**Abstract**

Adaptation to climate change requires, among others, the modification of river flow regimes to account for the change in household, agricultural, industry, and energy water consumption as well as their short/medium/long-term socioeconomic impact. In this study, the comparative analysis of the variation of the precipitation in relation to the availability of water in the Yautepec and Cuautla rivers in Morelos, Mexico, for the previous period and subsequent period is carried out, to determine the change in the availability of water in the ecosystem. In winter (February), an increase in rainfall on the Yautepec and Cuautla River was observed, where annual seasonal agriculture and Pine and Oyamel forest are the characteristic vegetation. In autumn (October), a decrease in precipitation takes place. The flows in some regions do not coincide with the increase in the percentage of precipitation (Oaxtepec and Las Estacas Stations) and point out the synergistic effect of the human use of the water resource and the effects of climate change. On Ticumán Station, the depletion of the flow only can be associated with the use of the resource by human influence. The modifications caused by alteration of a river's flow regime and climatic change must be studied through comparative multidisciplinary studies that give to decision-makers the design of environmental flows.

**Keywords:** climatic change, environmental flow, vulnerability
