【摘要】 种植结构调整目前是我国大中型灌区节水改造的一个重点。区域大幅度的种植结构调整势必导致农作物耗用水量发生剧烈变化,由此引发区域水循环运移过程和转换通量发生变化,对区域用水和水资源赋存及形成过程产生深刻影响。应用水循环模型,对宁夏平原区实施种植结构调整下的区域水循环过程、经济系统与生态系统的耗水变化进行模拟分析,研究表明:(1)种植结构调整改变了区域水循环过程:区域水循环强度减弱,水循环转化通量减少,地下水位下降,区域引排耗水量减少。(2)调整不同作物种植面积对水资源消耗的影响不同:减少水稻种植面积,农田土壤蒸发减少了0.19×108m3,植被蒸腾减少了0.83×108m3;减少套种面积,植被蒸腾减少了1.18×108m3,但农田土壤蒸发增大了0.16×108m3。(3)调整作物种植面积将对区域生态耗水带来重要影响:当水稻面积减少到4×104hm2,低效耗水减少了0.2×108m3,高效耗水减少了0.03×108m3;当套种面积减少到4×104hm2时,低效耗水和高效耗水分别减少了0.21×108m3和0.05×108m3。(4)区域高效耗水和低效耗水均减少。更多还原

【Abstract】 At present,the planting structure adjustment is one of the important water saving works in irrigation area of a large-middle scale.The great regional planting structure adjustment must be bring the water consumption to a great change which will have a profound influence on water cycle process and the whole region water use.For this reason,the mechanism change of water cycle induced by planting structure adjustment is analyzed on the start,and then according to the different water consumption of different land use types,the application is presented of water cycle model to simulate water cycle process and water consume with the measure of planting structure adjustment in Ningxia plain.The results show as follows:(1) the planting structure adjustment changes regional water cycle process: the strength of water cycle is weakened;the groundwater table is declined,the water-drawing and drainage consumption is also decreased.In the plain area of Ningxia municipality,the Yellow River is the main water source for agriculture irrigation,the Yellow River water consumption is occupied by above 75% in the whole water use.The planting structure adjustment will cause the reduce of the Yellow River water consumption for nature ecosystem;(2) the different planting structure adjustment has a different effect on water consumption: when the paddy planting area decreases,the soil evaporation and the crop transpiration separately reduce by 0.19×108 m3 and 0.82×108 m3,while the intercrop area decreases,the decrements of evaporation and transpiration are 1.18×108 m3 and 0.16×108 m3;(3) the planting structure adjustment has an important effect on water consumption of ecosystem: when the paddy area decreased by 0.6 million mu,low efficient water consumption and high efficient water consumption separately reduce 0.2×108 m3 and 0.03×108 m3,while the intercrop area decreased by 0.6 million mu,low efficient water consumption and high efficient water consumption separately reduce 0.21×108 m3 and 0.05×108 m3;(4) low efficient water consumption and high efficient water consumption of the whole region are all reduced,but low efficient water consumption also plays the important role.From the mentioned above,regardless of the regional water cycle process and the water consumption change,the planting structure adjustment also has a great effect on them.Meanwhile,compared with other engineering measures,the planting structure adjustment has the characteristics of time-saving and labour-saving,which make it become an important development aspect to improve the water use efficiency.更多还原