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土壤次生盐渍化和土地荒漠化与灌区地下水位埋深密切相关。将灌区地下水调控在合理的埋深范围内,可更有效地防治土壤次生盐渍化,从而改善自然植被或作物赖以生存的土壤环境,更有利于自然植被或作物的生长发育,进而提高植被的繁茂程度或作物的产量。根据干旱内陆河流域水资源开发利用及农业生产管理的特点,总结并探讨了灌区地下水位调控的措施。以新疆阿瓦提灌区为例,依据生产实践设置了维持现状、加大灌区节水改造、改变洗盐压碱模式和优选井灌井排等4个情景方案,以现状数据为基础设置相应的参数,应用区域水盐平衡模型对灌区的水平衡、耗水平衡、地下水平衡、供需水平衡和盐平衡等5个平衡进行模拟和预测,得到各方案各子灌区水盐平衡结果,分析了不同地下水位调控措施对地下水的影响。分析表明:不进行冬春灌而采用滴水适播或干播湿出,可使土壤冻融期地下水位下降到临界深度以下,将有效地抑制浅层土壤的返盐和积盐;井灌井排是灌区地下水调控最有效的措施,既开发利用地下水资源,又可控制地下水位、防治或改良盐碱地等。地下水位调控措施的选择需因地制宜,综合考虑灌区土壤盐碱化程度、地下水位埋深现状、灌溉排水条件等合理选择。
Soil secondary salinization and desertification are closely related to the groundwater level in the irrigation area. Controlling groundwater in irrigated area within a reasonable range of buried depth can effectively control secondary soil salinization so as to improve the soil environment in which natural vegetation or crops depend and is more conducive to the growth and development of natural vegetation or crop, The lushness of vegetation or crop yield. According to the characteristics of water resources development and utilization and agricultural production management in arid inland river basins, the measures of regulation and control of groundwater level in irrigation districts are summarized and discussed. Taking the Awati irrigation area in Xinjiang as an example, four scenarios of maintaining the status quo, increasing water saving in irrigation districts, changing the mode of washing salt and caustic soda, and optimizing well irrigation and drainage are set according to the production practice. The corresponding parameters are set based on the current situation data , The five balances of water balance, water consumption balance, groundwater balance, water supply and demand balance and salt balance in the irrigation area were simulated and predicted by using the regional water and salt balance model. The water and salt balance results of each sub-irrigation district in each program were obtained and the effects of different groundwater Influence of bit control measures on groundwater. The analysis shows that the application of either drip sowing or dry sowing wetting without winter and spring irrigation can reduce the groundwater level below the critical depth during the soil freezing and thawing period and effectively restrain the salt return and salt accumulation in the shallow soil. It is the most effective measure to control groundwater in irrigated area. It not only can exploit and utilize groundwater resources, but also can control groundwater level, prevent or improve saline-alkali land and so on. Groundwater level control measures to be selected according to local conditions, taking into account the degree of irrigation of soil salinization, the status of groundwater depth, irrigation and drainage conditions, such as a reasonable choice.