About Yellow Earth Forest Alliance
Yellow Yellow is associated together towns soil forest soil forest, is the development of debris flow in a body of freezing and thawing of ice water over the landscape.
Yellow Earth Forest Alliance Liangshan Yi Autonomous Prefecture in Sichuan Province, Xichang City, 30 km south of the Yellow associated towns, from the Xichang City in Sichuan Province more than 30 kilometers, the left bank of the Anning River Valley in the slope zone. The distribution area of forest land l.3 km2, elevation of 1500m, the mighty, in different styles, and some resemble the ancient castle, and if some of the vast forest, some like Heavenly Sword sword, some, such as gallop sky shouts and some, such as Panda naive, some, such as climbing Qunhou play, some, such as Liger It forces strive for a beautiful scenic area and the soil.
Huanglianguan berberine tree hill towns for more than the name.
Earth Forest is a specific material conditions, terrain conditions, geological conditions and external driving force, climate conditions, the formation of a special landscape, together with a certain amount of yellow earth Lin has a unique ornamental value and a certain scientific value.
Lin Department of yellow sand soil texture, rock. Geological experts said. Forest soil formation. Far can be traced back 8,000 years to a million years of ice age. In the outwash period. Ice water to bring debris flows, the formation of sand gravel layer. Diagenetic hardening sand gravel. Impact crustal movement by the new, there rip or (geologically known as crack.) Surface water (mainly water) along the crack down leakage, infiltration. Gap over time and gradually expanded to deepen because of erosion, and finally split into a mounds of earth, soil column into today's land forest. Department of Earth Forest sand rock items, the Department of glial calcium knot, can not easily be weathering, erosion, and so mostly mushroom.
Soil Lin Qi, also vary with time, because the situation varies. Childish eyes. Here is a zoo, gallop sky shouts and Panda naive. Qunhou climbing play, Liger, according to the competition between forces. Intended to shape with. Everything, Scholastic is the most wonderful evening, when the dim scenery, sound ceased, people will hear all kinds of fantasy among the odd sounds, all in the freezing, you need to fly to imagine.
Yellow associated natural geological environment, forest soil
Xichang is located near the towns Huang associated with the Xichang area belong to the subtropical plateau monsoon climate, annual average temperature of 17 ℃, 7 monthly average temperature of 22.6 ℃, 1 monthly average temperature 9.3 ℃, frost-free period 273 d, the average sunshine hours 2 431 h, The annual average precipitation 1 013 mm, distinct wet and dry seasons, rain and heat in the same quarter. Study area is located in the middle of Sichuan and Yunnan uplift axis, east of the Anning River fault, the fault of the North West, Wood River, the main north-south direction by a series of folds, the pressure of the fracture and its successful students contact times and low-order pressure-shear SHEAR FAULT or composition. Since the region near the Cenozoic tectonic activity still has a strong pull along the Anning River, the Wood River and Rossi faults formed a peaceful valley, respectively, in Xichang and Butuo settlement basin, the Tertiary and Quaternary local place small folds and faults, there are still many inherited fault activity, there are many hot springs along the faults exposed, strong and frequent seismic activity. Exposed strata in the study area is mainly freeze-thaw debris flow body (Q4slf), located in the piedmont Yellow associated towns piedmont gentle slope to the accumulation of platform. Bay, the surrounding rock as ginkgo group (T3bg) quartz sandstone. Yellow Earth Forest in Union left bank of the Anning River valley. Surface water supply mainly by atmospheric precipitation, forest soil distribution as low relief terrain slope, there are certain advantages of the catchment, the rainfall, surface water rich region. Piedmont valley surface water runoff through the row of Ru Anning River. Groundwater is mainly from the loose soil pore water and fracture water composition of bedrock, the main source of precipitation is still imported by the underground runoff peaceful valley.[1]
Causes of Yellow Earth Forest Alliance
1, the formation of the material composition of forest soil
Soil Linfa Yu District, located in tranquil valley on the slope of the piedmont alluvial fan. According to available data on the causes of deposits have different versions, according to "Luoji Glacier Geological Survey", the accumulation of material from the peaceful valley of the left bank of the main body composed of debris flow deposits, deposits composed mainly of silt from the tan - silty composed of clay, gravel sandwiched between layers, the particle size of crushed 2 ~ 10 cm, was angular or subangular sandstone fragments. Gravel soil occurrence, showing the output state of the alluvial fan debris flow, along the direction of the valley was the fan Mizoguchi distribution (Figure 3), angle of 6 ° or so. According to accumulation of body composition of a substance, presumably freezing and thawing ice debris. Accumulation takes the shape of semi-cemented status, type of iron clay cementation cementation in the middle sometimes there are the thin layer of gravel or crushed stone layer, the thickness of about 5 cm, lenticular, leaning downstream angle is less than 8 °. Accumulation gray and black top cover (weathering crust), its composition is mainly alumina - iron, these ingredients are more stable and less susceptible to leaching, after the formation of high strength, weathering ability. As for the semi-cemented accumulation of body state, vulnerable to rain leaching, erosion, while the protective effect of the top cover, coupled with the middle of soil column layer of crushed stone or gravel played a similar "stirrup" role, to ensure the stability of the soil column. The formation of the Earth Forest provides an important material foundation.
2, the soil conditions for forest landscape formed
In the Anning River valley sides, often piedmont debris flow can be seen that the body can not all of the accumulated body of soil can be developed into forest, or forest land development can achieve together as the yellow forest soil where the scale of towns. This is because the formation of the forest soil is also related to its topography: slope due to the slow accumulation of body platform is located in the transitional zone, so that the lot is often gully development, cutting deep valleys, the surface water leaching conditions provided. Through field investigation found that shallow cut in the valley can be seen where the development of soil column, but the soil column is very small-scale short, form is very simple. Therefore not difficult to find soil formation and development of forest landscape in which parts of its morphology and topography also has an important relationship.
3, forest soil conditions for the formation of new tectonic movement
Yellow is the formation of joint forest land area in the area of new construction completed during the movement. Tectonic subsidence phase in the formation of the Anning River valley basin, to accept the formation of ice water after freezing and thawing, and debris flow deposition of alluvial materials and other substances to form the material basis of landforms; then lift, making the debris flow body was cut to form various forms of crack, forming a soil Linfa Yu topography; of course, on the other hand, accumulation body in the deposition process because of the physical effects of soil will shrink during the formation of mud cracks and other cracks. When the new tectonic movement into the stable, the water flow will be carried out on the accumulation of erosion and leaching of the body for the formation of forest land have provided favorable conditions.
4, the formation of soil outside the forest dynamic conditions
Huang Union during the development of the forest soil, along with a variety of external dynamic action, such as: the role of water, gravity and physical weathering, etc., where the role of water is the most important role. On the one hand, surface water erosion surface cut in the formation of various forms of the valley, criss-cross the valley, in the original form on the accumulated body of soil columns, walls, screens and other topographic soil. On the other hand, leaching of surface water and other physical weathering, the formation of a mix of soil in the forest landscape.
5, the formation of the climatic conditions of soil forest
Forest soil formation, due to its material characteristics of the decision, its stability is poor, far compared with the Stone Forest. The formation of the forest soil and its environment is also climate-related. It requires dry climate, annual rainfall is not too large, low frequency of rainfall, on the whole dry season is longer than the rainy season. Yellow Pass of the Xichang area belongs to subtropical plateau monsoon climate, annual average sunshine hours 2 431 h, distinct wet and dry seasons, rain and heat in the same quarter, and the long dry season, air dry, just as the formation of forest land provides a good climatic conditions . Formed under such climatic conditions the soil cylinder high forest, which is difficult to be destroyed, the momentum is more spectacular.[1]
Yellow associated natural geological environment, forest soil
Xichang is located near the towns Huang associated with the Xichang area belong to the subtropical plateau monsoon climate, annual average temperature of 17 ℃, 7 monthly average temperature of 22.6 ℃, 1 monthly average temperature 9.3 ℃, frost-free period 273 d, the average sunshine hours 2 431 h, The annual average precipitation 1 013 mm, distinct wet and dry seasons, rain and heat in the same quarter. Study area is located in the middle of Sichuan and Yunnan uplift axis, east of the Anning River fault, the fault of the North West, Wood River, the main north-south direction by a series of folds, the pressure of the fracture and its successful students contact times and low-order pressure-shear SHEAR FAULT or composition. Since the region near the Cenozoic tectonic activity still has a strong pull along the Anning River, the Wood River and Rossi faults formed a peaceful valley, respectively, in Xichang and Butuo settlement basin, the Tertiary and Quaternary local place small folds and faults, there are still many inherited fault activity, there are many hot springs along the faults exposed, strong and frequent seismic activity. Exposed strata in the study area is mainly freeze-thaw debris flow body (Q4slf), located in the piedmont Yellow associated towns piedmont gentle slope to the accumulation of platform. Bay, the surrounding rock as ginkgo group (T3bg) quartz sandstone. Yellow Earth Forest in Union left bank of the Anning River valley. Surface water supply mainly by atmospheric precipitation, forest soil distribution as low relief terrain slope, there are certain advantages of the catchment, the rainfall, surface water rich region. Piedmont valley surface water runoff through the row of Ru Anning River. Groundwater is mainly from the loose soil pore water and fracture water composition of bedrock, the main source of precipitation is still imported by the underground runoff peaceful valley.[1]
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