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981.
This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moisture is closely correlated to groundwater depths. Soil volumetric water increased rapidly when close to water sources and finally stabilized in a saturated state. The soil moisture trend of CK(control) increased gradually at 0–50 cm of soil depth then decreased to 4% below 50 cm soil depth. C. microphylla can adapt to different soil environments by changes in ecological and physiological characteristics. By comparing the ecological characteristics of C. microphylla seedlings at various water tables, we found that a shallow water table of 40 cm depth inhibited seedling growth because of weak ecological characteristics. A groundwater depth of 120 cm was more advantageous for plant height and canopy growth of C. microphylla seedlings. During the first two years, the most suitable water depth for root biomass was 120 cm, and 180 cm for root length. The growth of vertical roots is positively correlated with groundwater depth, and root thickness is the determinate factor for root biomass while the fine root is the determinate factor for root length. A thick root would grow much more in a natural drought environment while access to ground water promotes the growth of fine roots. 相似文献
982.
Growth and physiological responses of wheat to sand burial were studied in Horqin Sandy Land, to determine the impact on productivity and survival as well as antioxidant enzymes responses. This study c... 相似文献
983.
《Geoforum》2015
Through a series of case studies, this paper discusses the three stakeholders in land development for housing in Dhaka city: the public and private sectors, and NGOs. In a scenario in which urban planning merely serves to the fulfil formal requirements and benefit certain groups, in which the public sector is an accomplice to the private sector, and where NGOs have their own private interests; urban planning in the public interest is interlocked with private interests. NGOs are important tertiary stakeholders in planning and service provision. While they vary in their types and objectives, environment NGOs in particular often find themselves in an antagonistic position concerning public and private land development. However, the interventions to the public and private sectors placed by the NGOs can provide a platform for future negotiation and participation in policy formulation. 相似文献
984.
针对城市及周边区域建造区和自然地表交织分布的特点,探讨了利用归一化植被指数(NDVI)和归一化建造指数(NDBI)构造趋势面的地表温度(LST)降尺度方法,以北京市市区及周边较平坦区域为例实现了LST自960 m向120 m的降尺度转换。分析了LST空间分布特征及NDVI、NDBI对地物的指示性特征;以北京市四至六环为界分析NDVI、NDBI趋势面对地表温度的拟合程度及各自的适用区域;在120 m、240 m、480 m和960 m 4个尺度上评价了NDVI、NDBI和NDVI+NDBI趋势面对LST的拟合程度和趋势面转换函数的尺度效应;对NDVI、NDBI和NDVI NDBI等3种方法的降尺度结果分覆盖类型、分区域对比评价。实验结果表明结合两种光谱指数的NDVI NDBI方法降尺度转换精度有所改善,改善程度取决于地表覆盖类型组合。 相似文献
985.
第二次全国土地调查作为一项重大的国情国力调查,现已全面展开。对于各作业队伍而言,要在短时间内完成这项较为复杂的系统工程,有着诸多难点,而外业调查又是重中之重,也是后续工作得以顺利开展的基石,为此笔者对外业调查的前、后期工作做了简要阐述。 相似文献
986.
朱剑 《测绘与空间地理信息》2013,36(6):51-54
将互联网在线交易技术、地理信息系统技术和信息安全技术整合应用到国土资源的权属交易领域,推进国有资源交易活动的公平、公正、公开原则,营造良好的市场环境已经成为推动国土资源市场建设的趋势,也成为地理信息系统技术向公众应用领域延伸的一个重要方向。文章以广西壮族自治区国土资源网上交易系统的建设为背景,研究国土资源网上交易系统开发的目标、功能以及关键技术,有效地解决了传统土地、矿业权交易受地域、时间的限制和私下串标、围标等问题,为省级国土资源部门开展网上交易系统建设提供了解决方案和思路。 相似文献
987.
Stuart N. Lane 《地球表面变化过程与地形》2013,38(1):106-110
This Commentary draws together recently published work relating to the relationship between climate change and geomorphology to address the surprising observation that geomorphic work seems to have had little impact upon the work of the Intergovernmental Panel for Climate Change. However, recent papers show that methodological innovation has allowed geomorphological reconstruction over timescales highly relevant to late 20th century and 21st century climate change. In turn, these and other developments are allowing links to be made between climatic variability and geomorphology, to begin to predict ‘geomorphic futures’ and also to appreciate the role that geomorphic processes play in the flux of carbon and the carbon cycle. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
988.
989.
990.
土地征收工作对保障建设、保护耕地、保障被征地农民的利益具有重要作用。随着经济社会发展,土地征收的制度设计出现了一些问题,该文通过探讨分析土地征收在制度层面的缺陷,提出了征地制度改革的一些对策建议。 相似文献