基于GRNN模型的岩溶地区城市水生态足迹分析与预测

Analysis and forecast of water ecological footprint in karst area based on GRNN model

为揭示岩溶地区城市生态足迹的驱动因子与机制,评估和预测水资源可持续利用程度,根据岩溶地区水文地质特征及其与水生态足迹的相关性,分析了贵阳市2002-2014年水生态足迹的变化特征,并利用GRNN模型对其进行了时间序列预测。结果表明,贵阳市水生态足迹由2002年的12.79万hm^2上升至2014年的15.74万hm^2,整体呈波动上升趋势,其中,水量生态足迹变化特征主要由工业用水量决定,水质生态足迹变化特征主要由氨氮排放量决定。水生态承载力波动变化明显,且小于水生态足迹需水量,导致水资源可持续利用系数介于0.31-0.63之间。对贵阳市2015-2019年水生态足迹进行GRNN预测,表明水生态足迹呈现先升后降得趋势,水生态承载力变幅在4.315-8.038万hm^2之间,但水生态足迹与承载力的缺口大,水资源可持续利用系数偏低。因此,在水生态承载力有限的贵阳市,降低水生态足迹才是实现水资源可持续利用的关键。

In order to reveal the driving factors and mechanism of urban ecological footprint, evaluating and predicting the degree of sustainable utilization of water resources in karst area, the change characteristics of water ecological footprint in Guiyang City from 2002 to 2014 were analyzed, according to the hydrogeological features in karst area and its correlation with the water ecological footprint, and the GRNN model was used to predict and evaluate the water ecological footprint time series. The results showed that the water ecologi cal footprint of Guiyang city rose from 12.79 Mhm^2 in 2002 to 15.74 Mhm^2 in 2014, of which the variety of water volume ecological footprint was determined by the industrial water consumption, water quality ecologi cal footprint change was determined by the ammonia emissions. The fluctuation of the water ecological car rying capacity was obvious, and the water demand was less than the water ecological footprint, which led to the coefficient of sustainable utilization of water resources was between 0.34 and 0.61. The water ecological footprint from 2015 to 2019 in Guiyang city is predicted by the GRNN model, which show that the trend of water ecological footprint first increase and then decrease, and the water ecological carrying capacity ranged from 4. 315 Mhm^2 to 8. 038 Mhm^2. But the gap between the water ecological footprint and the carrying ca pacityis huge; the water resources sustainable utilization coefficient is low. Therefore, the reduction of the water ecological footprint is the key to sustainable development of the water resources in Guiyang city, of which the water ecological carrying capacity is limited in karst area.