建立矢量缓冲区+合并矢量要素

以下程序包括两个功能：

1. 基于shapefile建立缓冲区

2. 把单个shapefile所有的要素都合并在一起

# -*- coding: utf-8 -*-
"""
Created on Tue Feb 28 11:38:39 2023

@author: Asus
"""

from pathlib import Path
from osgeo import ogr, osr
import geopandas as gpd


def buffer(inShp, fname, bdistance=10000):
    jingkai_polygon  = gpd.read_file(inShp)
    jingkai_polygon = jingkai_polygon.to_crs("EPSG:3413")  
#地理坐标系转投影坐标系，地理坐标意味着distance单位为度，而投影坐标单位为米
    jingkai_polygon=jingkai_polygon.buffer(bdistance)
    jingkai_polygon.to_file(fname,
           driver='ESRI Shapefile',
           encoding='utf-8')
    

def uni(shpPath, fname):
    """
    :param shpPath: 输入的矢量路径
    :param fname: 输出的矢量路径
    :return: 
    """
    driver = ogr.GetDriverByName("ESRI Shapefile")
    dataSource = driver.Open(shpPath, 1)
    layer = dataSource.GetLayer()

    # 新建DataSource，Layer
    out_ds = driver.CreateDataSource(fname)
    out_lyr = out_ds.CreateLayer(fname, layer.GetSpatialRef(), ogr.wkbPolygon)
    def_feature = out_lyr.GetLayerDefn()
    # 遍历原始的Shapefile文件给每个Geometry做Buffer操作
    # current_union = layer[0].Clone()
    print('the length of layer:', len(layer))
    if len(layer) == 0:
        return

    for i, feature in enumerate(layer):
        geometry = feature.GetGeometryRef()
        if i == 0:
            current_union = geometry.Clone()
        current_union = current_union.Union(geometry).Clone()

        if i == len(layer) - 1:
            out_feature = ogr.Feature(def_feature)
            out_feature.SetGeometry(current_union)
            out_lyr.ResetReading()
            out_lyr.CreateFeature(out_feature)

if __name__ == '__main__':
    inShp = 'G:\mask\simplified-land-polygons-complete-3857\simplified_land_polygons.shp'
    fname = 'G:\mask\simple\simple_land_10kmBuffer2.shp'
    finame='G:\mask\simple\simple_land_10kmBuffer2_merge.shp'
    # buffer(inShp, fname)
    uni(fname,finame)