云南省金沙江流域生态环境建设的问题与对策研究--长江上游生态屏障建设重点地区调查报告之一

生态环境保护和建设是我国西部大开发的重要战略之一。云南省金沙江流域是长江上游生态脆弱地区,也是生态环境保护和建设的重点地区．在实地调研的基础上分析云南省金沙江流域地区的生态环境状况,探讨该区域生态环境建设中存在的主要问题,并提出了进一步加强该地区生态环境建设的对策建议．     

和田河流域生态脆弱性成因辨识

通过献资料和野外考察,认为和田河流域的脆弱生态环境是长期的自然作用过程及人类活动干预下形成的。自然地理要素有脆弱性的一面,不合理的人类活动加剧了生态环境退化的进程。和田河流域脆弱生态环境是水、植被环境恶化导致的生态平衡失调形成的。总体表现为以荒漠化为主体的环境问题日益加剧,并通过土地沙漠化、土壤盐渍化、草场退化、生物多样性丧失,以及干旱、风沙、盐碱、洪灾等表现出来。综合评价结果表明,和田河流域的生态环境质量属中等脆弱。     

Regional patterns of particulate spectral absorption in the Pearl River estuary

Knowledge about the spectral absorption properties of marine particulate matters is of important signification for various goals of optical oceanography, among them the most concerns are the bio-optical algorithms for ocean color remote sensing[1], basic theory of light radiative transfer in water column[2], bio-optical models for estima-tion of primary productivity and simulation of the upper ocean ecological process[3,4]. The spectral absorption by marine particulate matter is combined influe…     

Change in the sedimentary environment of Wanquan River Estuary,Hainan Island,China

Pb geochronology and sediment core profiles of organic carbon, total sulfur and organic carbon isotope (d 13C) values were used to reconstruct the local environ-mental history of the Shamei Lagoon, located in the Wan-quan River Estuary, eastern Hainan Island, China. Totalsulfur and d 13C values decreased upwards in the top 30 cm of a sediment core that spanned the last 200 years of deposi-tion. Total sulfur concentration and d 13C values respectively decreased upward from 1.92% to 0.36%, and -20.63?to -23.64? The C/S ratio in the 19th century and earlier was relatively stable in the range of 0.47—0.80, and there was a positive correlation between organic carbon and total sulfur. Since around 1900 AD, the C/S ratio increased rapidly to a maximum of 3.94, but no simple correlation was found be-tween organic carbon and total sulfur during this more re-cent period. These results indicated that before 1800 AD, the lagoon had a fully marine character, and the location of to-day抯 Wanquan River Estuary was an open embayment.From 1800 to 1900, the salinity of Shamei Lagoon decreased noticeably. The amount of seawater which could enter thelagoon decreased gradually as the Yudai spit grew. Today,seawater scarcely affects the lagoon; it is essentially a fresh-water basin.     

Response of the accumulation of proline in the bodies of<Emphasis Type="Italic">Populus euphratica</Emphasis> to the change of groundwater level at the lower reaches of Tarim River

The content of proline in the plant bodies is closely related to the converse-succession-resistant capability of plants. Under the drought stress, the proline accumulates rapidly in the plant bodies for maintaining a certain mois-ture content and an expanding-pressure momentum in cells through the osmoregulation, thus the drought-resis- tant capability and the converse-succession-resistant ca-pability of plants are increased[1,2]. Many researches on the relationship between the proline and the…     

根溪河小流域高程和坡度对水土流失现状的影响

为了探讨福建省长汀水土流失严重的原因,选取地形因子中的高程和坡度,结合“3S”的空间分析技术,对根溪河小流域的水土流失现状进行分析.研究表明:流域内海拔为300～350m所占的面积最大,比例为34.06%,而坡度在25～35°之间的面积最大,占总面积的27.27%;海拔在300～400m之间,因人类活动频繁而又缺乏合理规划与保护措施,导致此区域内成为水土流失分布最广和最严重的地带,而坡度为15～20°的土壤侵蚀率最高.     

Discovery of a 1.0 Ma Yellow River terrace and redating of the fourth Yellow River terrace in Lanzhou area

Based on the aeolian loess sequence-stratigraphic division and paleomagnetic datings on terraces, we found that an undiscovered terrace with the age of 1.0 Ma BP lies between the Dunwashan terrace and Wuyishan terrace. This terrace recorded an intensive Yellow River incision event during that period. Results of paleomagnetic dating and optically stimulated luminescence (OSL) dating of the Wuyishan loess section and Zaoshugou loess section on the fourth Yellow River terrace (T4) show that the age of the fourth Yellow River terrace in Lanzhou area is 0.86 Ma BP rather than the previously believed 0.6 Ma BP. This result answers a long-term question in the geomorphology community of whether there exists a 0.8 Ma terrace in Lanzhou area. The discovery of the 1.0 Ma Yellow River terrace and redating of the age of 0.6 Ma terrace in Lanzhou area provide new insights into further research on the evolution of Yellow River.     

嘉陵江中游地区宗教旅游资源开发研究

嘉陵江中游地区宗教旅游资源丰富，极具开发价值，对其合理开发利用，推出宗教文化旅游，是促进该区域旅游业发展的有效选择之一。作者分析了嘉陵江中游地区宗教旅游资源的特点，指出目前开发利用中存在的问题，并提出进一步开发的对策与建议。     

洛阳盆地平原区全新世地貌环境演变

对洛阳盆地平原区典型剖面的物质组成、测年数据和考古遗址空间分布特点的综合分析显示,该地区全新世地貌环境经历了伊、洛河一、二级阶地形成、阶地面接受洪积冲积物质和风尘物质不断加积、伊、洛河夹河滩地不断扩大的演变过程.二级阶地形成于全新世初期,一级阶地形成于约3.1 ka BP,阶地形成的原因以气候变化为主,因此两级阶地为气候阶地;夹河滩地自晚全新世开始,因伊、洛河汇流点东移而不断扩大;引起滩地扩大的根本原因是人类活动的不断加强.     

Recent temperature increase recorded in an ice core in the source region of Yangtze River

Interests on climate change in the source region of Yangtze River have been raised since it is a region with the greatest warming over the Tibetan Plateau (TP). A 70-year history of precipitation δ~(18)O has been recovered using an ice core record retrieved in a plat portion of the firn area in the Guoqu Glacier (33°34′37.8″N, 91°10′35.3″E, 5720 m a.s.l.), Mt. Geladaindong (the source region of Yangtze River), in November, 2005. By using a significant positive relationship between ice core δ~(18)O record and summer air temperature (July to September) from the nearby meteorological stations, a history of summer air temperature has been reconstructed for the last 70 years. Summer temperature was relatively low in 1940s and high in 1950s to the middle of 1960s. The lowest temperature occurred in the middle of 1970s. Temperature was low in 1980s and dramatically increased since 1990s, keeping the trend to the begin-ning of the 21st century. The warming rate recorded in the ice core with 0.5℃/10 a since 1970s is much higher that that in the central TP and the Northern Hemisphere (NH), and it becomes 1.1℃/10 a since 1990s which is also higher than these from the central TP and the NH, reflecting an accelerated warm-ing and a more sensitive response to global warming in the high elevation region.