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为我国科技教育事业作出突出贡献的“全国优秀共产党员”“全国优秀教师”“时代楷模”黄大年同志,为实现国家富强、民族振兴、人民幸福的中国梦殚精竭虑地奉献了一生,他的先进事迹感人肺腑、催人奋进,他的爱国情怀、报国之志永远激励着自强不息的优秀中华儿女,他的奉献精神和高尚情操永远值得我们学习。 相似文献
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The Belt and Road Initiative(BRI)–a development strategy proposed by China – provides unprecedented opportunities for multi-dimensional communication and cooperation across Asia,Africa and Europe.In this study,we analyse the spatio-temporal changes in cultivated land in the BRI countries(64 in total) to better understand the land use status of China along with its periphery for targeting specific collaboration.We apply FAO statistics and Globe Land30(the world's finest land cover data at a 30-m resolution),and develop three indicator groups(namely quantity,conversion,and utilization degree) for the analysis.The results show that cultivated land area in the BRI region increased 3.73×10~4 km~2 between 2000 and 2010.The increased cultivated land was mainly found in Central and Eastern Europe and Southeast Asia,while the decreased cultivated land was mostly concentrated in China.Russia ranks first with an increase of 1.59×10~4 km~2 cultivated land area,followed by Hungary(0.66×10~4 km~2) and India(0.57×10~4 km`2).China decreased 1.95×10~4 km~2 cultivated land area,followed by Bangladesh(–0.22×10~4 km~2) and Thailand(–0.22×10~4 km~2).Cultivated land was mainly transferred to/from forest,grassland,artificial surfaces and bare land,and transfer types in different regions have different characteristics:while large amount of cultivated land in China was converted to artificial surfaces,considerable forest was converted to cultivated land in Southeast Asia.The increase of multi-cropping index dominated the region except the Central and Eastern Europe,while the increase of fragmentation index was prevailing in the region except for a few South Asian countries.Our results indicate that the negative consequence of cultivated land loss in China might be underestimated by the domestic-focused studies,as none of its close neighbours experienced such obvious cultivated land losses.Nevertheless,the increased cultivated land area in Southeast Asia and the extensive cultivated land use in Ukraine and Russia imply that the regional food production would be greatly improved if China' "Go Out policy" would help those countries to intensify their cultivated land use. 相似文献
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Land use and its dynamics have attracted considerable scientific attention for their significant ecological and socioeconomic implications.Many studies have investigated the past changes in land use,but efforts exploring the potential changes in land use and implications under future scenarios are still lacking.Here we simulate the future land use changes and their impacts on ecosystem services in Northeast China(NEC) over the period of 2000–2050 using the CLUE–S(Conversion of Land Use and its Effects at Small regional extent) model under the scenarios of ecological security(ESS),food security(FSS) and comprehensive development(CDS).The model was validated against remote sensing data in 2005.Overall,the accuracy of the CLUE–S model was evaluated at 82.5%.Obtained results show that future cropland changes mainly occur in the Songnen Plain and the Liaohe Plain,forest and grassland changes are concentrated in the southern Lesser Khingan Mountains and the western Changbai Mountains,while the Sanjiang Plain will witness major changes of the wetlands.Our results also show that even though CDS is defined based on the goals of the regional development plan,the ecological service value(ESV) under CDS is RMB 2656.18 billion in 2050.The ESV of CDS is lower compared with the other scenarios.Thus,CDS is not an optimum scenario for eco-environmental protection,especially for the wetlands,which should be given higher priority for future development.The issue of coordination is also critical in future development.The results can help to assist structural adjustments for agriculture and to guide policy interventions in NEC. 相似文献
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湖北省土壤侵蚀遥感调查与GIS制作 总被引:6,自引:0,他引:6
根据全国土壤侵蚀遥感调查技术规范和GIS制图精度要求,笔者在承担湖北省土壤侵蚀遥感调查项目工作中,引用图像信息理论和景观生态学理论,运用RS—GIS一次成图技术与数据库技术,在短时间内,多快好省地完成了全省国土(18.59万km2)土壤侵蚀分类分级的遥感判读分类及野外调查验证、GIS数字制图和分县市面积测算统计任务,为国土整治。环境治理、土壤侵蚀动态监测和水土保持规划设计提供了科学依据,取得了良好的社会经济效益。1.地质环境与景观生态学理论的应用从自然过程看,土壤侵蚀类型和等级受控于地球表层的岩石圈、土壤圈、… 相似文献
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