基于极限学习机的成都市水生态足迹分析与预测

Analysis and Prediction of Water Ecological Footprint in Chengdu Based on Extreme Learning Machine

鉴于水资源对城市发展至关重要,采用水生态足迹模型计算了2000~2019年成都市水生态足迹、生态承载力及生态压力指数;并运用IELM模型预测了2020年成都市水生态足迹、生态承载力及生态压力指数;分析了可能的影响因素和对策。研究表明,2000~2019年成都市水生态足迹总体介于685.50×10^(4)~1064.98×10^(4)hm^(2)之间,呈先上升后下降趋势。多年平均工业、农业、生活及生态水足迹分别占总水生态足迹的21.96%、52.49%、21.17%、5.64%。不同年份间的水生态承载能力差异显著,其中2018年的水生态承载力在20年内最高,为1656.48×10^(4)hm^(2);2015年最低,仅678.64×10^(4)hm^(2)。生态承载力受年降水量和自然灾害的影响较大。水生态压力指数介于0.56~1.28之间,部分年份大于1.1,说明水资源承载力在这20年内相对稳定。根据IELM模型,预计2020年的水资源生态足迹达897.10×10^(4)hm^(2),较2019年上升1.29%;承载力较2019年下降19.83%,降至1035.84×10^(4)hm^(2),压力指数较2019年上升26.56%,达0.867。该研究能对成都市水生态足迹作出合理预测,为政府部门制定水资源相关决策提供了参考。

Urban development relies heavily on water supplies.The ecological footprint,ecological carrying capacity,and ecological pressure index of Chengdu’s water resources were calculated using the water ecological footprint model from 2000 to 2019.And the IELM model was used to predict the ecological footprint,ecological carrying capacity,and ecological pressure index of Chengdu’s water resources in 2020.The potential influencing factors and countermeasures were analyzed.Chengdu’s ecological footprint of water resources ranged between 6.855 million and 10.6498 million hm^(2) from 2000 to 2019,with a rising and then dropping trend.The annual average industrial,agricultural,living,and ecological water footprints were 21.96%,52.49%,21.17%,and 5.64%,respectively,of the overall water resources ecological footprint.Water resources’ecological carrying capacity changes greatly from year to year.The ecological carrying capacity of water resources was at 16.5648 million hm^(2) in 2018,the greatest in 20 years,and the lowest was just 6.7864 million hm^(2) in 2015.Annual precipitation and natural calamities have a significant impact on ecological carrying capacity.The ecological pressure index of water resources ranged from 0.56 to 1.28,with some years above 1.1,showing that the carrying capacity of water resources has remained reasonably steady over the last two decades.According to the IELM model,it is estimated that the ecological footprint of water resources in 2020 reached 8.971 million hm^(2),an increase of 1.29% compared with 2019;The carrying capacity decreased by 19.83% compared with 2019,to 10.3584 million hm^(2);The pressure index increased by 26.56% compared with 2019,reaching 0.867.This study makes a reasonable prediction for the ecological footprint of water resources in Chengdu,and provides a reference for government departments to make decisions related to water resources.