气候变化条件下洪泽湖以上流域水资源演变趋势

基于IPCC对全球和中国的气候变化趋势,利用1990—2011年气象资料,采用增量情景设置方法,分析气候变化情景下洪泽湖以上流域水资源的演变趋势。结果表明:该流域水资源量对降雨变化有较强的敏感性,实际蒸散发对温度变化的敏感性较强。与基准期相比,在气温同等条件、降水增加情景下,流域水资源量呈增加趋势;在降水同等条件、气温升高情景下,流域的实际蒸发会增加,导致水资源量呈减少的趋势。径流年内分配受降水变化影响较大;随着降水增加,径流年内分配更集中,加大年内径流分配差异,可能加大流域湖泊调蓄压力。     

What Drives Warming Trends in Streams? A Case Study from the Alpine Foothills

We investigated the effects of climate warming and land‐use changes on the temperature and discharge of seven Swiss and Italian streams in the catchment of Lake Lugano. In addition, we attempted to predict future stream conditions based on regional climate scenarios. Between 1976 and 2012, the study streams warmed by 1.5–4.3 °C, whereas discharge showed no long‐term trends. Warming trends were driven mainly by catchment urbanization and two large‐scale climatic oscillations, the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. In comparison, independent influences by radiative forcing due to increased atmospheric CO₂ were uncertain. However, radiative forcing was predicted to further increase stream temperature (to +3–7 °C), reduce summer discharge (to ?46%) and increase winter discharge (to +96%) between the present and 2070–2099. These results provide new insights into the drivers of long‐term temperature and discharge trends in European streams subject to multiple impacts. The picture emerging is one of transition, where greenhouse‐gas forcing is gaining ground over climate oscillations and urbanization, the drivers of past trends. This shift would impress a more directional nature upon future changes in stream temperature and discharge, and extend anthropogenic warming to rural streams. Diffusing future impacts on stream ecosystems would require adaptation measures at local to national scales and mitigation of greenhouse‐gas emissions at the global scale. Copyright © 2014 John Wiley & Sons, Ltd.     

Development issues regarding Bunot Lake: the Lesser Lake among the seven lakes of San Pablo City,Philippines

Bunot Lake exhibits the worst conditions among the seven crater lakes of San Pablo City in the Philippines. It is the most polluted lake, being oversaturated with fish pens/cages. It also hosts the largest concentration of illegal settlements. These attributes strongly suggest that Bunot Lake merits much greater attention in the agenda of its two administrative agencies, the Laguna Lake Development Authority (LLDA) and the City Government. The reality, however, is that Bunot Lake is lacking key development initiatives and programmes and seems to occupy a low priority to the LLDA and the City Government. This reality is particularly perplexing as the lake is located very near the urban centre, is closest to the premier lake (Sampaloc Lake), and is the site of the first commercial production of tilapia in floating cages in the city. Against this background, the present study identifies and analyses the immediate development issues for Bunot Lake. It contends that Bunot Lake should be given preference by the LLDA and the City Government, specifically by: (i) modifying their model‐template approach; and (ii) taking steps to tackle a basic need of Bunot Lake, namely the formulation of a zoning‐development plan. The present study also was designed to directly address the lacuna in Philippine lake studies, namely the paucity of research under the social science perspective (which is currently dominated by the natural science perspective) and on small lakes (which is currently concentrated on the largest lakes in the country).     

Effects of habitat and fishing on fish assemblages in a tropical reservoir: Lake Kariba,Zimbabwe

This study investigated the effects of habitat and fishing on fish communities along inshore areas of the Sanyati Basin, Lake Kariba. A one‐year experimental gillnet survey was carried out in 2007 from eight sampling sites located in two different habitats (river mouths and sheltered bays), and in areas open or closed to fishing. A total of 16 species were captured, although the numbers caught at each site varied widely, with only four species recorded at each of the eight sampling sites. The numbers of fish were higher in the fished areas, mainly because of large numbers of Synodontis zambezensis, although the differences were not significant. In contrast, there were significant differences in the abundance of all species between habitats, with the exception of Cyphomyrus discorhynchus and Marcusenius macrolepidotus. There were no significant differences in the diversity of fish in these areas, although mean diversity and evenness were slightly higher in unfished areas and in sheltered bays. Overall, 90% of the fish specimens caught were within a 10–25 cm size range, although there were no systematic differences in the mean length in relation to fishing. In contrast, most fish were generally larger in river mouth areas than in sheltered bays. These data suggest that fishing had little effect on fish communities. This is in contrast to general habitat, which had a significant effect, a finding consistent with earlier studies showing that vegetation, in particular, had a significant effect on fish stocks.     

白洋淀水环境质量评价

由于流域人类活动和气候干旱化的影响,白洋淀水体污染与富营养化日趋严重。通过对白洋淀湖水化学成分的分析,并运用与湖泊富营养化关系最为密切的Chla、TN、TP、CODMn和SD作为评价参数,采用综合营养指数法确定湖水营养类型。湖水水质监测数据分析表明,白洋淀为重碳酸类钠组Ⅱ型水的偏碱性湖泊,综合营养指数法确定湖水为中-富营养级湖泊水体。主成分分析法结果显示,湖泊污染的主要因子是TP。借助硅藻及其组合分析了湖泊富营养化状况,发现白洋淀硅藻属种以耐营养种梅尼小环藻Cyclotellameneghiniana(20.43%)和Cyclostephanos tholiformis(25.40%)为组合特征,表明湖泊水体已处于富营养化状态,水环境状况堪忧。     

基于Landsat2T M 影像的洞庭湖水面动态变化

为了探究近20 年来洞庭湖萎缩状况, 定量评价其水面面积变化情况, 选择Landsat TM 遥感影像作为数据 源, 采用单波段阈值分析法、多波段谱间关系法、水体指数法、植被指数法和目视解译法对洞庭湖水体进行了解译, 探讨了1993 年- 2010 年洞庭湖水体面积动态变化状况。结果表明, 若以1949 年洞庭湖面积( km2 ) 作为历史参考 水面, 则18 年间湖面积萎缩严重, 秋季平水期萎缩比例均超40%; 若以1978 年洞庭湖水面为参考, 则萎缩比例少 于40%。研究还表明, TM 图像的72422 波段组合对于洞庭湖水体的解译非常有效, 可以作为地区水文水资源研究 的重要手段。     

环太湖地区城市群整体竞争力分析

环太湖地区五个地级城市和若干县级城市作为一个城市群整体竞争力有待提高。提高环太湖地区城市群整体竞争力必须打破行政区划造成的制度分割,构建城市群运转的协调机制,提高制度竞争力;利用优势,完善长三角经济圈腹地的循环功能,提高其区域竞争力;加强环太湖地区环境保护的协作力度,提高可持续发展的竞争力;以经济全球化为契机,以自主创新为动力,提高国际竞争力。     

呼伦湖沉积物中环境敏感粒度组分提取

2015年3月在中国北方呼伦湖采集100 cm湖泊沉积物岩芯并进行粒度分析,揭示了呼伦湖岩芯粒度参数的垂向分布序列。研究区柱状沉积物粒度组成以18 cm、60 cm和86 cm为界限分4个主要的阶段,并且小于16μm组分含量和大于32μm组分含量基本呈反向变化趋势,中值粒径的变化趋势和砂质组分含量的变化趋势一致。通过粒径-标准偏差法,获得了呼伦湖沉积物岩芯中对沉积时期环境变化较为敏感粒度组分范围约为大于30μm。利用主成分分析法,得到两个主控因子F1和F2,它们贡献了湖泊沉积物近88.12%的粒度变化特征。这两种方法相互结合,可以有效的探讨呼伦湖沉积物沉积时的古气候(降水,季风等)信息,同时其它一些环境要素也有较好地体现。     

贵州百花湖叶绿素a高光谱监测模型研究

为对百花湖的叶绿素a浓度进行高光谱模型监测,以更高效和在更大范围内监测湖水富营养化状况,结合百花湖水体的具体情况,对湖区水体布置采样点进行监测,获取了2012年4月和12月的实测水体高光谱数据和叶绿素a浓度数据。通过对获取数据的处理和分析,提取了叶绿素a的敏感波段并建立了叶绿素a浓度与水体光谱反射率相关模型。分析结果发现:1百花湖叶绿素a的敏感波段为706,707,678 nm和679nm,且敏感波段的组合运算可提高光谱数据与叶绿素a浓度之间的相关显著性;2通过对模型精度的对比分析,发现用(706+707)/(678+679)波段组合所建立的线性模型对叶绿素a浓度的反演精度最高;3以4月份的数据建立的模型经12月份的数据验证,精度也较高,说明该模型在一定范围内不受时间限制,可用来对百花湖叶绿素a的浓度进行及时监测。     

苏州市环太湖地区休闲度假旅游发展探讨

苏州是我国著名的旅游城市，但其旅游观光休闲业的发展很不平衡，严重影响了旅游业的稳定健康发展。本文从休闲度假旅游的相关理论入手，分析了苏州环太湖地区发展休闲度假旅游的优势，同时也指出其发展休闲度假旅游的劣势与存在的问题t并在此基础上提出了苏州环太湖地区发展休闲度假旅游的市场定位、发展原则、目标、发展思路和模式以及若干发展对策与建议。