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The Greenough River is a river in the Mid West region of Western Australia. ==Course== Greenough River has its headwaters near Woojalong Hills on the Yilgarn Plateau. It runs in a south-westerly direction through deep valleys for approximately , passing through the Waterloo Ranges before descending to the coastal plain. A few kilometres from the sea it is obstructed by dunes, and turns to the north-west, running along a dune swale parallel with the coast for about 35 km before finally discharging into the Indian Ocean at Cape Burney, about south of Geraldton, Western Australia. The ten tributaries that contribute to the Greenough are Woojalong Brook, Woolbarka Brook, Bangemall Creek, Urawa River, Kolanadgy Gully, Nangerwalla Creek, Wooderarrung River, Wandin Creek, Kockatea Creek and Wicherina Brook. The lower reaches of the Greenough are estuarine; how far upriver the estuary extends is not certain, but probably about 7 km to near Bootenal Springs. The river mouth is barred from the ocean by a sandbar that breaks only in periods of strong flow. Once open, it usually remains open for several months. The bar has now been reinforced with brushwood on the northern side, to force the bar to open only on the southern side, where the adjacent dune is more stable.〔 Evidence from wind gaps suggests that, thousands of years ago, the Greenough River turned to the north-west a few kilometres further from the coast than it does at present, at the present-day site of Walkaway. It then ran along the inside of a limestone ridge, following what is now the path of the Geraldton–Dongara railway line, to the vicinity of Rudds Gully. Both watercourses then flowed north to discharge into the Chapman River. Later, Rudds Gully cut its own path to the ocean, and the Greenough River discharged into it; and later still, the Greenough cut its own path through the limestone ridge at Walkaway, thus forming its own course.〔 The well-documented strong winds at Greenough have resulted in large mobile dune systems both to the south and north of the Greenough River mouth. Both are gradually moving northwards, and it is estimated that the southern dune will reach the mouth of the Greenough around 2045, at which point the Greenough may well become even more prone to flooding, or be forced to change its course.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Greenough River」の詳細全文を読む スポンサード リンク
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