近年来,武汉市城市内涝频发,湖泊的减少被认为是导致其发生的重要原因.然而目前尚未有一个统一、科学的数据来表示整个武汉市湖泊的历史变迁.为了掌握近几十年武汉市湖泊的时空变化规律,基于多源遥感数据,采用归一化差异水体指数(NDWI)和面向对象分割结合的水体提取算法,对1973-2015年武汉市的湖泊分布进行了提取,并结合武汉市气象资料和统计年鉴对引起其变化的影响因素进行了分析.结果如下:(1)1973年,武汉市辖区内的湖泊水域面积为1170.84 km2,2015年为856.27 km2,42年间减少了314.57 km2,剧烈减少时期发生在1973-2005年,2005年以后,基本趋于稳定.(2)1973年武汉市中心城区湖泊水域面积为148.90 km2,1973年到1996年,湖泊水域面积基本趋于稳定,而在1996年之后,武汉市中心城区湖泊水域面积开始剧烈减少,2010年之后,武汉市中心城区的湖泊水域面积基本趋于稳定;2015年,武汉市中心城区湖泊水域面积为99.94km2,相对于1973年,减少了48.96 km2.(3)1973年到2015年,武汉市年降水量呈现略增加的趋势,年平均气温则有一定的增加趋势;而在1990年之后,武汉市人口的增加、城镇的快速发展及房地产开发导致了大量的湖泊被侵占;气候变化和人类活动共同导致了武汉市的湖泊水域面积减少,其中人类活动是其变化的主要因素.%In recent years,the Wuhan city has suffered flood disasters frequently,and the decrease of lake area is thought to be an important factor.Up to now,there is no consistent data of Wuhan lakes area.In order to analyze spatial and temporal variation of the Wuhan lakes in recent decades,this study used multi-source satellite data,to retrieve the lake images with a combined algorithm of normalized difference water index (NDWI) and object-oriented segmentation from 1973 to 2015.The influence factors of this change were also analyzed in combination with meteorological data and Wuhan Statistical Yearbooks.The results are as follows:(1) in 1973,the area of lakes in Wuhan was 1170.84 km2,and was 856.27 km2 in 2015.The decrease was 314.57 km2 during the period,and the severe decrease period occurred in 1973-2005,after 2005,it basically stabilized.(2) In 1973,the area of lakes in central districts of Wuhan was 148.90 km2,and the area was basically stable from 1973 to 1996.After 1996,the area of lakes in central districts of Wuhan began to decrease drastically,and tends to be stable after 2010.In 2015,the area of lakes in Wuhan central districts was 99.94 km2,a decrease of 48.96 km2 compared to 1973.(3) From 1973 to 2015,the annual precipitation in Wuhan showed a slight increase trend,while the average annual air temperature showed a significant increase trend.After 1990,the population growth,urban development and real estate development in Wuhan led to a large number of lakes were encroached.Climate change combined with human activities led to the changes of lake area in Wuhan,in which human activity may be the main factor.
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