The Variation Of Hydrological Factors On Slopes In The Region Of Liupan Mountains

As looking for continuous determination of regional hydrological factors Liupanshan slope changing technology means, and to compare different soil and loess stone mountain, forest and grassland vegetation under different hydrological elements of a typical slope variation.In the south side of a semi-humid climate Liupanshan Features Perfume River watershed, using multi-electrode resistivity meter method in the two years from 2009 to 2010 (from May to October growing season). selected three typical vegetation of the slope (slope Honggou Larch Forests, the southeast slope, slope 35°, elevation of 2 500m, annual rainfall 600mm; Honggou birch woodland slope, northeast slope aspect, slope 45°, elevation of 2 500m, annual rainfall 600mm; grass slope furrow Cong Sparse tree forest, southwest slope, slope 45°, elevation of 2 468m, in rainfall 600mm), to carry out spatial and temporal changes in vegetation characteristics slope, the spatial distribution of soil physical properties, soil moisture and resistivity and spatial distribution; and communication in Mount piles of grass slope outside surface (northeast slope aspect, slope 30 o, altitude of 2 100m, annual rainfall 600mm), Yunwu Mountain loess grassland around the Liupan Mountain slope (SE slope, slope 20 o, altitude of 2 100m, annual rainfall 400mm) in Guyuan and Gansu Jingchuan official loess Hill slope (south-west aspect, slope 35 o, elevation 1 300 m, annual rainfall 550mm), and in early May 2010 for the soil moisture and spatial variation of the one-time resistance measurement. The main results obtained are as follows:1. Soil physical properties of the spatial distribution on the typical slope in Xiangshui watershedAll soil physical characteristics of vegetation type slope gradually increased with the soil depth, in the 0¹00cm soil layer gravel content gradually increased with the soil depth. With the thickness of soil depth increases, soil total porosity, capillary porosity, saturated water decreases, non-capillary porosity increases with depth then decreases. Bulk density size on the 0¹00cm slope level of Larix and Betula woodland in the 0 100cm soil layer is: middle slope (1.23g/cm3)> down slope (1.15g/cm3)>up slope (0.93g/cm3),down slope (1.09g/cm3)> up slope (1.06g/cm3)>middle slope (0.97g/cm3); the rate of saturated water of Larix is: up slope (35.01%)> middle slope (23.50%)> down slope (21.42%); Betula woodland slope of middle slope (25.55%)> down slope (24.07%)> up slope (16.34%); total porosity Larix is up slope (62.61%)> middle slope (60.37%)> down slope (58.58%); Betula middle Slope (65.49%)>up slope (60.91%)> down slope (58.80%); capillary porosity, Larix is down slope (43.99%)> middle slope (40.29%)> up slope (39.64%); Betula middle slope (49.68%)> down slope (42.21%)>up slope (40.15%); non-capillary porosity on the Larix up slope (22.97%)> middle slope (18.28%)> down slope (16.38%); Betula up slope (20.77%)> down slope (16.59%)> middle slope (15.81%).Vegetation type for the outstanding of the role differences in soil physical properties, select the 0-60cm layer of the primary root, soil physical properties were compared:volume gravel(%)of Grass clump sparse trees (19.3)>Larix (13.6)>Betula woodland (13.2); soil bulk density(g/cm3)Larix (1.10)>Grass clump sparse trees (1.05)> Betula woodland (1.03); the rate of saturated water (%)Grass clump sparse trees (29.60) > Larix (26.64)> Betula woodland (21.99); total porosity (%)of Betula woodland (61.73)> Larix (60.52)> Grass clump sparse trees (52.62); capillary porosity (%)Betula woodland (44.01)> Larix (41.31)> Grass clump sparse trees (28.24).2. Relationship between soil moisture, other characteristics and soil resistivity on different typical slopeResistivity of (Y, ?m) affected by a number of soil characteristics, such as total porosity (X1, v%), volumetric water content (X₂, v%), gravel volume content (X₃, kg/m3), bulk density (X4), saturation (X5), root content and so on.In order to distinguish between the different factors on the impact of soil resistivity using the slope for Larix was carried out man-made control of soil water content, gravel content, bulk density and porosity of the experiment. Control experiments based on the data, first of all, the single factor correlation analysis, regression results are good: Y = 560.89e^-0.3935x₁, R² = 0.94, Y = 2741.3e^2.1599x₂, R² = 0.82, Y = 666.67 e^1.1094x₃ , R² = 0.90. Then, the control of experimental data and field observations Larix slope data into a new data set, taking into account the establishment of three main soil characteristics and soil resistivity of the regression equation.the results of multiple regression equation: Y = 186.96 e-0.3935x₁ +913.77 e2.1599x₂ +222.23 e^1.1094x₃, R² = 0.89. On the resistivity and the relationship between a variety of soil characteristics, such as total porosity, volumetric water content, gravel volume content, bulk density, soil saturation and root content of stepwise regression analysis, Y = 60.04 X₁^0.964 * X₂ (-0.816), R² = 0.61, and the test was significant correlation.Through Yunwu Mountain at Guyuan by volumetric water content (X1, v%) and soil resistivity (Y, ?m) calibration correction, the results are statistical relationship (X1 = 39.596e-0.0075Y, R² = 0.78); the relationship of Jingchuan officials Loess Hill slope in Gansu: (X1 = 47.94e-0.0048Y, R² = 0.64); the relationship of outside the Liupan mountains of rocky grass slope in Diedie basin of Guyuan: (X1 =- 9.1987 Ln (x) +61.021, R² = 0.52); that the volume of soil resistivity and water content showed some inverse relationship; which Yunwu mountain has good results, some of the higher correlation coefficient.3. Temporal and spatial variation of soil moisture and resistivity variability on the main vegetation types slope in Xiangshui watershedThree vegetation types in 0-100cm soil layer soil volumetric content (%) of each month during the growing season schedule of Larix slope,order of the month is September(38.19)> August(37.66)>May(33.54)> July(30.29)> June(25.77),Betulawoodland is September(39.27) > August(38.26) > July(37.25) > May (37.56) > June(36.79);Grass furrow Sparse trees is August (28.74) > September (30.02) > May (29.38) > July (27.39) > June (41.21); the vegetation changes characteristics in soil volumetric content were shown on wet season large, dry season low, soil volumetric content decreases with soil depth deeper, showing the maximum resistivity of the surface soil, the minimum of the deepest surface soil layer.Throughout the growing season in 0-100cm soil layer soil volumetric content (%) of Larix on the slope order is down slope (38.57)>middle slope (37.65)>lower slope (35.62) >upper slope (34.92) > up slope (34.61), Betula slope is: middle slope (45.21) >down slope (39.76) >up slope (31.80), Grass furrow Sparse trees: up slope (35.64) >down slope (33.76) >middle slope (28.19); slope resistivity of different vegetation types in 0-60cm soil layer: from May to October Betula slope (31.33) >Larix slope (28.92) >Grass clump Sparse trees slope (26.15).4. Different impacts on spatial variability of soil resistivity and moisture on soil slope In early May 2010 Guyuan Yunwu mountain measured the grass slope loess, loess Hill Jingchuan officials slope, ditch Guyuan piles of grass slope in mountainous area in the depth of soil resistivity and the slope change.Yunwu Mountain on the Loess Plateau, the soil moisture from the up slope to the middle decreases, the down slope slightly increased; Jingchuan officials from the up slope of the mountain to the down slope, the soil moisture gradually became larger; Guyuan Diedie ditch soil water from the up to the downhill slope gradually increased; Slope resistance in 0-100cm soil layer of three vegetation types of the mountain order is Yunwu < Jingchuan <Diedie ditch, water content Yunwu > Jingchuan > Diedie ditch.Yunwu loess soil resisitivity in 0-100cm soil layer differences of soil arrange is the Southeast> Southwest> Northeast> Northwest; with depth decreases, the most profound changes in the surface slightly larger, the middle rate of change with depth layers are more stable; Sunny slope received more solar radiation, soil moisture content shady slope higher than sunny slope, different slopes between the soil moisture and has a very different resistivity. Soil moisture decreases with depth, the most change in the deepest layer, the middle layers are more stable. With three regions to deepen the depth of soil water in the range of 1.76%～15.44%, 1.59%～14.2%, 1.46%～10.89%. Loess slope in Yunwu mountain grassland studies have shown that in the loess mild soil dry layer of 5m, 10m and deeper occurring at the severe dry layers, and deep resistivity increased considerably with soil depth,Better rainfall conditions in the mountains Jingchuan officials and Guyuan layer of loess Diedie ditch slope, in the mild soil dry layer of only 3m, there is moderate in the 6m deep dry layer, and deeper in the 10m at the emergence of severe dry layer; thin layer of mountain gully in Guyuan, belonging to the grass rocky slope, and soil resistivity and water content analysis on different soil slope can deepen the degree of dry soil Liupanshan understanding .The impact of locust roots greatest of soil volumetric content in Gansu while the effect of Diedie slope Guyuan more affected by soil piles of gravel, Larix slope both affected by grass and roots in Liuppan mountain evenly, the associated Yunwu mountain highest with no roots and gravel. Control experiments based on in and outside data, get the statistical relationship between soil resistivity and soil physical characteristics, indicates that with the increase of soil moisture, gravel volume decrease, soil bulk density reduce, soil resistivity decreases.Therefore, the use of soil resistivity meter continuously measured in the hydrological factors on the slope change is aviable approach.