Because of the aridity, many animal species rely on protected migration corridors during droughty conditions. Loess is parent material for an extremely fertile, but droughty soil. Summer is warm and either humid and rainy or hot and droughty. Higher drainage becomes more droughty which hinders the establishment of certain grasses good for waterways. Summer always hot, droughty and long. They were concerned about the "droughty" conditions and perceived that was what was wrong.