**Preface to "Hydrology in Water Resources Management"**

Increasing human pressure, climate variability and change, and environmental issues are affecting the demand and supply of fresh water. It is common knowledge that many regions around the world are experiencing significant problems related to water scarcity, drought, and various types of flooding. In general, there is still an urgent need to address issues surrounding water resources and problems with water demands as a result of different human activities. For the appropriate management of water resources, wider and credible knowledge about the spatiotemporal distribution and quantity of water resources is needed. This knowledge is provided by hydrology. The effective use of hydrology in the framework of integrated water resources management contributes to sustainable development, assisting in risk reduction of water-related disasters, and supporting effective environmental management at basin, regional, and international levels. The purpose of this Special Issue is to exchange knowledge about the role of hydrology in the sustainable management and planning of water resources. In this context, the most important issues in need of deep discussion are the impact of the environment and human activity on water resources, especially with regard to the quality of hydrological data, the use of modern in situ and remote data acquisition tools, the accuracy of measurements, the link between hydrological processes and ecosystems, assessment of the impact of human activity on water resources, flood and drought risks, water shortage assessment, modeling of hydrological processes, and the description of methods that can be applied to ecohydrology.

> **Andrzej Wał ˛ega, Tamara Tokarczyk** *Editors*
