This study was conducted to analysis hydro-dynamic mechanism of soil detachment process for original soil core in loess region under the large range of flow discharge (0.5~2.0 L/s) and slope gradient (8.8%~46.6%).

S=0.149×1.1~B L=h·(1-cosB)/63.8sinB The formula of topographic factor can be written as: LS=0.00233×1.1~B·h(1-cosB)/sinB where L——slope length factor; S——slope gradient factor; LS——topographic factor;

. The changing tendency of the runoff Reynold's number , flow velocity ,runoffsediment concentration and sediment transport rate versus time was parabola curve in theexperiments, the critical slope gradient was about 21 ?

Generally, the total N, total P, total K, organic matter content and pH-value of soil were more important, as compared with elevation, size of gap and slope gradient of the sample plot.

8 disaster factors of soil erosion have been defined: surface material, landform and slope gradient, cover-degree, topographic, 30min rainfall intensity, engineering measure grade of conservation of water-soil, irregular subsidence and volume weight.

The slope(β) of linear regression between isotopic composition and SOC concentration was positively related to slope gradient of the landscape and negatively related to clay content,indicating that β could be used as a useful index to describe mineralization of SOC at the erosion position.

The results showed that slope runoff head loss was related to slope gradient,forest density,net rainfall intensity and slope length. The relationship of water head loss with the distance among trees and the diameter at the ground of tree was E∝(D/b)~(4/3).

The flow velocity, resistance coefficient and energy consumption ofsheet flow on steep smooth slope increased with the flow depth( flow discharge) and slopegradient, while there was little effect of slope gradient on the Darcy-Weisbach resistancecoefficient.

By choosing precipitation intensity, runoff intensity, soil particle diameter, thickness of soil layer, slope gradient, surface vegetation of 17 closed basins in a karst mountain region of Guizhou province as parameters, SPSS software and Multivariate Statistical Analysis are employed to build the dynamic remote sensing information model of soil and water loss to give a predication of the soil and water loss of Guizhou province.

The results show that the horizontal displacement of extrusion wall caused by side-pressure of cushion rolling is very slight, and the upper-reach slope gradient caused by cushion rolling can satisfy design and faceplate construction requirements.

In both therapeutic A and B groups the behavioral scores and slope gradient were found significantly larger at 12 days than 1 day P < 0.05 and that of traumatic group P < 0.05.

(7)When the slope gradient more than 20 , the placement of the instruments case vastness different in the result measured by double ring and Hood, at about 10° it can only have some effect, when at about 5 ° it seen no effect.

An estimate model was made with the middle and young artificial forest of Pinus elliottii in Xiajiang county as a population, the successively-surveyed sample plots as its samples, the slope gradient and aspect, the forest ages and the number of trees as its delarative variables, the ingrowth average diameters as its datum variables.

A series of two-dimensional simulations show the effects upon the drainage flow of changing slope gradient at the mountain-plain interface.

The objective of this study was to determine whether grid sampling efficiency can be improved using cokriging estimates with slope gradient as a secondary variable, which is easily obtained from high-resolution digital elevation models.

Soil Phosphorus and Potassium Mapping Using a Spatial Correlation Model Incorporating Terrain Slope Gradient

The slope gradient for eachroof was calculated in order to account for slopein the calculation of roof areas.

The soils of the investigated area were characterized by a relatively low slope gradient, a rigid framework of gravel and a homogeneous physico-chemical behaviour, due to the predominance of Ca among exchangeable bases.

In this paper the feature of transmission of direct light in plantation of Cunninghamia lanceolata in Huitong county was described and discussed, according to the theoretical distribution and observational data in 1982—1988. The results obtained are summarized follows:1. The direct radiant flux on the surface of canopy at southern slope is larger than that at eastern and western slope, and it is smallest at northern slope.2. The slope gradient has a great influnce on direct radiant flux on forest floor....

In this paper the feature of transmission of direct light in plantation of Cunninghamia lanceolata in Huitong county was described and discussed, according to the theoretical distribution and observational data in 1982—1988. The results obtained are summarized follows:1. The direct radiant flux on the surface of canopy at southern slope is larger than that at eastern and western slope, and it is smallest at northern slope.2. The slope gradient has a great influnce on direct radiant flux on forest floor. It decreases as the slope gradient increases, except southern slope. The decrement of direct radiant flux is largest at northern slope. It shows complicated feature at southern slope. In winter half year, it increases as the slope gradient. But in summer half year, it is reversed.3. The transmissivity of direct radiant or it's flux on the forest floor decreases, under an exponential manner, as the leaf area index increases. The transmissivity of summer half year is larger than winter half year.

Erosion and loss of soil are related and distinct each other. Amount of soil loss greatly depends on locality designed. The soil loss on slope, in some conditions, is determined mainly by slope gradient and slope length. The gradient and length of slope are varied everywhere in the reoded mountain and hill regions Therefore, it is difficult to get the value of topographic factor of the USLE, This paper derived the formula from data of the Three Gorges, by which the value of the gradient...

Erosion and loss of soil are related and distinct each other. Amount of soil loss greatly depends on locality designed. The soil loss on slope, in some conditions, is determined mainly by slope gradient and slope length. The gradient and length of slope are varied everywhere in the reoded mountain and hill regions Therefore, it is difficult to get the value of topographic factor of the USLE, This paper derived the formula from data of the Three Gorges, by which the value of the gradient factor and the length factor could be calculated. The formulas are as following. S=0.149×1.1~B L=h·(1-cosB)/63.8sinB The formula of topographic factor can be written as: LS=0.00233×1.1~B·h(1-cosB)/sinB where L——slope length factor; S——slope gradient factor; LS——topographic factor; h——relative average altitude; B——average slope gradient. According to the formulas above, the value of topographic factor in the Three Gorges could be gotten.

Soil erosion is closely related to meteorological , topographic , geological and vegetative factors . It is introduced in this paper that relationships between soil erosion and some natural elements such as precipitation , rainfall rate , slope gradient , vegetation and soil function . The laws for evolution of layer sheet erosion , splash erosion, gully erosion , gravity erosion and wind erosion processes are discussed and the scheme for controlling soil erosion is presented.