| Supply service | Freshwater supply | Market valuation method${{V}_{w}}=\frac{{{V}_{GRC}}\times {{\rho }_{g}}}{{{\rho }_{w}}}\times {{P}_{w}}$ | Vw is the value of the glacier freshwater supply (yuan); VGRC is the annual change of glacier volume (km3 / a); glacier density (ρg) is 0.917 × 103 kg/m3; water density (ρw) is 1.0 × 103 kg/m3; Pw is the price of freshwater, with reference to the price of water supplied in the Qilian Mountains in 2016 (1.75 yuan/m3). | The annual change of glacier volume was converted into the annual freshwater provided to the social and natural environment by glaciers, and its economic value was calculated according to water prices. |
| Hydropower | Shadow price${{V}_{p}}={{V}_{m}}\times RC\times {{P}_{p}}$ | Vp is the value of glacier hydropower (yuan); Qilian Mountains glacial meltwater (Vm) has a volume of 11.32 × 108 m3/a (Qin et al., 2017); RC is the energy generated from a unit of reservoir capacity (kW·h / m3); Pp is the price of hydropower. The 2016 on-grid price of small hydropower in the Qilian Mountains was 0.257 yuan/kW·h. | The glacial meltwater was converted into the total storage capacity of reservoirs in the Qilian Mountains, and the value of glacier hydropower was calculated based on the energy generated from a unit of reservoir capacity in the area and the price of hydropower. |
| Regulation service | Climate regulation | Shadow price${{V}_{c}}=({{W}_{s}}+{{W}_{g}})\times \eta \times {{P}_{e}}$.${{W}_{s}}={{S}_{g}}\times R\times {{\alpha }_{g}}\times {{\alpha }_{s}}$${{W}_{g}}={{V}_{GRC}}\times {{\rho }_{g}}\times {{q}_{g}}$ | Vc is the glacier climate regulation value (yuan); Sg is the Second Glacier Inventory glacier area (km2); R is the annual total solar radiation of a unit area in the Qilian Mountains (MJ / m2·a); glacier albedo (αg) is 0.6 (Qin et al., 2017); terrain occlusion rate (αs) is 0.5; VGRC is the annual change of glacier volume (km3/a); ρg is the density of glaciers; the latent heat of melting of glaciers (qg) is 3.35 × 105 J/kg; Pe is the average electricity price of 0.51 yuan/kW·h for various industries in the region in 2016; η is the thermal-power conversion efficiency. | The sum of the solar energy reflected by the glacier surface and the heat absorbed by the glacier melt was used as the contribution of the glacier to suppress climate warming. The heat energy was converted into electrical energy, and the value of glacier climate regulation was calculated by reference to the electricity price (Zhang et al., 2019). |
| Runoff regulation | Shadow engineering${{V}_{r}}={{V}_{m}}\times {{P}_{r}}$ | Vr is the glacier runoff regulation value (yuan); Vm is the Qilian Mountains glaial melt water (m3 / a); Pr is the engineering cost of a unit of reservoir storage capacity in 2016 (7.131 yuan / m3). | The glacial meltwater was converted into mountain reservoir capacity, and then combined with the engineering cost of the unit reservoir storage capacity to calculate the glacier runoff adjustment value. |
| Gaseous pollutant regulation | Shadow price${{V}_{g}}={{V}_{S{{O}_{2}}}}+{{V}_{N{{O}_{x}}}}$${{V}_{S{{O}_{2}}}}={{Q}_{S{{O}_{2}}}}\times {{S}_{g}}\times {{P}_{S{{O}_{2}}}}$${{V}_{N{{O}_{\text{x}}}}}={{Q}_{N{{O}_{x}}}}\times {{S}_{g}}\times {{P}_{N{{O}_{x}}}}$ | Vg is the glacier gaseous pollutant regulation value (yuan); Qso2 and QNOx are the amounts of sulfur dioxide and nitrogen oxides absorbed by a unit area of glaciers, respectively, with reference to the sulfur dioxide and nitrogen oxide emission intensity of Gansu and Qinghai provinces; Sg is the glacier area of the Second Glacier Inventory (km2); Pso2 and PNOx are the sulfur dioxide and nitrogen oxide treatment costs in 2016 (1.689 and 0.887 yuan/kg, respectively). | The gaseous pollutant regulation value was calculated according to the amount of sulfur dioxide and nitrogen oxide absorbed by the glacier area of the Qilian Mountains and their treatment costs. |
| Environmental purification | Shadow price${{V}_{e}}={{Q}_{dust}}\times {{S}_{g}}\times {{P}_{dust}}$ | Ve is the environmental value of glacier purification (yuan); Qdust is the amount of dust absorbed by a glacier of unit area, with reference to the dust emission intensity of Gansu and Qinghai provinces; Sg is the glacier area of the Second Glacier Inventory (km2); the dust treatment cost (Pdust) is 0.211 yuan/kg. | The value of environmental purification services was calculated based on the amount of dust adsorbed on the glacier area of the Qilian Mountains and its treatment costs. |
| Service | Evaluation index | Formula | Parameters | Calculation basis |
| Support service | Habitat support | Expense payment method${{V}_{h}}={{S}_{g}}\times {{P}_{h}}$ | Vh is the value of the glacier habitat support (yuan); Sg is the glacier area of the Second Glacier Inventory (km2); Ph is the average annual amount invested in Qilian Mountain ecological protection and governance per unit area, with reference to the “Qilian Mountains Ecological Protection and Construction Comprehensive Management Plan (2012-2020)”. The total investment was 7.99 billion yuan, and the estimated Ph was 6262.98 yuan/km2. | By considering glaciers to be an important feature of nature reserves, the value of glacier habitat support was estimated based on the investment in major ecological protection and construction management projects in the Qilian Mountains per unit area. |
| Cultural service | Aesthetic appreciation and recreation | Combination of travel cost method and conditional value method${{V}_{t}}=S\times {{R}_{g}}\times \frac{{{S}_{\text{g}}}}{{{S}_{t}}}$ | Vt is the value of glacier aesthetic appreciation and recreation (yuan); S is the total annual tourism income of Gansu and Qinghai provinces; Rg is glacier-related tourism expenses as a proportion of total tourism expenses; Sg is the glacier area of the Second Glacier Inventory (km2); St is the total area of glaciers in Gansu and Qinghai provinces (km2). | Statistics from a questionnaire survey that was distributed to Chinese and foreign tourists were used to obtain glacier tourism-related expenses as a proportion of total tourism expenses. Together with the total annual tourism income of Gansu and Qinghai provinces, this was used to estimate the value of glacier aesthetic appreciation and recreation. |
| Scientific research and environmental education | Expense payment method${{V}_{s}}={{P}_{t}}+{{P}_{f}}$ | Vs is the value of glacier scientific research and environmental education (yuan); Pt is the annual economic value of the Qilian Mountains glacier's for teaching practices (529.4 × 104 yuan) (Wang et al., 2012); Pf is the research funding for the Qilian Mountain Glacier in the National Natural Science Foundation of China in 2016 (4.14 million yuan). | The value of glacier scientific research and environmental education was evaluated based on the cost of the actual teaching practices undertaken and the level of National Natural Science Foundation project funding. |
