厦门下潭尾红树林修复区景观类型与鸟类群落动态     

刘劲涛  黄毓薇  黄智君  林清贤 《湿地科学与管理》2021,17(1):23-26

2018年10月—2019年9月调查厦门下潭尾红树林修复区鸟类群落变化,利用遥感图像解译红树林修复区景观格局,为修复区后续景观格局优化与鸟类保护提供技术支持。结果显示:修复区鸟类共有26科62种,鹭类(8种2047只)与鸻鹬类(16种786只)种类及数量较多。春季鸟类种数及数量最多,其中3月鸟类种数最多25种,5月数量最多828只。下潭尾修复区景观格局在低潮位与高潮位存在周期性变化,不同景观鸟类种类及数量有较大差异;鸻鹬类在低潮位时的种类较多但数量较少,高潮位时仅分布于高潮裸露湿地和建设用地。建议修复区增加鸻鹬类高潮停息的滩涂湿地及游禽类生活需要的生态塘区,进一步提高水鸟多样性。  相似文献   

区域历史人口空间格局精细化重建:方法与实证   总被引：1，自引：0，他引：1  

薛樵风  金晓斌  韩娟  杨绪红  周寅康 《地理科学》2019,39(12):1857-1865

以清中期（1736~1820年）苏州府为例,探索历史时期人口空间分布的影响机制,构建历史人口空间分布适宜性计算方法,在2个典型时段（1776年、1820年）重建1 km×1 km空间格网下的人口数据集。研究结果表明:① 在数量上,1776年,苏州府人口总量为511.1万,其中城市人口120.1万,农村人口391.0万;1820年,总人口为590.8万,其中城市168.7万,农村422.1万;城市人口增长速率明显快于农村人口。② 空间格局上,1776~1820年,苏州府中部的吴县、长洲、元和等县人口较为集中,东北部昭文、新阳及中南部吴江、震泽等县较为稀疏,但区域间差异渐趋缩小;人口增长主要集中在城镇区域,较高等级城镇人口集聚特征更为显著。③ 通过与当地历史文献及现代人口格局进行相关性和趋势检验,总体特征、分布趋势和变化特点具有一致性。  相似文献   

中国粮食生产时空演变规律与耕地可持续利用研究     

郑亚楠  张凤荣  谢臻  张天柱  李超  王秀丽 《世界地理研究》2019,28(6):120-131

随着全球粮食贸易格局的日益紧张，如何利用有限的耕地资源保证中国粮食安全成为新阶段的难题。本文从耕地可持续利用视角提出粮食稳产、增产策略，以期为粮食安全、耕地保护等国家战略提供理论支撑。基于1985—2015年中国31个省（自治区、直辖市）统计数据，以农业生态区为基本单元，采用比较分析法和GIS空间分析法，对中国粮食生产时空演变及其影响因素进行规律性探究。研究结果表明：（1）中国粮食产量呈“波动-上升”的趋势，但长江中下游区、江南和华南区粮食增长率较低，甚至出现减产现象。（2）中国粮食产量主产区逐渐由长江中下游区、江南和华南区向东北区、黄淮海区转移。（3）中国粮食生产的影响因素呈现阶段性和区域性规律。例如，东北区、西北区粮食生产主要受粮食单产、耕地面积等影响；黄淮海区、内蒙古高原和黄土高原区、云贵高原和横断山区主要受粮食单产影响。（4）中国各区耕地存在不同类型和不同程度的耕地非持续问题，在西北区、内蒙古高原和黄土高原等生态脆弱区域较严重。  相似文献   

Modelling the spatial dynamics of Mainland China-born migrants in Australia     

Siqin Wang  Thomas Sigler  Jonathan Corcoran  Yan Liu 《The Australian geographer》2019,50(2):201-219

Over the past two decades, migration from Mainland China (MC) to Australia has become increasingly significant. In contrast to previous migrant waves, post-2000 MC-born migrants in Australia are more likely to be highly skilled and/or financially independent, and often migrate under skilled, business and investment visa programs. Though scholarship has explored various facets of MC-born migrants’ settlement in Australian cities, the spatial dynamics of settlement, and change over time associated with these shifts in socio-economic profile, have remained unexplored. This paper draws on three census periods, and employs a local indicator of spatial autocorrelation together with a geographically weighted regression. We conclude that the settlement patterns of MC-born migrants in Australia do not follow the ‘straight-line’ assumptions of spatial assimilation theory, nor are they tied explicitly to socio-economic factors in the majority of capital cities. Instead, the settlement patterns of MC-born migrants vary by city: Sydney and Melbourne display the most spatially segmented settlement patterns; while Adelaide and Perth exhibit increasing levels of concentration as the number of MC-born migrants grows. Results indicate that while MC-born migrants are somewhat likely to cluster at the early stage of group formation, within-group spatial patterns are articulated by social attributes as the group grows in size and significance in a metropolitan context.  相似文献   

Study of isotopic seasonality to assess the water source of proglacial stream in Chhota Shigri Glaciated Basin,Western Himalaya     

Naveen Kumar  Alagappan Ramanathan  Aman Arora  Mohd Soheb  Arindan Mandal  Parmanand Sharma  Shyam Ranjan 《水文研究》2020,34(5):1285-1300

The impact of surface melt patterns and the Indian summer monsoon (ISM) is examined on the varying contributions of end member (snow, glacier ice, and rain) to proglacial streamflow during the ablation period (June–October) in the Chhota Shigri glaciated basin, Western Himalaya. Isotopic seasonality observed in the catchment precipitation was generally reflected in surface runoff (supraglacial melt and proglacial stream) and shows a shift in major water source during the melt season. Isotopically correlated (δ¹⁸O–δD) high deuterium intercept in the surface runoff suggests that westerly precipitation acts as the dominant source, augmenting the other snow- and ice-melt sources in the region. The endmember contributions to the proglacial stream were quantified using a three-component mixing. Overall, glacier ice melt is the major source of proglacial discharge. Snowmelt is the predominant source during the early ablation season (June) and the peak ISM period (August and September), whereas ice melt reaches a maximum in the peak melt period (July). The monthly contribution of rain is on the lower side and shows a steady rise and decline with onset and retreat of the monsoon. These results are persistent with the surface melt pattern observed in Chhota Shigri glacier, Upper Chandra basin. Moreover, the role of the ISM in Chhota Shigri glacier is unvarying to that observed in other glacierized catchments of Upper Ganga basin. Thus, this study augments the significant role of the ISM in glacier mass balance up to the boundary of the central-western Himalayan glaciated region.  相似文献   

鄂尔多斯草原沙漠交错区生态系统健康评价——以十大孔兑为例     

白雪莲  王理想  季树新  陈正新  常学礼 《中国沙漠》2020,40(1):187-194

生态系统健康是生态学在景观和区域尺度的主要研究领域，应用RS技术判读生态系统格局变化是生态系统健康评价有效手段。十大孔兑地处中国草原沙漠交错区，受到的干扰较多，生态系统健康状况在中国生态交错区具有代表性。基于生态系统（土地利用）格局和相应生态系统服务价值当量应用RS和GIS技术评价了十大孔兑地区不同地理类型区生态系统健康状况。结果表明：（1）十大孔兑生态系统以健康区为主，面积为686 925.72 hm²，占总面积64.66%；研究区南部（草原区）、中部（沙漠区）和北部（平原区）健康区比例都大于50%。（2）健康区最大斑块指数（LPI）总体为62.47%，从北到南分别为22.42%、65.04%、66.25%；平均欧几里得距离（ENN_MN）总体为526.51 m，从北到南分别为293.47、287.14、298.09 m。（3）健康区在十大孔兑以集中连片团聚结构为绝对优势，尤其是南部和中部表现明显，但是北部团聚性较南部和中部弱；良好区和恶化区呈现为低频率离散分布，北部较南部和中部良好区分布频率更高、更聚集，南部较中部和北部恶化区分布频率更低、更离散；较好区和较差区呈现高频率离散分布。  相似文献   

天山北坡经济带“三生空间”发展格局 与智能水网体系建设          下载免费PDF全文

邓铭江 《干旱区地理》2020,43(5):1155-1168

天山北坡经济带是新疆生产力集中度较高，现代工业、农业、交通信息、教育科技等较为发达的区域，是国家丝绸之路经济带建设的核心区，对新疆经济社会发展具有重要的带动和辐射作用，国内生产总值均占全疆 53%以上，工业增加值占全疆 67%，城镇化率 68.9%，远高于全疆 42.1%的平均水平，然而水资源却仅占11%。为破解资源性缺水困境而实施的“两河调水”工程正在陆续建成发挥效益,如何优化配置原水与客水、高水与低水、地表水与地下水等各种水源，统筹协调区域、城乡、兵地、产业、经济社会与生态环境等各种需求，已成为亟待研究决策的重大现实问题。通过分析天北带水资源可利用量、生态环境需水量、水资源开发利用现状及存在问题，结合调水工程新增水量，提出了水资源优化配置的原则、贯彻新时期“十六字”治水思路和“五大”发展理念的实践路径与综合调控措施，主要学术观点和结论为：（1）结合“两河调水”工程，在天山北坡建设东西连通的输水大通道，将由南向北流的逐条河流交叉连接起来，形成一个南北交汇，东西贯通，覆盖整个区域的“大水网”，实现全域水源优化配置。（2）按照“以水定地，以水定产，以水定城，适水发展”的原则，强化国土空间管控，按照“生产空间集约高效，生活空间宜居适度，生态空间自然和谐”为原则，优化“三生空间”发展格局。（3）打破旱区弱水资源承载力、高生态胁迫压力、低经济发展能力的桎梏，从水资源—经济社会—生态环境三个维度，科学把控“大水网”建设和水利发展定位，合理配置“三生用水”，耦合协调“三生关系”,实现生态保护和高质量发展。（4）面向未来和新基建工程的喷涌发展，建设水物理网、水信息网、水管理网“三网合一”的智能水网势在必行，代表智慧水利的发展方向，也是当代水利科技前沿。  相似文献   

Optimal lake-marsh pattern determination in lake-marsh systems based on the eco-hydrological processes management     

Wuxia Bi  Baisha Weng  Denghua Yan  Meng Li  Zhilei Yu  Lin Wang  Hao Wang 《水文研究》2020,34(26):5260-5277

The major hydrological factors in lake-marsh systems are water level (depth), water surface area, and water volume. The key index for determining the lake-marsh pattern is water level, which leads to the variation of lake-marsh patterns under natural hydrological alternations. In addition, the vegetation structure also affects the lake-marsh pattern. With socioeconomic development and climate change, the ‘land use’ and ‘water use’ competitions appear more seriously between a lake-marsh system and its surrounding socioeconomic system, also inside the lake-marsh system. The possible optimal lake-marsh pattern could solve the contradictions mentioned above. As few studies focus on this issue, this study proposed an optimal lake-marsh pattern determination method with eco-hydrological management on relieving the land use and water use competitions. The optimal lake-marsh pattern determination method considers the protection objects (water depth demands), water supply (precipitation, surface water, and groundwater), and water demand (especially evapotranspiration) in the system at annual and monthly scales. Calculation and analysis were performed for the optimal pattern of the Wolonghu Wetlands as an example. The results mainly showed that the lake-marsh pattern of the Wolonghu Wetlands cannot be achieved on meeting both the maximum ecological services values and minimum water shortage amount under present natural condition. With artificial regulation measures, the possible optimal annual lake-marsh patterns can be obtained based on both ecological and hydrological objectives, with the area ratio of lake and marsh in the range of 0.650:0.350 and 0.726:0.274, the corresponding water level of lake body was of 86.85 to 87.0 m. This study could provide references for the Wolonghu Wetlands management, also for similar lake-marsh systems and other ecological systems.  相似文献   

中国省级要素市场扭曲程度的时空格局及影响因素     

孙湘湘  周小亮 《地理科学》2020,40(2):182-189

基于超越对数函数对2000~2015年中国30个省份要素市场扭曲程度进行测算,分析要素市场扭曲的空间格局和演化进程,并利用空间计量模型分析影响要素市场扭曲的因素。研究表明：① 中国要素市场存在扭曲现象且总体呈现缓解趋势。从区域分布看,高要素市场扭曲程度的地区集中在西部地区,中等要素市场扭曲在中部地区,而低要素市场扭曲程度分布在东部地区及东北地区。② 中国要素市场扭曲有显著的空间自相关性,Moran指数呈现波动减小趋势,要素市场扭曲邻近地区的集聚效果有所减弱。③ 对影响要素市场扭曲的因素分析发现,城镇化、财政分权、外商直接投资和基础设施建设改善要素市场扭曲;国有经济占比加剧要素市场扭曲。  相似文献   

全国行业COD和TN污染物产强环境准入基准体系研究     

梁生康  王淑萍  张艳军  李克强  李雁宾  杨燕群  王修林 《中国海洋大学学报(自然科学版)》2020,(3):44-53

围绕当前中国源头治理与产业转型升级之间脱节严重的突出问题,在编制行业小类污染源全覆盖且取值简便的产强系数等级划分表的基础上,构建全国行业小类农业、工业、服务业和生活源化学耗氧量(COD)和总氮(TN)污染物产强环境准入基准体系,并以青岛市为例,评价污染源产强环境准入基准的可靠性和准确性。通过聚类分组和归并,“全国产强列表手册”编列的3022个COD和1734个TN亚小类污染源归一化产强系数都可划分为13个等级。对于“全国产强列表手册”编列的321个COD和133个TN行业小类,产强准入基准等级构成有显著差异,分别有10和12个等级,其中不同等级占比分别是II-2和IV-6最高,V-9和VI-12最低。根据产强系数检验性监测结果按从严标定准入基准表明,对于青岛市254个COD和109个TN行业小类,产强准入基准构成与全国有所不同,分别有10和11个等级,其中分别有77和14个低于全国准入基准等级。根据青岛市陆源COD和TN产污数量比较分析表明,分级比分类产强核算结果平均相差约6%,远远低于产强系数检验性监测偏差(49%)和13等级产强等级内变幅(39%)。这说明,在按“全国行业小类COD和TN污染物产强环境准入基准体系”建立完善中国污染源产强环境准入制度中,不仅按产污数量分级产强核算结果具有相当的准确性,而且按从严标定准入基准的原则也具有相当的可靠性。  相似文献