Guanting Gorge

Guanting Gorge

Guanting Gorge is located in western Beijing and is a first-order tributary of the upper Yongding River. It spans three districts and counties across two provinces/cities: Huailai County in Hebei Province, and Mentougou District and Changping District in Beijing. Within Mentougou, the watershed area covers 1,291 square kilometers, accounting for 88.7% of the total water area in the district. The Guanting Gorge region in Mentougou belongs to the northern end of the Taihang Mountain range, featuring a terrain that is higher in the west and lower in the east. The area has steep slopes, numerous cliffs, deep valleys, complex rock formations, and exposed bedrock. The northwest and southeast sections are predominantly composed of various types of limestone. The main soil types are mountain meadow soil, mountain brown soil, and cinnamon soil. The vegetation is of the warm temperate deciduous broadleaf forest type, although the original forests have been largely destroyed, with only small patches of natural secondary forest remaining. There is a relatively rich variety of plant species, distributed vertically according to altitude. The area has a monsoon climate typical of the eastern mainland, with an average annual temperature of 12°C, a frost-free period of 160 days, and an average annual rainfall of 539 millimeters. Most precipitation occurs between June and August, accounting for over 70% of the annual total. The Guanting Gorge watershed in Mentougou spans nine towns and subdistrict offices, comprising 196 administrative villages, with an agricultural population of 61,852 people and a labor force of 28,031. The agricultural population density is 48 people per square kilometer. In 1992, the watershed had 76,600 mu of cultivated land, with an average of 1.24 mu of farmland per agricultural person. Forested land covered 424,300 mu, including 274,400 mu of timber forest and 10,100 mu of economic forest. Livestock farming was primarily based on free-range practices. Secondary industries were mainly engaged in mining, building materials, transportation, processing, as well as commercial and catering services. In 1992, the total agricultural output value was 12.833 million yuan. Due to relatively poor natural conditions, economic development was slow, with an average per capita income of 1,155 yuan, and poverty affecting 42% of the agricultural population. Harsh natural conditions combined with human activity have led to intensified soil erosion. The watershed's eroded area spans 854.7 square kilometers, accounting for 66.2% of the total area, including 694 square kilometers with slight erosion, 160.7 square kilometers with moderate erosion, as well as areas suffering from severe erosion and debris flow erosion. The average annual soil erosion in the watershed amounts to 2.582 million tons.