Shapely Polygon缓冲区Y坐标翻倍问题排查求助

我使用Shapely几何图形处理轮廓，需为不同尺寸的场地轮廓按给定值固定距离扩展边界，而非按比例缩放。尝试了两种实现方式：

代码1 #

from shapely.geometry import Polygon, LinearRing
coords = [(30.3283020760901, 59.929340439331035), (30.32625283518726, 59.929669569762034), (30.326617897500824, 59.93065894162025), (30.328354001537814, 59.93056342794558), (30.329838363175877, 59.93089851628186), (30.330225213253033, 59.929729335995624), (30.3283020760901, 59.929340439331035)]
poly_B = Polygon(coords)
poly_A = s.buffer(0.005, quad_segs=10.0, cap_style=1, join_style=2, mitre_limit=10.0)

代码2 #

r = LinearRing(coords)
poly_B = Polygon(r)
poly_A = Polygon(s.buffer(0.005).exterior, [r])

但每次生成的轮廓均出现Y坐标翻倍问题（见附图），需大轮廓相对小轮廓保持均匀扩展距离，恳请排查问题原因。

内容的提问来源于stack exchange，提问作者Denis