Method for evaluating thicknesses of cobalt-rich crusts on seamounts
Disclosed is a method for evaluating thicknesses of cobalt-rich crusts on seamounts, which comprises following steps: dividing a study area of cobalt-rich crusts into geological grid units, assigning crust thickness values to geological grid units; obtaining the crust thicknesses of the geological sampling stations in a preset influence range in the adjacent areas based on geological sampling station information; estimating the crust thicknesses in a certain distance range of the stations by a “distance-slope” spatial interpolation method, and through a spatial similarity of a crusts spatial distribution caused by a relationship between the distance and the slope, assigning values to grid units outside adjacent areas and within an influence range of the spatial similarity relationship; assigning values to the geological grid units that failed to obtain crust thickness value through an expected assignment method, and obtaining the crust thicknesses of the study areas.
1. A method for evaluating thicknesses of cobalt-rich crusts on seamounts, the method comprising following steps:
S1, dividing a study area of cobalt-rich crusts resources into geological grid units, and dividing the study area into adjacent areas based on geological sampling stations, wherein the adjacent areas comprise the geological grid units and the geological sampling stations;
S2, obtaining thicknesses of crusts of the geological sampling stations in a preset influence range in the adjacent areas based on geological sampling information of the geological sampling stations;
S3, assigning values to the geological grid units in the adjacent areas based on the thicknesses of crusts in the preset influence range in the adjacent areas, and obtaining the thicknesses of crusts of the geological grid units in the adjacent areas;
S4, assigning the values to the geological grid units failing to be assigned by using an expected assignment method, so as to obtain the thicknesses of crusts of the study area; and
S5, evaluating resources of the cobalt-rich crusts on the seamounts based on the thicknesses of crusts of the study area to obtain an evaluation result, and mining, based on the evaluation result, the resources of the cobalt-rich crusts on the seamounts.
2. The method for evaluating the thicknesses of cobalt-rich crusts on the seamounts according to claim 1 , wherein dividing the study area into the adjacent areas comprises:
drawing normals of connecting lines between two adjacent points of the geological sampling stations, obtaining intersection points between the normals and boundaries of the study area, obtaining cross nodes between the normals, dividing the study area into the adjacent areas based on the normals, the intersection points and the cross nodes, wherein when there is a cross node between the normals, a part of a normal beyond the cross node and an intersection point formed by an end of every normal beyond the cross node and a boundary of the study area is removed.
3. The method for evaluating the thicknesses of cobalt-rich crusts on the seamounts according to claim 2 , wherein dividing the study area into the adjacent areas further comprises:
combining the geological sampling stations with preset spatial thresholds into one geological sampling station, and connecting lines based on the combined geological sampling stations.
4. The method for evaluating the thicknesses of cobalt-rich crusts on the seamounts according to claim 1 , wherein obtaining the thicknesses of crusts in the preset influence range in the adjacent areas comprises:
obtaining the thicknesses of crusts of preset buffer zones based on the geological sampling information of the geological sampling stations, and obtaining the thicknesses of crusts in the preset influence range in the adjacent areas by combining Thiessen polygons and the preset buffer zones based on the thickness of crusts of the preset buffer zones.
5. The method for evaluating the thicknesses of cobalt-rich crusts on the seamounts according to claim 1 , wherein assigning the values to the geological grid units in the adjacent areas comprises:
estimating the thicknesses of crusts of the geological sampling stations in the preset influence range based on a “distance-slope” spatial interpolation method, and through a spatial similarity of a spatial distribution of crusts caused by a relationship between a distance and a slope, and assigning the values to the geological grid units inside and outside the adjacent areas and within an influence range of the spatial similarity.
6. The method for evaluating the thicknesses of cobalt-rich crusts on the seamounts according to claim 5 , wherein the “distance-slope” spatial interpolation method comprises:
acquiring slopes of the geological grid units in the adjacent areas;
carrying out a spatial overlay and a spatial correlation on the slopes of the geological sampling stations and the geological grid units to obtain an average slope of each geological sampling station;
obtaining an isobath distance from each geological sampling station to a lower boundary of the study area, taking the isobath distance as a coordinate value of a “distance-slope” coordinate system of the geological sampling stations, regenerating the geological sampling station into a spatial layer based on the coordinate value, carrying out a variogram simulation on crust thickness data by age statistical analysis method for the geological sampling stations in the spatial layer, and carrying out a spatial interpolation with a preset radius according to simulation result parameters of the variogram simulation and investigation experiences on crusts.
7. The method for evaluating the thicknesses of cobalt-rich crusts on the seamounts according to claim 5 , wherein assigning the values to the geological grid units failing to be assigned by using the expected assignment method, so as to obtain the thicknesses of crusts of the study area, comprises:
acquiring topographic slope data of the study area, performing an unsupervised classification on the topographic slope data, dividing the study area into different terrain type boundaries according to a topographical change, performing a micro landform classification on the study area based on the different terrain type boundaries, and obtaining a micro landform classification area, and thereby obtaining geological blocks;
dividing the study area into preset geomorphic type areas based on the micro landform classification area and combined with original topographic characteristics and intuitive forms of slope changes, and obtaining the geological blocks related to mineralization stages of seamount crusts based on geomorphic types;
obtaining an original crust thickness average of the geological sampling stations in the preset geomorphic type areas and a crust thickness average of the geological sampling stations in the micro landform classification area based on a spatial distribution of known sampling stations, and obtaining a final crust thickness of the preset geomorphic type areas by superimposing the original crust thickness average of the preset geomorphic type areas and the crust thickness average in the micro landform classification area; assigning the values to areas outside the preset influence range of the geological sampling stations in the adjacent areas based on crust thickness of the preset geomorphic type areas, and finally obtaining crust thickness values of the geological grid units in the study area.
8. A method for evaluating thicknesses of cobalt-rich crusts on seamounts, the method comprising following steps:
S1, dividing a study area of cobalt-rich crusts resources into geological grid units, and dividing the study area into adjacent areas based on geological sampling stations, wherein the adjacent areas comprise the geological grid units and the geological sampling stations;
S2, obtaining thicknesses of crusts of the geological sampling stations in a preset influence range in the adjacent areas based on geological sampling information of the geological sampling stations;
S3, assigning values to the geological grid units in the adjacent areas based on the thicknesses of crusts in the preset influence range in the adjacent areas, and obtaining the thicknesses of crusts of the geological grid units in the adjacent areas;
S4, assigning the values to the geological grid units failing to be assigned by using an expected assignment method, so as to obtain the thicknesses of crusts of the study area, comprising:
acquiring topographic slope data of the study area, performing an unsupervised classification on the topographic slope data, dividing the study area into different terrain type boundaries according to a topographical change, performing a micro landform classification on the study area based on the different terrain type boundaries, and obtaining a micro landform classification area, and thereby obtaining geological blocks;
dividing the study area into preset geomorphic type areas based on the micro landform classification area and combined with original topographic characteristics and intuitive forms of slope changes, and obtaining the geological blocks related to mineralization stages of seamount crusts based on geomorphic types; and
obtaining an original crust thickness average of the geological sampling stations in the preset geomorphic type areas and a crust thickness average of the geological sampling stations in the micro landform classification area based on a spatial distribution of known sampling stations, and obtaining a final crust thickness of the preset geomorphic type areas by superimposing the original crust thickness average of the preset geomorphic type areas and the crust thickness average in the micro landform classification area; assigning the values to areas outside the preset influence range of the geological sampling stations in the adjacent areas based on crust thickness of the preset geomorphic type areas, and finally obtaining crust thickness values of the geological grid units in the study area; and
S5, evaluating resources of the cobalt-rich crusts on the seamounts based on the crust thickness values in the study area to obtain an evaluation result, and mining, based on the evaluation result, the resources of the cobalt-rich crusts on the seamounts.