淮河中下游洪泽湖水域动态变化研究

DYNAMIC ANALYSIS OF WATER AREA IN THE LAKE OF HONGZE BASIN

近年来,随着人口的增长和经济的发展,湖泊水域面积日益缩小,不仅影响了湖泊调蓄洪水的能力,也造成了湖泊生态环境与生物资源的破坏及湖泊水环境质量的下降。以淮河中下游洪泽湖为例,通过收集洪泽湖地区1930～2001年不同时期的地形图和遥感影像数据,在地理信息系统(GIS)与遥感(RS)技术的支持下对洪泽湖地蛆70多a来水域动态变化特征进行研究。研究结果表明:1930～1961年,洪泽箕面积减少了130.3km2,年均递减率为0.23%;1961～1971年,洪泽湖面积减少了31.99km2,年均递减率为0.17%;1971～2001年,洪泽湖面积减少了154.93km2,年均递减率为0.3%;1930～2001年,洪泽湖面积减少了317.22km2,减少了1930年总面积的16.92%,年均递减率0.24%。洪泽湖水域面积变化主要集中在湖的西部和东北部的湿地沼泽处。同时应用分形理论中的计盒维数及基于岸线发育系数方法,对洪泽湖1971～2001年30a来湖泊岸线变化进行了定量分析,研究结果显示:30a来,洪泽湖的岸线曲折度降低,岸线长度减少,岸线结构趋于单调。岸线曲折率下降与该时期洪泽湖的滩地围垦、水利建设等人类经济活动对湖泊形态的改变有密切关系,沿湖兴修水利工程,联圩并圩以及围湖垦殖等人类活动对洪阵湖岸线的演变起到了不可低估的作用,加速了湖泊岸线的演化进程,导致湖泊岸线的计盒分形维数值降低。湖泊水域动态变化是自然因素和人类活动综合作用的结果,人类活动的作用更为突出,针对湖泊水域日益减少的现状,在以上结果分析及实地调查的基础上,对如何合理利用与保护洪泽湖水资源、水环境进行了探讨,以实现湖泊资源的持续利用和湖区社会经济的可持续发展。

In recent years,the water area of lake is reducing with the development of the economic and increasing of the population.It is not only affect the ability of flood diversion and storage,but also lead to the destruction of the ecological environment and decreasing of the water environment quality.Taking the Hongze Lake as an object of study,the dynamic changing of the water area was studied in 70 years（1930~2001） with the support of the technology of GIS and RS by collecting the topographic map and remote sensing image in different stage.The results showed that water area of Hongze Lake reduced 130.3 km2 from 1930 to 1961 and the annual decrease rate was 0.23%;from 1961 to 1971 Hongze Lake area reduced 31.99 km2 and the annual decrease rate was 0.17%;from 1971 to 2001 Hongze Lake area reduced 154.93 km2 and the annual decrease rate was 0.3%;from 1930 to 2001 Hongze Lake area reduced 317.22 km2 and the annual decrease rate was 0.24%.The main change of water area was located at the west and northeast of the Hongze Lake where wetland resource was abundant.At the same time,we also studied the dynamic changes of the lake shorelines in Hongze basin based on the two physical properties of lake,perimeter and area,applying the box-dimension and the fractal dimension.The result showed that the sinuosity of shoreline and the perimeters reduced,and the structure of shorelines became monotonous during the past 30 years.At that time,human activities such as some irrigation works built up around the lake and reclaimed lake wetlands were the immediate cause leading to the decreasing of fractal dimension of the shoreline in the Hongze Lake.In order to realize the sustainable development of economy and society of the Hongze Lake,we discussed the issue how to use water resources in reason and protect water environment at the end of this article based on the above analysis and investigation on the spot.