# New Landslide Disaster Monitoring System: Case Study of Pingding Village
## 4 Discussion
[PERSON] [42] discussed the influence of rainfall seepage recharge on slope land collapse through the concept of watershed-based water balance using the following steps: (1) Estimating the base flow volume through the river flow volume qualification line method and the base flow estimation mode, and related to base flow as the seepage recharge of underground water; (2) taking into consideration the correlation system of rainfall, seepage, run-off, evapotranspiration, and underground water recharge through the unsaturated soil water balance method. These two modes were both shown to have similar results. The next step was to carry out a sensitivity analysis through STEDWIN (STEDwin is the smart editor to simplify working with Purdue or PennDOT* STABL programs) and to discuss its influence on the side slope stability. This revealed that the internal friction angle variability affects the side slope stability most significantly, followed by sloped variability and the rise of the underground water level, while the coherence and unit weight come next. From the figure of the area's rainfall and safety factor relationship, it can be seen that as the steepness of the slope reaches 35 degrees and the rainfall reaches 400-500 mm, according to the analysis of [PERSON]'s simplified method, the safety factor reaches 1.0, forming an imminent risk of collapse. Regarding the discussion of practical examples, a correlation was found between the locations in the Cingshuei River basin that have suffered from collapse and the estimated rainfall recharge factors. [PERSON] [43] discussed the effects of the relevant factors that have affected the mechanism of side slope slips through on-site measurements and theoretical analyses. Long-term monitoring work regarding information such as land surface and stratum heterotaxies, rainfall, the underground water level, and the underground water flow volume of the surrounding areas of Wuwanzi along the Taiwan 18 th Line Highway (29 K + 900 \(\sim\) 31 K + 500) has been carried out since the beginning of 2000. Serious failures took place on 26 June 2003, leading to the depletion of 150 m of the road base of the 31 K + 340 section and a 1.5-month highway disruption. The causes of this event's side slope failures were analyzed, discussed, and compared with the on-site monitoring results. With the theoretical analyses and the estimation of the stability of falling residual slopes, a final possible restoration solution was proposed. [PERSON] [44] studied the slope lands near Wuwanzi along the Taiwan 18 th Line Highway. An unexpected slip failure struck the 31 K + 340 section on 26 June 2003, causing disruption of the entire highway. A simulation of dry seasons and rainy seasons based on the underground water level was conducted using SLOPES/W software (SLOPE/W is the leading slope stability software for soil and rock slopes, GeoStudio company, head office in Calgary, Alberta, Canada). The load input was increased during rainy seasons to achieve the side slope's failure conditions. The failure mode was then integrated, analyzed, and compared with the observation statistics of the tiltmeter. The Japanese Society for Landslip Solution Technologies [45] suggested a classification of the displacement speed effect on unstable side slope activities, as shown in Table 2. Such a classification is the displacement speed obtained through dividing the obtained stratum displacement by the observation time. The basis of classification depends on the level of speed and the trend of displacement. The table shows that unstable side slope activities can be roughly classified into four categories. The first three categories are side slopes with (1) emergency movements, (2) definite movements, and (3) semi-definite movements, which are moving slopes with confirmed problems that require immediate effective solutions.