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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 is to accept Hunan, capital, Yuan, 澧 four water and swallow the Yangtze River flood control lake. Due to the neglect of environmental remediation and ecological construction during the development of the lake area, there is no coordination between man and land, man-lake relations, the aggravation of soil erosion in the upper and middle reaches of the tributaries, the lake sedimentation and over-reclamation of the lake and irrational agricultural distribution and planting system in high- And other human factors led to the Lake District regulation and storage capacity decreased, the flood level rose and lasted a long time; embankment low, flooding flood interweave, disaster frequency increases, the disaster increased. In order to resist floods, the higher the embankment is, the vicious circle of “high water level, high water level, high water level, high water level and high water level” has also emerged, causing side effects of raising flood level, prolonging flood process and reducing drainage capacity in the embankment. According to the principle of coordinated development between mankind and nature, six ecological mitigation and watershed management strategies are proposed: 1) Ecological mitigation is listed as one of the important contents of the national security strategic system. 2) The reclamation of non-flood storage should be adjusted to the reclamation of reclaimed land and moved out of settlements. The normal years of continuous reclamation should be followed and the flood years should be used for flood storage. , Transformed into semi-enclosed embankment farming and lake storage and storage. 3) Resettlement of urban residents in the environment, agricultural and commercial employment simultaneously to ease the population pressure on land and lakes. 4) Adjust the layout and planting system of agriculture in the lake area, carry out flood-avoidance and water-resistant ecological design to adapt to the occurrence of flood and water disasters, and establish a compound and efficient eco-engineering mode that adapts to shallow water bodies, lakes and lakes. 5) The adjustment of hillock use structure and the reconstruction of mountainous vegetation are the fundamental measures for disaster reduction. Large amount, a wide range of soil and water?