Large-scale topographic analyses show that hemisphere-scale climate variations are a first-order control on the morphology of the Andes. Zonal atmospheric circulation in the Southern Hemisphere creates strong latitudinal precipitation gradients that, when incorporated in a generalized index of erosion intensity, predict strong gradients in erosion rates both along and across the Andes. Cross-ra...

The majority of Iran’s area is covered by arid and semiarid climates. In these areas, wind causes more erosion compared to water. Therefore, determination of wind characteristics especially its velocity is very important. One of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photo...

A rectangular gridded ion thruster discharge chamber is investigated for operation with multiple discharge cathode assemblies. The multiple-cathode approach attempts to increase thruster throughput and lifetime by operating three discharge cathode assemblies sequentially, possibly providing a threefold increase in discharge chamber life. Previous multiple-cathode electric propulsion devices, su...

This paper describes a method of soil erosion and soil movement measurements using 137Cs as a tracer. This technique has been used successfully employed for more than 30 years. Caesium-137 is a valuable tracer to study soil erosion. Its chemical and biological movement in soil is limited. Practically all redeposition of caesium-137 in soil after fallout occurs with soil particles due to strong ...

soil erosion is undoubtedly one of the most important problems in natural areas and has a devastating impact on grassland ecosystems. the present study was conducted to assess the ability of rangeland hydrology and erosion model for estimating sediment yield on rangeland’s hill slopes in dry regions at shahid noori paired watershed of kakhk. rhem is a mathematical, distribution and physical mod...

in this research introduced the lapsus model as a runoff, erosion and sediment model in iran. this model for the first time has operatedin iran at kakhk paired catchment of gonabad. lapsus model is a landscape evolution model that can estimate the runoff, erosion and sediment at the four stage include: calculate the effective rainfall, runoff routing, calculate the capacity of sediment transpor...