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To realize the accurate extraction of surface water in complex environment, this study takes Sri Lanka as the study area owing to the complex geography and various types of water bodies. Based on Google Earth engine and Sentinel-2 images, an automatic water extraction model in complex environment(AWECE) was developed. The accuracy of water extraction by AWECE, NDWI, MNDWI and the revised version of multi-spectral water index (MuWI-R) models was evaluated from visual interpretation and quantitative analysis. The results show that the AWECE model could significantly improve the accuracy of water extraction in complex environment, with an overall accuracy of 97.16%, and an extremely low omission error (0.74%) and commission error (2.35%). The AEWCE model could effectively avoid the influence of cloud shadow, mountain shadow and paddy soil on water extraction accuracy. The model can be widely applied in cloudy, mountainous and other areas with complex environments, which has important practical significance for water resources investigation, monitoring and protection.

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Aiming at the problems of comprehensive development and reuse of land resources and water resources in urban fringe areas, this paper puts forward that land is the basis of construction and sustainable development of urban fringe areas, and the cleanness, health and safety of land resources and water resources are the premise of urban fringe development. Taking shichuan river comprehensive regulation and development project of fuping as an example, this paper summarizes the key technologies of land comprehensive development and management in urban fringe areas, and discusses the new mode of land regulation and development in urban fringe areas. It is expected to provide scientific basis for soil and water resources optimization allocation and ecological environment quality improvement in the process of urban fringe area governance, and open up new ways.

As an extreme phenomenon of water pollution, odorous-black water not only cause ecological damage and threaten human health, but also severely restrict urban development. This paper mainly summarizes the main points, applicability, advantages and disadvantages of the current comprehensive treatment technology of odorous-black water, and analyzes the later development direction of odorous-black water treatment technology. It is considered that the treatment of odorous-black water is a systematic project, which involves many sources such as external source interception, water purification, quality assurance of living water, ecological restoration are the important technical means.

Minerals are the main composition of soils. Soil minerals, especially secondary minerals, determine physical and chemical properties of soils. In this study, the X-ray diffraction ray experiments were carried out to study the mineral composition of eleven different color soft rocks and sands. The study found that the soft rock in Mu Us Sandy Land is mainly composed of quartz, potassium feldspar, plagioclase, calcite, montmorillonite, illite and kaolinite. The soft rock has various color types, such as yellow, grayish white, purple, grayish green. Different color soft rocks have different mineral composition. The grayish white soft rock has the lowest secondary mineral, accounting for only 5.4%; the light brown soft rock has the highest secondary mineral, up to 59%. The sands are composed of quartz, potassium feldspar, plagioclase, calcite, hornblende, montmorillonite, illite, of which the original mineral accounted for 93.5%, and the secondary mineral accounted for 6.5%.

IntroductionChemical industry is closely related to human survival and development. With the rapid development of industrialization, urbanization and urban civilization in China, chemical enterprises located near cities are incompatible with the concept of urban green development. The cities then require serious pollution enterprises in and around the city to switch production or shut down, and at the same time eliminate the chemical enterprises with serious environmental

An urban ecological zone (UEZ) is an important part of a city, focusing on environmental conservation and ecological economic development simultaneously. During the past decade, the urban scale of Xi’an city in China has been expanding, and the population has been increasing rapidly. This dramatic change is a huge challenge to urban sustainability. It puts forward higher requirements for the construction of an UEZ. Under different spatial resolution scales, this study adopted Landsat8-OLI and gaofen-2 (GF-2) satellite high-resolution remote sensing data to interpret the land use/cover change (LUCC) of the Weihe River UEZ. The ecosystem service value (ESV) was assessed, and the ecological effect was analyzed based on LUCC. The results showed that the spatial distribution of land types in the Weihe River UEZ changed significantly from 2014 to 2020. The construction land gathered to the southeast. Especially, the vegetative land (i.e., forestland, grassland and other green land) and water body showed a slightly increasing trend since the official establishment of the UEZ in 2018. The cultivated land area gradually reduced, and the vegetative land area tended to be concentrated as well as expanded. Through the interpretation of GF-2 remote sensing data, the ESV at the Weihe River UEZ showed a downward trend in general. The high-value areas were mainly distributed in the Weihe River and its surrounding beach areas, which were greatly affected by river water scope. Construction land normally had low ESV, and it was affected by human activities obviously. Therefore, the development of urban construction had significant impacts on the Weihe River UEZ.