Initial public release

backend/app/services/flood_hazard_acquisition_service.py

@@ -0,0 +1,643 @@
+from __future__ import annotations
+
+import hashlib
+import json
+import math
+import time
+from dataclasses import dataclass
+from datetime import UTC, datetime
+from email.parser import BytesParser
+from email.policy import default
+from pathlib import Path
+from typing import Any, Callable
+from urllib.error import HTTPError, URLError
+from urllib.parse import urlencode
+from urllib.request import Request
+from uuid import UUID
+from xml.etree import ElementTree
+
+from geoalchemy2.shape import to_shape
+from pyproj import Transformer
+from shapely.geometry import box, mapping
+from shapely.ops import transform as shapely_transform
+
+from app.core.config import Settings, get_settings
+from app.core.errors import AppError
+from app.services.outbound_request_guard import guarded_opener
+from app.models import Area, Dataset, Project
+from app.schemas.flood_hazard import FloodHazardAcquireRequest, FloodHazardAcquisitionResult, FloodHazardProductRead
+from app.services.dataset_service import DatasetService
+
+
+@dataclass(frozen=True)
+class FloodHazardProduct:
+    key: str
+    display_name: str
+    mechanism: str
+    climate_context: str
+    probability_class: str
+    return_period_years: int
+    coverage_id: str
+    published_on: str
+    catalog_url: str
+
+
+class FloodHazardAcquisitionService:
+    PROVIDER = "vmm_flood_hazard"
+    SOURCE_CRS = "EPSG:31370"
+    NATIVE_RESOLUTION_M = 2.0
+    SOURCE_VALUE_UNIT = "cm"
+    NORMALIZED_VALUE_UNIT = "m"
+    NODATA = -9999.0
+    SOURCE_VERSION = "VMM OGRK flood hazard maps"
+    ATTRIBUTION = "Bron: VMM"
+    LICENSE_NOTE = "Publieke toegang; gebruik en bronvermelding volgens de metadata van VMM/GDI-Vlaanderen."
+    # The VMM WCS rejects generated coverages above 4.88 MB. At the default
+    # 5 metre resolution a 5 km square stays below that provider-side limit.
+    WCS_TILE_SIDE_M = 5_000.0
+    WCS_REQUEST_INTERVAL_SECONDS = 1.0
+    WCS_RETRY_DELAY_SECONDS = 3.0
+    WCS_TRANSIENT_STATUS_CODES = frozenset({400, 429, 502, 503, 504})
+    # The VMM WCS rounds the grid size of partial edge tiles to an integer
+    # number of cells. Keep that provider artefact bounded and auditable.
+    WCS_EDGE_RESOLUTION_REL_TOLERANCE = 0.05
+    WCS_EDGE_RESOLUTION_ABS_TOLERANCE_M = 0.25
+    SERVICE_CATALOG_URL = "https://www.vlaanderen.be/datavindplaats/catalogus/publieke-inspire-coverage-service-van-ogrk"
+    LIMITATION = (
+        "Gemodelleerde maximale overstromingsdiepte voor een vast kans- en klimaatscenario. "
+        "Dit is geen actuele waterstand, geen bathymetrie en geen permanente diepte of inhoud van een waterlichaam."
+    )
+
+    @staticmethod
+    def _products() -> dict[str, FloodHazardProduct]:
+        products: list[FloodHazardProduct] = []
+        probability = {
+            10: ("grote kans", "grote-kans"),
+            100: ("middelgrote kans", "middelgrote-kans"),
+            1000: ("kleine kans", "kleine-kans"),
+        }
+        for mechanism, code in (("pluviaal", "PLU"), ("fluviaal", "FLU")):
+            for climate_key, climate_code, climate_label, published_on in (
+                ("current", "noCC", "huidig klimaat", "2021-08-31"),
+                ("future_2050", "hCC", "klimaatprojectie 2050", "2021-08-31" if mechanism == "fluviaal" else "2019-12-22"),
+            ):
+                for period, (probability_label, probability_slug) in probability.items():
+                    climate_slug = (
+                        "huidig-klimaat"
+                        if climate_key == "current"
+                        else "toekomstig-klimaat-met-klimaatprojectie-2050"
+                    )
+                    catalog_url = (
+                        "https://www.vlaanderen.be/datavindplaats/catalogus/"
+                        f"overstromingsgevaarkaart-waterdiepte-{mechanism}-{climate_slug}-{probability_slug}"
+                    )
+                    products.append(
+                        FloodHazardProduct(
+                            key=f"{mechanism}_{climate_key}_t{period}",
+                            display_name=(
+                                f"{mechanism.capitalize()} - {climate_label} - {probability_label} (T{period})"
+                            ),
+                            mechanism=mechanism,
+                            climate_context=climate_label,
+                            probability_class=probability_label,
+                            return_period_years=period,
+                            coverage_id=(
+                                f"Overstromingsgevaarkaarten-{code.replace('PLU', 'PLUVIAAL').replace('FLU', 'FLUVIAAL')}:"
+                                f"waterdiepte_{code}_{climate_code}_T{period}"
+                            ),
+                            published_on=published_on,
+                            catalog_url=catalog_url,
+                        )
+                    )
+        return {product.key: product for product in products}
+
+    @staticmethod
+    def list_products() -> list[dict[str, Any]]:
+        return [
+            FloodHazardProductRead(
+                key=product.key,
+                display_name=product.display_name,
+                mechanism=product.mechanism,
+                climate_context=product.climate_context,
+                probability_class=product.probability_class,
+                return_period_years=product.return_period_years,
+                coverage_id=product.coverage_id,
+                native_resolution_m=FloodHazardAcquisitionService.NATIVE_RESOLUTION_M,
+                source_crs=FloodHazardAcquisitionService.SOURCE_CRS,
+                source_value_unit=FloodHazardAcquisitionService.SOURCE_VALUE_UNIT,
+                normalized_value_unit=FloodHazardAcquisitionService.NORMALIZED_VALUE_UNIT,
+                published_on=product.published_on,
+                catalog_url=product.catalog_url,
+                attribution=FloodHazardAcquisitionService.ATTRIBUTION,
+                limitation_message=FloodHazardAcquisitionService.LIMITATION,
+            ).model_dump()
+            for product in FloodHazardAcquisitionService._products().values()
+        ]
+
+    @staticmethod
+    def _product(product_key: str) -> FloodHazardProduct:
+        product = FloodHazardAcquisitionService._products().get(product_key.strip().lower())
+        if product is None:
+            raise AppError(
+                code="FLOOD_HAZARD_PRODUCT_NOT_SUPPORTED",
+                message="Select a governed VMM fluvial or pluvial flood-depth scenario",
+                details={"product_key": product_key},
+                status_code=422,
+            )
+        return product
+
+    @staticmethod
+    def _prepared_request(payload: FloodHazardAcquireRequest, settings: Settings) -> dict[str, Any]:
+        if not settings.flood_hazard_enabled:
+            raise AppError(code="FLOOD_HAZARD_NOT_CONFIGURED", message="VMM flood-hazard acquisition is disabled", status_code=503)
+        product = FloodHazardAcquisitionService._product(payload.product_key)
+        resolution_m = float(payload.resolution_m or settings.flood_hazard_resolution_m)
+        values = (payload.bbox.min_x, payload.bbox.min_y, payload.bbox.max_x, payload.bbox.max_y)
+        if not all(math.isfinite(value) for value in values) or payload.bbox.min_x >= payload.bbox.max_x or payload.bbox.min_y >= payload.bbox.max_y:
+            raise AppError(code="INVALID_BBOX", message="Flood-hazard selection must be a finite non-empty rectangle", status_code=400)
+        transformer = Transformer.from_crs("EPSG:4326", FloodHazardAcquisitionService.SOURCE_CRS, always_xy=True)
+        metric_bounds = transformer.transform_bounds(*values, densify_pts=21)
+        width_m = float(metric_bounds[2] - metric_bounds[0])
+        height_m = float(metric_bounds[3] - metric_bounds[1])
+        if width_m < settings.flood_hazard_min_side_m or height_m < settings.flood_hazard_min_side_m:
+            raise AppError(
+                code="FLOOD_HAZARD_SELECTION_TOO_SMALL",
+                message=f"Select an area of at least {settings.flood_hazard_min_side_m:g} by {settings.flood_hazard_min_side_m:g} metres",
+                status_code=422,
+            )
+        if width_m > settings.flood_hazard_max_side_m or height_m > settings.flood_hazard_max_side_m:
+            raise AppError(
+                code="FLOOD_HAZARD_SELECTION_TOO_LARGE",
+                message=f"Select an area no larger than {settings.flood_hazard_max_side_m:g} by {settings.flood_hazard_max_side_m:g} metres",
+                details={"width_m": width_m, "height_m": height_m},
+                status_code=422,
+            )
+        width = max(1, math.ceil(width_m / resolution_m))
+        height = max(1, math.ceil(height_m / resolution_m))
+        if width * height > settings.flood_hazard_max_pixels:
+            raise AppError(
+                code="FLOOD_HAZARD_SELECTION_TOO_LARGE",
+                message="Flood-hazard selection exceeds the configured raster cell limit",
+                details={"pixel_count": width * height, "max_pixels": settings.flood_hazard_max_pixels},
+                status_code=422,
+            )
+        bbox_4326 = [float(value) for value in values]
+        bbox_31370 = [float(value) for value in metric_bounds]
+        identity = {
+            "provider": FloodHazardAcquisitionService.PROVIDER,
+            "coverage_id": product.coverage_id,
+            "bbox_epsg4326": [round(value, 8) for value in bbox_4326],
+            "bbox_epsg31370": [round(value, 3) for value in bbox_31370],
+            "resolution_m": resolution_m,
+            "area_id": str(payload.area_id) if payload.area_id else None,
+        }
+        request_hash = hashlib.sha256(json.dumps(identity, sort_keys=True).encode()).hexdigest()
+        return {
+            **identity,
+            "product": product,
+            "request_hash": request_hash,
+            "bbox_epsg4326": bbox_4326,
+            "bbox_epsg31370": bbox_31370,
+            "width": width,
+            "height": height,
+        }
+
+    @staticmethod
+    def _wcs_request_url(settings: Settings, product: FloodHazardProduct, bounds: tuple[float, float, float, float], resolution_m: float) -> str:
+        crs = "urn:ogc:def:crs:EPSG::31370"
+        query = [
+            ("SERVICE", "WCS"),
+            ("VERSION", "1.1.0"),
+            ("REQUEST", "GetCoverage"),
+            ("IDENTIFIER", product.coverage_id),
+            ("BOUNDINGBOX", f"{bounds[0]:.3f},{bounds[1]:.3f},{bounds[2]:.3f},{bounds[3]:.3f},{crs}"),
+            ("FORMAT", "image/tiff"),
+            ("GRIDBASECRS", crs),
+            ("GRIDCS", "urn:ogc:def:cs:OGC:0.0:Grid2dSquareCS"),
+            ("GRIDTYPE", "urn:ogc:def:method:WCS:1.1:2dSimpleGrid"),
+            ("GRIDORIGIN", f"{bounds[0]:.3f},{bounds[3]:.3f}"),
+            ("GRIDOFFSETS", f"{resolution_m:g},-{resolution_m:g}"),
+        ]
+        return f"{settings.flood_hazard_wcs_url}?{urlencode(query)}"
+
+    @staticmethod
+    def _tile_bounds(prepared: dict[str, Any]) -> list[tuple[float, float, float, float]]:
+        min_x, min_y, max_x, max_y = prepared["bbox_epsg31370"]
+        tiles: list[tuple[float, float, float, float]] = []
+        y = min_y
+        while y < max_y:
+            tile_max_y = min(y + FloodHazardAcquisitionService.WCS_TILE_SIDE_M, max_y)
+            x = min_x
+            while x < max_x:
+                tile_max_x = min(x + FloodHazardAcquisitionService.WCS_TILE_SIDE_M, max_x)
+                tiles.append((x, y, tile_max_x, tile_max_y))
+                x = tile_max_x
+            y = tile_max_y
+        return tiles
+
+    @staticmethod
+    def _scope_geometry(db, project_id: UUID, area_id: UUID | None, bbox_epsg4326: list[float]):
+        if not db.get(Project, project_id):
+            raise AppError(code="PROJECT_NOT_FOUND", message="Project not found", status_code=404)
+        selection = box(*bbox_epsg4326)
+        if area_id is None:
+            return selection
+        area = db.get(Area, area_id)
+        if not area:
+            raise AppError(code="AREA_NOT_FOUND", message="Area not found", status_code=404)
+        if area.project_id != project_id:
+            raise AppError(code="INVALID_DATASET_SCOPE", message="Area does not belong to this project", status_code=400)
+        intersection = to_shape(area.geometry).intersection(selection)
+        if intersection.is_empty or intersection.area <= 0:
+            raise AppError(code="FLOOD_HAZARD_SELECTION_OUTSIDE_AREA", message="Selection does not overlap the selected work area", status_code=422)
+        return intersection
+
+    @staticmethod
+    def _fetch(request_url: str, settings: Settings, opener: Callable[..., Any] | None = None) -> tuple[bytes, str]:
+        request = Request(request_url, headers={"Accept": "*/*", "User-Agent": "GeoIntel/0.1 bounded-vmm-flood-hazard-acquisition"})
+        max_bytes = settings.flood_hazard_max_response_mb * 1024 * 1024
+        try:
+            with (opener or guarded_opener(request_url))(request, timeout=settings.flood_hazard_timeout_seconds) as response:
+                content_type = str(response.headers.get("Content-Type", ""))
+                content_length = response.headers.get("Content-Length")
+                if content_length and int(content_length) > max_bytes:
+                    raise AppError(code="FLOOD_HAZARD_RESPONSE_TOO_LARGE", message="Official VMM response exceeds the configured size limit", status_code=502)
+                content = response.read(max_bytes + 1)
+        except AppError:
+            raise
+        except HTTPError as exc:
+            preview = exc.read(300).decode("utf-8", errors="replace")
+            raise AppError(
+                code="FLOOD_HAZARD_PROVIDER_UNAVAILABLE",
+                message="The official VMM WCS could not complete the bounded request",
+                details={"reason": str(exc), "provider_status_code": int(exc.code), "response_preview": preview},
+                status_code=502,
+            ) from exc
+        except (URLError, TimeoutError, OSError) as exc:
+            raise AppError(
+                code="FLOOD_HAZARD_PROVIDER_UNAVAILABLE",
+                message="The official VMM WCS could not complete the bounded request",
+                details={"reason": str(exc)},
+                status_code=502,
+            ) from exc
+        if len(content) > max_bytes:
+            raise AppError(code="FLOOD_HAZARD_RESPONSE_TOO_LARGE", message="Official VMM response exceeds the configured size limit", status_code=502)
+        return content, content_type
+
+    @staticmethod
+    def _extract_geotiff(content: bytes, content_type: str) -> bytes:
+        if content.startswith((b"II*\x00", b"MM\x00*")):
+            return content
+        if "multipart" not in content_type.lower():
+            provider_exception = None
+            if "xml" in content_type.lower() or content.lstrip().startswith(b"<"):
+                try:
+                    root = ElementTree.fromstring(content)
+                    exception_texts = [
+                        (element.text or "").strip()
+                        for element in root.iter()
+                        if element.tag.rsplit("}", 1)[-1] in {"ExceptionText", "ServiceException"}
+                        and (element.text or "").strip()
+                    ]
+                    provider_exception = " ".join(exception_texts) or None
+                except ElementTree.ParseError:
+                    pass
+            raise AppError(
+                code="FLOOD_HAZARD_PROVIDER_INVALID_RESPONSE",
+                message="The official VMM service did not return a GeoTIFF coverage",
+                details={
+                    "content_type": content_type,
+                    "provider_exception": provider_exception,
+                    "response_preview": content[:300].decode("utf-8", errors="replace"),
+                },
+                status_code=502,
+            )
+        message = BytesParser(policy=default).parsebytes(f"Content-Type: {content_type}\r\nMIME-Version: 1.0\r\n\r\n".encode() + content)
+        for part in message.walk():
+            payload = part.get_payload(decode=True) or b""
+            if part.get_content_type() == "image/tiff" and payload.startswith((b"II*\x00", b"MM\x00*")):
+                return payload
+        raise AppError(
+            code="FLOOD_HAZARD_PROVIDER_INVALID_RESPONSE",
+            message="The official VMM multipart response contains no valid GeoTIFF coverage",
+            status_code=502,
+        )
+
+    @staticmethod
+    def _mosaic_geotiffs(
+        coverages: list[bytes],
+        expected_resolution_m: float,
+        diagnostics: dict[str, Any] | None = None,
+    ) -> bytes:
+        if len(coverages) == 1:
+            return coverages[0]
+        try:
+            from rasterio.io import MemoryFile
+            from rasterio.merge import merge
+        except ImportError as exc:
+            raise AppError(code="RASTER_PROCESSING_UNAVAILABLE", message="Rasterio is required to assemble VMM flood-hazard tiles", status_code=503) from exc
+        memories = [MemoryFile(content) for content in coverages]
+        sources = []
+        try:
+            sources = [memory.open() for memory in memories]
+            invalid_crs = [
+                index
+                for index, source in enumerate(sources)
+                if source.crs is None or source.crs.to_epsg() != 31370
+            ]
+            invalid_bands = [index for index, source in enumerate(sources) if source.count != 1]
+            tile_resolutions = [
+                [abs(float(source.res[0])), abs(float(source.res[1]))]
+                for source in sources
+            ]
+            invalid_resolution = [
+                {
+                    "tile_index": index,
+                    "resolution": tile_resolutions[index],
+                }
+                for index, source in enumerate(sources)
+                if not all(
+                    math.isclose(
+                        abs(float(value)),
+                        expected_resolution_m,
+                        rel_tol=FloodHazardAcquisitionService.WCS_EDGE_RESOLUTION_REL_TOLERANCE,
+                        abs_tol=FloodHazardAcquisitionService.WCS_EDGE_RESOLUTION_ABS_TOLERANCE_M,
+                    )
+                    for value in source.res
+                )
+            ]
+            if invalid_crs or invalid_bands or invalid_resolution:
+                raise AppError(
+                    code="FLOOD_HAZARD_TILE_MISMATCH",
+                    message="VMM coverage tiles do not match the governed CRS, band layout and resolution",
+                    details={
+                        "invalid_crs_tile_indexes": invalid_crs,
+                        "invalid_band_tile_indexes": invalid_bands,
+                        "invalid_resolution_tiles": invalid_resolution,
+                        "expected_resolution_m": expected_resolution_m,
+                    },
+                    status_code=502,
+                )
+            harmonized_tile_indexes = [
+                index
+                for index, resolution in enumerate(tile_resolutions)
+                if not all(
+                    math.isclose(value, expected_resolution_m, rel_tol=0.02, abs_tol=0.05)
+                    for value in resolution
+                )
+            ]
+            if diagnostics is not None:
+                diagnostics.update(
+                    {
+                        "source_tile_resolutions_m": tile_resolutions,
+                        "target_resolution_m": expected_resolution_m,
+                        "harmonized_tile_indexes": harmonized_tile_indexes,
+                        "harmonization_method": (
+                            "rasterio_merge_target_resolution" if harmonized_tile_indexes else None
+                        ),
+                    }
+                )
+            mosaic, transform = merge(sources, res=(expected_resolution_m, expected_resolution_m), nodata=0.0, dtype="float32")
+            profile = sources[0].profile.copy()
+            profile.pop("blockxsize", None)
+            profile.pop("blockysize", None)
+            profile.update(driver="GTiff", width=mosaic.shape[2], height=mosaic.shape[1], count=1, dtype="float32", crs=FloodHazardAcquisitionService.SOURCE_CRS, transform=transform, nodata=0.0, compress="deflate", predictor=3)
+            with MemoryFile() as output_memory:
+                with output_memory.open(**profile) as output:
+                    output.write(mosaic)
+                return output_memory.read()
+        except AppError:
+            raise
+        except Exception as exc:
+            raise AppError(code="FLOOD_HAZARD_TILE_MOSAIC_FAILED", message="VMM flood-hazard tiles could not be assembled", details={"reason": str(exc)}, status_code=502) from exc
+        finally:
+            for source in sources:
+                source.close()
+            for memory in memories:
+                memory.close()
+
+    @staticmethod
+    def _fetch_coverage(prepared: dict[str, Any], settings: Settings, opener: Callable[..., Any] | None = None) -> tuple[bytes, dict[str, Any]]:
+        product: FloodHazardProduct = prepared["product"]
+        request_urls = [
+            FloodHazardAcquisitionService._wcs_request_url(settings, product, bounds, prepared["resolution_m"])
+            for bounds in FloodHazardAcquisitionService._tile_bounds(prepared)
+        ]
+        raw_hash = hashlib.sha256()
+        coverage_hash = hashlib.sha256()
+        content_types: list[str] = []
+        coverages: list[bytes] = []
+        for index, request_url in enumerate(request_urls):
+            if index > 0 and opener is None:
+                time.sleep(FloodHazardAcquisitionService.WCS_REQUEST_INTERVAL_SECONDS)
+            try:
+                raw_content, content_type = FloodHazardAcquisitionService._fetch(request_url, settings, opener)
+            except AppError as exc:
+                provider_status = (exc.details or {}).get("provider_status_code")
+                if opener is not None or provider_status not in FloodHazardAcquisitionService.WCS_TRANSIENT_STATUS_CODES:
+                    raise
+                time.sleep(FloodHazardAcquisitionService.WCS_RETRY_DELAY_SECONDS)
+                raw_content, content_type = FloodHazardAcquisitionService._fetch(request_url, settings, opener)
+            coverage = FloodHazardAcquisitionService._extract_geotiff(raw_content, content_type)
+            raw_hash.update(len(raw_content).to_bytes(8, "big"))
+            raw_hash.update(raw_content)
+            coverage_hash.update(len(coverage).to_bytes(8, "big"))
+            coverage_hash.update(coverage)
+            content_types.append(content_type)
+            coverages.append(coverage)
+        mosaic_diagnostics: dict[str, Any] = {}
+        mosaic = FloodHazardAcquisitionService._mosaic_geotiffs(
+            coverages,
+            prepared["resolution_m"],
+            diagnostics=mosaic_diagnostics,
+        )
+        return mosaic, {
+            "tile_count": len(request_urls),
+            "request_urls": request_urls,
+            "response_content_types": content_types,
+            "response_sha256": raw_hash.hexdigest(),
+            "coverage_sha256": coverage_hash.hexdigest(),
+            "grid_harmonization": mosaic_diagnostics,
+        }
+
+    @staticmethod
+    def _normalize_raster(content: bytes, scope_geometry_4326, prepared: dict[str, Any]) -> tuple[bytes, dict[str, Any]]:
+        try:
+            import numpy as np
+            from rasterio.io import MemoryFile
+            from rasterio.mask import mask
+        except ImportError as exc:
+            raise AppError(code="RASTER_PROCESSING_UNAVAILABLE", message="Rasterio and numpy are required for flood-hazard validation", status_code=503) from exc
+        try:
+            with MemoryFile(content) as source_memory, source_memory.open() as source:
+                if source.crs is None or source.crs.to_epsg() != 31370:
+                    raise AppError(code="FLOOD_HAZARD_INVALID_CRS", message="VMM flood-hazard coverage must use EPSG:31370", status_code=502)
+                if source.count != 1:
+                    raise AppError(code="FLOOD_HAZARD_INVALID_BANDS", message="VMM flood-hazard coverage must contain one depth band", status_code=502)
+                resolution = max(abs(float(source.res[0])), abs(float(source.res[1])))
+                if not math.isclose(resolution, prepared["resolution_m"], rel_tol=0.02, abs_tol=0.05):
+                    raise AppError(code="FLOOD_HAZARD_INVALID_RESOLUTION", message="VMM coverage resolution differs from the governed request", status_code=502)
+                transformer = Transformer.from_crs("EPSG:4326", FloodHazardAcquisitionService.SOURCE_CRS, always_xy=True)
+                scope_metric = shapely_transform(transformer.transform, scope_geometry_4326)
+                clipped, transform = mask(source, [mapping(scope_metric)], crop=True, filled=False, indexes=[1])
+                source_values = np.ma.asarray(clipped[0], dtype="float32")
+                raw_cm = np.asarray(source_values.filled(0.0), dtype="float32")
+                positive = (~np.ma.getmaskarray(source_values)) & np.isfinite(raw_cm) & (raw_cm > 0.0)
+                normalized_m = np.full(raw_cm.shape, FloodHazardAcquisitionService.NODATA, dtype="float32")
+                normalized_m[positive] = raw_cm[positive] / 100.0
+                valid_values = normalized_m[positive].astype("float64")
+                profile = source.profile.copy()
+                profile.pop("blockxsize", None)
+                profile.pop("blockysize", None)
+                profile.update(driver="GTiff", width=normalized_m.shape[1], height=normalized_m.shape[0], count=1, dtype="float32", crs=FloodHazardAcquisitionService.SOURCE_CRS, transform=transform, nodata=FloodHazardAcquisitionService.NODATA, compress="deflate", predictor=3)
+                with MemoryFile() as output_memory:
+                    with output_memory.open(**profile) as output:
+                        output.write(normalized_m, 1)
+                    normalized_content = output_memory.read()
+                return normalized_content, {
+                    "width": int(normalized_m.shape[1]),
+                    "height": int(normalized_m.shape[0]),
+                    "inundated_pixel_count": int(positive.sum()),
+                    "nodata_value": FloodHazardAcquisitionService.NODATA,
+                    "resolution_m": resolution,
+                    "minimum_depth_m": float(valid_values.min()) if valid_values.size else None,
+                    "maximum_depth_m": float(valid_values.max()) if valid_values.size else None,
+                    "source_value_unit": FloodHazardAcquisitionService.SOURCE_VALUE_UNIT,
+                    "normalized_value_unit": FloodHazardAcquisitionService.NORMALIZED_VALUE_UNIT,
+                }
+        except AppError:
+            raise
+        except Exception as exc:
+            raise AppError(code="FLOOD_HAZARD_RASTER_INVALID", message="The official VMM response is not a valid georeferenced flood-depth raster", details={"reason": str(exc)}, status_code=502) from exc
+
+    @staticmethod
+    def _cached_dataset(db, project_id: UUID, filename: str) -> Dataset | None:
+        candidate = (
+            db.query(Dataset)
+            .filter(Dataset.project_id == project_id, Dataset.name == filename, Dataset.source_name == FloodHazardAcquisitionService.PROVIDER, Dataset.status == "ready")
+            .order_by(Dataset.imported_at.desc())
+            .first()
+        )
+        if candidate and candidate.storage_path and Path(candidate.storage_path).is_file():
+            return candidate
+        return None
+
+    @staticmethod
+    def acquire(db, project_id: UUID, payload: FloodHazardAcquireRequest, *, settings: Settings | None = None, opener: Callable[..., Any] | None = None) -> dict[str, Any]:
+        resolved_settings = settings or get_settings()
+        prepared = FloodHazardAcquisitionService._prepared_request(payload, resolved_settings)
+        product: FloodHazardProduct = prepared["product"]
+        scope_geometry = FloodHazardAcquisitionService._scope_geometry(db, project_id, payload.area_id, prepared["bbox_epsg4326"])
+        resolution_token = f"{prepared['resolution_m']:g}".replace(".", "p")
+        filename = f"vmm_flood_depth_{product.key}_{resolution_token}m_{prepared['request_hash'][:12]}.tif"
+        if not payload.force_refresh:
+            cached = FloodHazardAcquisitionService._cached_dataset(db, project_id, filename)
+            if cached is not None:
+                metadata = cached.source_metadata or {}
+                raster = cached.metadata_json or {}
+                return FloodHazardAcquisitionResult(
+                    output_dataset_id=cached.id,
+                    reused=True,
+                    provider=FloodHazardAcquisitionService.PROVIDER,
+                    product_key=product.key,
+                    display_name=product.display_name,
+                    mechanism=product.mechanism,
+                    climate_context=product.climate_context,
+                    probability_class=product.probability_class,
+                    return_period_years=product.return_period_years,
+                    coverage_id=product.coverage_id,
+                    resolution_m=float(metadata.get("analysis_resolution_m", prepared["resolution_m"])),
+                    width=int(raster.get("width", prepared["width"])),
+                    height=int(raster.get("height", prepared["height"])),
+                    inundated_pixel_count=int(metadata.get("inundated_pixel_count", 0)),
+                    bbox_epsg4326=prepared["bbox_epsg4326"],
+                    bbox_epsg31370=prepared["bbox_epsg31370"],
+                    attribution=FloodHazardAcquisitionService.ATTRIBUTION,
+                    limitation_message=FloodHazardAcquisitionService.LIMITATION,
+                ).model_dump(mode="json")
+        content, transfer = FloodHazardAcquisitionService._fetch_coverage(prepared, resolved_settings, opener)
+        normalized, validation = FloodHazardAcquisitionService._normalize_raster(content, scope_geometry, prepared)
+        acquired_at = datetime.now(UTC)
+        dataset = DatasetService.import_raster_bytes(
+            db,
+            project_id=project_id,
+            area_id=payload.area_id,
+            filename=filename,
+            content=normalized,
+            source=f"VMM OGRK WCS {product.coverage_id}",
+            source_name=FloodHazardAcquisitionService.PROVIDER,
+            source_version=FloodHazardAcquisitionService.SOURCE_VERSION,
+            content_type="image/tiff",
+            source_metadata={
+                "provider": FloodHazardAcquisitionService.PROVIDER,
+                "service": "WCS",
+                "service_version": "1.1.0",
+                "product_key": product.key,
+                "product_display_name": product.display_name,
+                "mechanism": product.mechanism,
+                "climate_context": product.climate_context,
+                "probability_class": product.probability_class,
+                "return_period_years": product.return_period_years,
+                "coverage_id": product.coverage_id,
+                "native_resolution_m": FloodHazardAcquisitionService.NATIVE_RESOLUTION_M,
+                "analysis_resolution_m": validation["resolution_m"],
+                "source_crs": FloodHazardAcquisitionService.SOURCE_CRS,
+                "source_value_unit": FloodHazardAcquisitionService.SOURCE_VALUE_UNIT,
+                "normalized_value_unit": FloodHazardAcquisitionService.NORMALIZED_VALUE_UNIT,
+                "inundated_pixel_count": validation["inundated_pixel_count"],
+                "minimum_depth_m": validation["minimum_depth_m"],
+                "maximum_depth_m": validation["maximum_depth_m"],
+                "bbox_epsg4326": prepared["bbox_epsg4326"],
+                "bbox_epsg31370": prepared["bbox_epsg31370"],
+                "published_on": product.published_on,
+                "catalog_url": product.catalog_url,
+                "service_catalog_url": FloodHazardAcquisitionService.SERVICE_CATALOG_URL,
+                "attribution": FloodHazardAcquisitionService.ATTRIBUTION,
+                "license_note": FloodHazardAcquisitionService.LICENSE_NOTE,
+                "theme": "flood_hazard",
+                "layer_name": "modelled_flood_depth",
+                "coverage_scope": "municipality" if payload.area_id else "bounded_selection",
+            },
+            provenance_metadata={
+                "acquisition": "explicit_bounded_tiled_wcs_coverage",
+                "acquired_at": acquired_at.isoformat(),
+                "request_hash": prepared["request_hash"],
+                "tile_count": transfer["tile_count"],
+                "tile_request_urls": transfer["request_urls"],
+                "response_content_types": transfer["response_content_types"],
+                "response_sha256": transfer["response_sha256"],
+                "coverage_sha256": transfer["coverage_sha256"],
+                "grid_harmonization": transfer["grid_harmonization"],
+                "normalized_sha256": hashlib.sha256(normalized).hexdigest(),
+                "bbox_epsg4326": prepared["bbox_epsg4326"],
+                "bbox_epsg31370": prepared["bbox_epsg31370"],
+                "requested_resolution_m": prepared["resolution_m"],
+                "clipped_to_area_id": str(payload.area_id) if payload.area_id else None,
+                "validation": validation,
+                "limitation_message": FloodHazardAcquisitionService.LIMITATION,
+                "bathymetry_available": False,
+                "permanent_water_depth_available": False,
+                "permanent_water_volume_available": False,
+                "concurrent_flood_volume_available": False,
+            },
+        )
+        return FloodHazardAcquisitionResult(
+            output_dataset_id=dataset.id,
+            reused=False,
+            provider=FloodHazardAcquisitionService.PROVIDER,
+            product_key=product.key,
+            display_name=product.display_name,
+            mechanism=product.mechanism,
+            climate_context=product.climate_context,
+            probability_class=product.probability_class,
+            return_period_years=product.return_period_years,
+            coverage_id=product.coverage_id,
+            resolution_m=validation["resolution_m"],
+            width=validation["width"],
+            height=validation["height"],
+            inundated_pixel_count=validation["inundated_pixel_count"],
+            bbox_epsg4326=prepared["bbox_epsg4326"],
+            bbox_epsg31370=prepared["bbox_epsg31370"],
+            attribution=FloodHazardAcquisitionService.ATTRIBUTION,
+            limitation_message=FloodHazardAcquisitionService.LIMITATION,
+        ).model_dump(mode="json")