The distribution, mineralization, and transformation of soil organic phosphorus (P) exhibits strong regional characteristics because of variations in climate and pear varieties in Yanbian apple–pear orchard. Soil samples were collected in 11, 25, 40, and 63-year-old apple-pear orchards, at the depths of 0–20 cm, 20–40 cm, and 40–60 cm. Soil aggregates were sieved using the dry sieving method, and the concentrations of organic P were determined using the improved Bowman-Cole method. Differences in organic P in soil aggregates were analyzed in respect to planting year, soil layer, and season. According to the results, with an increase in planting years, labile, moderately labile, moderately stable, highly stable, and total extracted organic P in soil aggregates increased and then decreased. The concentrations were the lowest in the 11-year-old orchard and the highest in the 25-year-old orchard. With an increase in soil layer depth, all the forms of organic P concentrations in soil aggregates decreased linearly, and there were significant differences among different levels. In addition, with shifting seasons from spring, summer, to autumn, the labile organic P concentrations in soil aggregates decreased gradually, and the moderately labile, highly stable, and total extracted organic P concentrations first increased and then decreased, while the moderately stable ones first decreased and then increased. All the forms of organic P concentrations in soil aggregates were the highest in the <0.25 mm aggregate size fraction, followed by the 0.25–0.5 mm fraction. The concentrations of total extracted organic P decreased with an increase in aggregate size fraction. According to the results, organic P is accumulated relatively easily in smaller aggregates, and moderately labile organic P was the major form of organic P in the apple-pear orchard soil, followed by highly stable organic P.

Seepage of groundwater within rock fractures is widespread. The seepage conditions in the fractures can be affected by the stress and temperature conditions. Shale seepage conditions are a complicated coupling of stress and temperature. Experiments were carried out on shale samples containing three types of fractures: a single short fracture (type A), a single long fracture (type B), and symmetrical short fractures (type C). Three temperature conditions were set for type A. The coefficient C, which is defined as the ratio between the seepage pressure and the flow rate, is constant when the temperature effects are slight. Linear correlations between the coefficient C and the temperature were simulated. For type B, four confining pressures were applied using the confining pressure pump. As the confining pressure increases, the seepage pressure increases. The seepage pressure distribution is nonlinear when the flow rate increases to 6 ml/min under a confining pressure of 12 MPa. For type C, three temperature conditions with three confining pressure conditions were analyzed to determine the seepage pressure. The effects of the confining pressure on the seepage pressure are different from those of type B. Nonlinear curves occur under confining pressures of 3 MPa and 6 MPa at 50°C. The seepage pressure values at 70°C are smaller than those at 30°C and 50°C. The coefficient C contour is depicted for the experimental ranges of temperature and confining pressures. The small value region of coefficient C occurs at about 6 MPa and 50°C. The nonlinear increase in the seepage pressure in the fractures occurred when the confining pressure was larger for a single fracture and when the confining pressure was lower for double fractures.

Geothermal resource is green and clean energy, and geothermal field is widely distributed in the world. Its development and utilization has little harm to the environment, can change the current situation of energy consumption mainly based on fossil energy, reduce carbon emissions, and promote the development of techniques for sustainable processing of natural resources. However, each geothermal field has its own characteristic structure, origin, and storage, so it is necessary to carry out targeted research. In this paper, the geothermal characteristics and geological characteristics of the geothermal belt in Lushan County, China are analyzed by means of remote sensing interpretation, field investigation and observation, geophysical exploration, long-term observation, pumping test, and hydrochemical analysis. Result of this study shows that the geothermal belt of Lushan geothermal fields is as a result of primary thermal control and heat conduction structures of the near east-west Checun-Xiatang deep fault as well as secondary thermal control and heat conduction structures of near north-east and north-west secondary faults; and annual recoverable geothermal energy of whole geothermal field is 4.41 × 10¹¹ MJ. The research results will be beneficial for the development and utilization of Lushan hot springs. At the same time, it also provides reference for more geothermal research.