析了历史地震引起的地质灾害,剖析了历史震灾的主要成因。  相似文献   
110.
The snowline in Himalaya is rising ceaselessly due to regional and global climatic change. Upward rising of snowline leads to the formation of moraines. Due to extreme environmental conditions the existing vegetation of the moraine is scanty, rigorous and possesses different ecological adaptation. Ablation zone of the glacier is covered by a thick pile of supra glacial moraines and is characterized by several serrac ice sections, melting into pools of supra glacial lakes because of subsidence and fast degenerating nature of the glacier. Anaphalis triplinervis was observed to have highest importance value in ablation moraine zone. Here the species richness increased remarkably partially due to the invasion of plant species from lower alpine belt. The fresh lateral moraine displays distressed soil features with mosaic type of vegetation. Gaultheria trichophylla is a dominant plant species here and is associated with other stunted and cold resisting species. The old lateral moraine is dominated by Potentilla atrosanguinea with co-dominant species Iris kemaonensis and Danthonia cachemyriana.  相似文献   
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