巢湖杭埠河流域湖相沉积物多指标揭示的全新世以来环境演变     

周慧  吴立  马春梅  管后春  孙小玲  路曙光  尚广春  汪勇  徐仪红  徐军  陈晔  鲍远航 《湖泊科学》2020,32(6):1869-1881

在巢湖杭埠河流域中的古湖盆中心——三河圩区获取28.6 m长的湖相岩芯（SZK1507孔），利用AMS¹⁴C测年技术建立可靠的地层年代序列，通过对SZK1507孔738 cm以上段湖相沉积物平均粒径、磁化率、总氮（TN）、总有机碳（TOC）及C/N的综合分析，高分辨率重建了巢湖杭埠河流域全新世以来的古环境演变过程.结果表明，本区域的环境变化过程可以分为4个阶段，阶段Ⅰ（约10050—9700 cal.a B.P.）与阶段Ⅲ（约9250—5300 cal.a B.P.）气候较为湿润，巢湖水位较高，平均粒径、磁化率值较低，TN、TOC、C/N也偏低；阶段Ⅱ（约9700—9250 cal.a B.P.）与阶段Ⅳ（约5300 cal.a B.P.以来）气候干燥，巢湖水量减少，水位降低，平均粒径、磁化率值、TN、TOC、C/N均较高.一些全球范围内显著发生的气候突变事件在SZK1507孔沉积记录中也有体现，如9.3、8.2和4.2 ka B.P.事件等.将巢湖杭埠河流域10000 cal.a B.P.以来的平均粒径、磁化率、TN、TOC、C/N沉积记录与全新世以来的北纬30°夏季太阳辐射量、太阳黑子数、火山喷发对大气中硫酸盐含量贡献率等进行对比，发现巢湖杭埠河流域全新世气候突变事件主要受控于北半球夏季太阳辐射量变化、太阳活动以及火山活动等因素，并与它们之间复杂的响应机制有关.  相似文献   

以鲢、鳙养殖为主的长江中下游武山湖浮游植物群落结构特征     

张佳敏  高健  杨诚  张泽慧  潘超  廖明军  赵以军  王和云  杨雨慧 《湖泊科学》2020,32(6):1771-1783

武山湖是紧邻长江的通江型富营养化湖泊，是国家级湿地公园.为切实了解该湖在以鲢、鳙养殖为主的情况下浮游植物结构特征，于2017年9月-2018年8月对其浮游植物群落结构特征及水质开展了监测.监测结果表明武山湖水质全年处于轻度富营养到重度富营养水平之间；12次共采集浮游植物7门100种（属），浮游植物优势种共有23种，其中蓝藻门有9种，绿藻门有8种，硅藻门和隐藻门各有3种.夏季和秋季蓝藻门优势种最多且优势度高，冬季和春季绿藻门和硅藻门优势种多且优势度高.武山湖浮游植物每月优势度最大的种类主要有蓝藻门微囊藻和细小平裂藻、绿藻门小球藻以及硅藻门小环藻.浮游植物生物量峰值出现在6月，达34.77 mg/L；丰度峰值出现在7月，达341.46×10⁶ cells/L.冗余分析（RDA）和线性相关分析均表明浮游植物丰度和生物量与总磷、温度和pH均呈显著正相关，且蓝藻门生物量和丰度以及优势属与总磷和温度均呈显著正相关.研究结果表明武山湖浮游植物丰度和生物量在夏季均很高，发生蓝藻水华的风险较大.相对于氮，磷是更重要的限制浮游植物生长的营养元素.  相似文献   

Developing a comprehensive evaluation method for Interconnected River System Network assessment: A case study in Tangxun Lake group     

Yang  Wei  Zhang  Liping  Zhang  Yanjun  Li  Zongli  Xiao  Yi  Xia  Jun 《地理学报(英文版)》2019,29(3):389-405

Journal of Geographical Sciences - The Interconnected River System Network (IRSN) plays a crucial role in water resource allocation, water ecological restoration and water quality improvement. It...  相似文献   

流域尺度土地利用调蓄视角的雨洪管理探析     

苏伟忠  汝静静  杨桂山 《地理学报》2019,74(5):948-961

发达国家雨洪管理焦点历经管网设计、不透水面阈值控制、低影响开发及土地利用管理等过程,呈现“多尺度多视角衔接”趋势。本文聚焦太湖流域土地利用调蓄功能变化机制及管理应用,揭示了1985-2015年来建设占用耕地是调蓄功能降低的主要原因;发现基于小流域的调蓄功能变化与建设用地强度整体低关联,但局部高相关,高相关的地区位于大城市或某些乡镇周边的建设增长热区,而这些热区的建设用地与调蓄空间规模较大且接触机会更多,是开发之前调蓄空间保护、开发控制以及开发之后综合管理等3个土地利用调蓄目标因子协调不当的结果;最后提出流域尺度土地利用调蓄视角的雨洪管理“345”模式,即以3个目标因子和5类控制要素为基础,实施土地利用调蓄创建、防御、拓展与保护等4类差别化战略模式,从更大尺度认识老城区和新区的雨洪关联,拓展海绵城市建设的本土认知和视野。  相似文献   

黑龙江省兴凯湖自然保护区生态系统固碳服务功能评价     

肖红叶  戴慧敏  杨泽  刘国栋  高铁  杨佳佳  张一鹤 《地质与资源》2020,29(6):570-573

湿地是自然界中重要的“碳汇”，其碳储量变化对全球气候变化和温室效应有重要的影响.选择地理位置独特的黑龙江兴凯湖自然保护区作为研究区，根据保护区内不同土壤类型采集表层（0～20 cm）土壤样品，利用遥感解译的保护区土地利用图、土壤储碳量和植物固碳量计算公式，核算兴凯湖自然保护区生态系统固碳服务总量，同时借鉴瑞典碳税法和中国造林成本法，估算兴凯湖保护区固碳服务功能价值为4.9亿元.结果显示，兴凯湖自然保护区湿地固碳服务功能高于全国平均水平，且高于同纬度同属东北平原的莫莫格湿地，为保护区今后的保护管理策略提供了有效的参考依据.  相似文献   

艾比湖原核微生物菌群结构演变与环境因子关系分析          下载免费PDF全文

马雪莉  吕杰  马媛  吕光辉 《盐湖研究》2020,28(4):79-90

用非培养法获得新疆维吾尔自治区艾比湖湖底沉积物原核微生物菌群组成,并与已有盐湖原核微生物菌群数据进行比对,分析湖泊由淡水湖向盐湖演替过程中原核微生物群落结构变化规律。实验获得艾比湖原核微生物16S rRNA基因序列,并从NCBI数据库下载赛里木湖、柴窝堡湖和顿巴斯他乌盐湖3个湖泊的非培养原核微生物16S rRNA基因序列数据。用不同盐湖细菌和古菌16S rRNA序列信息构建系统发育树并与其理化指标进行典型性相关分析。同源比对及聚类结果显示,艾比湖湖底沉积物中细菌包括4个门,拟杆菌门(Bacteroidetes)占克隆文库的64%,变形菌门(Proteobacteria)占9.4%,厚壁菌门(Firmicutes)占3.4%,放线菌门(Actinobacteria)占2.6%,此外含有未分类类群20.6%。古菌含有两个门,广古菌门(Euryarchaeota,98.3%)和盐纳古菌门(Nanohaloarchaeota,1.7%)。不同盐湖系统发育树结果显示,随盐度增加,盐湖细菌从变形菌门向拟杆菌门演替；古菌从奇古菌门和泉古菌门向广古菌门和盐纳古菌门演替。RDA结果显示,Na⁺、Cl-、SO₄2-和矿化度对盐湖原核微生物多样性结构起到决定性的作用,K⁺、Mg²⁺和Ca²⁺对艾比湖菌群结构影响作用最为显著。原核微生物群落会随着湖水盐浓度的增加和盐湖化学成分的不同而发生演替。  相似文献   

国内盐湖卤水硼资源提取专利分析          下载免费PDF全文

李玉婷  李禾禾  倪颖  王瑜  葛飞 《盐湖研究》2020,28(3):109-114

基于中国盐湖硼资源开发动态,选择国家知识产权局专利数据,从盐湖卤水硼资源提取相关专利申请时间、地域分布、主要方法等方面进行分析。发现中国专利包含多种盐湖硼资源提取方法,并且逐步走向成熟,其中萃取法已成为研究重点。近期关于多种伴生资源综合开发的专利越来越受到关注。对国内盐湖硼资源提取技术后续开发和产业发展提出了建议。  相似文献   

A note on the lake level variations of Nam Co,south-central Tibetan Plateau from 2005 to 2019     

ShiQiao Zhou 《寒旱区科学》2020,12(6):430-435

Tibetan lake levels are sensitive to global change, and their variations have a large impact on the environment, local agriculture and animal husbandry practices. While many remote sensing data of Tibetan lake level changes have been reported, few are from in-situ measurements. This note presents the first in-situ lake level time series of the central Tibetan Plateau. Since 2005, daily lake level observations have been performed at Lake Nam Co, one of the largest on the Tibetan Plateau. The interannual lake level variations show an overall increasing trend from 2006 to 2014, a rapid decrease from 2014 to 2017, and a surge from 2017 to 2018. The annual average lake level of the hydrological year (May-April) rose 66 cm from 2006 to 2014, dropped 59 cm from 2014 to 2017, and increased 20 cm from 2017 to 2018, resulting in a net rise of 27 cm or an average rate of about 2 cm per year. Compared to the annual average lake level based on the calendar year, it is better to use the annual average lake level based on the hydrological year to determine the interannual lake level changes. As the lake level was stable in May, it is appropriate to compare May lake levels when examining interannual lake level changes with fewer data. Overall, remote sensing results agree well with the in-situ lake level observations; however, some significant deviations exist. In the comparable 2006-2009 period, the calendar-year average lake level observed in-situ rose by 10-11 cm per year, which is lower than the ICESat result of 18 cm per year.  相似文献   

Socio-hydrological framework for investigating farmers’ activities affecting the shrinkage of Urmia Lake; hybrid data mining and agent-based modelling     

Parsa Pouladi  Amir Molajou  Mohammad Hadi Afshar 《水文科学杂志》2020,65(8):1249-1261

ABSTRACT

Developing a general framework to capture the complexities associated with the non-linear and adaptive nature of farmers facing water resources scarcity is a challenging problem. This paper integrates agent-based modelling (ABM) and a data mining method to develop a hybrid socio-hydrological framework to provide future insights for policy-makers. The data associated with the farmers’ main characteristics were collected through field surveys and interviews. Afterwards, the association rule was employed to discover the main patterns representing the farmers’ agricultural decisions. The discovered patterns were then used as the behavioural rules in ABM to simulate the agricultural activities. The proposed framework has been was applied to explore the interactions between agricultural activities and the main river feeding the Urmia-Lake, Iran. The outcomes indicate that farmers’ acquisitive traits and belongings have significant impacts on their socio-hydrological interactions. The reported values of the efficiency criteria may support the satisfactory performance of the proposed framework.  相似文献   

Prediction of the calcium carbonate budget in a sedimentary basin: A “source-to-sink” approach applied to Great Salt Lake,Utah, USA     

Anthony Bouton  Emmanuelle Vennin  Philippe Amiotte-Suchet  Christophe Thomazo  Jean-Pierre Sizun  Aurélien Virgone  Eric C. Gaucher  Pieter T. Visscher 《Basin Research》2020,32(5):1005-1034

Most source-to-sink studies typically focus on the dynamics of clastic sediments and consider erosion, transport and deposition of sediment particles as the sole contributors. Although often neglected, dissolved solids produced by weathering processes contribute significantly in the sedimentary dynamics of basins, supporting chemical and/or biological precipitation. Calcium ions are usually a major dissolved constituent of water drained through the watershed and may facilitate the precipitation of calcium carbonate when supersaturating conditions are reached. The high mobility of Ca²⁺ ions may cause outflow from an open system and consequently loss. In contrast, in closed basins, all dissolved (i.e. non-volatile) inputs converge at the lowest point of the basin. The endoreic Great Salt Lake basin constitutes an excellent natural laboratory to study the dynamics of calcium on a basin scale, from the erosion and transport through the watershed to the sink, including sedimentation in lake's waterbody. The current investigation focused on the Holocene epoch. Despite successive lake level fluctuations (amplitude around 10 m), the average water level seems to have not been affected by any significant long-term change (i.e. no increasing or decreasing trend, but fairly stable across the Holocene). Weathering of calcium-rich minerals in the watershed mobilizes Ca²⁺ ions that are transported by surface streams and subsurface flow to the Great Salt Lake (GSL). Monitoring data of these flows was corrected for recent anthropogenic activity (river management) and combined with direct precipitation (i.e. rain and snow) and atmospheric dust income into the lake, allowing estimating the amount of calcium delivered to the GSL. These values were then extrapolated through the Holocene period and compared to the estimated amount of calcium stored in GSL water column, porewater and sediments (using hydrochemical, mapping, coring and petrophysical estimates). The similar estimate of calcium delivered (4.88 Gt) and calcium stored (3.94 Gt) is consistent with the premise of the source-to-sink approach: a mass balance between eroded and transported compounds and the sinks. The amount of calcium deposited in the basin can therefore be predicted indirectly from the different inputs, which can be assessed with more confidence. When monitoring is unavailable (e.g. in the fossil record), the geodynamic context, the average lithology of the watershed and the bioclimatic classification of an endoreic basin are alternative properties that may be used to estimate the inputs. We show that this approach is sufficiently accurate to predict the amount of calcium captured in a basin and can be extended to the whole fossil record and inform on the storage of calcium.  相似文献