吉林省西部盐碱地综合开发多情景模拟与水资源效应

Multi-scenario Simulation and Water Resource Effects of Integrated Utilization of Saline-alkali Land in Western Jilin Province

[目的]盐碱地综合开发利用是提高农业生产力、践行大食物观的必然选择。但受限于开发利用模式单一、耗水压力较大,亟待探索多元化治理模式并依据其水资源效应开展优化调控。[方法]以吉林省西部地区为研究区,采用FLUS模型预测2030年盐碱地资源在自然发展、粮食安全、粮饲综合开发和生态安全4种情景下的开发利用格局,并对不同情景下的产水量变化进行评估。[结果](1)2000—2020年研究区开发利用盐碱地1540.18 km^(2),主要被恢复为草地或开垦为耕地,但其中旱地次生退化风险较高。(2)不同情景下盐碱地开发均以耕地利用为主。粮食安全情景下水田和旱地开垦面积占比分别为67.48%,4.23%。相较于自然发展情景,粮饲综合开发情景下盐碱地恢复为草地的面积增加139.18 km^(2),生态安全情景下生态用地规模显著提高。(3)至2030年,4种发展情景下研究区产水量较基期均有所下降,生态安全情景下降幅度最大,达到3.71×10^(8)m^(3)。相比之下,粮饲综合开发情景充分保障粮食和饲草生产,同时缓和盐碱地治理所导致的水资源压力。[结论]松嫩平原盐碱地开发利用应充分考虑粮饲综合开发模式,统筹粮食和饲草供应,协调粮食和生态安全,以大食物观引领国土空间生态修复和退化土地的开发利用。

[Objective]The integrated utilization of saline-alkali land remains a quintessential stratagem to enhance grain yield whilst embracing the principle of Greater Food.The current simplistic reclamation approaches and the intensive water demands,however,call for a thorough investigation of diversified management strategies and interventions that take into account the impact on water resources.[Methods]The study selected the western part of Jilin province as the study area and adopted the FLUS model to forecast the utilization patterns of saline-alkali land resources until 2030 under four scenarios:Natural progression,grain security,integration of grain and forage production,and ecological protection.The InVEST model was then applied to evaluate the variations in water yield across these scenarios.[Results](1)From^(2)000 to 2020,1540.18 km^(2)of saline-alkali land in the study area was put to use,predominantly restored to grassland or reclaimed as cultivated land,with a substantial risk of secondary salinization in drylands.(2)Under all scenarios,the reclamation of saline-alkali land for agriculture prevailed.In the grain security scenario,the paddy fields and drylands accounted for 67.48%and 4.23%,respectively.When compared with the natural progression scenario,the grassland area was set to expand by 139.18 km^(2)in the integration of grain and forage production scenario,and ecological land would increase substantially under the ecological protection scenario.(3)By 2030,water yield is projected to decrease in all four scenarios relative to the baseline period,with the ecological protection scenario facing the steepest reduction at 3.71×10^(8)m^(3).Conversely,the integration of grain and forage scenario offered a well-balanced solution,ensuring the output of crops and forage while easing the water pressures initiated by the management of saline-alkali land.[Conclusion]Utilization of saline-alkali land in the Songnen Plain requires a balanced and strategic approach that supports both grain and forage production.Efforts should be made on maintaining the equilibrium between the supply of agricultural and fodder resources whilst ensuring food and ecological security.The overarching goal is to regulate the ecological restoration of our territorial space and utilization of degraded lands following the concept of Greater Food.