摘要
洞庭湖是承纳湘、资、沅、澧四水和吞吐长江的洪道型调蓄湖泊．由于湖区发展过程中忽视了环境整治与生态建设，没有协调好人地、人湖关系，中上游干支流水土流失加剧、湖泊泥沙淤积与过度围湖垦殖、高水位地段农业布局与种植制度不合理等人为因素导致湖区调蓄能力下降，洪水位抬升且历时持久；垸高田低，外洪内涝交织，灾害频率上升，灾情增大．为抗御洪水，堤防越筑越高，出现了“水涨堤高水再涨堤再高”的恶性循环现象，造成抬高洪水位、延长洪水过程、降低垸田内排涝能力等副作用．根据人类和自然协调发展原理，提出６条生态减灾和流域管理对策：１）将生态减灾列为国家安全战略体系的重要内容之一．２）将非蓄洪性质的围垦，调整为蓄洪性质的围垦，迁出聚落，正常年份继续耕种，较大洪水年份则用来蓄洪；适度退田还湖，弃耕从渔，将封闭式围垦种植，改造成为半封闭型的筑垸养殖与留湖调蓄．３）环境移民城镇安置，农业与工商业就业并举，缓解人口对土地、湖泊的压力．４）调整湖区农业布局与种植制度，进行适应洪涝灾害发生规律的避洪、耐渍型生态设计，建立适应浅水水体、湖洲和低湖渍害田的复合高效生态工程模式．５）调整丘岗地利用结构与重建山区植被是减灾的治本措施．量大、面广的水土?
Dongting Lake, a lake reservoir characterized by flood course, receives water from rivers of Xiangjiang,Zishui,Yuanshui,Lishui and a part of Yangtze, and inflows into Yangtze River. In the development of the Dongting Lake region, the environmental management and ecological construction were neglected, the relationships between mankind and land and between mankind and lake were not soundly harmonized, the soil and water erosion in the upper and middle reaches of Yangtze River was aggravated, the sediment deposited in lakes, the lands at lake marshes were excessively reclaimed, and the cropping system at high water level zones was irrational. Consequently, the flood regulating capacity was descending, the level and the duration of flooding were raised and prolonged, the protective embankments were high and fields were low, the flooding happened out the protective embankments and the fields waterlogged, the frequency of disasters enlarged, and the damage increased. To prevent and fight against floods, the protective embankments were constructed more and more highly, emerging vicious circle of “flood raising embankment leveling flood re raising embankment re leveling”, making flood level go up and flood duration lengthen, and decreasing the draining ability of waterlogged fields. According to the principle of harmonious development between mankind and nature, six ecological strategies for reducing disasters and watershed management were put forward.
出处
《应用生态学报》
CAS
CSCD
1998年第6期561-568,共8页
Chinese Journal of Applied Ecology
基金
中国科学院区域开发前期研究资助
关键词
洞庭湖
自然灾害
洪涝
生态系统
减灾
流域管理
Dongting Lake, Natural disaster, Flooding and waterlogging, Ecosystem, Disaster relief, Watershed management, Ecological engineering.
