For the past 50 million years, the Indian subcontinent, which includes the territory of Pakistan, India and Bangladesh, has been colliding with the Eurasian Plate; this collision has crumpled up the Himalayas, the youngest and highest mountain range on our planet. Contiguous with the mountains of Afghanistan and northwestern Pakistan, this topographic wall curves across the northern edge of the subcontinent, trapping the lowlands between the mountains and the sea. Snowmelt and rainfall in the mountain ranges is drained by three major river systems: the Indus of Pakistan and the Ganges and Brahmaputra Rivers of India and Bangladesh.
In June, as heat builds over the lower terrain, air rises from the land and low pressure forms; this creates an onshore flow of moist air, known as the seasonal monsoon, which usually lasts into October. During most years, intermittent heavy rains inundate the coastal areas as warm, humid air from the Indian Ocean is swept northward across the subcontinent. Occasionally, tropical storms and typhoons exacerbate the rainfall and abundant moisture may be pushed farther to the north where the mountains force the air to rise, triggering periods of torrential rain.
This year, extremely heavy precipitation in the mountains of Pakistan and the western Himalayas has produced catastrophic flooding along the Indus River system, which runs the length of Pakistan, from the Kashmir region to the Arabian Sea. While much of the southeastern border of the country lies within the Great Indian Desert, the Indus Valley has become a heavily populated swath of irrigated croplands. As we have seen, the extensive flooding has displaced millions of people, inundated most of the cropland and, to date, taken more than 1500 lives. Recovery from this devastation, which may continue until November, will take many years; your support, via International Relief Organizations, is strongly encouraged.
