1984-2017年洪泽湖湿地植被覆盖度变化及对水位的响应 |
Response of Vegetation Coverage to Varying Hydrological Conditions in Hongze Lake Wetland, 1984-2017 |
投稿时间:2020-06-12 修订日期:2020-09-22 |
DOI:10.15928/j.1674-3075.2020.05.012 |
中文关键词:洪泽湖 像元二分模型 植被覆盖度 时空变化 水位 |
英文关键词:Hongze Lake dimidiate pixel model vegetation cover temporal and spatial variation water level |
基金项目:国家重点研发计划课题“湖沼系统生态需水核算及调控技术”(2017YFC0404504) |
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中文摘要: |
研究洪泽湖湿地植被覆盖的时空变化特征及其与水面面积、水位的关系,为湿地植被保护及湿地生态系统健康发展提供理论依据。选用1984-2017年42期的TM/ETM+/OLI数据,采用像元二分模型估算洪泽湖湿地植被覆盖度,分析研究区域植被覆盖度的整体特征及动态变化趋势;利用归一化差异水体指数提取洪泽湖的水体信息,同时结合植被覆盖度与其对应的水位监测数据,运用统计分析的方法构建洪泽湖四季的植被覆盖度-水体面积-水位关系模型。结果表明:(1)洪泽湖湿地的整体植被覆盖度呈略微降低的趋势,中高和高植被覆盖区主要分布于研究区域的西北部及南部;(2) 1984-2017年,洪泽湖的植被覆盖情况以退化为主,退化面积约为668.6 km2,其中不显著退化面积占72.9%;1989-1992年植被覆盖度迅速下降,变化率为-34.9%;(3) 整体上看,研究区的植被覆盖度、水体面积与水位极显著相关,四季的最适宜水位为春季12.3 m、夏季12.9 m、秋季12.1 m和冬季12.2 m。充分考虑多因素如气候、植被类型和人类活动等对洪泽湖湿地植被的影响和使用高分辨率遥感数据动态监测湖区的生态状况是今后研究的重点。 |
英文摘要: |
Hongze Lake wetland is the largest wetland in the Huaihe River basin, playing a vital role in regulating water quality of the lower Huaihe River basin and the eastern route of the South-to-North Water Diversion Project. It also provides excellent habitat for many aquatic and terrestrial animals and plants, but human activities and environmental change have accelerated the succession of vegetation in the wetland. In this study, we explored the temporal and spatial variation of vegetation cover in Hongze Lake wetland and analyzed its relationship with water area and level. The extent of vegetation cover was estimated using a dimidiate pixel model based on 42 sets of TM/ETM/OLI data on Hongze Lake wetland, gathered from 1984 to 2017. The results were then used to analyze trends in vegetation cover. Data on vegetation cover was obtained from the normalized difference vegetation index (NDVI), and a model relating seasonal vegetation cover to water area and water level was constructed. The empirical model was based on statistical analysis of the vegetative cover corresponding to water area and level. Results show that:(1) Vegetative cover in Hongze Lake wetland was higher in dry year, followed by normal year and then a wet year. The fractional vegetation cover (FVC) presented obvious seasonal differences, higher in spring, summer and autumn (May-November), and lower in winter (January). The vegetation cover decreased slightly overall from 1984 to 2017, and areas with high to very high vegetation coverage were mainly distributed in the northwest and south of the study area. (2) During this time, vegetation coverage of Hongze Lake wetland decreased by 668.6 km2, but insignificant degradation accounted for the largest proportion (72.9%). Vegetation coverage declined sharply (34.9%) from 1989 to 1992. (3) In general, vegetation coverage, water area and water level in the study area were highly correlated. The optimal water level was 12.3 m in spring, 12.9 m in summer, 12.1 m in autumn and 12.2 m in winter. In the future, we intend to focus on monitoring the ecology of Hongze Lake wetland and using high resolution remote sensing images to study the influence of climate, vegetation type and human activities on vegetation cover. Our results provide theoretical support and technical reference for scientifically managing the ecology of Hongze Lake wetland. |
龙昊宇,翁白莎,黄彬彬,刘猛.2020.1984-2017年洪泽湖湿地植被覆盖度变化及对水位的响应[J].水生态学杂志,41(5):98-106. |
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