Centre Eau Terre Environnement, Institut national de la recherche scientifique, 490 rue de la Couronne Street, Québec G1K 9A9, Québec, Canada; Water Resources Management Group, Wageningen University, PO Box 47 6700AA, Wageningen, Netherlands.
Centre Eau Terre Environnement, Institut national de la recherche scientifique, 490 rue de la Couronne Street, Québec G1K 9A9, Québec, Canada.
Sci Total Environ. 2022 Apr 15;817:153038. doi: 10.1016/j.scitotenv.2022.153038. Epub 2022 Jan 10.
Different methods have been proposed in population dynamics to estimate carrying capacity (K). This study estimates K for Iran, using three novel methods by integrating land and water limits into assessments based on Human Appropriated Net Primary Production (HANPP). The first method uses land suitability as the limiting resource. It gives theoretical estimates for K. The second method which is based on the first method, uses land suitability and water resources availability as limiting resources assuming highly efficient agriculture, also resulting in theoretical estimates for K. The third method is based on the second method assuming a lower, more realistic agricultural efficiency. The third therefore results in more realistic estimates. Four spatial hydrological scale levels were considered to estimate food production. Also, nine scenarios were defined: a reference one reflecting the current situation, five others for the first method, two for the second method, and finally, one scenario for the third method. Results show severe limitations on food production by the availability of suitable land, water availability, and crop productivity for agriculture. We estimated theoretical values for K using land and water limiting resources separately. Two realistic scenarios considering realistic agricultural productivity and water use at national and local levels were assessed, resulting in 35.5 and 20 million people, respectively. These are alarming values compared to the current population of Iran (84 million). Moreover, our conservative estimations are still higher than any assessment when considering social, economic, or political barriers. This research provides a systematic analysis of carrying capacity in Iran, showing the importance of food import on Iranians' lives, relevant to land, water, and food policies.
不同的方法已被提出在人口动态估计承载能力 (K)。本研究采用三种新方法，将土地和水资源限制纳入基于人类占用净初级生产力 (HANPP) 的评估，对伊朗的 K 进行了估计。第一种方法使用土地适宜性作为限制资源。它给出了 K 的理论估计。第二种方法基于第一种方法，使用土地适宜性和水资源可用性作为限制资源，假设农业高度高效，也导致了 K 的理论估计。第三种方法基于第二种方法，假设农业效率较低，更符合实际情况。因此，第三种方法产生了更符合实际情况的估计。考虑了四个空间水文尺度水平来估计粮食产量。此外，还定义了九个情景：一个反映当前情况的参考情景，五个用于第一种方法，两个用于第二种方法，最后一个用于第三种方法。结果表明，适合农业的土地、水的可用性和作物生产力对粮食生产有严重的限制。我们分别使用土地和水资源限制资源对 K 的理论值进行了估计。考虑到全国和地方层面的实际农业生产力和水资源利用情况，评估了两个现实情景，结果分别为 3550 万人和 2000 万人。与伊朗目前的 8400 万人口相比，这些数字令人震惊。此外，我们的保守估计仍然高于任何考虑社会、经济或政治障碍的评估。本研究对伊朗的承载能力进行了系统分析，显示了粮食进口对伊朗人生活的重要性，与土地、水和粮食政策有关。
