Xianfeng Cheng

Geological remote sensing information extraction of the lithology has always been the hotspot and difficulty in remote sensing applications. Carbonate rocks covered more than 3.4 million km² in China. The study area is located around Stone Forest, which is World Natural Heritage. Sedimentary rocks distributes mainly in the area, and their spectral characteristics are complex and difficult to be recognized by remote sensing. Landsat OLI data was selected as the information source. The false color synthesis, principal component change, band ratio and other processing technologies of OLI data were applied to the lithological enhancement identification of carbonate rocks. Selected information will be used to improve the quality of the land-use planning.

Jamda-Weixi continent marginal arc belt is an important component to understand the evolution of Paleotethyan. For the first time, the occurrence of peperite is being reported at the bottom of Pantiange Formation in western Yunnan, China. Two types of peperites have been identified, namely fluidal peperite and blocky peperite. LA-ICP-MS U–Pb dating results (253.6±0.7Ma) of dacitic lava showed that the peperite was formed during the late Permian. The peperite was formed during the alternation of active period and quiet period of the volcano in an apparent shallow ocean margin.

Water samples (rivers, streams, mine adits, tailings ponds) from Jinding zinc-lead polymetallic mining area and Bi River Basin were analysed for 32 indicators including major hydrochemical components and heavy metals. The correlation analysis of water chemical parameters and Gibbs diagram show that the water composition of the Bi River is influenced by human activities in addition to the rock weathering. In the streams, the main cations and anions are derived from the rock weathering of formations rich in gypsum, calcite and dolomite. Nemerow comprehensive pollution index method was performed to evaluate water quality. The water of streams and one pond is clean. Mine adits water pollution level is medium-heavy pollution. The water samples flowing through the mining area and from tailings ponds are heavy polluted.

Dongchuan, located in Yunnan Province, China, is well known as "debris flow museum" in the world because of its special geological background and intensive mining activities. There are more than 100 ravines of debris flow in the area of 1859 km², which have caused disastrous damages. Regional gullies for debris flow susceptibility evaluation can play an important role in reducing damage of debris flows in Dongchuan. In this paper, we selected Dongchuan as a case study to research the susceptibility evaluation of debris flow based on experience weight method combined with "3s" technology. The result shows that most of debris flow gullies in Dongchuan face high risk, while few face moderate risk or very high risk.

Yunnan is one of most important provinces with mineral resources and exploration in China. Meanwhile, Yunnan is Chinese ecological protective screen and try to be Pacesetter of ecological civilization. However, mining industry always disturbs ecological environment seriously. So green mine construction is inevitable and the best choice for Yunnan. In this paper, achievement of green mine construction in Yunnan was summarized. Then the paper takes two mines from Dahongshan and 4 mines from Yunnan Phosphate Chemical Group Co., Ltd (YPC for short) as case studies. Technological innovation in Dahongshan Fe Mine and Dahongshan Cu Mine guarantees their success of green mine construction. Land rehabilitation and harmonious community are highlights of 4 mines from YPC. These modes and experience could be referential to construct green mine.

Mining-induced geo-hazards have caused enormous destruction and threat to mines. Known as the "kingdom of nonferrous metals" and located in Southwest China, Yunnan Province developed mining-induced geo-hazards well with characteristics of multiple types, widespread distribution and serious damage. Landslides and debris flows are two common sub-types of geohazards causing most serious damage in Yunnan, and some of them were very representative in the world. Two landslides and two debris flows were chosen to analyze deeply. Both Laojinshan Landslide and Sunjiaqing Landslide possess the characteristic of rock avalanches. The high sliding speed and long distance made the landslides translate into clastic flows with impact force and caused enormous destruction. Rainstorm and mining waste rock were two main factors to induce debris flows in Yunnan mines. Heishan valley debris flow of Dongchuan copper mine was a super large rainstorm type viscose debris flow with very low frequency, which brought a good caution to utilize valleys which looked an unlikely debris flow. Nandagou Valley of Jinding lead-zinc mine in Lanping County was a rainstorm stimulating, gully-type, high frequency and large scale debris flow, which was induced by mining activities. Many countermeasures have been used for Yunnan mines, including engineering treatment technology and ecological remediation, monitoring and forecasting, relocation and public administration.

Heavy metal contamination due to mining activity is a global major concern because of its potential health risks to local inhabitants. The heavy metal contamination of surface water and ground water by mining activities in Gejiu tin-polymetallic mining area, South - west China, was studied. Surface water and ground water were sampled and analyzed using AAS for Cr 6+ , Cd, As, Hg, Cu, Pb, Zn, Se, Fe and Mn. Analysis of HCO 3 – , Cl – , SO 4 2 – , F – and NO 3 – in water samples was also undertaken by ion chromatography. It was shown that none of water samples exceeded the guideline of Cr 6+ , Se and Hg, while the contamination degree of heavy metals was Mn > Fe > Cd > Zn > Pb > As > Cu, all of which were serious contamination except mild contamination for Cu. The ground waters were polluted much worse than surface water.