Considering temporal flow variability of non-perennial rivers in assessing ecosystem service provision

Abstract The basis for the assessment of ecosystem services (ES) of non-perennial rivers to date has been a comparison of the ES provision among three different hydrological phases: flowing conditions, isolated pools, and dry streambeds. Being of an opinion that this practice might promote an incomplete and hence biased ES assessment, we propose two considerations for the ES assessment of non-perennial rivers. First, the conditions of each hydrological phase can vary based on the nature of multiple aquatic states. Second, the duration, frequency, timing, and magnitude of the aquatic states matter in the ES provision. Different scenarios of flow regime should be compared instead of hydrological phases in ES assessments. Our proposal sheds some light on the complexity of non-perennial rivers and allows for a better understanding of relationships between non-perennial rivers and society. Therefore, it can serve as the basis for the proper and participatory ES assessment, face for trade-offs between ecosystem conservation and resource use and reduce conflicts among stakeholders within river and water management.