The role of global dietary transitions for safeguarding biodiversity     

《Global Environmental Change》2019

Diets lower in meat could reduce agricultural expansion and intensification thereby reducing biodiversity impacts. However, land use requirements, associated with alternate diets, in biodiverse regions across different taxa are not fully understood. We use a spatially explicit global food and land system model to address this gap. We quantify land-use change in locations important for biodiversity across taxa and find diets low in animal products reduce agricultural expansion and intensity in regions with high biodiversity. Reducing ruminant meat consumption alone however was not sufficient to reduce fertiliser and irrigation application in biodiverse locations. The results differed according to taxa, emphasising that land-use change effects on biodiversity will be taxon specific. The links shown between global meat consumption and agricultural expansion and intensification in the biodiverse regions of the world indicates the potential to help safeguard biodiverse natural ecosystems through dietary change.  相似文献   

海南岛不同土地覆盖资料对WRF模拟的影响_*     

冯箫  施萧 《沙漠与绿洲气象(新疆气象)》2019,13(2):123-129

提取GLC2009土地覆盖数据,将其运用到WRF数值模式并与模式自带的MODIS、USGS土地覆盖进行对比,以海南岛做为研究区域,选择一次海风锋天气过程进行敏感性分析,结果表明：①GLC2009对海南岛农耕地、森林的划分最接近实际情况,在海南岛平原以及丘陵地带,MODIS和USGS划分的农耕地比例过高,而在山区森林比例偏低;②GLC2009、MODIS、USGS对海南岛北部的降水模拟出现了空报,但是GLC2009对东海岸的强降水模拟的较好,并避免了MODIS和USGS在海南西南部的降水空报的情况;③GLC2009模拟的10米风场清晰刻画了东海岸海风锋辐合,其相对合理的森林覆盖提高了地表粗糙度并增强了风场辐合、低反照率对地面气温的增加和海陆热力差异的增强有一定的促进作用。④GLC2009对这次海风锋过程中模拟的感热通量和潜热通量都要高于MODIS和USGS,这种陆气间的热通量交换利于强对流天气的触发,发展。  相似文献   

Regional evapotranspiration rate of oasis and surrounding desert     

Jihong Jia  Wenzhi Zhao  Shoubo Li 《水文研究》2013,27(24):3409-3414

The surface energy balance algorithm for land method was used in this study to calculate the evapotranspiration (ET) rate for the middle reaches of the Heihe River Basin, Gansu Province, China, to analyse ET distribution within the oasis and the surrounding desert and, especially, on the edge zone of the oasis. Five profile graphs were created vertical to the river. Because of the inverse humidity phenomenon, the least amount of evapotranspiration occurred on the desert close to the oasis. The average evapotranspiration rate was roughly proportioned from the edge of the oasis to inside and outside its boundary. Two meteorological ground stations located close to the oasis edge showed a notable difference in net radiation flux that led to the difference found in ET. The primary reason for the significant differences observed in net radiation may be largely the result of differences in flux reflectivity and surface temperature. Meteorological data show that water supply also played an important role. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

High‐Arctic climate conditions for the last 7000 years inferred from multi‐proxy analysis of the Bliss Lake record,North Greenland     

Jesper Olsen  Kurt H. Kjær  Svend Funder  Nicolaj K. Larsen  Anna Ludikova 《第四纪科学杂志》2012,27(3):318-327

The Arctic is more vulnerable to climate change than are mid latitudes. Therefore, palaeolimnological studies from the High Arctic are important in providing insights into the dynamics of the climate system. Here we present a multi‐proxy study from one of the world's northernmost lakes: Bliss Lake, Peary Land, Greenland. The early Holocene (10 850–10 480 cal. a BP) is characterized by increased erosion and gradually more marine conditions. Full marine conditions developed from 10 480 cal. a BP until the lake was isolated at 7220 cal. a BP. From its marine isolation at 7220 cal. a BP Bliss Lake becomes a lacustrine environment. Evidence from geochemical proxies (δ¹³C and total organic carbon) suggests that warmer conditions prevailed between 7220 and 6500 cal. a BP, corresponding to the Holocene thermal maximum, and from 3300 until 910 cal. a BP. From 850 to 500 cal. a BP colder climate conditions persisted. The transition from warmer to colder climate conditions taking place around 850 cal. a BP may be associated with the transition from the Medieval Warm Period to the Little Ice Age. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

重视和加强中国东部地区土地退化整治研究   总被引：2，自引：0，他引：2  

郑度  卢金发 《地球科学进展》1994,9(5):1-5

根据《２１世纪议程》土地荒漠化定义，从全球环境研究角度，论述了中国东部湿润、半湿润地区土地退化及其危害和开展中国东部地区土地退化研究的必要性和可行性，并提出了点面结合的初步研究设想。  相似文献   

Prediction of tension crack location and riverbank erosion hazards along destabilized channels     

Stephen E. Darby  Colin R. Thorne 《地球表面变化过程与地形》1994,19(3):233-245

Riverbank erosion, associated sedimentation and land loss hazards are a land management problem of global significance and many attempts to predict the onset of riverbank instability have been made. Recently, Osman and Thorne (1988) have presented a Culmann-type analysis of the stability of steep, cohesive riverbanks; this has the potential to be a considerable improvement over previous bank stability theories, which do not account for bank geometry changes due to toe scour and lateral erosion. However, in this paper it is shown that the existing Osman-Thorne model does not properly incorporate the influence of tension cracking on bank stability since the location of the tension crack on the floodplain is indirectly determined via calculation or arbitrary specification of the tension crack depth. Furthermore, accurate determination of tension crack location is essential to the calculation of the geometry of riverbank failure blocks and hence prediction of land loss and bank sediment yield associated with riverbank instability and channel widening. In this paper, a rational, physically based method to predict the location of tension cracks on the floodplain behind the eroding bank face is presented and tested. A case study is used to illustrate the computational procedure required to apply the model. Improved estimates of failure block geometry using the new method may potentially be applied to improve predictions of bank retreat and floodplain land loss along river channels destabilized as a result of environmental change.  相似文献   

土地类型系列制图的几个理论问题   总被引：1，自引：0，他引：1  

蔡运龙 《地理研究》1994,13(1):76-83

实际存在的不同尺度地域分异规律是土地类型系列制图的客观基础。多种尺度制图构成的土地类型系列制图可以全面揭示区域土地类型的形成因素、分布规律和空间结构特征,也为不同层次土地规划管理之间的相互补充、协调提供了重要基础。  相似文献   

云南元谋干热河谷土地退化及其防治对策^*   总被引：5，自引：1，他引：5  

崔书红 《地理研究》1995,14(1):66-71

本文探讨了云南元谋干热河谷土地退化的特点、分布及其危害,提出了加强基础教育、控制人口增长、改革耕作制度、继续农业基础设施建设、因地制宜发展林业和农业等于热河谷土地退化防治对策。  相似文献   

冷空气爆发时陆地边界层的数值模拟   总被引：1，自引：0，他引：1       下载免费PDF全文

张雷鸣  赵鸣 《大气科学》1993,17(2):239-248

本文建立了一个三维中尺度模式,分别模拟了平坦地形及规则山地情形下冷空气爆发过程,并模拟了无冷空气时天气演变过程作为比较.模拟结果合理地给出了冷空气爆发后边界层内诸要素的变化规律,如大风的出现、风向的改变、动量通量的增大、气压的升高等.  相似文献   

地理信息系统支持区域土地利用决策的研究   总被引：31，自引：1，他引：31  

黄杏元  倪绍祥 《地理学报》1993,48(2):114-121

本文以江苏省溧阳县为例,研究地理信息系统技术在区域土地利用多目标规划中的应用,着重探讨地理信息系统支持的区域土地利用决策原理和方法。研究表明,在地理信息系统的支持下,通过单项适宜性评价模型和生产布局决策模型的建立与运行,可以有效地进行研究区合理的土地利用布局和为区域土地管理提供依据。  相似文献