Marco conceptual

In terms of both natural environment and culture, the northwestern borderland is a transitional or intermediate zone linking up China proper and Inner Asia. With such background, the northwestern region was never fully integrated with China proper and was persistently regarded by the Chinese regimes as a perilous area full of uncertainty and potential rivalry. Hence, the northwestern frontier zone had been a prime security concern of the imperial states and an important topic among statecraft writings until the late nineteenth century. However, as a modern Chinese historical geographer has pointed

out, there are minor differences in the definition and delimitation of the northwest in different historical periods, and it is important to study the northwestern region in a contemporary context.8 This study focuses on Liang province, which was the northwestern region of the Han dynasties, for which the geographical area is not exactly the same as what is called northwestern provinces in China today.9 The territories of Liang province largely correspond to present-day provinces of Gansu and Ningxia, with the addition of small portions of northeastern Qinghai province and western and southern Inner Mongolia. Although it is somewhat anachronistic to call the territories “Liang province” before its formal establishment during the reign of Emperor Wu, this chapter will sometimes employ the term to roughly refer to the whole area for convenient description. Considering the ecology and environment of the region have been changing since antiquity under the influence of natural and human-induced changes, such as desertification and deforestation, the following descriptions can only be in general terms and aim to portray some salient geographical features of the region.

Chinese geographers have generalized four salient features of the natural environment

8 _{Li Xiaocong 李孝聰, Zhongguo quyu lishi dili 中國區域歷史地理 (Beijing: Beijing daxue chubanshe,} 2004), 10. Tighe has also pointed out that “Exactly what the term Northwest included was imperative. Different writers and users of the term intended different spatial meanings.” See idem, Constructing Suiyuan, 92.

in the northwestern region. First, it is an arid area with an average annual precipitation of less than 200 millimeters per year. There are micro-regional variations with the amount of rainfall diminishes from east to west. Second, the terrain is generally flat as most parts of the region are constituted by semi-desert, sand desert, stony desert (specifically referring to the Gobi Desert), mountain desert, and terrene flatland. These areas have been subjected to long term erosions under the arid climate, which in turn contributes to the coarse soil texture of the region. Third, this region has long been suffering from the problem of scarce water resources. Except for the drainage areas of the Yellow River, most areas only have in-ward flowing rivers which lack permanent flow. Streams source from the glacier on the surrounding mountains are quickly absorbed by the arid soil once they reach the flatland below the mountains. Fourth, layers of vegetation in this region are thin and scattered. Except for certain areas of pasture and forest, most areas are covered by desert shrubs.10

The natural landscape of Liang province can be divided into four sectors, namely southeast, northwest, northeast, and southwest.

1. The southeast sector is roughly equivalent to the southeastern part of present-day

Gansu province. It is on the eastern bank of the Yellow River and is part of the loess plateau of North China. The deepest layer of the loess reaches 400 meters, which is also the thickest in the world. Compared with other sectors, this one enjoys a lower altitude (800-2200 meters in elevation), warmer weather, and larger amount of rainfall.11 According to the archaeological and phytogeographic studies, the loess plateau was more humid and more fertile in ancient times than it is today. During the Qin-Han period, lush forests existed over large areas in this sector. Although the whole sector gradually underwent a process of deforestation from the pre-Qin period onwards, dense forests could still be found in some areas no later than the mid-eleventh century CE.12 This sector was suitable for both agricultural and pastoral activities. Therefore, conflicts between farmers and pastoralists over land resources in this sector persistently happened in Chinese history.13 During the Qin-Han period,

11 _{Ibid, 13-15.}

12 _{Shi Nianhai 史念海, “Huangtu gaoyuan jiqi nonglinmu fenbu diqu de bianqian” 黄土高原及其農林牧}

分佈地區的變遷, in idem, Huangtu gaoyuan lishi dili yanjiu 黄土高原歷史地理硏究 (Zhengzhou: Huanghe shuili chubanshe, 2001), 386-391.

13 _{The contenders of conflicts over land resources in this sector cannot be easily placed in the conventional} and yet questionable dichotomy between Inner Asian pastoral nomads from the steppes and sedentary Chinese farmers. As those pastoralists were not necessarily nomads, nor did they all come from the Inner Asian steppes. In fact, in order to adapt to the natural conditions, most people of this sector practiced mixed economy with various degree of reliance on agriculture and animal breeding. For the pastoralists, pastoralism was the predominant economic activity, but agriculture was still in a secondary and supplementary capacity. On the other hand, farmers also practiced animal husbandry to a certain extent. Conflicts between the two groups were mainly caused by farmers’ encroachment, usually under state sponsorship, on the grazing lands and attempted to turn them into arable lands.

For the definitions and classifications of nomadism and pastoralism, see Anatoly M. Khazanov, Nomads and the Outside World. Julia Crookenden trans. (Madison: The University of Wisconsin Press, 1994),

with the help of irrigation works under state sponsorship, this sector was capable of producing a considerable amount of agricultural products. On the other hand, the pastures provided an excellent environment for horse breeding. The Former Han state therefore set up a certain number of horse ranches as a major source of supplying war horses. Needless to say, this sector was an important base of supporting military logistics for Liang province.

2. The northwest sector is the famous Hexi Corridor. As mentioned in Chapter One, it is on the western bank of the Yellow River and therefore corresponds to the western part of present-day Gansu province. Being confined by the mountain ranges on its north and south, Hexi Corridor is a long and narrow stretch of land with east-west distance of around 1000 kilometers and south-north distance varies from several kilometers to a hundred strong kilometers. The average altitude of this sector varying from 1000 to 1500 meters and the altitude increases from south to north and east to west. This sector forms a flat passageway between mountain ranges. Within this passageway, desert and semi-desert areas are studded with oases.14 Although precipitation rate of this area is low, some rivers flowing down from the mountains sustain the oases,

15-25.

which provide good havens for both human and animals.15 According to the Hanshu, during the Former Han dynasty, the good pastureland there provided the most abundant sources of cattle, sheep, and horses in the empire.16 This sector was an important land of strategic sources for the Xiongnu and became their great loss when it was captured by the Former Han.

3. The northeast sector corresponds to present-day Ningxia province. This sector is located between desert and loess plateau and its climate is under the joint influence of the monsoon zone to its east and the arid zone to its northwest. The mountainous terrain and the widely scattered basins make the area looks like a checkerboard. It is an area of dry weather, little rainfall, high evaporation, and strong sandy wind, with an annual average temperature of 5-9 degrees centigrade. Generally speaking, it is a semi-desert area and not suitable for agricultural activities.17 However, after conquering this area, the Former Han put great efforts to send labor forces in, digging ditches at certain locations for irrigation and setting up military and farming settlement points; certain parts of this area were therefore capable of providing a

15 _{Li, Zhongguo quyu lishi dili, 13-15.}

16 _{Ban Gu 班固, comp. Hanshu 漢書 (hereafter HS), (Beijing: Zhonghua shuju, 1996), 28B:1645.} 17 _{Lattimore, Inner Asian Frontiers of China, 163-168.}

considerable amount of farm produce.18

4. The southwest sector occupies the northeastern portion of present-day Qinghai province, where is also the northeastern tip of the Qinghai-Tibetan Plateau. The average annual temperature of this area is between 3-9 degrees centigrade. Under the influence of the easterly monsoon, this area enjoys a relatively warmer temperature and higher amount of rainfall than its environs. As the Yellow River and its tributary Huang River (Huangshui 湟水) pass through this area, the river valleys also provide ideal places for both agricultural and pastoral activities.19 Therefore, the He-Huang

河湟 (Yellow River and Huang River) region had long been a focal point for resource struggles in Chinese history between autochthonous peoples and Han settlers. In the Han times, as will be shown in Chapter Four, it was the area where military conflicts between the Qiang people and the Han settlers usually broke out. As we now have a general picture of the natural landscape of the northwestern region, we can turn to the political landscape in the following sections. I will first give a general description of the human geography in the northwest in prehistoric era. Then, it will be followed by a chronological account of the processes of expansion in the northwestern

18 _{Li, Zhongguo quyu lishi dili, 18-21.} 19 _{Ibid, 26-28.}

frontier during the Qin-Han period. Based on the division of the four sectors mentioned above, we will start from the southeast sector, which was close to the Jing 涇 River and Wei River valleys where the political centers of the Western Zhou (ca. 1045-771BCE), Qin and Former Han located and was therefore the first northwestern frontier zone during those periods. Then, we will follow the footprints of the Han armies and advance northwestward to the Hexi Corridor. Since the following sections focus mainly on the political landscape of the northwestern borderlands, the cultural and ethnic characteristics will only be briefly mentioned if necessary and we will return to these features in the succeeding chapters.