116
AFGHANISTAN
on the maps of the Indian Survey. The frontier valleys belong to two distinct geological types. They are either deep, steep-, sided valleys, with rapid streams carrying quantities of debris, or, where the upheaval of the river bed has been too rapid for the cutting-down action of the river, and the grade has been lessened, an alluvial plain has been formed, which affords a broad, open, and gently-rising ramp leading up to the Afghan plateau. Such are the valleys of the Kuram and the Tochi. The general flow of all these frontier affluents of the Indus from the Afghan plateau to the plains of the Derajat is directly across the axis of the minor frontier ranges, which lie packed in parallel lines of ridge and furrow, forming a series of grades, or steps, from the lower to the higher level. The streams rise on the plateau west of, and beyond, the prominent line of highest elevation, breaking straight through the hard sandstone or limestone ranges, and forming deep gorges where they pass; whilst their tributaries, joining almost at right angles in long narrow lateral valleys, wash the softer clays and shales from off' the surface of the harder rocks, and carry down the debris to assist in grinding through the limestone barriers. The frontier hills between the Gomul and the Kuram present many instances of such narrow gateways to the Afghan highlands ; to the south of the Gomul they form the most prominent type of opening into the hills. Two important river basins of Afghanistan, belonging to that central system which has no connexion wdth the sea, have been examined, and many interesting facts connected with them remain to be recorded. The Hari Rud, or river of Herat, which loses itself in the Tejend oasis north of the Trans-Caspian Railway, and west of Merv, rises in the western slopes of the Koh-i-Baba, the mountain mass which abuts on, and closes, the Hindu Kush to the west of Kabul. It runs a remarkably straight course westward through a narrow trough from Daolatyar to Obeh. This trough lies between the southern ridge of the great Central Afghan watershed, which holds the head - waters and sources of the Murghab on the north, and the narrow water-parting formed by the Band-i-Baian and Koh-i-Sufed on the south. From this latter divide the tributaries of the Farah Rud and other rivers of the Sistan basin take their rise. The deeply-eroded valley of the Hari Rud, filled in with the detritus washed down by periodical floods from the soft loess formations of sand and clay which enclose it, is of great fertility in its lower and wider reaches between Obeh and Kuhsan, 50 miles west of Herat; but its upper course is barren and sand-spread, winding amidst the bleak wind-swept uplands of the highest central elevations in Afghanistan. The most notable features about the Lower Hari Rud are the absolute exlteustion of its waters in the early summer seasons of irrigation, and the rapidity with which natural processes of denudation are lowering its bounding watersheds. Immediately north of Herat the central water-divide, which is locally known by the name of Siah Bubuk (but to which the general term Paropamisus has been given in order to preserve a historical designation which belongs more correctly to the Hindu Kush), is being reduced so rapidly to a final stage of rounded curves and gentle declivities that it is already possible to drive a wheeled carriage across it without any preliminary road-making. The sources of the Helmand, like those of the Hari Rud, lie in the recesses of the Koh-i-Baba to the west of Kabul, its infant stream parting the Unai pass from the Irak, the two chief passes on the well-known road from Kabul to Bamian. For fifty miles from its source its course is ascertained, but beyond that point for the next fifty no European has followed it. About the parallel of 33° N. lat. it enters the Zamindawar province, which lies to the north-wTest of Kandahar, and thenceforward it is a well-mapped river to its termination in the Lagoons, or Hamun, of Sistan. This great central depression, which is about 1700 feet above sea-level, also receives the waters of several northern affluents, of which the Harut, the Farah, and the Khash are the principal. They drain the highlands occupied by the Taimani section of the Chahar Aimak. About the upper affluents of the Farah lie the fertile valleys which surrounded Taiwara, the capital of the ancient kingdom of Ghor, and here the Taimani highlands culminate in peaks rising to a height of over 12,000 feet above sea-level. For 200 miles due east of Taiwara there stretches a region of barren highland desolation marked by peaks of 11,000 to 13,000 feet, the home of the Hazaras. Herein is enclosed a northern section of the valley of the Helmand, and in this portion of the valley is situated Ghizao, marking a great road from north to south. Ko other place of any significance is known in this region. All these northern affluents of the Sistan Hamuns partake more of the nature of highland rivers than the broad and comparatively placid Helmand. Throughout its great southern curve the Helmand shapes an even and solitary course, receiving no contributions from either side, through a valley which is exceedingly narrow, but fertile and green, and full of the last relics of departed townships belonging to that Kaiani kingdom which once centred on Kala Fath. From the Helmand, near its great bend northwards, a most extensive system of irrigation was
[geography
once devised, a system which watered hundreds of square miles of now barren plain to the west. A noteworthy feature of the Sistan lagoon is that in times of excessive flood it overspreads a vast area of country, both to the north and south, shutting off the capital of Sistan (Nasirabad) from surrounding districts, and spreading through a channel southwards known as Shelag to another great depression called the Gaud-i-Zirreh. This great salt swamp is about 1000 feet lower in elevation and is situated so close to the Helmand as to leave but a few miles of broken ridge between. By that ridge all communication with Sistan must pass in time of flood. Sistan becomes a promontory connected with the desert south of the Helmand by that isthmus alone. Recent boundary proceedings have included it within the Amir’s territory. The Afghan basin of the Oxus includes a part of the Pamirs and all Badakshan and Afghan Turkestan. Badakshan is drained by two main rivers—the Kokcha (or river of Faizabad) and the Khanabad, which takes its name from a town on its banks. Above the Kokcha junction the Oxus is a mountain-bred river, receiving no contributions of any importance from the Afghan side. Below the Khanabad the Oxus is a river of the plains; and as far as Khamiab, where it ceases to be the boundary of Afghanistan, no Afghan river of any importance reaches it. The Tashkurghan river, the Band-i-Amir or Balkh river, the Shiburghan, and the Andkhui, all start for it, bringing down snow-fed torrents from the Koh-i-Baba, and Band-i-Turkestan in spring, and tailing off into the countless irrigation channels in the Balkh plain ; but neither in winter nor in summer do any of them cross the fringe of sand desert that lies south of the Oxus river in cultivation. This appears to be due to the alteration of the plain levels by a gradual process of upheaval quite as much as to the absorption of the water-supply in irrigation. Where these rivers run into irrigation the plain is highly cultivated ; but the Oxus itself is no longer utilized for agricultural purposes, except within a comparatively narrow fringe. This fringe is, however, of considerable local importance (see Oxus). On the western borders of Afghan Turkestan the Murghab river and the Hari Rud lose themselves in the Merv and Tejend oases. The Murghab starts from the Firozkhoi highlands (the northern scarp of which is defined by the Band-i-Turkestan), and, after traversing that plateau from east to west, it turns north through deeply-cut defiles to Bala Murghab, and effects a final junction with the Kushk near Panjdeh. At Bala Murghab the valley is open, with the loess formation of the Chul bounding it on either hand. Beyond Panjdeh it emerges into the Yulatan desert. Mountain Systems.—The dominant mountain system of Afghanistan is the Hindu Kush, and that extension westwards of its water-divide which is indicated by the Koh-i-Baba to the north-west of Kabul, and by the Firozkhoi plateau (Karjistan), which merges still farther to the west by gentle gradients into the Paropamisus, and which may be traced across the Hari Rud to Mashad. The culminating peaks of the Koh-i-Baba overlooking the sources of the Hari Rud, the Helmand, the Kunduz, and the Kabul, very nearly reach 17,000 feet in height (Shah Fuladi, the highest, is 16,870), and from them to the south-west long spurs divide the upper tributaries of the Helmand, and separate its basin from that of the Farah Rud. These spurs retain a considerable altitude, for they are marked by peaks exceeding 11,000 feet. They sweep in a broad band of roughly parallel ranges to the south-west, preserving their general direction till they abut on the Great Registan desert to the west of Kandahar, where they terminate in a series of detached and broken anticlinals whose sides are swept by a sea of encroaching sand. The long, straight, level-backed ridges which divide the Argandab, the Tarnak, and Arghastan valleys, and flank the route from Kandahar to Ghazni, determining the direction of that route, are outliers of this system, which, geographically, includes the Khojak, or Khwaja Amran, range in Baluchistan. North of the main water-divide of Afghanistan the broad synclinal plateau into which the Hindu Kush is merged is traversed by the gorges of the Saighan, Bamian, and Kamard tributaries of the Kunduz, and farther to the west by the Band-iAmir or Balkh river. Between the debouchment of the Upper Murghab from the Firozkhoi uplands into the comparatively low level of the valley above Bala Murghab, extending eastwards in a nearly straight line to the upper sources of the Shiburghan stream, the Band-i-Turkestan range forms the northern ridge between the plateau and the sand formations of the Chul. It is a level, straight-backed line of sombre mountain ridge, from the crest of which, as from a wall, the extraordinary configuration of that immense loess deposit called the Chul can be seen, stretching away northwards to the Oxus—ridge upon ridge, wave upon wave, like a vast yellow-gray sea of storm-twisted billows. The Band-iTurkestan anticlinal may be traced eastwards of the Balkh-ab
