近50年来江汉湖群水域演化定量研究

根据江汉平原湖区发育背景、资源环境结构和社会经济功能等方面因素,将研究区界定为湖北省境内以江汉平原为依托、海拔50 m等高线以内的所有地区。其范围在东经 111°36′38.76″~116°7′52.14″、北纬29°25′59.25″~31°27′14.45″之间，按自然界线计算面积4.664万km2，按行政区统计面积为6.475万km2。运用RS/GIS技术，分析得知：近50年来，江汉湖群湖泊总数量和总面积均表现出总体下降、中间年份有波动的趋势，20世纪50年代、60年代、70年代、80年代、90年代和21世纪初(2000年)，0.1 km2以上的湖泊总数量分别是1 309、611、612、838、768、771个，0.1 km2以上的湖泊总面积分别是8 503.7、5 462.5、2 933.8、2 977.3、3 451.4、3 188.1 km2。围湖垦殖是近50多年来江汉湖群演化的主要原因和主导因子。

QUANTITATIVE ANALYSIS ON THE EVOLUTION OF JIANGHAN LAKES REGION OVER THE LAST 50 YEARS

According to the growth background, the structure of resources and environment, and the social economic function, Jianghan Lakes Region is defined as the area under the altitude of 50 m in Jianghan Plain of Hubei Province, which covers the area from E111°36′38.76″ to E116°7′52.14″ in longitude and from N29°25′59.25″ to N31°27′14.45″ in latitude. The area is 46.64×103 km2 in geographic calibration and 64.75×103 km2 in regionalism. With the help of RS/GIS, a conclusion can be drawn that the amount of lakes in Jianghan Lakes Region decreased in the last 50 years, however it fluctuated in some years. From 1950s to the beginning of 20th Century(year 2000), the number of lakes with the area above 0.1 km2 has decreased as a whole in each decade, and the total area decreased as well. The number in 1950s is 1 309, and in the following decades, it decreased to 611, 612, 838, 768, and then to 771 in year 2000. The total area in 1950s is 8 503.7 km2, and it also decreased to 5 462.5 km2, 2 933.8 km2, 2 977.3 km2 and 3 451.4 km2 in following decades, and then to 3 188.1 km2 in year 2000. In the recent 50 years, the area of most lakes reduced or some of them withered away, and the main reason of such evolution in Jianghan Lakes Region is because of excessive exploitation.