THE CURRENT SITUATION OF GEOLOGICAL ENVIRONMENTAL HAZARDS IN THE MINING AREAS OF NATURAL BUILDING MATERIALS IN PHU LOC DISTRICT, THUA THIEN PROVINCE.

Abstract

The article introduces some research results on the current status of geological environmental hazards in the mining areas of natural building materials in Phu Loc district, Thua Thien Hue province. On the basis of sampling for analysis phase 1 (9/2019), surface water and groundwater are polluted with some parameters such as pH, COD, BOD₅ and Pb. It is alarming that the Pb content in surface water exceeds the permitted limit of 45 - 1380 times and in the underground water is 190 - 710 times, both at extremely serious pollution levels. The reason for this increase may be due to the regional geological environment that already contains high levels of this element and mining activities can also contribute significantly to the dispersion of Pb into the environment. However, the results of sampling for analysis phase 2 (11/2020) showed that except for pH, all other analytical parameters were within the allowable limits. These results have different values ​​compared to the analysis results of phase 1. The reason is that this sampling was carried out after the historic flood (10 – 11/2020), the water sources were diluted. because rain water leads to lower analytical indicators. Besides surface water and groundwater samples, soil samples (surface sediments) taken in phase 1 (9/ 2019) also have much higher values ​​of analytical criteria than those taken in phase 2 (11/2020). The cause is also due to the historic flood (10 – 11/2020) that washed away surface sediments. On the other hand, mining activities are also one of the causes of the decrease in forest cover due to the reduction of forest cover and loss of vegetation cover, leading to biodiversity loss, changing the nature landscape, changing topography - geomorphology of many points in the area.