从洪涝灾害谈生态平衡

去年汛期，我国东北和长江中下游地区发生了自１９５４年以来最大的洪涝灾害，影响和损失都是巨大的。洪涝灾害的形成与气候异常、水利设防等级不够等客观因素有关，但不可否认，我国洪涝灾害之所以年年发生，一个最主要原因，是生态环境遭受严重破坏的结果，尤其是上游地...     

以生态智慧引导下的城市韧性应对洪涝灾害的威胁与发生

应跳出技术层面,从智慧层面看待洪涝灾害问题。阐述了生态智慧与城市韧性的含义,以生态智慧引导城市韧性建设的角度,从观念引导、权衡引导、功能引导、学习引导、协作引导、实施引导等6个方面提出了建设韧性城市以及应对洪涝灾害的建议。     

浑太流域洪涝灾害及其治理方略

抚顺、鞍山、辽阳等在内的中部城市群提供年用水量７．０×１０９ｍ３的７０％［５］,对辽宁经济发展与生态环境建设具有至关重要的作用．本文试图剖析浑河、太子河洪涝灾害问题,找出其成因与特点,从生态与工程结合角度提出治理方略,为防洪减灾,振兴经济服务．２　洪涝灾害成因分析２．１　洪涝灾害的一般分析　　洪涝灾害是天降暴雨和下垫面综合作用的结果．它通常依赖气象、水文地理和生态环境三方面因素．气象因素主要指暴雨,包括雨量、雨强和降雨落区．暴雨主要受大气环境制约,目前人类难以左右．然而,通过人工控制增减局地降雨…     

南方洪涝灾害综合风险评估

利用中国南方地区12个省(市)2004—2012年的洪涝灾情资料,在综合表征洪涝灾情特点的基础上,选取具有可比性的受灾面积比重、受灾人口比重和直接经济损失比重等相对灾情指标,剔除耕地复种、人口变化、物价上涨和地域尺度限制等因素的影响,通过灰色关联法、正态信息扩散法,构建洪涝灾害综合相对灾情指数及其风险估算模型,对南方地区洪涝灾害的综合风险进行了研究。结果表明:综合相对灾情指数能较好反映不同省份每年受灾的差异情况,各省(市)的综合相对灾情指数与实际灾情的相关系数均达0.7以上(P0.05);洪涝灾害主要为中灾和小灾,江西、湖北、四川、重庆发生大灾的可能性较大,福建、湖南、广西和安徽次之,广东、云南、江苏和浙江可能性较小;在排除热带气旋带来的洪涝灾害影响下,洪涝灾害综合相对灾情风险分布特征为内陆地区高于沿海地区,内陆地区中湖北的风险最高,沿海地区中江苏最低。本研究结果解决了区域间综合相对灾情等级的风险量化及可比性问题,可为区域防洪救灾对策措施以及洪涝灾害保险政策制定提供科学依据。     

鄱阳湖区灰鹤越冬种群数量与分布动态及其影响因素

1998—2011年,采用地面同步调查法开展了鄱阳湖越冬灰鹤种群监测,并整合1984—2011年鄱阳湖国家级自然保护区历年的越冬灰鹤最大种群数量,分析了鄱阳湖灰鹤越冬种群动态以及影响其数量变化与空间分布的环境因素。结果表明,近13年来鄱阳湖区越冬灰鹤种群平均数量为(2 335±651)只,种群数量呈增长趋势,2011年冬季记录到最大种群数量7 640只。灰鹤越冬种群数量与10月平均最低气温以及10月平均气温存在显著正相关,与10月平均最大风速存在显著负相关,与各月的平均水位没有显著的相关性。每年冬季灰鹤在鄱阳湖呈聚集型分布。大湖池、大莲子湖、三湖、汉池湖、企湖、珠湖、南湖(共青)、大汊湖等8个湖泊是灰鹤的重点活动区,(74.9±5.6)%的越冬灰鹤分布在保护区之外。灰鹤的空间分布与滩地面积存在显著的正相关,与农田面积、人口密度、村庄数量、8月份初级生产力、11月份初级生产力等环境因子存在显著负相关。滩地面积是影响灰鹤空间分布的重要因子,对灰鹤利用频次空间变化的解释率为15.0%,与11月份初级生产力共同解释了灰鹤年平均群体数量空间变化的24.6%。如竞争、小生境结构、干扰等局地尺度的环境要素对灰鹤空间分布的影响研究将有助于更全面地认识鄱阳湖越冬灰鹤种群动态的影响机制。     

基于土地利用变化情景的城市暴雨洪涝灾害风险评估——以深圳市茅洲河流域为例

近年来频发的暴雨洪涝成为威胁城市可持续发展的主要灾害类型,而土地利用变化改变了区域原有的景观结构和水文过程,是城市暴雨洪涝灾害风险加剧的重要诱因,定量探讨土地利用变化对暴雨洪涝灾害及其风险影响具有重要意义。以深圳市茅洲河流域为例,基于CLUE-S模型、SCS模型及等体积淹没算法等,对12种暴雨洪涝致灾-土地利用承灾情景下的城市暴雨洪涝灾害风险进行定量模拟。研究结果显示,相同土地利用空间格局下城市暴雨洪涝灾害随暴雨致灾危险性增加风险加剧显著;在同等致灾危险性水平下随建设用地面积增加,中等风险和高风险区面积均呈现较为明显的增加趋势,中、高风险区面积与建设用地面积的增加率表现出较高的协同变化特征;以50年遇危险性水平为例,随着建设用地面积由基期的15368.85hm~2增加至近期16076.07hm~2和远期16750.89hm~2,高风险区面积由254.07hm~2增加至276.48hm~2和286.2hm~2。由此可见,尽管暴雨强度的增加是城市暴雨洪涝灾害风险加剧的根本诱因,但是以建设用地面积增加为表征的土地利用变化对暴雨洪涝灾害风险的影响不容忽视。     

“水质与我们的生活”专题综合实践活动

调查广州地区5个公园湖的水体浊度、pH、电导率、氮、磷和叶绿素含量。结果表明广州动物园湖、广州麓湖、广州流花公园湖、番禺宾馆湖的氨、磷、叶绿素等含量均已超过富营养化湖的指标,为了保护公园的优美环境,提出了进一步加强公园湖水管理的措施。     

全球温暖化对淡水生态系统的影响及适应对策

在全球水资源中,淡水只占２．７％左右,而分布在江、河、湖、泊中的不足０．０２％。同海水,甚至同淡水的总量相比,江、河、湖、油等陆地淡水水量虽微不足道,却起着重要的作用,是全球水循环中重要的一环,与人类生产和生活联系密切,极大地影响着人口的分布和经济的发展。江、河、湖、油等陆地淡水及生活在其中的形形色色的生物就构成淡水生态系统。淡水生态系统具有自身的特点。一方面,由于水的比热和溶解热较大,对气温变化的影响有一定的缓冲作用,因而为水生生物创造了一个比陆栖生物相对稳定的温度环境,也正是这一“温床”使水…     

相依为命,衡水电厂与衡水湖

坐落在秀丽的衡水湖畔的“湖北衡丰发电有限责任公司”,当地人习惯地称之为“衡水电厂”。说起衡水湖与衡水电厂的关系,当地水务局的官员有一个很有趣的说法,即“有衡水湖才有衡水电厂,有衡水电厂才有衡水湖”。     

达里湖 美丽与忧患同在

达里诺尔(诺尔,蒙古语即湖,人们也习惯称达里湖。)意为“像大海一样宽阔美丽的湖”,位于内蒙古赤峰市克什克腾旗境内,是内蒙古四大内陆湖之一。达里湖周长百余公里,还有岗更诺尔和多伦诺尔两个姊妹湖,通过亮子河、贡格尔河、沙里河、耗来河像引线一样将三个湖泊穿在一起,形成面积238平方公里的高原湖区,总储水量达16亿立方米,最深13米。浩瀚的达里湖既是鸟类栖息繁衍的良好场所,又是西伯利亚到中国东南沿海候鸟迁徙的重要歇脚地。达里诺尔自然保护区始建于1986年,1997年被国家列为以保护珍稀鸟类及其赖以生存的湖泊、湿地、草原、林地等多样的生态系统为主的综合性国家级自然保护区。     

A Mixed Method to Evaluate Burden of Malaria Due to Flooding and Waterlogging in Mengcheng County,China: A Case Study

Background

Malaria is a highly climate-sensitive vector-borne infectious disease that still represents a significant public health problem in Huaihe River Basin. However, little comprehensive information about the burden of malaria caused by flooding and waterlogging is available from this region. This study aims to quantitatively assess the impact of flooding and waterlogging on the burden of malaria in a county of Anhui Province, China.

Methods

A mixed method evaluation was conducted. A case-crossover study was firstly performed to evaluate the relationship between daily number of cases of malaria and flooding and waterlogging from May to October 2007 in Mengcheng County, China. Stratified Cox models were used to examine the lagged time and hazard ratios (HRs) of the risk of flooding and waterlogging on malaria. Years lived with disability (YLDs) of malaria attributable to flooding and waterlogging were then estimated based on the WHO framework of calculating potential impact fraction in the Global Burden of Disease study.

Results

A total of 3683 malaria were notified during the study period. The strongest effect was shown with a 25-day lag for flooding and a 7-day lag for waterlogging. Multivariable analysis showed that an increased risk of malaria was significantly associated with flooding alone [adjusted hazard ratio (AHR)  = 1.467, 95% CI = 1.257, 1.713], waterlogging alone (AHR = 1.879, 95% CI = 1.696, 2.121), and flooding and waterlogging together (AHR = 2.926, 95% CI = 2.576, 3.325). YLDs per 1000 of malaria attributable to flooding alone, waterlogging alone and flooding and waterlogging together were 0.009 per day, 0.019 per day and 0.022 per day, respectively.

Conclusion

Flooding and waterlogging can lead to higher burden of malaria in the study area. Public health action should be taken to avoid and control a potential risk of malaria epidemics after these two weather disasters.     

Composition and relative health of remnant vegetation fringing lakes along a salinity and waterlogging gradient

Extensive land clearing for agriculture in south-west Western Australia has led to highly fragmented patches of remnant vegetation. In this landscape, the fringing vegetation of lakes has an important conservation priority in a biologically diverse region but is vulnerable to altered hydrological regimes and easily degraded by waterlogging and salinity. Protection of the fringing vegetation with direct intervention approaches such as drainage or pumping schemes requires knowledge of the tolerance or ‘coping’ range of species targeted for conservation. To obtain this information the health of vegetation in relation to waterlogging and salinity is assessed in two lake systems north of Esperance in south-western Australia. The lower reaches of both systems are dominated by healthy halophytic species. Mesophytes, phreatophytes, xerophytes, and combinations of these classes dominate the upper reaches but are mostly degraded. There are unhealthy and healthy pockets of mesophytic, phreatophytic, xerophytic species, and combinations of these classes occurring at similar elevations above shallow groundwater, indicating that temporal hydroperiod thresholds are important for these species.     

涝渍胁迫对不同树种生长和能量代谢酶活性的影响

为了解涝渍条件下不同树种的耐涝性和适应性,通过田间模拟试验,分析了涝渍胁迫对1年生落羽杉、美国山核桃和乌桕实生苗生长及能量代谢酶的影响.试验分为对照、渍水和淹水3个处理,处理时间为60 d.结果表明：在渍水和淹水条件下,3种树种的相对生长率均表现为落羽杉>美国山核桃>乌桕,落羽杉耐涝性最强,乌桕耐涝性最弱.涝渍条件下,3种树种的根冠比显著增加,更多的光合产物被分配到根系.3树种乙醇脱氢酶和乳酸脱氢酶活性显著升高,其中耐涝性强的落羽杉增加幅度不大,但一直维持在较高水平;而乌桕和美国山核桃在处理初期增幅较大,在处理后期呈下降趋势.3种树种的苹果酸脱氢酶、磷酸己糖异构酶和葡萄糖-6-磷酸脱氢酶-6-磷酸葡萄糖酸脱氢酶的活性均低于对照,其中落羽杉降幅最低,淹水条件下分别下降35.6%、21.0%和22.7%.耐涝性强的树种能够通过自身的调节,维持各种能量代谢途径的强度,为树种在低氧条件下的生命活动提供能量,进而维持一定的生长量.     

Two mechanisms of aquatic and terrestrial habitat change along an Alaskan Arctic coastline

Arctic habitats at the interface between land and sea are particularly vulnerable to climate change. The northern Teshekpuk Lake Special Area (N-TLSA), a coastal plain ecosystem along the Beaufort Sea in northern Alaska, provides habitat for migratory waterbirds, caribou, and potentially, denning polar bears. The 60-km coastline of N-TLSA is experiencing increasing rates of coastline erosion and storm surge flooding far inland resulting in lake drainage and conversion of freshwater lakes to estuaries. These physical mechanisms are affecting upland tundra as well. To better understand how these processes are affecting habitat, we analyzed long-term observational records coupled with recent short-term monitoring. Nearly the entire coastline has accelerating rates of erosion ranging from 6 m/year from 1955 to 1979 and most recently peaking at 17 m/year from 2007 to 2009, yet an intensive monitoring site along a higher bluff (3–6 masl) suggested high interannual variability. The frequency and magnitude of storm events appears to be increasing along this coastline and these patterns correspond to a greater number of lake tapping and flooding events since 2000. For the entire N-TLSA, we estimate that 6% of the landscape consists of salt-burned tundra, while 41% is prone to storm surge flooding. This offset may indicate the relative frequency of low-magnitude flood events along the coastal fringe. Monitoring of coastline lakes confirms that moderate westerly storms create extensive flooding, while easterly storms have negligible effects on lakes and low-lying tundra. This study of two interacting physical mechanisms, coastal erosion and storm surge flooding, provides an important example of the complexities and data needs for predicting habitat change and biological responses along Arctic land–ocean interfaces.     

Physiological responses of cotton to a single waterlogging at high and low N-levels

Surface-irrigated cotton (Gossypium hirsutum L.) grown on slowly draining clay soil is subjected to short-term periods of waterlogging at each irrigation which generally results in reduced productivity. The sequence of above- and below-ground plant responses to transient waterlogging and the role of N availability in modifying the immediate responses were studied. Lysimeters of Marah clay loam (a Natrustalf) were instrumented to monitor soil and plant responses to a 7-day waterlogging event beginning 67 days after sowing. Cotton (‘Deltapine 61’) plants (8 per lysimeter) were grown with two levels of added N (300 kg ha⁻¹ and 30 kg ha⁻¹) and two irrigation treatments (flooded and control). Measured soil-O₂ levels decreased rapidly upon surface flooding because water displaced air and root zone respiration consumed O₂. The rate of O₂ consumption was 2.7 times greater in the high-N treatment than the low-N treatment. This difference was associated with a 1.8 fold difference in numbers of observed roots. Root growth was only slightly affected by flooding. Leaf growth decreased by 28%, foliage temperature increased 2.3% and apparent photosynthesis decreased by 16%. It is suggested that flooding reduced photosynthetic activity within 2 days while other stress symptoms became apparent after about 6 days. Although this stress was reflected in a trend for decreased plant productivity, the effect of flooding on boll dry mass at harvest was not significant at the level of replication used. The single waterlogging did not cause yield reductions comparable to those observed elsewhere when several waterlogging events were imposed. Contribution from the CSIRO, Centre for Irrigation Research, Griffith, NSW, Australia and USDA-ARS, Morris, MI, USA, in cooperation with the univ. of Minnesota.     

Nutrient accumulation and translocation in maturing wheat plants grown on waterlogged soil

Wheat plants (Triticum aestivum L., cv. Arina) growing in large pots (perforated at the bottom for controls, intact for flooding) were embedded in the field in spring. Waterlogging was initiated at anthesis and was maintained throughout the maturation period. Grain yield as well as potassium, phosphorus and magnesium contents in the shoot were decreased on flooded soil, while manganese and iron contents increased considerably. Total calcium and zinc contents per shoot remained comparable to those in controls. The reduction of potassium, phosphorus and magnesium contents by waterlogging was greatest in the grains, while manganese and iron accumulated mostly in the vegetative parts and the glumes. Zinc contents were also lowered in the grains during waterlogging due to an inhibited redistribution from the vegetative parts to the grains. Our results indicate that flooding caused not only an accumulation of manganese and iron in the shoot, but also affected the redistribution of macro- and micronutrients to the maturing gains.     

Antioxidative responses and morpho-anatomical adaptations to waterlogging in Sesbania virgata

Sesbania virgata (Leguminosae) is tolerant of long periods of soil inundation. However, its morphological adaptations to anoxia and its response to possible damage from oxidative stress are still unknown. Here, we provide new information that helps to explain the ability of S. virgata plants to grow in flooded environments. Plants containing six expanded leaves were placed in masonry tanks and were subjected to the following conditions: control (well watered), soil waterlogging (water to the setup level of 1 cm above the soil surface—roots and parts of the stems flooded), and complete submergence (whole plant flooded). Plants exposed to flooding (soil waterlogging and complete submergence) significantly increased their production of hydrogen peroxide (H₂O₂), indicating the extent of oxidative injury posed by stress conditions. We demonstrate that plants exposed to flooding develop an efficient scavenger of ROS (generated during stress) in the roots through the coordinated action of nonenzymatic ascorbic acid (Asc) and dehydroascorbate (DHA) as well as the enzymatic antioxidants superoxide dismutase (SOD), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) that are present in the tissues. Moreover, we observed the development of morpho-anatomical structures such as adventitious roots, lenticels, and cracks in the stem of plants under soil waterlogging. The secondary root of plants under soil waterlogging showed a thinner cortex and larger number of elements of small diameter vessels. Numerous aerenchymas were observed in the newly formed in the adventitious roots. We conclude that these antioxidative responses and morpho-anatomical adaptations in the roots are part of a suite of adaptations that allow S. virgata plants to survive long periods of flooding, notably under waterlogged conditions.     

土壤盐分及水分含量对落羽杉幼苗生长的影响

One year old Taxodium distichum seedlings were grown in pots with varied soil water and salt (NaC1) levels (alone and in combination) under greenhouse conditions to determine their effects on the growth and biomass allocation of the seedlings. The results showed that there were significant effects of soft salt and water contents on the relative height growth, relative stem diameter growth, biaomass increment and allocation, shoot/root ratio, seedling survival, ratio of branch to stem area, ratio of leaf mass to stem area, and ratio of leaf mass to branch area. According to the biomass increment, relative height growth and relative stem diameter growth, 20 treatments were classified into 3 groups by means of systematic cluster analysis. The first one was the treatments waterlogging, flooding, waterlogging 0.15% NaC1, flooding 0.15% NaC1, and waterlogging 0.3% NaC1, which had a high growth, the second one was the treatments flooding 0.45% NaC1, flooding 0.3% NaCl, 75% of field capacity, and 75% of field capacity 0.15% NaCl, which had a medium growth, and the last onewas the treatments 50% of field capacity, 50% of field capacity 0.15% Nat1, waterlogging 0.45% Nat1,25% of field capacity, 25% of field capacity 0.15% NaC1, 75% of field capacity 0.3% NaC1, 75% of field capacity 0.45% NaC1, 25% of field capacity 0.3% NaC1, 50% of field capacity 0.3% NaC1, 50% of field capacity 0.45% NaC1, and 25% of field capacity 0.45% NaC1, which had a poor growth.     

Reversal of eutrophication in four Swiss lakes: evidence from oligochaete communities

One purpose of river maintenance within Britain is to deliver given standards of land drainage service relating to the control, within acceptable limits, of flooding and waterlogging on riparian, mainly agricultural land. Aquatic weed removal is a major maintenance activity. Authorities responsible for cost-effective river maintenance need to determine the extent and timing of vegetation removal in channels of various types. The impact of maintenance is being studied on 12 sites in five regions of the National Rivers Authority (NRA) in England and Wales. The impact of differing maintenance regimes on flooding and waterlogging and the consequences for agricultural performance are assessed. The longevity of maintenance in terms of the time taken for the without maintenance watercourse condition to be reinstated following maintenance has been determined for gravel, sand and silt bed rivers on which vegetation cutting has been performed. The estimated benefits of river maintenance are set against costs to help formulate best maintenance strategies and prioritise and justify maintenance works.