Distribution charateristics of hillslope curvature and its effects on hydological processes:A real-world test

Hillslope curvature includes the characters e.g.divergent/convergent and convex/concave etc.These characters are second-order topographic parameters contrasted to slope and length of hillslope.In this study,a 10 m×10 m DEM dataset was created using the 1:10000 elevation contour maps for the Jiangwan catchment of Tiaoxi River, on the Taihu basin.The curvature distribution within hillslopes can thus be studied.The averaged profile and plan curvature for the catchment are found to be -4.62×10^-4 and 3.49×10^-4,respectively,indicating the catchment is overall convergent and divergent.Through dividing of the catchment into two types of hillslopes headwater and side-slope,we find that the headwater hillslope is generally convergent,while the sideslope hillslope tends to be more divergent.Divergent,convergent,convex and concave are coexisting within an individual hillslope.A total of ninety soil moisture samples were taken from the Hemuqiao sub-catchment.Soil moisture contents and corresponding curvatures were analyzed.It is shown that the concave or convergent hillslopes are always with higher soil moisture values, while convex or divergent hillslopes with lower ones.Soil moisture contents decline with the increase of elevations.