本研究采用1955年至今的气象资料和1993年至今的水文和土壤盐分定位观测数据,研究气候变化对河套灌区土壤全盐和灌溉水量的影响。结果表明:1)近18年来,河套灌区(义长灌域)土壤全盐质量分数与年平均温度呈一定相关性,且有明显的增加趋势。2)巴177、巴233和巴300观测井土壤全盐分别增加了0.011、0.111和0.048g/kg;当温度增加0.5~3.0℃时(未来10~60年间),淋洗土壤增加盐分所需的灌水量为682.16~2 171.20m3/hm2。3)河套引黄灌区淋洗由于温度升高0.5~3.0℃引起土壤盐分增加所需的灌水量为3.92~12.46亿m3。4)根据测算结果,义长灌域引水量(1 044.43m3/hm2)已接近993.02m3/hm2。
Temperature rise will accelerate the soil water evaporation, and also induce salinization degree to some extent. Meanwhile,the irrigation water usage showed a downward trend as a result of the decrease of diversion from Yellow River to the irrigated district and more implementation of local water-saving projects. As such, it will be of significance in relation to soil salt variations in the context of climate change,so as to prevent worsening salinization and establish reasonable water-saving schemes. This paper analyzed the climatic data as well as soil salt data from fixed site observation during the last 18 years. The results showed that the soil total salt contents in the irrigated district presented a significant upward trend with the increase of temperature;as the temperature increased by 0. 5- 3.0 ℃ (in the future 10- 60 years),the increment of soil total salts was estimated to be 0.03- 0.28 g/kg and the relevant irrigation requirements for leaching the soil salts in fixed observation sites will then be around 682. 16 - 2 171.20 m3/hm2,