Investigating karst dissolution loss caused by different intensity
droughts using field control experiment
Abstract
Abstract It is well known that droughts have a significant impact on
karst dissolution. However, it is not clear how much karst dissolution
will be lost under the impact of droughts, especially the loss of
different intensity droughts. The present study used a simple but direct
standard carbonate tablet to investigated the karst dissolution loss
caused by different intensity droughts for four types of land cover in
three sites by a field comparative control experiment. Experiment
results showed that the drought had caused a significant loss to karst
dissolution. Moreover, with the drought increasing, the karst
dissolution showed a clear upward trend. From light to rare level,
drought caused a 0.4451 to 2.0546 mg cm-2 of a mean
loss of karst dissolution for the forest, 0.3044 to 1.9405 mg
cm-2 for cropland, 0.5580 to 2.2760 mg
cm-2 for shrubland, and 0.5131 to 4.5336 mg
cm-2 of a mean loss of karst dissolution for
grassland, respectively, which equivalent to a 31.83 to 54.55% of
average loss for the forest, 27.80 to 55.97% for cropland, 39.97 to
48.03% for shrubland, and 36.56 to 64.34% of karst dissolution loss
for grassland. Subsequent impact mechanism analysis indicated that soil
water plays a crucial role in karst dissolution loss of different
intensity droughts. Specifically, drought occurs leads to a decline in
precipitation, which in turn undoubtedly reduces the soil water, weakens
the karst dissolution process, and finally causes the loss of karst
dissolution.