Effects of Temperature Variability and Warming on the Timing of Snowmelt Events in Southern Finland during the Past 100 Years

This study analyses the first and last days of snowmelt events and the number of days (duration) between those throughout a water year (September-August). The snowmelt duration (SD) as well as its first (SFD) and last (SLD) days were estimated using daily precipitation and temperature measurements at the Kaisaniemi meteorological station in southern Finland during 1909-2008 as input datasets to a temperature-index snowmelt model. As snowmelt is a sensitive hydrological variable to temperature, this study also evaluated historical variations and trends in November-May (SDt), November-January (SFDt), and March-May (SLDt) temperatures corresponding to SD, SFD, and SLD at Kaisaniemi. The trends in all these parameters as well as their correlations with the well-known climate teleconnections over Finland were investigated. Long-term average values indicated the longest SD was about 131 days between 15 December and 25 April at Kaisaniemi. The SD significantly (p<0.05) shortened by 0.37 (days/year) at Kaisaniemi during 1909-2008 mainly due to the earlier (0.32 days/year) SLD. Such trends in SD and SLD were principally associated with century-long significant warming trends (0.02 °C/year) in both SDt and SLDt. The Arctic Oscillation (AO) was the most influential climate teleconnection for historical variations in SD, SLD, SDt, SFDt, and SLDt at Kaisaniemi.

Research on the Framework of Intelligent Command Decision System for Flood Control

Starting from the process of flood control and flood control decision-making, the shortcomings of the traditional flood control and flood control command and decision-making system are analyzed, and an intelligent decision-making system for flood control and flood control is proposed. The structure and functions of the system framework are elaborated in detail, and the key issues in the process of building intelligent systems are pointed out. Based on the real-time information monitoring system, this intelligent system can predict the next phase of hydrometeorology, flood and other related information, help decision makers to identify risks, and optimize the best flood control dispatching plan for decision makers to choose.

Crack Treatment of Sprayed Concrete Layer in Tail Water Surge Chamber of Guandi Hydropower Station During Operation

The dimensions of the tail water surge chamber of Guandi Hydropower Station are 205m × 21.5m × 57 (length × width × height), and the top 21.5m area is permanently lined with net-jet concrete. Sprayed concrete cracking occurred during the excavation construction process, and cracking, peeling, and block dropping occurred again after the power station was in operation. According to geological conditions, field surveys, and monitoring instrument data analysis, it is believed that the surrounding rock is stable overall, and the cracks are mainly manifested by shallow surface relaxation caused by stress release in the shallow surface rock mass of the tailing chamber and cracking failure of the concrete spray layer. The cracked and damaged sprayed concrete cracking was treated while the power station remained in operation. Processing was completed in November 2015 and the power station is currently running well.

An Analysis on the Construction Technology and Management of Water Resources and Hydropower Projects

As an important national infrastructure, the construction quality of water conservancy and hydropower projects is not only related to people's production and life, but also directly linked to the development of the national economy. Therefore, ensuring the quality of construction works is of great significance. The construction quality of water conservancy and hydropower projects depends to a large extent on the level of construction technology. In addition, construction technology is also inextricably linked to construction efficiency and construction cost. Therefore, construction companies must pay attention to the construction technology management of water conservancy and hydropower projects, and adopt scientific and reasonable construction technology to ensure the project according to the actual situation of construction Quality, give full play to the economic and social benefits brought by the construction of water conservancy and hydropower projects.

An Analysis on the First-Stage Diversion Construction Method of the Dam of the Congo (ZO) ZONGO II Hydropower Station

The dam of the ZONGOII hydropower station in the Congo is located 800m downstream of the tail water outlet of the ZONGOⅠplant. The first phase of the diversion of the dam is carried out by installing a cofferdam on the left bank of the Inkisi River to carry out sand sluice and other projects. Due to the feasibility of the construction plan and the reasonable organization of the on-site personnel, the first phase of the diversion task was successfully completed.