GUO Jianfang, senior engineer, majors in electromagnetic and fluid monitoring and analysis forecasting, E-mail: gjfzyy76@sina.com
The wavelet method is used to calculate the coherence spectrum of the ground resistivity and the theoretical value of surface strain Earth tide at Changli station during 1981 to 2020. The results show that the 12 h and 24 h period spectra of the calculated results are significantly correlated, with a frequency of about 1 to 4 times/month, each lasting about 2 to 3 d, but the time is irregular. The positive and negative correlations of each periodic component are chaotic and unstable in time domain. The results of daily value calculation mainly have two types of cycle components, one is the short cycle of 8 d, 10 d, 15 d and 30 d within 8 to 30 d, and the other is the longer half-year and annual cycle. The continuity of short-period components is poor, the frequency is about 3 to 5 times/year, and the positive and negative correlations are chaotic in the time domain. The correlation between the half-year and annual scales is relatively significant, the duration is more continuous and the change is relatively stable, and the annual cycle component appears longer than the half-year cycle. The correlation of annual cycle is the most stable and negative correlation, and the correlation of half-year cycle is slightly worse, with both positive and negative correlation. The daily wavelet coherence spectrum also shows the existence of long and short period gaps, which are related to the seismic conditions, mainly reflecting the stress field changes in the area and the modulation effect of far-field large earthquakes.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |