Jamieson, Fausset and Brown on 2 Chronicles 26:10

10. Also he built towers in the desert--for the threefold purpose of defense, of observation, and of shelter to his cattle. He dug also a great many wells, for he loved and encouraged all branches of agriculture. Some of these "were in the desert," that is, in the district to the southeast of Jerusalem, on the west of the Dead Sea, an extensive grazing district "in the low country" lying between the mountains of Judah and the Mediterranean; "and in the plains," east of the Jordan, within the territory of Reuben (De 4:43; Jos 20:8).

in Carmel--This mountain, being within the boundary of Israel, did not belong to Uzziah; and as it is here placed in opposition to the vine-bearing mountains, it is probably used, not as a proper name, but to signify, as the word denotes, "fruitful fields" (Margin).

2Ch 26:11-15. His Host, and Engines of War.