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Qijiang District is a high-risk area for geological hazards in Chongqing. In this study, Qijiang District is selected as the research area. Based on the topography, geomorphology, geological structure, and DEM data of the region, seven main factors of geological hazards within slope units were extracted, including slope structure, slope gradient, density of geological disaster points, engineering geological lithology, distance to the water system, inclination angle of rock strata, and geological structure. These factors were quantitatively analyzed and combined with field inspection of geological hazards to revise the weights and grading of each factor. The analytic hierarchy process was used to evaluate the susceptibility of geological hazards within slope units. Through this process, this study aims to establish a geological disaster susceptibility evaluation system suitable for Qijiang District. [ABSTRACT FROM AUTHOR]

In this paper, glasshouse experiments were conducted to determine the accumulation, distribution and transformation of DDTs and HCHs by maize under pot culture conditions. The culture soil was spiked with the organic pollutants and samples were collected in different durations. Analysis of the plants at harvest showed that the selected plant varied widely in their ability to remove and translocate DDTs and HCHs from the soil, the bioconcentration factor ranged from 0.004 to 0.027 for the shoot and from 0.036 to 0.097 for the roots, and the translocation factors were lower than 0.1 with variation between DDTs and HCHs, but no significant differences were observed. DDTs appeared to have accumulated by both passive adsorption and active absorption, p,p'-DDT and p,p'-DDE were the major metabolite and the transformation was mediated by reductive dehalogenation, the affinity of the OCPs for lipids is one of the major factors affecting their uptake and translocation within the plants. [ABSTRACT FROM AUTHOR]

Surface sediment and water samples were collected from Daihai Lake to study the biogeochemical characteristics of nitrogen and phosphorus, to estimate the loads of these nutrients, and to assess their effects on water quality. The contents and spatial distributions of total phosphorus (TP), total nitrogen (TN), and different nitrogen forms in sediments were analyzed. The results showed that concentrations of TN and TP in surface sediments ranged from 0.27 to 1.78 g/kg and from 558.31 to 891.29 mg/kg, respectively. Ratios of C:N ranged between 8.2 and 12.1, which indicated that nitrogen accumulated came mainly from terrestrial source. Ratios of N:P in all sampling sites were below 10, which indicated that N was the limiting nutrient for algal growth in this lake. Effects of environment factors on the release of nitrogen and phosphorus in lake sediments were also determined; high pH values could encourage the release of nitrogen and phosphorus. Modified Carlson's trophic state index (TSI(M)) and comprehensive trophic state index (TSI(C)) were applied to ascertain the trophic classification of the studied lake, and the values of TSI(M) and TSI(C) ranged from 53.72 to 70.61 and from 47.73 to 53.67, respectively, which indicated that the Daihai Lake was in the stage of hypereutropher.