近35年官厅水库消落带消涨特征及分区

发布时间：2018-07-10 07:56

本文选题：水位变化 + 消落带分区　；参考：《生态学报》2017年16期

【摘要】：水库消落带作为重要的生态交错带,是深入分析生态要素内在作用机制的特殊区域。以华北内陆大型水库——官厅水库为研究对象,选择1979—2013年Landsat MSS/TM/ETM+/OLI影像作为数据源,分析35年来官厅水库消落带的消涨特征、时空分布差异及其变化趋势,在此基础上进行消落带淹水时长和淹水频次的分区研究,揭示消落带生态结构的形成过程。研究结论如下:(1)近35年来,官厅水库水位落差较大,达8.19m,水位变化分为3个特征时期:1979—1996年,涨落周期约为4—5a的间歇涨落期;1996—2007年,水位持续下降达7.12m的持续萎缩期;2007—2013年,涨落周期为2 a,且年际变化差稳定在0.75m的频繁涨落期。(2)35年来,官厅水库水位消涨形成118.31km~2的消落带,对应3个特征时期形成消落带的面积依次为80.20km~2,76.81 km~2和19.89km~2。间歇涨落期形成的消落带主要分布在永定河河口及平坦的康西草原一带;持续萎缩期的消落带有明显向西北河岸带扩张的趋势;频繁涨落期的消落带以库心区域水位回升为主,面积仅19.89 km~2。(3)1979—2013年,基于淹水累计时长的分区中,消落带整体上表现为淹水累计时长随边岸向库区中心逐渐递增的趋势,25.85%的消落带淹水时长不足5a,71.77%的消落带淹水时长大于16 a,但随着淹水时长减少,消落带区域植物旱化现象突出,同时植被群落盖度和多样性降低。淹水频次分区中,相同淹水频次的区域在空间上离散分布,一次淹水区面积为32.79km~2,在消落带中所占比例优势明显,但累计淹水时长差异同样显著,分别为2 a和26 a,淹水最为频繁的消落带共经历了9次淹水过程;分区中的土壤有机质含量差异表明,淹水频次越高越有利于土壤有机质的积淀。
[Abstract]:As an important ecotone, reservoir collapse zone is a special area for deep analysis of the inherent mechanism of ecological factors. Based on Landsat MSS / TM / TM / ETM / OLI image of Landsat MSS / TM / ETM / OLI from 1979 to 2013, this paper takes Guanting Reservoir in North China as the research object, and analyzes the characteristics, temporal and spatial distribution difference and its changing trend of the collapse zone of Guanting Reservoir in the past 35 years. On the basis of this, the subdivision study on the duration and frequency of flooding in the declination zone was carried out to reveal the formation process of the ecological structure of the zone. The conclusions are as follows: (1) in the last 35 years, the water level drop of Guanting Reservoir has reached 8.19 m.The variation of water level can be divided into three characteristic periods: 1: 1979-1996, and the fluctuation period is about 4-5 years from 1996 to 2007. The water level continued to decline by 7.12m during the period of 2007-2013, and the fluctuation period was 2 years, and the annual variation difference was stable in the frequent fluctuation period of 0.75 m. (2) in the past 35 years, the water level of Guanting Reservoir has declined to form the 118.31km~2 fluctuation zone. The areas corresponding to the three characteristic periods are 80.20km2 27.81 km~2 and 19.89kmm2 respectively. The fluctuating zones formed during the intermittent fluctuations are mainly distributed in the mouth of Yongding River and the flat grassland of Kangxi, the decline and fall in the continuous shrinking period have an obvious tendency to expand to the northwestern riparian zone, and in the frequent fluctuation period, the water level in the reservoir center is mainly rising. The area is only 19.89 km2. (3) in 1979-2013, based on the cumulative duration of flooding, As a whole, the cumulative duration of flooding is increasing gradually along with the edge bank to the center of the reservoir area. The submergence time of 25.85% of the belt is less than 5a or 71.77% of the submergence zone, but with the decrease of the duration of flooding, the flooding duration of the zone is longer than 16 years. The phenomenon of plant drought is prominent and the coverage and diversity of vegetation community decrease. In the subzone with the same frequency of flooding, the area with the same frequency of flooding was dispersed in space. The area of primary flooded area was 32.79 km2 / 2, which was dominant in the area of the collapse zone, but the difference of cumulative flooding duration was also significant. For 2 years and 26 years respectively, the most frequent submergence zone experienced 9 flooding processes, and the difference of soil organic matter content in the subzone indicated that the higher the flooding frequency was, the more favorable the accumulation of soil organic matter was.
【作者单位】：三维信息获取与应用教育部重点实验室;资源环境与地理信息系统北京市重点实验室;北京市环境保护监测中心;
【基金】：国家国际科技合作专项(2014DFA21620)
【分类号】：TV697

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