基本结构以及计算降雨栅格

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wzy-warehouse
2026-05-05 19:49:12 +08:00
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"""
Business logic services package
"""
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"""
降雨数据Service - 业务逻辑层
"""
import numpy as np
from scipy.spatial import Delaunay, ConvexHull
from typing import List, Dict, Any, Tuple, Optional
from datetime import datetime
from app.repositories.rainfall_repository import RainfallRepository
from app.utils.logger import setup_logging
logger = setup_logging()
class InterpolationService:
"""插值服务类"""
@staticmethod
def inverse_distance_weighting(
points: List[Tuple[float, float]],
values: List[float],
grid_lon: np.ndarray,
grid_lat: np.ndarray,
power: float = 2.0,
max_distance: float = 0.5,
edge_buffer: float = 0.15
) -> np.ndarray:
"""
反距离权重插值 (IDW) - 向量化优化版本
Args:
points: 已知点坐标 [(lon, lat), ...]
values: 已知点的值 [rainfall, ...]
grid_lon: 网格经度数组
grid_lat: 网格纬度数组
power: 距离幂次
max_distance: 最大影响距离(度),超出此距离的点不参与插值
edge_buffer: 边缘缓冲距离,站点外围扩展此距离再计算凸包
Returns:
插值后的栅格数据,无效区域为 NaN
"""
points_array = np.array(points)
values_array = np.array(values)
# 创建网格
lon_grid, lat_grid = np.meshgrid(grid_lon, grid_lat)
result = np.full_like(lon_grid, np.nan)
# 计算站点的凸包(带边缘缓冲)
hull_mask = None
if len(points_array) >= 3:
try:
# 创建缓冲站点:在原始站点外围添加虚拟点
buffer_points = InterpolationService._create_buffer_points(
points_array,
buffer_distance=edge_buffer
)
# 合并原始站点和缓冲站点
all_points = np.vstack([points_array, buffer_points])
# 计算凸包
hull = ConvexHull(all_points)
hull_points = all_points[hull.vertices]
tri = Delaunay(hull_points)
# 向量化判断所有网格点是否在凸包内
grid_points = np.column_stack([lon_grid.ravel(), lat_grid.ravel()])
hull_mask = tri.find_simplex(grid_points) >= 0
hull_mask = hull_mask.reshape(lon_grid.shape)
except:
hull_mask = np.ones_like(lon_grid, dtype=bool)
else:
hull_mask = np.ones_like(lon_grid, dtype=bool)
# 向量化计算所有网格点到所有站点的距离
# grid_lon shape: (num_lat, num_lon)
# points_array[:, 0] shape: (num_stations,)
# 使用广播机制
lon_diff = lon_grid[:, :, np.newaxis] - points_array[np.newaxis, np.newaxis, :, 0]
lat_diff = lat_grid[:, :, np.newaxis] - points_array[np.newaxis, np.newaxis, :, 1]
distances = np.sqrt(lon_diff**2 + lat_diff**2)
# 过滤超出最大距离的站点
valid_mask = distances <= max_distance
# 对于每个网格点,检查是否有有效站点
has_valid_stations = np.any(valid_mask, axis=2)
# 合并凸包掩码和有效站点掩码
final_mask = hull_mask & has_valid_stations
# 避免除零
distances = np.where(valid_mask, distances, np.inf)
distances = np.maximum(distances, 1e-10)
# IDW权重计算
weights = 1.0 / (distances ** power)
weights = np.where(valid_mask, weights, 0)
# 加权平均
weighted_sum = np.sum(weights * values_array[np.newaxis, np.newaxis, :], axis=2)
weight_total = np.sum(weights, axis=2)
# 计算最终结果
result = np.where(
final_mask & (weight_total > 0),
weighted_sum / weight_total,
np.nan
)
return result
@staticmethod
def get_rainfall_color(rainfall: float) -> str:
"""
根据降雨量获取颜色(蓝色渐变)
Args:
rainfall: 降雨量(mm)
Returns:
颜色字符串 "rgba(r,g,b,a)"
"""
if rainfall < 0.1:
return "rgba(200,200,200,0)" # 透明 - 无雨
elif rainfall < 10:
return "rgba(173,216,230,0.5)" # 浅蓝 - 小雨
elif rainfall < 25:
return "rgba(100,149,237,0.6)" # 矢车菊蓝 - 中雨
elif rainfall < 50:
return "rgba(30,144,255,0.7)" # 道奇蓝 - 大雨
elif rainfall < 100:
return "rgba(0,0,205,0.8)" # 中蓝 - 暴雨
else:
return "rgba(0,0,139,0.9)" # 深蓝 - 大暴雨
class GeoJSONService:
"""GeoJSON生成服务"""
@staticmethod
def create_feature_collection(
grid_metadata: Dict[str, Any],
rainfall_array: np.ndarray,
grid_lon: np.ndarray,
grid_lat: np.ndarray
) -> Dict[str, Any]:
"""
创建GeoJSON FeatureCollection用于Cesium渲染
Args:
grid_metadata: 栅格元数据
rainfall_array: 降雨量数组
grid_lon: 经度网格
grid_lat: 纬度网格
Returns:
GeoJSON格式的FeatureCollection
"""
features = []
# 将栅格数据转换为矩形要素
for i in range(len(grid_lat) - 1):
for j in range(len(grid_lon) - 1):
rainfall_value = float(rainfall_array[i, j])
# 跳过无数据的区域
if np.isnan(rainfall_value) or rainfall_value < 0:
continue
# 创建矩形多边形
lon_min = float(grid_lon[j])
lon_max = float(grid_lon[j + 1])
lat_min = float(grid_lat[i])
lat_max = float(grid_lat[i + 1])
feature = {
"type": "Feature",
"geometry": {
"type": "Polygon",
"coordinates": [[
[lon_min, lat_min],
[lon_max, lat_min],
[lon_max, lat_max],
[lon_min, lat_max],
[lon_min, lat_min]
]]
},
"properties": {
"rainfall": round(rainfall_value, 2),
"color": InterpolationService.get_rainfall_color(rainfall_value)
}
}
features.append(feature)
return {
"type": "FeatureCollection",
"features": features,
"metadata": {
"resolution": grid_metadata['resolution'],
"grid_size": [len(grid_lon), len(grid_lat)],
"bounds": {
"min_lon": float(grid_lon.min()),
"max_lon": float(grid_lon.max()),
"min_lat": float(grid_lat.min()),
"max_lat": float(grid_lat.max())
}
}
}
class RainfallService:
"""降雨数据业务服务类"""
def __init__(self):
self.repository = RainfallRepository()
self.interpolation_service = InterpolationService()
self.geojson_service = GeoJSONService()
def get_stations_data(
self,
query_time: datetime
) -> List[Dict[str, Any]]:
"""
获取站点降雨数据
Args:
query_time: 查询时间(自动查询前12小时数据)
Returns:
站点数据列表
"""
return self.repository.query_stations_rainfall(query_time)
def generate_rainfall_grid(
self,
query_time: datetime,
resolution: float = 0.01
) -> Dict[str, Any]:
"""
生成降雨栅格数据
Args:
query_time: 查询时间(自动查询前12小时数据)
resolution: 栅格分辨率
Returns:
GeoJSON格式的栅格数据
"""
logger.info(f"查询降雨数据: {query_time}")
# 查询站点数据(自动查询前12小时数据)
stations_data = self.get_stations_data(query_time)
if not stations_data:
return None
# 提取站点坐标和降雨量(过滤空值)
valid_stations = [row for row in stations_data if row['rainfall'] is not None]
if not valid_stations:
logger.warning("所有站点的降雨量数据均为空")
return None
points = [(row['lon'], row['lat']) for row in valid_stations]
values = [float(row['rainfall']) for row in valid_stations]
# 确定栅格范围(西安大致范围)
lon_min, lon_max = 107.5, 109.5
lat_min, lat_max = 33.5, 34.5
# 创建栅格网格
num_lon = int((lon_max - lon_min) / resolution) + 1
num_lat = int((lat_max - lat_min) / resolution) + 1
grid_lon = np.linspace(lon_min, lon_max, num_lon)
grid_lat = np.linspace(lat_min, lat_max, num_lat)
logger.info(f"生成栅格: {num_lon}x{num_lat}, 分辨率: {resolution}")
# 执行IDW插值(带凸包裁剪和距离阈值)
rainfall_grid = self.interpolation_service.inverse_distance_weighting(
points=points,
values=values,
grid_lon=grid_lon,
grid_lat=grid_lat,
power=2.0,
max_distance=0.3 # 最大影响距离0.3度(约30公里)
)
# 创建栅格元数据
grid_metadata = {
"query_time": query_time.isoformat(),
"resolution": resolution,
"station_count": len(stations_data),
"grid_size": [num_lon, num_lat]
}
# 转换为GeoJSON格式
geojson_data = self.geojson_service.create_feature_collection(
grid_metadata, rainfall_grid, grid_lon, grid_lat
)
logger.info("降雨栅格数据生成成功")
return geojson_data
def get_rainfall_at_point(
self,
longitude: float,
latitude: float,
query_time: datetime
) -> Optional[Dict[str, Any]]:
"""
查询指定点位的降雨量(使用IDW插值)
Args:
longitude: 经度
latitude: 纬度
query_time: 查询时间(自动查询前12小时数据)
Returns:
点位降雨量信息
"""
# 获取站点数据(自动查询前12小时数据)
stations_data = self.get_stations_data(query_time)
if not stations_data:
return None
# 提取站点坐标和降雨量
points = [(row['lon'], row['lat']) for row in stations_data]
values = [float(row['rainfall']) for row in stations_data]
# 使用IDW插值计算该点的降雨量
target_point = np.array([[longitude, latitude]])
points_array = np.array(points)
# 计算距离
distances = np.sqrt(
(points_array[:, 0] - longitude) ** 2 +
(points_array[:, 1] - latitude) ** 2
)
# 避免除零
min_dist = 1e-10
distances = np.maximum(distances, min_dist)
# IDW公式
power = 2.0
weights = 1.0 / (distances ** power)
rainfall_value = np.sum(weights * values) / np.sum(weights)
# 返回结果
return {
"longitude": longitude,
"latitude": latitude,
"rainfall": round(float(rainfall_value), 2),
"level": self._get_rainfall_level(rainfall_value),
"color": InterpolationService.get_rainfall_color(rainfall_value),
"station_count": len(stations_data),
"query_time": query_time.isoformat()
}
@staticmethod
def _get_rainfall_level(rainfall: float) -> str:
"""获取降雨等级"""
if rainfall < 0.1:
return "无雨"
elif rainfall < 10:
return "小雨"
elif rainfall < 25:
return "中雨"
elif rainfall < 50:
return "大雨"
elif rainfall < 100:
return "暴雨"
else:
return "大暴雨"