苏北地区代表性森林土壤理化特性的比较研究

在苏北地区5种代表性森林植被下设置样地,进行植被因子调查及土壤理化特性分析。结果表明:不同植被类型林下土壤硬度的平均值变化范围在11.86(±3.59)~18.57(±10.26)kg/cm2、土壤有机质平均含量为1.89(±0.27)%~2.36(±0.08)%;常绿针叶林下土壤的平均容重、粘粒组成、田间持水量等指标均小于落叶阔叶林,并且该林下样地的土壤养分含量及pH值也低于落叶阔叶林下的土壤;常绿针叶林下土壤通透性及保肥能力较好,落叶阔叶林尤其是刺槐(Robinia pseudoacacia)林下土壤有机质、氮、磷等养分含量相对较高,供肥能力较强。     

兰坪—思茅盆地钾盐矿床的物质来源探讨

云南兰坪—思茅盆地是我国重要的成钾盆地。综合前人的研究成果,简要介绍了该地区的地质概况。对兰坪—思茅盆地钾盐矿床的物质来源进行了阐述和讨论,认为该盆地钾盐矿床的物质来源以残存古海水为主,并有陆源水体的补给。盆地内的富钾火山凝灰岩、古盐和风化盐也可能为该盆地钾盐矿床提供物源,至于深部地下卤水是否提供物源还需更深入的研究论证。兰坪—思茅盆地钾盐矿床成矿物源具有多源性。     

Coping with water scarcity in Kashafroud G-WADI Basin,Iran: climate change or growing demands?

This paper assesses the various factors contributing to climate change in the region of the Kashafroud G-WADI Basin in Iran; quantifies the local impacts of climate change, especially local water scarcity; and simulates and discusses several proposed methods to combat these impacts. Hydrologic and climatic data are statistically analyzed and VENSIM modeling is used for various simulations of water resources in the basin. Results show that the natural climate changes affecting Kashafroud Basin include increased temperature, less rainfall, more frequent droughts, and changes in rainfall patterns, all of which are local symptoms of climate change in recent years. However, the most important challenge in the basin is the overexploitation of surface and groundwater resources to meet the growing water demands, especially domestic needs. Changes in land use, reallocation of water uses, groundwater depletion, and degradation of the quality of surface waters have all contributed to significant changes in the environmental features of this basin, and are the main reason why water demands now exceed the renewal capacity of the basin. Proposed response measures include reallocation of resources among different uses, inter-basin water transfers, drawing water from six small dams on the Kashafroud River, reducing groundwater extraction, and replacing groundwater extraction for agriculture by reuse of urban wastewater. This study concludes that although changes in global climatic parameters have altered environmental features in the basin, local factors, such as water utilization beyond the renewable capacity of the basin, are more significant in worsening the impacts of climate change.     

江苏淤泥质潮滩对海平面变化的形态响应

通过对江苏滨海平原淤泥质潮滩1980年以来19个固定潮滩断面112个测次滩面高程测量的统计分析，探讨典型淤泥质潮滩剖面形态对海平面变化的形态响应过程。结果表明，典型淤涨岸段海平面上升，多年平均潮位线以上滩面仍将淤积加高，但淤高幅度除多年平均高潮线附近滩面相对较大外，其余均较小，表明随海平面上升该滩带总体淤积速率将趋于减小；与此相反，多年平均潮位线以下滩面则趋于蚀低，且侵蚀强度较大，表明该滩带的侵蚀有加剧趋向，最终滩面总体形态将因上带不断淤高和下带不断蚀低而逐渐变陡，剖面上凸形态的曲率不断加大。曲型侵蚀岸段，海平面上升的效应则相反，海平面上升，多年平均潮位线以上滩面强烈蚀低；而多年平均潮位线以下滩面则强烈淤积加高，剖面的上凹形态最终将因上带不断蚀低和下带不断淤高而趋于平直。     

贵州和四川盆地云量的气候研究

贵州和四川盆地是我国云量最多的地区,素有“天无三日晴”和“蜀犬吠日”之说,盆地西缘的雅安古时还有“雅州天漏”的谚语。从全球日照百分率分布推知,川黔地区也是世界上天气最阴沉的地区之一。川黔之阴一向为国内外气象界所注意,本文根据1951—1980     

The timing of salt structure growth in the Southern Permian Basin (Central Europe) and implications for basin dynamics

In this paper, a literature‐based compilation of the timing and history of salt tectonics in the Southern Permian Basin (Central Europe) is presented. The tectono‐stratigraphic evolution of the Southern Permian Basin is influenced by salt movement and the structural development of various types of salt structures. The compilation presented here was used to characterize the following syndepositional growth stages of the salt structures: (a) “phase of initiation”; (b) phase of fastest growth (“main activity”); and (c) phase of burial’. We have also mapped the spatial pattern of potential mechanisms that triggered the initiation of salt structures over the area studied and summarized them for distinct regions (sub‐basins, platforms, etc.). The data base compiled and the set of maps produced from it provide a detailed overview of the spatial and temporal distribution of salt tectonic activity enabling the correlation of tectonic phases between specific regions of the entire Southern Permian Basin. Accordingly, salt movements were initiated in deeply subsided graben structures and fault zones during the Early and Middle Triassic. In these areas, salt structures reached their phase of main activity already during the Late Triassic or the Jurassic and were mostly buried during the Early Cretaceous. Salt structures in less subsided sub‐basins and platform regions of the Southern Permian Basin mostly started to grow during the Late Triassic. The subsequent phase of main activity of these salt structures took place from the Late Cretaceous to the Cenozoic. The analysis of the trigger mechanisms revealed that most salt structures were initiated by large‐offset normal faults in the sub‐salt basement in the large graben structures and minor normal faulting associated with thin‐skinned extension in the less subsided basin parts.     

硫化物风化产酸对流域岩石风化和碳循环的影响——以黄河支流三川河流域为例

硫化物风化产酸可加速岩溶作用但抑制大气二氧化碳参与流域碳循环,其复杂的地球化学机制和过程待阐明。本文以黄河二级支流三川河流域为例,通过采集20个三川河及其支流地表水点样和30个柳林泉地下水点样,经实验测试获得了流域比较系统的水化学资料和δ¹³C、δ³⁴ S数据,运用碳、硫同位素分析与水化学平衡计量方法,量化了流域硫化物风化产酸对岩石风化作用的贡献以及对碳循环的影响。计算结果表明：煤系地层硫化物和矿床硫化物的氧化及大气酸沉降所形成的硫酸明显促进了流域碳酸盐岩的溶蚀,对碳酸盐岩溶蚀的贡献约占64.59%;柳林泉水石膏溶解来源的SO₄^2-占69%,河水中石膏溶解来源的SO₄^2-占30%,但这些部分SO₄^2-没有参与溶蚀作用,应当扣除;三川河流域平均岩石风化速率为10.02 mm/ka,其中碳酸盐岩、硅酸盐岩的风化速率分别为9.14 mm/ka和0.88 mm/ka,低于国内外很多流域;由于硫酸抵消了碳酸盐岩石风化作用对大气二氧化碳的吸收,流域岩石风化消耗大气/土壤CO₂通量为116.58 mmol/（km² ·a）,不足珠江流域的1/5,且硅酸盐岩风化的贡献占63.3%。

     

新疆塔里木河流域水资源承载力评价研究

结合塔里木河2002年自然、社会和经济以及水资源资料,选取了耕地灌溉率、水资源利用率、供水模数、需水模数、人均供水量、生态用水率6个主要因素作为评价因素,应用模糊综合评判模型对塔里木河流域水资源承载能力进行了评价研究。结果表明,流域水资源开发利用已经达到相当规模,在现有经济技术条件下,该地区的水资源承载潜力已相对较小,水资源供需矛盾突出,应由耗水型经济结构向节水型经济结构转变,加强水资源的综合管理,以便科学、合理地利用流域内有限的水资源。     

苏浙皖边界地区苏皖运动的有关问题

苏皖运动的存在于否,对研究苏浙皖边界地区的地质发展史和正确认识长兴阶地层有重要意义。笔者论证了长兴组的厚度变化、界线粘土层的性质与成因、底砾岩的确认和地层接触关系、古生物群的突变等问题,认为:1)区内苏皖运动是存在的;2)砺山-江阴海堤不可否定;将安徽广德牛头山经江苏宜兴至江阴条带内的龙潭组上部地层作为长兴组的相变产物是不妥的。     

玛纳斯河流域人工绿洲扩张对社会经济和生态环境的影响分析

 利用2007—2009年的实地调查资料,结合1958—2006年的5期遥感影像解译数据,从干旱区内陆河流域典型绿洲的演变进程出发,分析了新中国成立以来近60 a玛纳斯河流域人工绿洲快速扩张的影响,强调了保持绿洲适宜规模的重要性,并从可持续发展的角度探讨了绿洲今后发展的方向。主要结论为:①近60 a玛纳斯河流域耕地和绿洲分别以107.756 km2·a-1和122.401 km2·a-1的速度迅速增长,二者扩张的方向基本一致;②绿洲的快速扩张对社会经济产生一定推动作用的同时,也带来了一系列的环境问题。如地表水利用率超过90%,地下水过度开采并以0.5~1 m·a-1的速度下降,水质污染增加,防护林大量死亡,森林破坏严重,草地从1958年到2006年减少4 316.39 km2,土地荒漠化威胁严重等;③从可持续发展的角度看,控制绿洲规模,适度开采地下水,转变产业结构,建立生态补偿机制等是今后本区发展的关键。