黄河三角洲滨海湿地的演变过程与驱动机制

黄河三角洲拥有我国暖温带最完整的滨海湿地。同时，由每年黄河携带的大量泥沙淤积于河口区域发育而成的新生湿地，仍保留有湿地的原生特点。这使得黄河三角洲成为我国湿地生态研究的理想之地。在全球气候变化的背景下，由于海陆交互，黄河三角洲的湿地演变十分剧烈，这成为影响区域发展的重要因素。&ldquo;十一五&rdquo;以来，随着黄河三角洲高效生态经济区的建设和山东半岛蓝色经济区的提出，黄河三角洲成为区域发展交汇点。如何保证发展与环境的平衡？这对区域的生态环境有了高的要求，而湿地在是黄河三角洲的环境维护中居于核心地位。因此，了解黄河三角洲滨海湿地的演变过程，识别推动其演变的驱动因素，分析其演变的机制，并预测其未来的发展趋势显得极为重要。本文由此立题，以&ldquo;3S&rdquo;技术为手段，综合湿地学、生态学和地理学等方面的知识，通过对黄河三角洲湿地的调查、采样、实验与模拟研究了黄河三角洲的洲体发育和湿地自1976年改道清水沟以来的演变过程，并探讨了引起湿地演变的驱动因素及驱动机制。研究结果如下：①1976年以来，黄河三角洲的海岸线发生了较大的变化，30余年间，其岸线长度增长了10%。黄河三角洲的岸线结构组成也发生了很大的变化。人工岸线类型越来越多，分布空间越来越广，长度越来越长，占总岸线的比重已经由27.96%增加到了84.65%。②黄河三角洲的面积变化也十分显著。具体来看，面积变化可以分为三个阶段，即：1976-1986年的快速增长阶段；1986-2000年的增长停滞，甚至缓速减少阶段；2000-2013年的缓速增长阶段。30余年间，三角洲的面积共增加了699.45 km2，年均面积增长为18.90 km2/a。③影响黄河三角洲洲体发育、演变的因素可以归结为海陆交互作用、黄河水情和人类活动三个方面。④1991年以来，黄河三角洲的湿地分布和湿地组成结构发生了较明显变化，自然湿地在逐渐萎缩，而人工湿地在不断扩张。1991-2013年，三角州的自然湿地面积由1997.20 km2减少为1485.91 km2，面积年均变化率为-23.24 km2/a。人工湿地的面积由112.22 km2上升为560.21 km2，面积年均变化率为20.36 km2/a。而且，各自然湿地亚类的面积变化情况差异也很大。⑤从黄河三角洲的地表覆被类型转化来看：草本沼泽、灌丛湿地、森林湿地、盐沼、滩涂、积水洼地、养殖池、水田和盐田构成了1991-2013年三角洲滨海湿地转化的主体。⑥从湿地的退化来看：1991-2013年，三角洲湿地的退化现象分布范围广、变动大。其中，1999-2004和2004-2009年是三角洲湿地退化最严重的年份，每个阶段发生退化的湿地面积接近于700 km2，占到了自然湿地总面积的近40%。⑦通过模拟发现，黄河三角洲湿地未来整体上的发展趋势不容乐观。同2013年相比，2021年湿地类土地占区域陆地面积的比重已下降到了60%，自然和人工湿地的面积均有下降。⑧推动黄河三角洲自然湿地发育演变的驱动力可以分为自然因素和人为因素。其中，海洋、黄河、道路、土地利用方式、人为设施、油气开发、政策法规等是具体滨海湿地演变的最重要的驱动力。这些驱动因子通过某种方式耦合在一起，共同构成了湿地演变的驱动机制。这些研究成果将会为为区域湿地的可持续发展提供参考和指导。<br /

黄河改道以来黄河三角洲演变过程及其驱动机制.

基于1976--2009年的23期遥感影像,并结合1976--2008年利津站水沙数据以及黄河流域年均降水量数据,定量分析黄河入海水沙特征以及黄河三角洲演变过程及其驱动机制.结果表明:1976--2008年间,黄河入海年径流量和年输沙量呈现出年际变化大和丰枯水(沙)年交替的特征,但总体均呈下降趋势;清水沟流路河口三角洲岸线和面积变化总体呈淤积增长趋势,三角洲的发育过程大致分1976--1985年,1986--1995年和1996--2009年3个阶段,3个阶段的增长速率逐阶段递减;黄河三角洲岸线和面积与利津站累积输沙量之间均呈显著的指数函数关系;黄河流域降水量的年际波动与利津站入海输沙量年际波动基本同步,并具有相关性,说明黄河流域降水量的年际波动是引起入海径流量和输沙量波动的重要原

Germination strategies of Suaeda salsa at different temperature and under different salt stress

为了研究黄河三角洲优势种盐地碱蓬在不同胁迫环境条件下的萌发策略,分别在不同温度、盐度、碱度以及海水原溶液条件下,进行了室内萌发实验,并且测量了其幼苗体内的Na+和K+含量。结果表明,盐地碱蓬种子发芽所需要的积温和最低温度分别为24.57℃.d和0.62℃,最适发芽温度为20℃~35℃,在温度5℃~40℃下均表现出较高的发芽率而且5℃~35℃下发芽速度随温度升高而显著增加。盐地碱蓬具有较高的耐盐性,当盐浓度达到500 mmol.L-1时,发芽率均高于50%,并且在100%海水溶液浓度下发芽率也能达到38%,高盐条件下未萌发的种子转移到淡水中,均表现出较高的复萌率。盐地碱蓬幼苗体内Na+含量随盐度(NaCl溶液浓度)升高而显著增加,而K+含量在该盐度下差异不显著;幼苗体内Na+、K+含量在高碱度(200和300 mmol.L-1NaHCO3)中均显著低于其在低碱度(100 mmol.L-1NaHCO3溶液)中的含量,说明碱胁迫对幼苗生长产生了显著性影响;Na+、K+含量均随着海水溶液浓度增加而显著增加。因此,盐地碱蓬种子萌发的广温性、高耐盐性、高盐环境中的种子高存活率以及幼苗的较强的耐盐能力是盐地碱蓬种群在黄河三角洲适应滨海盐碱湿地复杂环境的主要生存策略。

Spatial and temporal dynamics of sandy coastal geomorphology in the east of Laizhou Bay over recent 60years

Based on the results of field surveys,the spatial and temporal dynamics of sandy coastal geomorphology along the eastern Laizhou Bay over the last 60years was investigated using the comprehensive methods of digital shoreline analysis,remote sensing and geographic information system technologies.The data mainly derived from the nautical charts,topographic maps and high resolution remote sensing images which measured and imaged in different periods.The results show that there are significant spatial-temporal variations in both the sandy coast shoreline migration and the subaqueous slope erosion-deposition evolution along the eastern Laizhou Bay.The alternate regulation of forward and backward for shoreline migration is caught in this study.There is a remarkable non-linear characteristic in the time process.The proportion of the erosional shoreline is fluctuated and phased from 1959to 2013.The average annual evolution rate of eroded coast is divided into two stages by 1985.The erosion rate decreased from the maximum value of 4.95m/a(during the period of 1959-1969)to minimum value 1.97m/a (1969-1985)at prophase.In the late period,the erosion rate increased from 1.97m/a to 4.43m/a(1985- 1998),and the coast was in serious erosion state since then.The characteristics of shoreline migration in four headland bays are not consistent with overall trend.At the same time,the scouring strips distribute alternating with the silting of the subaqueous slope.The trend of scouring and silting evolution was basically opposite in the same coast between the periods of 1959-1985and 1985-2008.Further analysis indicate that there are 5alternations of erosion and deposition and the changes of rate of erosion and siltation,under the control of geomorphic effects of anthropogenic activities such as sediment trapping by reservoirs,fishing culture in supratidal zone and coastal engineering, in the east of Laizhou Bay during recent 60years

Spatial and Temporal Evolution and Driving Mechanism of Man-made Ditches in the Yellow River Delta from 1976 to 2015

人工沟渠作为湿地中高强度人类活动的缩影,强烈影响着湿地的水文过程与生态环境,成为湿地演变的主要驱动力之一.基于1976&mdash;2015年黄河三角洲27期遥感影像和1∶10万地形图,通过目视解译获得人工沟渠(农业沟渠和道路沟渠)数据,定量分析了人工沟渠的时空演变过程及驱动机制.结果表明:(1)黄河三角洲人工沟渠长度、密度呈明显的线性上升趋势,其长度、密度年均分别增长160km和53m/km2.农业沟渠长度、密度变化可分为两个发展阶段:2000年以前符合s型函数增长,2000年以后呈现出线性增长的趋势.道路沟渠的长度、密度变化一直表现为明显的线性上升趋势,其长度、密度年均分别增长141km和47m/km2.(2)黄河三角洲人工沟渠长度与农田面积呈显著的线性相关(P&lt;0.05),与养殖池面积具有良好的对数关系(P&lt;0.0001),与道路长度呈极显著的线性关系(P&lt;0.0001).(3)多元回归分析结果表明,农田面积和道路长度对人工沟渠长度的协同影响达到99.9%(P&lt;0.0001).&nbsp

Intensity Change of Human Disturbance and Its Response to Landscape Pattern in the Yellow River Delta

The coastal wetlands of the Yellow River Delta is the most integral, broadest and youngest wetland ecosystem in the warm temperate zone of China. Also, it has unique ecological landscape as well as important ecological service functions. With the increase in population and the intensification of high- intensity development and construction activities, the sensitivity/fragility of the area is highlighted, which poses a great threat to the sustainable development of coastal areas. Aiming at the unique geographic location and resource characteristics of the Yellow River Delta, based on RS and GIS, the hemeroby model as well as the man-made ditches density were used in this study to intuitively reveal the temporal and spatial characteristics of human disturbance intensity in 1995,2004 and 2015 at the regional and local scales. The response of the wetland landscape pattern to human interference activities was explored as well. A grid analysis method was used to calculate the hemeroby index and man- made ditches density. The data source included the following: Landsat TM、ETM~+ and OLI Remote Sensing Data (30 m resolution) in 1995、2004、2015, SPOT image of 2004(5m resolution), GF-1 image of 2015 (2 m resolution) and topographic map. This study aims to provide decision support for ecological regulation and spatial control on human activities in coastal wetlands of the Yellow River Delta. The results showed that: (1) From 1995 to 2015,both the hemeroby index and the density of artificial ditches in the Yellow River Delta had increased significantly, and its spatial distribution showed a trend of expansion from the southwest to the east and north, and from inland to coastal areas; (2) With the increase of human activities, the area of natural wetlands in the study area have been decreased from 3232.11km~2 in 1995 to 2165.48km2 in 2015,the landscape diversity and spatial heterogeneity increased, ecological connectivity weakened, the plaque shape tended to be regular and simplistic. (3) The response of landscape pattern to hemeroby index varies regionally and temporally. In the Kenli Agricultural Area, Hekou Agricultural Area and Shengli Oil Field Area, where the intensity of human interference activities had been relatively high, the intensity increased significantly, and the regional landscape pattern changed obviously in different phases. In the Yiqianer Management Station and the Yellow River Estuary Management Station area, where the intensity of human interference activities had been relatively low, due to the increase in the density of artificial ditches, the landscape pattern had presented a decreasing trend in landscape diversity, patch complexity and ecological connectivity from 2004 to 2015. (4) The indices of hemeroby and the density of man-made ditches supplement each other and confirm each other, which can reflect the degree of human disturbance activities in the Yellow River Delta more comprehensively and objectively

Construction ofWetland Ecological Networks under Four Kinds of Resistance of Rivers in the Yellow River Delta and Their Comparison

Ecological network is an efficient tool to increase the landscape connectivity which plays important roles in maintain of ecosystem integrity and protection of key habitats. Resistance surface is one of the most important features of ecological network, determining the effectiveness of ecological network construction. The main objective of this paper was to analyze how water resistance surface can influence the connectivity of potential wetland ecological corridors in a typical coastal wetland of the Yellow River Delta. Four water resistance surface schemes were designed based on the values of water resistance cost, respectively: (1) a basic cost value, according to the current references; (2) half of the basic value, (3) the minimum cost value, and (4) decreasing of the cost interval. The cost distances and potential wetland ecological corridor for these four schemes were generated based on the least cost path method. The structure features and landscape connectivity characteristics of these networks of the four different schemes were evaluated using both network constructive indices and landscape connectivity indices. The results showed significant differences among the four potential wetland corridors. Both water cost and the cost interval had affected the ecological corridors significantly. When the value of water cost was decreased by half, the pattern of network 2 was similar with that of the network 1 which based on the referenced value. The number of nodes, the pattern of the potential corridors and their total length have changed slightly. However, when the cost value was the minimum, the number of nodes and the length of potential corridors had increased greatly. The potential corridors have overlapped with the real river networks, especially in the Yellow River tail channel and old channels. In addition, when the cost interval was decreased, the structure of network 4 became complex and the number of nodes, length of potential corridors have also increased. The assessment results of network connectivity also showed that the four designations were able to generate the closed networks and the landscape connectivity indices have increased due to the increasing of threshold values. In particular, when the threshold values were larger than 12 km, the landscape connectivity of network of the third scheme was the highest. The results also showed that the density of new nodes was more intensive in inland areas than that in other parts of the delta, indicating a more fragmented landscape pattern. Consequently, the connection between these wetland habitats should be strengthened. This research could give scientific suggestions for protection and management of the wetlands in the Yellow River Delta

Evolution of coastal wetlands under the influence of sea reclamation in Bohai Rim during 1985-2015

Coastal wetlands are unique ecosystems formed by amphibious mutual effects. Human activities severely affect wetland evolution. Since the 1950s,China has experienced a massive sea reclamation,which resulted in extremely rapid degradation and loss of coastal wetlands. Studies on the evolution of coastal wetlands and its correlation with human activities are of great significance for managing and protecting wetland resources. The spatial-temporal evolution characteristics of coastal wetlands under the influence of sea reclamation were examined based on the TM remote sensing images in four years (1985,1995,2005,and 2015). The transfer matrix of land use and approach of landscape pattern analysis were used in this study. These data were analyzed by 3S technology and the software of eCognition 9.0,and FRAGSTATS 4.2. The results showed that the hotspots of changes in coastal wetlands were Yellow River Delta,Laizhou Bay,Bohai Bay and Liaohe River Delta. The natural wetland area decreased by 45.37%,whereas the artificial wetlands expanded by 57.23% in the past 30 years. Aquatic farm and salt field increased most significantly,which were mainly changed from moor and intertidal zone. Natural wetlands were converted into artificial ones,and artificial wetlands were converted into non-wetlands. Natural wetlands became more artificial. The landscape pattern tended to be fragmented and equilibrated. Meanwhile,the landscape heterogeneity decreased due to the strong human disturbance. Sea reclamation occupied a large area of natural wetlands such as moor and intertidal zone,with an increment of 1606.79 km~2 in the past 30 years. The main land use types were aquatic farm and construction land. The national policy and economic factors drastically affected the evolution of coastal wetlands. Human activities,including farmland reclamation,urban construction,and tidal flats exploitation were the main driving forces for the evolution of the Bohai Rim coastal wetlands

Change of industrial structure and eco－environmental effect of the typical coastal cities in the Yellow Ｒiver Delta

在系统分析东营市及所辖县区产业结构类型发展基础上,通过构建生态环境影响指数(IIISNE),定量评价东营市及其所辖县区1990-2013年三次产业结构转变及其对生态环境的影响。结果表明,研究时段内东营市产业结构发展处第二阶段,第二产业比重较高,重工业占主导,第一、第三产业发展滞后。各县区IIISNE指数较高且随GDP的上升而逐步升高,表明研究时段内研究区产业结构变动对生态环境产生了一定的负效应,区域社会经济的快速发展已经对生态环境造成了干扰,产业结构布局亟待调整升级

Coastline change detection of the Yellow River Delta by satellite remote sensing

以黄河三角洲的Landsat TM/ETM+影像(1989~2009年)为数据源;采用遥感与地理信息系统技术;对黄河三角洲的岸线与面积变化进行监测。结果表明:1989年以来;黄河三角洲的岸线形状及长度均发生了较大变化;其中北部的刁口河流路区岸线向内陆蚀退明显;清水沟流路区的岸线整体向海域推进;部分区域有蚀退现象;神仙沟流路区主要为人工海堤;岸线变化不大。黄河三角洲的整体面积在1989~2009年处于增加中;但2006~2009年;面积变化为负值。从淤蚀情况来看;1989~2009年;黄河三角洲的淤蚀强度经历了"和缓-剧烈"的过程。这说明20年来黄河三角洲整体上处于增长发育中;但2006年后三角洲整体上呈现蚀退现象;同时黄河三角洲的淤蚀情况变得比以往更剧烈;意味着更强的海陆交汇作用和岸线变化。黄河的入海流路、水沙量、降水量等是影响三角洲岸线变化的重要因素;而人工堤坝能够在一定程度上维持海岸线的稳定。对黄河三角洲海岸线变化的研究有助于有效地管理和保护区域的社会和生态环境