4.4 Results comparison and validation
Unlike the loss of drought in the economic and social fields, few records are about the loss of karst dissolution. On the other hand, most previous studies pay a little attention to the drought loss of karst dissolution due to different purposes. Therefore, it is quite challenging to compare the results of such studies, especially based on the same experiment material. Nevertheless, we obtained the 365 days of natural karst dissolution can be used for results comparison and validation. At least it can increase the understanding of our experimental methods and results.
The most formal and credible karst dissolution data was published by Yuan & Cai in 1988 (Table 6). Moreover, Yuan & Cai (1988) use the same materials and methods as ours. They carried out experiments on three layers of ground, underground 20 cm and underground 50 cm (Yuan & Cai, 1988), while our results were from the underground 5cm, 20cm, and 50cm. The difference is that Yuan & Cai (1988) only launched one experiment in each area, while we did four types of the land cover of karst dissolution experiments. For easy comparison, we summarized the dissolution data of the sites near the study area and shown in Table 6. The results of this study are shown in Table 7.
On average, karst dissolution of Yuan & Cai (1988) is range from 0.5803 to 7.4511 mg cm-2 in one year (Table 6), and our dissolution data is range from 1.4251 to 9.7855 mg cm-2 (Table 7), which is slightly higher than the data of Yuan & Cai (1988). We then calculated the average karst dissolution amounts of four land types in each experiment site, ranging from 2.1783 to 6.2011 mg cm-2 a-1 (Table 7). This data is close to the result of Yuan & Cai (1988). A detailed comparison results show that the dissolution data of the present study is higher than Guangzhou and lower than Guilin on average value under similar conditions (Table 6, Table 7). Among the six experimental sites of Yuan & Cai (1988), Guiyang is very close to Site B, but the karst dissolution is lower than our result (Table 6, Table 7). Of course, the reason for the difference in results is not apparent.
In 2010, Zhang (2010) conducted a similar experimental research, obtained a 0.1117 mg cm-2 a-1 of dissolution rate for the cropland, 5.0031 mg cm-2a-1 for forest, 0.7617 mg cm-2a-1 for shrub grass, and 4.3407 mg cm-2 a-1 for grassland on average, respectively. Among them, the karst dissolution of cropland and shrub grass is less than our results, and the rest are proximity to us (Table 2, Table 7). Some kindred studies have been conducted to test the karst dissolution, and the results have resembled Zhang. Almost certainly, these results indicated that there is some difference between our results to the formerly studies, but there was a notable difference was found. Furthermore, each of our dissolution data has three parallel data, and there should be a high degree of credibility.