# Soil and Rockfill Dams Safety Assessment for Henan Province: Monitoring, Analysis and Prediction
## 2 Study Area and Data
### Data Source  
A total of 55 ascending orbit Sentinel-1A images covering the study area from March 2017 to September 2021 with an incidence angle of 39.65\({}^{\circ}\) (path 113) and 39.72\({}^{\circ}\) (path 40,11) at the dam position, precise orbit ephemerides data (POD), and Shuttle Radar Topography  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Dam** & **Area** & **Dam Type** \\ \hline Xiaolangdi Reservoir Dam & Mengjin County & Clay-inclined core wall rockfill dam \\ Baisha Reservoir Dam & Yuzhou & Homogeneous soil dam \\ Luhun Reservoir Dam & Song County & Inclined wall soil and rockfill dam \\ Baiguishan Reservoir Dam & Lushan County & Homogeneous soil dam \\ Gusitan Reservoir Dam & Ye County & Clay core wall sand and pebble dam \\ Yanshan Reservoir Dam & Fangcheng County & Inclined wall soil and rockfill dam \\ Zhaopingtai Reservoir Dam & Lushan County & Thin clay sloping wall sand and \\  & & cobble dam \\ Zhaikou Reservoir Dam & Lingbao City & Clay heart wall sand shell dam \\ Yahekou Reservoir Dam & Nanzhao County & Clay heart wall sand shell dam \\ Nanwan Reservoir Dam & Xinyang City & Clay heart wall sand shell dam \\ Shishankou Reservoir Dam & Luoshan County & Clay heart wall sand shell dam \\ Wuyue Reservoir Dam & Guangshan County & Clay heart wall sand shell dam \\ Pohe Reservoir Dam & Guangshan County & Clay heart wall sand shell dam \\ Nianyushan Reservoir Dam & Shangcheng County & Clay heart wall sand shell dam \\ Boshan Reservoir Dam & Queshan County & Clay heart wall sand shell dam \\ Songjichang Reservoir Dam & Miyang County & Clay heart wall sand shell dam \\ Banqiao Reservoir Dam & Zhumadian City & Clay heart wall sand shell dam \\ \hline \hline \end{tabular}
\end{table}
Table 1: Some large soil and rockfill dams in Henan Province.  
Figure 1: Schematic diagram of the geographical location of the study area.  
Mission Digital Elevation Model (SRTM-1 DEM) were collected for deformation monitoring of large soil and rockfill dams in Henan Province to improve satellite orbit accuracy and remove terrain phase. The coverage is shown in Figure 2[43]. The water level data of Xiaolangdi Reservoir Dam were obtained from the daily water conditions published on the official website of the Yellow River Conservancy Commission of the Ministry of Water Resources ([[http://www.yrec.gov.cn/](http://www.yrec.gov.cn/)]([http://www.yrec.gov.cn/](http://www.yrec.gov.cn/)), accessed on 31 December 2022). The rainfall data were obtained from the monthly water conditions data published by the Henan Provincial Hydrology and Water Resources Measurement and Reporting Center ([[http://www.hnssw.com.cn/](http://www.hnssw.com.cn/)]([http://www.hnssw.com.cn/](http://www.hnssw.com.cn/)), accessed on 31 December 2022). These data were used to analyze the correlation between dam deformation, water level, and rainfall.  
Meanwhile, the 171 Sentinel-1A images of Xiaolangdi Reservoir Dam from January 2017 to November 2022 were processed to obtain long-time series deformation. In order to increase the experimental accuracy and prevent accidental situations, multiple buffer zone with a radius of 5 m was established in the center of characteristic regions in the upper deformation area of the dam. All of the time series points were selected in the buffer to calculate the average value of each period deformation. It is combined into a set of data as the training dataset and validation dataset of the model. The first 80% of the experimental data are selected as the training set and the last 20% as the test set.