中国跨境风电项目的建设模式、梯度转移及减排潜力研究

作为“一带一路”倡议的样板工程和旗舰项目,中巴经济走廊中的风电项目建设已经初现规模。中国在巴基斯坦的工程建设中,风电优先项目涉及的项目金额约为6.47亿元,运营期累计发电量可以达到近180亿千瓦时,可累计减少二氧化碳排放13.90兆吨。伴随跨境风电项目的梯度转移,中国可再生能源项目落地并网取决于东道国的政策制度安排、建设运营模式、设备供应体系以及电价收购协议等。本研究有助于协助沿线国家完善能源政策制度、加快清洁电力发展、应对气候变化、落实碳减排承诺,为绿色“一带一路”建设中可再生能源项目的推广提供借鉴。     

中国国际河流研究进展及展望

我国因发育了亚洲大陆的主要国际河流而成为全球最重要的上游水道国。近30年来,在全球化趋势下,国际河流的合理利用与保护、生态变化与跨境影响、地缘合作与安全维护等,广受国际关注,成为地理、生态和地缘政治等学科交叉研究的热点。本文按“国际河流”、“跨境水资源”、“跨境生态安全”等关键词,从《地理学报》及其英文版J. Geographical Sciences中检索近30年来发表的相关文献,以此为主要依据,回顾地理学对我国国际河流研究取得的主要进展,判识存在的问题和所面临的挑战;在此基础上,结合科学发展的趋势和我国地缘合作等重大需求,展望研究前景。     

用于盐湖提锂的聚酰胺复合纳滤膜制备及其性能研究

纳滤膜技术以其环境友好、装置集成度高和智能化控制等优势,在卤水锂资源绿色开发领域具有良好的应用前景。实验通过添加聚乙烯醇对纳滤膜功能层进行改性,考察了聚乙烯醇相对含量对纳滤膜性能的影响。结果表明,聚乙烯醇参与界面聚合反应,纳滤膜功能层O/N比增加,聚乙烯醇分子链间氢键作用降低纳滤膜表面粗糙度。羟基官能团的引入有效改善纳滤膜材料亲水效果,膜面羧基密度随聚乙烯醇相对添加量的增加逐渐增加。聚乙烯醇改性纳滤膜截留效果优异,纳滤膜对镁离子的截留率高于95%,锂离子截留率低于-44%,不可逆通量衰减指数低于15%。聚乙烯醇改性纳滤膜材料具有较好的镁锂分离选择效果及抗污染能力,为用于盐湖卤水镁锂分离国产化纳滤膜材料的开发提供新思路。     

Suspended sediment transport and deposition in a high arctic meromictic lake

A study of sedimentary processes and sediment yields in a high arctic meromictic lake (Lake C2, Taconite Inlet, Northern Ellesemere Island, Canada) was undertaken from May 1990 through August 1992 to understand the links between climatic controls, hydrology, and the laminated sediment record preserved in the lake. Understanding the relationships between processes and the sediment record is critical for interpreting the climatic significance of the laminated sediments in a region where high resolution climate proxy records are quite limited.Sediment transport to Lake C2 is dominated by fluvial processes. During the early part of the melt season slushflows transport sediment to the lake surface. Subsequently, suspended sediment is delivered to the lake by the main inlet stream and distributed lakeward by a plume emanating the main inlet channel. Due to the strong density stratification of the water column the plume distributes sediment downlake by overflows and interflows in the epilimnion. In general, overflows are generated by lower discharge events whereas interflows penetrate to the halocline during high discharge with increased suspended sediment concentration.Sediment trap analysis demonstrates that suspended sediment transport and deposition responds to diurnal through annual changes in stream discharge. Seasonal and annual sediment trap yields agree with average accumulation rates determined from varve thickness measurements and cumulative suspended sediment discharge from the main inlet stream indicating a close link between climatological, hydrological, and sedimentological controls and varve deposition.This is the fourth in a series of papers published in this issue on the Taconite Inlet Lakes Project. These papers were collected by Dr R. S. Bradley.     

最近十年来中国地理科学的进展

最近十年来中国地理科学的最重要进展有:自然地理学与人文地理学的平衡发展,人口、资源、环境的研究,遥感的应用与地理信息系统的建立,自然地理定位观测,青藏高原隆起对自然环境的影响,城市与城市规划,中国历史地理研究等。最近,并已开始研究气候变化与海平面上升对中国的影响,使我国地理科学研究紧紧跟上世界发展的步伐。     

腾格里沙漠东南缘沙丘形态示量特征及其影响因素

对腾格里沙漠东南缘主要类型沙丘形态示量及其影响因素分析认为,沙丘高度与间距之间具有明显的幂函数关系,而且这种关系所反映的沙丘动态(加积或前移)随沙丘类型、分布而异。影响沙丘规模与间距的因素比较复杂,粒度的影响没有普遍性;背风侧次生气流尺度对简单横向沙丘具有一定的控制作用;输沙率的影响表现在,各尺度等级风成床面形态及规模对输沙率的变化具有不同时空尺度的响应。     

近50年青藏高原东部降雪的时空演变

选用1967-2012年青藏高原东部60个站点的观测资料,分析了该地区降雪的时空演变特征,并结合降水和气温的变化,探讨了降雪与积雪的关系,结果表明：青藏高原东部年降雪量在1.3~152.5 mm范围内变化,空间分布差异显著;秋季降雪表现出中间多、周边少的特征,冬季降雪表现出由东南向西北递减的特征,春季降雪最多且空间分布与年降雪基本一致;降雪可划分为青南高原区、藏北高原区、柴达木盆地区、青藏高原东南缘区、川西高原西北部区、青藏高原南缘区、青海东北部区及藏南谷地区;就青藏高原整体而言,除秋季外,整年、冬季和春季降雪均表现出“少—多—少”的年代际变化特征,其中冬季降雪在1986年发生了由少到多的突变,整年、冬季和春季降雪均在1997年发生了由多到少的突变;不同区域降雪的时间变化规律各具特点;降雪与积雪的关系十分密切,春季降雪受气温的影响最为显著,秋季次之,冬季最弱;20世纪末,春季降雪受气温升高的影响表现出与降水变化相反的由多到少的气候突变特征。     

Issues of Spatial and Temporal Variability in Climate Impact Studies

The accuracy of impact estimates relating climate change to regional-scale agricultural production is constrained by the temporal and spatial resolution of climate change projections. Several techniques have been used to compensate for these limitations in order to provide reasonable estimates of the impact of climate change on crop yield. One approach assumes that variability over time can substitute for spatial variability, thereby reducing the need to estimate the impacts at a spatially dense network of stations—an assumption that has not been generally tested. This study evaluates this assumption using methods similar to those employed in the climate impact literature. The findings suggest that current practices are generally defensible if the goal is to provide a range of possible crop responses to climate change. However, the results also show that the assumption is highly sensitive to specific interactions at the soil-plant-atmosphere interface and, consequently, does not hold under certain circumstances.     

1985-2005年环渤海地区土地利用变化时空格局

Based on TM image data and other survey materials, this paper analyzed the spatiotemporal patterns of land use change in the Bohai Rim during 1985–2005. The findings of this study are summarized as follows: (1) Land use pattern changed dramatically during 1985–2005. Industrial and residential land in urban and rural areas increased by 643,946 hm², of which urban construction land had the largest and fastest increase of 294,953 hm² at an annual rate of 3.72%. (2) The outward migration of rural population did not prevent the expansion of residential land in rural areas by 184,869 hm². This increase reveals that construction of rural residences makes seriously wasteful and inefficient use of land. (3) Arable land, woodland and grassland decreased at a rate of −0.02%, −0.12% and −1.32% annually, while unused land shrank by 157,444 hm² at an annual rate of −1.69%. (4) The change of land use types showed marked fluctuations over the two stages (1985–1995 and 1995–2005). In particular, arable land, woodland and unused land experienced an inversed trend of change. (5) There was a significant interaction between arable land and woodland. Industrial construction land in urban and rural areas showed a net trend of increase during the earlier period, but only adjustment to its internal structure during the second period. The loss of arable land to the construction of factories, mines and residences took place mainly in the fringe areas of large and medium-sized cities, along the routes of major roads, as well as in the economically developed coastal areas in the east. Such changes are closely related to the spatial differentiation of the level of urbanization and industrialization in the region.     

1480-1940年广东地区气候干湿变化与旱涝灾害区域分异特征

1 IntroductionThe natural disasters, especially the flood and drought disasters, have occurred frequently inG uangdong area since ancienttim es.A ccording to historic statisticaldata,since the 17th century,the occurrence of the flood and drought disasters…