【作者】 刘章勇；

【导师】 陈阜；

【作者基本信息】 中国农业大学 ， 作物栽培学与耕作学， 2004， 博士

【摘要】 江汉平原现有涝渍地76.4万hm~2，占耕地总面积的40.6％。尽管该地区有丰富的自然资源和区位优势，但由于大量涝渍地的存在使其农业生产长期处于大起大落且不高不稳的状态之中，生态环境退化趋势明显。本研究通过长期定位试验、野外调查和文献查阅等途径获取了大量数据，运用点面结合及系统分析等方法，分析了江汉平原涝渍地的成因及涝渍农业生态系统的主要特征，探讨了涝渍生态系统恢复与重建的生态学机制，并从防灾减灾和农业生产结构调整两方面提出了涝渍地生态恢复与资源优化利用的途径和技术模式。主要结果如下： (1) 江汉平原的涝渍灾害是由其所处的特殊地理位置、大平小不平的地貌条件、特殊的气象和水文变化等自然因素和过度围垦及不合理的种植制度等人为因素共同作用形成的。江汉平原涝渍农业生态系统的主要特征是：气候变率加大，分布更加不均；涝渍相随，旱涝并存，且发生愈来愈频繁，水质劣变速度也在加快：土壤潜育化、湖泊沼泽化趋势加重，土壤养分的有效性变差；生物资源出现衰退趋势，土地生产力逐步下降；涝渍地域相对贫困人口增加，血吸虫疫区不断扩展等。 (2) 江汉平原涝渍地的演变过程主要由地质构造运动和气候变化等自然因素和围湖垦殖、筑堤修坝、农业政策等人为因素共同驱动。湖泊在江汉平原涝渍生态环境的演变中起着特殊重要的调控和指示作用，近代大规模的围湖垦殖大大加快了涝渍地的形成速度。 (3) 江汉平原涝渍地域在地势、水文、土壤、气候、生物等方面存在着明显的梯度分异规律。按照地面高程、地下水位、水域面积等8个主要因素对潜江市的涝渍地域进行了综合分类和分区；通过在6个不同类型的典型涝渍微地域上实施的各具特色的开发利用技术试验示范，表明对涝渍地域进行有针对性的分类开发利用可以取得良好的效益。 (4) 对南方易涝易渍地区而言，采用除涝、排渍两个独立标准进行排水规划设计是不完善的，本研究将除涝与排渍作为一个连续过程，研究了涝渍地主要作物持续受渍的排水控制指标和在涝渍综合胁迫下的排水控制指标。结果显示，在持续受渍状态下，地下水超标水位和持续时间的累积值(SEW30)与棉花、大豆和油菜的相对产量Ry(或减产幅度Rf)之间显著相关；在涝渍胁迫条件下，涝渍综合超标水位累积值(SFEW80)与棉花和大豆的相对产量Ry(或减产幅度Rf)显著相关。 (5) 除了涝渍地域的分类开发利用之外，在涝渍微地域上实施梯级开发模式和适度退田还湖也是其生态恢复与开发利用的有效手段。在碟形涝渍微地域上可以实施梯级开发模式，即在碟形洼地的底部实施退田还渔方案，在中下部利用水生和湿生经济生物进行开发利用，在中上部结合田间排水降渍工程技术因地制宜选用各种优化种植模式，在上部发展庭园经济、设施农业等；在滨湖涝渍微地域上可以适度退田还湖，退田还湖控制高程应在22.0 m～26.0 m之间，退田还湖的对象是未列入重点垸、蓄洪垸的一般垸，可以采取退人不退耕的“单退”和既退人又退耕的“双退”两种方式。更多还原

【Abstract】 The areas of waterlogging land were about 7.64 X105 hm2 in Jianghan Plain, correspond to 40.6 % of all farming areas. Despite there are the abundance natural resources and the advantage of geographic location, because of a great deal of the waterlogging land, the agricultural productivity was also not high and instability so much as tempestuously undulation, and the degenerate trend of ecological environment was very obvious in this areas. Based on the amount information coming from the plot trials, some field investigations and annals datum, and exerted the methods of microcosmic combining macroscopic and system analysis, the paper studied the characters of agricultural ecosystem in waterlogging area, then discussed the ecological principium of restoration and rebuilding for the waterlogging ecosystem, and put forward the approach and technology model about the ecological restoration and resources utilization for the waterlogging land, so attain to the two aims of preventing and decreasing the disaster and regulating of farming structure. The results were as follows:(1) The formation reasons of the waterlogging land in Jianghan Plain were the special geographical position, not level landforms, the special change of climate and hydrology and the artificial factors, for example, the excessive reclaiming land from the lake and the unreasonable farming system. The mostly characteristic of waterlogging ecosystem in Jianghan Plain were about: the frequency of climate change was becoming big, the distribution of rainfall in a year was becoming more not uniformity; the emergence of waterlogging and be soiled was going with together, and either the waterlogging or aridity were existing in this area; the water was becoming of low quality; the trend of soil gleyization and lake swamping were also continuing, and the availability of nutrient was becoming little; the degraded trend of biology resources was appearing, the .soil productivity was also declining; the amount of relative poor population was increasing, and the Schistosome disease was diffusing in waterlogging area.(2) The succession was driving by both natural and artificial factors. The natural factors were about the geological structure motion and climate change, and the artificial factors were mainly the excessive reclaiming land from the lake, the constructing dam and the agricultural policy. The lakes of this area played the regulating and indication role in the ecological succession course of the waterlogging land. The big scale reclaiming land from the lake of latter-day expedited the formation of waterlogging land greatly.(3) The step diversification rule for the topography, the geological settings, the hydrology, the soils, the climate and the biology was very distinct in waterlogging micro-area in Jianghan Plain. Based on the step diversification rule, the waterlogging area of Qianjiang city was classified as 6 types and 6 reaches. The technologies of exploitation and utilization were tested separately in 6 typical different types of the waterlogging micro-area, the results showed that the exploitation based on the classifying were very effective.(4)It was not perfect that separating the waterlogging process and the being soiled process when drawing up the drainage plan for the waterlogging land in south ChinaThe drainage controlling indexes of the most crops were studied under the conditions of the abidance being soiled and the synthesize role from waterlogging and be soiled, as the waterlogging and being soiled to a continuum process. The results showed that the cumulate value (SEW30) between the exceeded part to the standard of soil water level below the soil surface and the abidance times was correlation to the relative yield (Ry) of the cotton and soybean (or the extent of yield reduce Rf) observably under the conditions of the abidance being soiled, and the cumulate value (SFEW80) of the exceeded part to the standard of soil water level below the soil surface under the synthesize role of waterlogging and being soiled was correlation to更多还原