It is important to consider reducing energy use while improving occupants’ indoor thermal comfort. The actual thermal comfort needs and demands should be considered to determine the indoor thermal environment design. In previous studies, research has not been carried out on thermal comfort in karst areas. Thus, a long-term field investigation was carried out on multi-storey residential buildings in the karst area of Guilin city centre during summer (from August 2019 to September 2019) and winter (from December 2019 to January 2020). In this study, the indoor thermal environments of three categories of dwellings were analysed. A total of 77 residential buildings with 144 households were randomly selected, and 223 occupants from 18 to 80 years old participated. A total of 414 effective questionnaires were collected from the subjects. The results show that there was an obvious conflict between the predicted mean vote (PMV) and the thermal sensation vote (TSV). The neutrality temperatures calculated by the regression method were 24.2 °C in summer and 16.2 °C in winter. The thermal comfort range was observed at operative temperatures of 20.9–27.5 °C in summer and 12.2–20.1 °C in winter. The desired thermal sensation for people in the Guilin karst area was not always reflected in the thermal neutrality range. A preference for warmness was identified in the survey.

Hengshui Lake Wetland is the only national wetland and bird nature reserve in the North China Plain. It plays an important role in maintaining the species diversity and ecological balance. In recent years, due to industrial and agricultural production, infrastructure and ecological environment construction and other reasons, the infiltration, runoff, evapotranspiration and other water balance elements was changed, which reduced runoff into the lake. In order to ease the tense water resources situation in the region, Hengshui Lake is replenished each year by Yellow River water. Although Diversion Yellow River Wetland has made direct water supply protection, but also affected the ecology and environment of Hengshui Lake wetlands. In order to understand how artificial water diversion can affect the ecological environment of natural lakes, this paper analyzes the effects of artificial water storage on the water quality of the lake by using the measured data of water samples in the lake. The results showed that the water level of Hengshui Lake showed an upward trend after the diversion from the Yellow River. Comprehensive pollution index showed a downward trend, but Hengshui Lake wetlands are still slightly polluted. Diversion of Yellow River diversion into the lake of the ecological health of Hengshui also caused some impact.