The Indus Civilization (Cambridge History of India, Supplementary Volume) c8.3.1

c8.3.1

It is, with all safeguards, sufficiently clear that the rainfall in the Indus zone was somewhat more ample and equable in the third millennium B.C. than it is to-day. Indications from the upland have just been given. On the river-plain, almost the whole terrain, except for the riverine strips and artificially irrigated areas, is now sandy desert with, at the most, a covering of desert-scrub or small bushy trees such as the tamarisk. The subterranean salt, dragged to the surface by the unimpeded evaporation of such moisture as the soil contains, forms a crust which has been well described as "a satanic mockery of snow".¹ It would be hard to imagine a more repelling environment for great cities such as Mohenjo-daro or Harappā, each of these more than three miles in circumference. But we know that in fact their environment was of a very different kind.² The millions of baked bricks of which they are built suggest former vast reserves of local fuel other than scrub though they do not firmly prove this inference; we have to remember that sites on or near the great rivers could be supplied in part by timber floated down, then as to-day, from the Himalayan forests, and it is noteworthy that burnt bricks are especially characteristic of those sites—Harappā, Mohenjo-daro, Chanhu-daro, Sutkagēn-dōr—which are accessible by water, whilst other sites, less accessible, were seemingly content with stone and mud-brick.