澜沧江流域河流泥沙发展趋势初步研究

本文将澜沧江划分成上、中、下三段。根据实测水文泥沙资料,分析了50年代以来该三段各自的水沙变化过程,以及它们之间的差别,发现水量变化比较平稳,泥沙则有增加趋势。文章从自然和人类活动两方面对变化原因作了探讨。     

哈萨克斯坦巴尔喀什湖沉积物粒度特征及其对区域环境变化的响应

湖泊沉积物中的粒度参数记载了丰富的流域环境变化信息,可为无器测资料地区重建古环境变化序列提供可靠的途径。通过对巴尔喀什湖岩芯沉积物中粒度、磁化率等环境代用指标的分析,结合放射性137Cs定年以及流域气候、湖泊水位等器测记录数据,研究了巴尔喀什湖沉积物中粒度变化特征及其环境指示意义。结果表明:巴尔喀什湖沉积物中黏土质(4μm)组分平均含量为20.32%,细粉砂质(4～16μm)为40.13%,中粉砂质(16～32μm)为22.86%,粗粉砂质(32～64μm)为10.55%,砂质(64μm)为6.13%。通过粒径标准-偏差法提取了沉积物中环境细颗粒敏感组分(F1,6.61～10.00μm)和粗颗粒敏感组分(F2,45.71～69.18μm)。研究表明在人类活动影响不断加强的背景下,粒度敏感组分的含量变化不能敏感的反映湖泊水位、入湖径流乃至区域气候的变化,而与沉积物中磁化率所反映的人类活动强度变化存在较为显著的相关关系(r=0.870,P0.01),这可能与人类活动增强导致的流域内富含磁性物质的细颗粒碎屑物质被搬运入湖有关,湖泊沉积物中磁化率升高的同时,湖泊沉积物中细颗粒物质增加。研究结果可为长时间尺度下古环境重建研究提供重要参考依据,同时也对揭示流域人类活动对湖泊环境的影响具有一定的科学意义。     

青藏高原湖泊沉积物对古气候环境变化的响应

随着全球变化研究的不断深入,青藏高原湖泊沉积物的研究得到很大发展。作为高分辨率古环境变化的“记录仪”,湖泊沉积物在重建晚第四纪全球环境变化中具有特殊的地位和意义。湖泊沉积物中储存的各种信息反映了矿物学、同位素地球化学、生物学、沉积学等方面对气候环境变化的响应。在古环境变化研究中,湖泊沉积物已经从定性化研究逐渐过渡到定量化研究。     

艾比湖流域抛物线沙丘表层沉积物粒度特征

对艾比湖流域抛物线沙丘表层沉积物样品的实验分析结果表明：沙丘表层沉积物粒径分布在0.4~2116.5 μm。沙丘表层沉积物主要成分为沙,且含有一定量的细砾和黏土成分;平均粒径从两翼间地至丘顶逐渐变粗,丘顶至背风坡脚逐渐变细;沉积物分选性整体较差,平均粒径愈小,分选性愈好;粒径频率曲线为正偏、基本对称、负偏和极负偏混合存在。沙丘表层沉积物的平均粒径与分选系数存在不显著的负相关性,与峰态呈现显著负相关,分选系数与峰态呈现显著正相关性。沙丘不同地貌部位沉积物的粒级、平均粒径、分选系数呈现出有规律的变化,系风沙流、沙丘形态、植被和沉积物综合作用的结果。艾比湖流流域内抛物线沙丘的物质来源为两个或两个以上的沉积物混合形成的多源供应物。     

澜沧江-湄公河流域资源环境与可持续发展

澜沧江-湄公河流跨亚洲中国、泰国、柬埔寨、越南和缅甸6国,是亚洲第一国际大河。从北至南流经了多样的气候区和地理单元,有丰富的自然资源和生态资源。随着流域内各国经济的发展,大量的人类经济活动已给流域的生态环境带来许多问题。为维持整体流域的可持续发展,流域内各国必须通力合作．促进全流域整体规划和其同制定各国都应遵循的生态环境保护法规;在加快对河流和其它自然资源开发利用的同时．必须把生志环境的退化与资源浪费作为整治的重点,使流域的巨大天然财富造福于人民。     

克里雅河中下游流域地表沉积物的粒度与化学元素空间分布

通过对克里雅河流域的实地考察、地形测量、取样,分析其流经沙漠过渡带地表沉积物的粒度、化学元素的空间分布,得出以下结论：河流—沙漠过渡带地表沉积物的粒度组成以>2 φ的粒径为主,粒度特征明显表现出风成特点;化学组成上以Si、Al为主,和上陆壳平均化学组成相比,除Ca、Co、As外都有一定的亏损;不同河段自上游至下游,在不同动力条件下,地表物质粒度特征表现出河漫滩砂与阶地风成砂呈相反的递变趋势;不同河段A-CN-K图解及CIA揭示了克里雅河不同河段地表物质化学风化程度均很低,处于较弱的去Na、Ca阶段,其他元素未发生明显的化学风化或迁移,不同河段化学风化程度差异与物源及地貌格局息息相关;同一河段不同地貌单元,随距河道远近不同,粒度特征与化学风化程度呈现出一定的递变规律;克里雅河平均粒径与一些元素的相关性,说明粒径大小与表征化学风化程度数值的大小有一定关系。总之,在不同空间尺度上,克里雅河地表沉积物理化学特征的分异实质上反映风动力和水动力的差异性分选。     

呼伦湖沉积物粒度特征及其环境指示意义

通过对呼伦湖湖心沉积岩芯粒度机械组成和频率分布曲线的分析,辅以²¹⁰Pb年代测定,重建了1865~2016年粒度演变特征并揭示其环境指示意义。研究表明：湖心沉积物主要为粉砂和黏土,中值粒径同粗粉砂和砂组分显著正相关,在垂直剖面上表现为减小、波动变化和增大的变化趋势。应用对数正态分布函数对粒度频率曲线进行拟合,提取出大气粉尘源、湖心相标志组分和风沙尘暴组分3个环境敏感组分。粒度机械组成与环境敏感组分的垂向特征变化同历史时期的湖泊水位变化、降水量强度变化,及沙尘暴事件较为一致,能够较好的重建150 a来湖区气候干湿变化和风沙活动特征,可用于恢复区域环境变化历史。     

艾比湖流域主要河流径流量的多年变化

1 主要河流的选择历史上与艾比湖有联系的河流约有23条,较大的有塔城地区的奎屯河及其主要支流四棵树河和古尔图河,博尔塔拉蒙古自治州的托托河、精河、阿卡尔河、博河和大河沿子河.上述河流大部源于天山北坡,部分源自阿拉套山南坡:根据上述河流产流特性,本文选择博河、精河、奎屯河及其支流四棵树河为代表(以下概称四河),探讨径流变化趋势,四河均在河流出     

1960-2005年澜沧江流域极端降水变化特征

极端降水事件是气候变化的一个重要方面。澜沧江流域纵贯13个纬度,最大相对高差近5000 m,跨6种气候带,是全球少见的南北向大江,它在气候、水文、地理、生态学等多方面都具有重要的科学研究价值。自1960年以来,流域经历了显著的气温上升。探讨在气候变暖背景下这一复杂流域的极端降水变化具有重要意义。本文利用澜沧江流域及其周边35个气象站1961-2005年的日降水资料,分析了小于5 mm、5～10 mm、10～50 mm以及大于50 mm 4个不同量级降水的降水量、降水日数和日平均降水强度的变化趋势。并计算了每种量级降水占总降水量的百分比及降水频率。结果表明,各量级各项指标均存在明显的区域变化特征,流域总体上极端降水频率的增加态势明显。对典型地区站点分析表明,极端降水的增加可能与气候系统随机性变强有关。     

青土湖沉积物粒度特征及其古环境意义

青土湖沉积物的粒度特征反映了青土湖降水、水动力搬运强度以及湖面水位高低的变化。利用石羊河古终端湖泊青土湖剖面沉积物的粒度资料，分析了粒度组成、粒度参数等粒度特征，并探讨了古终端湖泊的沉积环境。结果表明青土湖从11000aBP年以来大致经历了4次极端干旱时期和4次温暖时期。通过对青土湖沉积物粒度频率曲线的分析，讨论了湖泊的几种可能沉积作用，区分出了湖相沉积、风成沉积浅湖相沉积以及水流和风力作用混合沉积，从而揭示了沉积时的古环境特征。青土湖全新世以来的环境演变，具有连续和沉积速率大的特点，不仅可以作为古环境与古气候变化的自然记录，而且为研究本区土地退化、荒漠化等问题提供了自然背景。     

基于SPOT-VGT数据的流域植被覆盖动态变化及空间格局特征——以淮河流域为例

为探明近10多年来淮河流域的植被覆盖状况动态变化及其空间格局,本研究基于SPOT-VGT的NDVI数据和淮河流域土地利用/覆被数据,利用ArcGIS空间分析工具,设计植被动态空间计算模型,分析了1999-2007年淮河流域植被变化的时空格局,包括年内各月变化规律、年际变化趋势、不同景观类型的植被指数特征及其变化趋势等.结果表明:①SPOT-VGT数据结合GIS空间分析和建模工具,可以较好的计算和分析流域尺度的植被状况时空格局;②淮河流域绝大部分地区(71.33％)在1999-2007年NDVI有显著增加趋势,表明流域整体植被覆盖明显改善;③淮河流域NDVI年内变化曲线呈双峰型,4月份和8月份分别出现波峰,8月波峰高于4月;④淮河流域植被覆盖状况空间差异显著,NDVI多年平均值的空间格局为:平原地区较高,淮河干流北岸高于南岸;山丘区差异较大,大别山区植被指数最高,沂蒙山区植被指数最低,水土流失风险较高;大中城市及其周边地区,植被指数低;⑤不同景观类型的NDVI多年变化趋势存在一定的差异:耕地、林地、草地、盐碱地的平均值增长趋势显著且较为平稳.滩地在波动中有小幅度增长;沼泽地波动幅度最大.本研究可为淮河流域森林保育、水土流失防治等措施的制定提供科学依据.     

流域主体功能区划方法与指标体系构建——以长江流域为例

在对国内外空间区划与流域规划研究成果评析、主体功能区划与流域规划关系梳理的基础上,针对目前自然单元主体功能区划不足与流域协调发展实践需要,以长江流域为例,开展流域主体功能区划理论与方法研究。阐述了流域主体功能区划的内涵与特征,提出其本质是主体功能区划与流域规划的有机结合体,进而构建区划逻辑思路与方法路线。基于科学性、系...     

River and basin morphometric indexes to detect tectonic activity: a case study of selected river basins in the South Indian Granulite Terrain (SIGT)

Abstract

The effects and influence of tectonic processes on the Anjarakandy, Thalassery, Mahe, and Kuttiyadi watersheds and rivers of the South Indian Granulite Terrain in Kerala were examined to determine their spatial heterogeneity. Drainage basin asymmetry (Af), transverse topographic symmetry factor (T), hypsometric integral and curve (HI), longitudinal profile, stream length gradient index (SL), and stream concavity index (SCI) suggest heterogeneity in tectonic influence. Clusters of geomorphic anomalies in similar lithology rule out lithologic control on drainage development. However, the orientations of the drainage networks and predominant fractures/lineaments compare closely and reveal strong tectonic influence. Though the watersheds are considered to be in an advanced stage of erosion by the low HI (<30) and high values of SCI, variations in the shape of the hypsometric curves and differences in the SCI values indicate the different influence of tectonic process from watersheds in the north to the south. Among the watersheds, the Mahe and Kuttiyadi are more sensitive to tectonic processes than the Anjarakandy and Thalassery and indicate spatial heterogeneity in the influence of tectonic activity, confirming the grouping of watersheds based on structural and drainage patterns.     

干旱内陆河流域人居环境适宜性评价——以石羊河流域为例(英文)

The study employs slope,aspect,relief degree of land surface,land use,vegetation index,hydrology and climate,as evaluation indexes to set up the Human Settlements Environmental Index(HEI) model to evaluate the environmental suitability for human settlements in the Shiyang River Basin.By using GIS spatial analysis technology,such as spatial overlay analysis,buffer analysis and density analysis,the environmental suitability of the human settlement spatial situation and spatial pattern are established to analyze their spatial distribution.The results show that the index of suitability for human settlements in the Shiyang River Basin is between 17.13 and 84.32.In general,suitability for human settlements decreases from the southwest to the northeast.Seen from an area pattern,the suitable region is mainly distributed in the Minqin oasis,Wuwei oasis and Changning basin,which are about 1080.01 km 2 and account for 2.59% of the total area.Rather and comparatively suitable region is mainly distributed around the counties of Gulang,Yongchang and north of Tianzhu,which is about 1100.30 km 2.The common suitable region is mainly distributed outside the counties of Yongchang,Jinchuan and most parts of Minqin County,which are about 23328.04 km 2,accounting for 56.08% of the total area.The unsuitable region is mainly distributed upstream and to the north of the river,which is about 9937.60 km 2,accounting for 23.89% of the total area.Meanwhile,the least suitable region is distributed around the Qilian Mountains,which are covered by snow and cold desert and lie in the intersecting area between the Tengger Desert and Badain Jaran Desert.The total area is about 6154.05 km 2,accounting for 14.79% of the total area.Suitable regions for human habitation are mainly distributed around rivers in the form of ribbons and batches,while others are scattered.The distribution pattern is identical to the residential spatial pattern.In addition,the relationships between HEI and other factors have been analyzed.There is a clear logarithmic correlation between the residential environment and population,that is,the correlation coefficient between the evaluation value and population density reaches 0.851.There is also a positive correlation between the residential environment and economy,which reaches an evaluation value of 0.845 between the residential environment and GDP.Results also show that the environment is out of bearing with the existing population in Shiyang River Basin.Spatial distribution of population is profoundly affected by severe environmental problems,such as the expanded deserts,the hilly terrain and the changing climate.Surface water shortage and slow economic growth are bottlenecks for suitable human settlement in the Shiyang River Basin.Combining these problems with planning for construction of new country and the exploitation of local land,some residential areas should be relocated to improve the residential environment.     

流域尺度生态需水的估算模型与应用--以克里雅河流域为例

以我国西部典型干旱区新疆南部的克里雅河流域为研究区,通过分析各生态系统需水的结构特征,估算了生态需水的规模,讨论了生态需水的供需平衡问题。研究发现,全流域生态需水总量约为6.93×10⁹m³/a,平均每公顷植被的最小生态需水为413.9m³/a。在各植被类型中,沼泽地耗水、草地耗水、林地耗水分别约占植被总生态需水量的47.6%、43.4%与9.0%,由此可见,沼泽地和草地耗水是该流域植被生态需水的主体。研究结论对于制定水土资源开发利用规划,保障当地水资源的良性循环,实现水资源的可持续利用,恢复和重建生态环境,具有重要的参考价值。     

青海湖流域河川径流特征及其对降水的滞后效应

以青海湖流域的布哈河为例,采用变差系数、集中度和集中期等指标,对青海湖流域内径流量、降水量在年代、年际、季节等时间尺度上进行分析,并用集中期来反映河川径流对降水的滞后效应。结果显示,河川径流年内主要集中在6—10月,特别是7月中旬至8月中旬之间;降水主要集中在5—9月,特别是7月;径流量与降水量存在极大的相关性（r=0.746＞0.443=α0.001(47)）,径流对降水具有滞后效应,多年平均滞后时间为20 d左右。     

河西内陆河流域绿洲面积对地表径流的响应

利用NASA AVHRR NDVI 3g遥感资料计算得出河西内陆河流域植被归一化指数(Normalized Difference Vegetation Index,NDVI),将NDVI＞0.20区域视为绿洲,通过计算绿洲区NDVI的变差系数和线性斜率分析1982-2013年绿洲面积变化,并进一步分析其对地表径流的响应...     

20世纪下半叶中国地理环境的巨大变化--关于全球环境变化区域研究的思考

全球环境变化研究越来越重视全球问题与区域问题的结合,强调全球环境变化的问题应主要通过区域研究来解决。资源环境问题已经成为全球环境变化研究的一个重要内容。20世纪下半叶,强烈的人类活动与全球变化背景叠加,使我国地理环境发生了巨大变化。主要自然过程与环境要素的变化包括:全球变暖背景下气候带的明显摆动,降水南增北减使南方洪涝增加、北方干旱日趋严重,巨大的物质和能源需求与日趋严重的环境污染,天然水文过程的重大改变。在地理格局变化方面,工业化过程带来的产业与经济格局变化,改变了人口格局和城市格局以及自然资源供需格局,地表景观格局因此而发生显著的改变。资源环境已经从发展的条件演变为制约我国国家安全的一个关键因素。对中国地理环境特征与资源环境问题认识上的不确定性是未来社会发展的潜在威胁。对此,需要从全球的视角开展深入的研究。     

澜沧江流域农业灌溉需水的时空变化(英文)

Based on the data of eight meteorological stations from the 1950s to 2007, current cropping patterns, field water moisture management, we use the Mann-Kendall and the Re-scaled Range Analysis methods to research the changes of humidity and crop irrigation water requirements in the Lancang River Basin. The results show that the annual and dry season average temperatures significantly increased, and the dry season rainfall increased while wet season rainfall decreased. Evaportranspiration (ET0) increased during both dry and wet seasons at all stations except Dali, Jianchuan and Gengma, and the aridity-humidity index decreased at most of the stations. The turning points of weather factors, ET0, the arid-ity-humidity index, paddy irrigation requirements and total agricultural water requirements occurred from the 1960s to the 1990s. The spatial changing tendency of paddy irrigation quota increased with the increase of altitude and latitude, and the correlation coefficients are 0.513 and 0.610, respectively. The maximum value is observed in Weixi, while the minimum in Mengla.     

Applicability evaluation of the SWIM at river basins of the black soil region in Northeast China: A case study of the upper and middle Wuyuer River basin

In this paper, we selected the middle and upper reaches of the Wuyuer River basin in the black soil region of Northeast China as the study area. We adopted the soil and water integrated model (SWIM) and evaluated the parameter sensitivity using partial correlation coefficient. We calibrated and validated our simulation results based on the daily runoff data from Yi’an hydrological station at the outlet of the river basin and the evaporation data recorded by various weather stations from 1961 to 1997. Following evaluation of the modeling data against the observed data, we present the applicability of SWIM in the river basin of the black soil region, and discuss the resulting errors and their probable causes. Results show that in the periods of calibration and validation, the Nash-Sutcliffe efficiency (NSE) coefficients of the monthly and daily runoffs were not less than 0.71 and 0.55, and the relative errors were less than 6.0%. Compared to daily runoffs, the simulation result of monthly runoffs was better. Additionally, the NSE coefficients of the potential monthly evaporation were not less than 0.81. Together, the results suggest that the calibrated SWIM can be utilized in various simulation analyses of runoffs on a monthly scale in the black soil region of Northeast China. On the contrary, the model had some limitations in simulating runoffs from snowmelt and frozen soil. Meanwhile, the stimulation data deviated from the measured data largely when applied to the years with spring and summer floods. The simulated annual runoffs were considerably higher than the measured data in the years with abrupt increases in annual precipitation. However, the model is capable of reproducing the changes in runoffs during flood seasons. In summary, this model can provide fundamental hydrological information for comprehensive management of the Wuyuer River basin water environment, and its application can be potentially extended to other river basins in the black soil region.