Whose work first explained how sand deserts can form from old river systems?

Research in geomorphology has shown that not all deserts began as deserts; many developed from regions that once had rivers, lakes, and wetter climates. As rainfall patterns shifted over geologic time, these landscapes dried out, leaving buried channels, fossil lake beds, and sediment records. This is especially well documented in parts of North Africa, Arabia, and central Asia. The idea is supported by satellite imagery, drilling, and sediment analysis rather than one single discovery.