Recently, water extraction based on the indices method has been documented in many studies using various remote sensing data sources. Among them, Landsat satellites data have certain advantages in spatial resolution and cost. After the successful launch of Landsat 8, the Operational Land Imager (OLI) data from the satellite are getting more and more attention because of its new improvements. In this study, we used the OLI imagery data source to study the water extraction performance based on the Normalized Difference Vegetation Index, Normalized Difference Water Index, Modified Normalized Water Index (MNDWI), and Automated Water Extraction Index (AWEI) and compared the results with the Thematic Mapper (TM) imagery data. Two test sites in Tianjin City of north China were selected as the study area to verify the applicability of OLI data and demonstrate its advantages over TM data. We found that the results of surface water extraction based on OLI data are slightly better than that based on TM in the two test sites, especially in the city site. The AWEI and MNDWI indices performs better than the other two indices, and the thresholds of water indices show more stability when using the OLI data. So, it is suitable to combine OLI imagery with other Landsat sensor data to study water changes for long periods of time.

Increased reclamation activity has adversely affected the conservation of coastal environments. The interactions between reclamation activities and their interference with the natural and functional properties of coastal zones increase the difficulty of marine spatial planning and eco-environmental management. In this study, an evaluation method for describing the intensity of the reclamation activity (RAI) based on regional planning theory and human–marine coordination theory was proposed, and a quantitative evaluation index system was constructed. The method was applied to Shandong Province in China via geographic information system (GIS) spatial analysis. The results reveal that there was an obvious increase in the RAI from 1974 to 2021, with the total reclamation scale index and coordination of reclamation activities index being the most prominent. In addition, it was found that 2007–2017 was the peak period of infilling reclamation in Shandong Province. The natural coastlines are mainly occupied by enclosed mariculture and saltern, which should be strictly managed. The proposed index system can effectively identify the spatiotemporal characteristics of the reclamation intensity and can be used to efficiently determine management priorities. It provides a theoretical basis for regional reclamation management and can be conveniently adopted by management departments for coastal environmental protection.