Climate variables including temperature, rainfall intensity, rainfall acidity, and lithological properties are among the most important factors affecting rock weathering. However, the relative contribution of these four factors on rock weathering, especially on chemical weathering, is still unclear. In this study, we carried out a series of weathering-leaching rainfall simulations on four types of badland sediments under controlled conditions of two levels of temperature, rainfall intensity, and rainfall acidity based on the real field data from representative weather scenarios. The main objectives are 1) to explore the progressive change of sample surface and leachate characteristics and 2) to reveal the independent effects of temperature, rainfall intensity, rainfall acidity, and lithology and their relative contribution as well, on both mechanical and chemical weathering. Qualitative analysis on crack development and fragmentation of sample surface and quantitative analysis on the leachate volume, pH, electrical conductivity, and total cation and anion releases of sample leachate together demonstrated that for the investigated sediments, under the conditions of temperature, intensity, and acidity of rain that can be achieved in nature, high drying temperature obviously increases mechanical disintegration by promoting the rate and magnitude of moisture variations (wetting–drying alterations), while high rainfall intensity and acid rain have no obvious effect. Impact and importance of the drying process caused by high temperature between wetting events need more attention, rather than high rainfall intensity. Low temperature, high rainfall intensity, and acid rain contributing more hydrogen ions required for cation exchanges, rock type with more soluble minerals, all promote chemical weathering, and the influence of climatic and lithological factors on chemical weathering decreases in the following order: mineral composition> rainfall intensity > temperature > rainfall acidity. Climatic variations on temperature can modify weathering processes and in that way conditioned hydro-geomorphological processes in badland areas. Such changes should be considered for direct and indirect implications on badland dynamics.
<p>Badlands, between researcher also known as natural field laboratories, present areas formed in a wide range of lithologies and different climate conditions. Complex mineralogical and physico-chemical sediment composition make them suitable for numerous laboratory experiments that can replicate changes that occur in the field.</p><p>As climate is one of the most significant factors in badlands forming and since climate changes are one of the biggest environmental concerns nowadays in this research badlands material was exposed to different conditions with the aim to monitor changes caused by extreme climate.</p><p>Three samples of badlands from China were organized in twelve sets and treated with rain, acid rain, ice (presenting snow) and acid ice (frozen acid rain). Six sets were treated with rain and acid rain of different intensity and under high and low temperatures during fifteen cycles, while the other six were treated with ice and acid ice during fifteen cycles, dried at 50&#176;C for three cycles and then treated with ice and acid ice for additional five cycles. All of the samples were photographed after each cycle to follow physical change occurring on the sample surface Leachate was collected and volume, electrical conductivity, pH and ion concentration were measured.</p><p>Generally parameters did not oscillate much neither between samples, nor between treatments except electrical conductivity that was higher in the samples treated with ice and acid ice. Physical changes that occurred during the experiment present the main difference. In all of the samples high temperature caused the most noticeable decay, in samples treated with rain, sediment decay was minimal, while in samples treated with ice a noticeable decay occurred.</p><p>This experiment confirmed that high temperature/drought has great impact on land degradation, but interestingly pointed out that ice/snow and its thawing have greater impact on degradation then rain and its intensity. These kind of result opens up a new perspective on climate impact on forming and badlands evolution that should be further examined.</p>
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