temporary pools that dry up during a certain part of the year

Periodic pools or telms (water reservoirs of any type) are among the lentic stagnant waters. This refers to small water reservoirs that contain water only occasionally, for only a few months or even weeks. They form in specific places after snowmelt (especially in spring) and after rains or due to rising groundwater levels. They can form on impermeable subsoil (e.g. clay, rock) due to precipitation or on permeable subsoil (sand, loam).