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31.
Estimating tropical biomass is critical for establishment of conservation inventories and landscape monitoring. However, monitoring biomass in a complex and dynamic environment using traditional methods is challenging. Recently, biomass estimates based on remotely sensed data and ecological variables have shown great potential. The present study explored the utility of remotely sensed data and topo-edaphic factors to improve biomass estimation in the Eastern Arc Mountains of Tanzania. Twenty-nine vegetation indices were calculated from RapidEye data, while topo-edaphic factors were taken from field measurements. Results showed that using topo-edaphic variables or vegetation indices, biomass could be predicted with an R2 of 0.4. A combination of topo-edaphic variables and vegetation indices improved the prediction accuracy to an R2 of 0.6. Results further showed a decrease in biomass estimates from 1162 ton ha?1 in 1980 to 285.38 ton ha?1 in 2012. This study demonstrates the value of combining remotely sensed data with topo-edaphic variables in biomass estimation. 相似文献
32.
The application of ICTs makes structural change of the development and effective utilization of airspace. Next generation air transportation system (NextGen) includes new automation concepts with automated information to support the traffic control decision-making. As a result, in the field of academia and industry, air traffic controllers integrate information automatically while making decisions to change the previous manually integrated and decided pattern. The safety ability of airspace is reduced and airspace system is endangered under risky weather conditions of airspace. So there is an urgent demand for new information and communication technologies. The paper is an overview of the information constitution and support of NextGen and provides the study of the development of technique of airspace collaborative decision-makings to confirm the new features based on ICTs. It contains basic application-the input of data and output of the routes of airspace management and collaborative decision-making, and general application-the choose of probability nets of avoiding risky weather, and special application-the affection in the management of the air routes, which are made up of position and direction. The research shows the accurate schedule characteristics of airspace management and collaborative decision-making based on ICTs, which made the space accurate by time accurate. Second, the visualization of airspace management and collaborative decision-making based on ICTs made the maps of flight path under mobile data quickly generated. This could make the fully development and utilization of national airspace, ensure safety, and reduce air traffic controllers’ workload and the costs in delaying and operating in risky weather. 相似文献
33.
《Marine Policy》2016
The scarcity of data on fish catches difficult management of small-scale fisheries in developing countries. This study applies fishers’ knowledge to investigate temporal changes in the amount (biomass) and composition (major ecological categories) of fishing resources exploited by small-scale coastal fisheries in the southeastern Brazilian coast. Four hypotheses were investigated: (1) The amount of fish caught reported by fishers would decrease over time. (2) Older fishers would report higher fish catches than younger fishers. (3) Recent interviews would mention large-sized predators less often. (4) Recent interviews would mention less high valued fishing resources. Interviews with 421 fishers in 36 communities in the southeastern Brazilian coast were analyzed, covering a time span of 14 years, from 1995 to 2009. The hypothesis 1 was confirmed, 3 was partially confirmed, while 2 and 4 were not confirmed. Fishers’ age was unrelated to all variables. The results from fishers’ interviews indicated the temporal trends of: (1) a decrease in the biomass of fish caught; (2) an increase in the occurrence of smaller fish and invertebrates in the catch; (3) an increase of high value fishing resources; and (4) maintenance of large predators. The first two indicators suggest excessive fishing, but the later indicators (3 and 4) suggest that the socioecological system of the southeastern Brazilian coast had not yet undergone major ecological shifts. 相似文献
34.
The development of groundwater favourability map is an effective tool for the sustainability management of groundwater resources in typical agricultural regions, such as southern Perak Province, Malaysia. Assessing the potentiality and pollution vulnerability of groundwater is a fundamental phase of favourability mapping. A geographic information system (GIS)-based Boolean operator of a spatial analyst module was applied to combine a groundwater potentiality map (GPM) model and a groundwater vulnerability to pollution index (GVPI) map, thereby establishing the favourable zones for drinking water exploration in the investigated area. The area GPM model was evaluated by applying a GIS-based Dempster–Shafer–evidential belief function model. In the evaluation, six geoelectrically determined groundwater potential conditioning factors (i.e. overburden resistivity, overburden thickness, aquifer resistivity, aquifer thickness, aquifer transmissivity and hydraulic conductivity) were synthesized by employing the probability-based algorithms of the model. The generated thematic maps of the seven hydrogeological parameters of the DRASTIC model were considered as pollution potential conditioning factors and were analysed with the developed ordered weighted average–DRASTIC index model algorithms to construct the GVPI map. Approximately 88.8 and 85.71% prediction accuracies for the Groundwater Potentiality and GVPI maps were established using the reacting operating characteristic curve method and water quality status–vulnerability zone relationship scheme, respectively. Finally, the area groundwater favourability map (GFM) model was produced by applying a GIS-based Boolean operator on the Groundwater Potentiality and GVPI maps. The GFM model reveals three distinct zones: ‘not suitable’, ‘less suitable’ and ‘very suitable’ zones. The area analysis of the GFM model indicates that more than 50% of the study area is covered by the ‘very suitable’ zones. Results produce a suitability map that can be used by local authorities for the exploitation and management of drinking water in the area. The study findings can also be applied as a tool to help increase public awareness of groundwater issues in developing countries. 相似文献
35.
黄河流域人地耦合与可持续人居环境 总被引:4,自引:2,他引:2
黄河流域是中国人地矛盾最为紧张的区域之一,承担着生态安全建设和经济社会发展的重任。自古以来人类和黄河始终处于共同进化的过程中,近年来伴随经济发展而来的生态保护压力也日益增加,流域水资源脆弱性和风险更甚,为化解人地矛盾,需探究城镇聚落和河流的动态耦合机制。在“黄河流域生态保护和高质量发展”上升为重大国家战略之际,从城乡规划、自然地理、环境考古、生态学、水文水资源、土地资源管理等多领域视角,聚焦黄河流域人地关系的空间分异和演化规律,以及资源和生态保护的困境与机遇。建成环境与自然环境的平衡是可持续发展的基础,应将黄河流域视为自然及人文环境相互影响与依存的“生命共同体”,并从系统性和交叉性、地方性和适应性等方面探讨可持续发展策略。 相似文献
36.
注册测绘师制度作为保证测绘成果质量、强化法律责任和全面贯彻落实《中华人民共和国测绘法》的重要举措,对测绘企业乃至测绘地理信息行业都有着深远影响。本文试从人力资源管理的角度进行解读,分析注册测绘师制度对人力资源规划、岗位设置和人力资源供求关系的影响,并结合自身的工作经验和所思所想提出了特定项目试点执业、建立信息共享平台和实行绩效管理等执业建议,以实现注册测绘师、测绘企业和测绘地理信息行业的协同发展。 相似文献
37.
李明 《测绘与空间地理信息》2020,(3):9-11,15
国民经济建设对测绘地理信息档案的需求旺盛,如何对测绘地理信息数据进行归档管理,提高测绘地理信息档案存储的安全性及方便再利用,已经成为测绘地理信息档案管理部门需要研究的重要课题。本文通过分析当前测绘地理信息档案管理的现状,指出存在的问题,提出有力的改进措施。 相似文献
38.
Understanding what drives farmers’ voluntary adoption of nutrient and soil best management practices has important consequences for many environmental outcomes including water quality. We build on research revealing the need for simultaneous use of multiple nitrogen best management practices to achieve water quality improvement goals. Using social, economic and attitudinal variables we predict the use of multiple nitrogen best management practices at three time points: current use (2013), past use (before 2013), and likelihood of use on their largest field in the next three years. Our empirical analysis uses structural equation modeling with latent variables and 2014 farmer survey data from three Midwestern US states. Most farmers in our sample used at least one of the six best management practices. Our results reveal that farmers’ attitudes, use of information sources, and conservation program participation affect the number of nitrogen best management practices concurrently in use at multiple time points. 相似文献
39.
基于部件可靠度和多阶段动态库存理论,分析了备件需求与库存管理。提出了基于部件可靠度的动态需求模型;以部件的寿命服从指数分布为例,结合实际生产中备件的使用情况,通过确定备件储备的时间点,动态确定各周期备件的需求量。在确定备件动态需求量的基础上,采用多阶段动态库存理论确定了订货次数和每次订货数量,使库存量更符合实际和趋于合理。通过算例分析,给出了最小库存费用,表明基于部件可靠度和多阶段动态库存的备件管理具有一定的实际意义。 相似文献
40.
The herring roe fishery in Canada's southern Gulf of St. Lawrence is a productive fishery that lies outside the confines of privatized arrangements. Yet, this fishery is compromised by its dependence on the Japanese seafood market. Consideration of the efficiency of this fishery needs to account for the role assumed by this market in setting fishing practices. A more ecologically and economically efficient use of the herring resource requires greater attention to supply chain integration by local harvesters, processors and buyers prior to engaging with distant markets. This is necessary regardless of the property rights regime that is in place. 相似文献