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| 1 | Acquire high‑density multi‑return LiDAR and nadir RGB over the area of interest under applicable aviation permissions, tied to Survey of India control where available, targeting ≥150–200 pts/m² on drainage corridors (≥50–100 pts/m² area‑wide) and absolute accuracy ≤3–5 cm horizontal and ≤5–10 cm vertical validated by independent RTK checkpoints, with full trajectory processing and boresight calibration. Deliver classified LAS 1.4, hydro‑flattened DTM (0.25–0.5 m), DSM, 2–3 cm Ortho mosaic, 0.25–0.5 m contours, enforced break lines and hydro features, drainage centrelines, cross/long sections every 20–50 m, culvert/bridge clearance sheets, GIS geodatabase with schema, coverage/density and RMSE QA reports, metadata lineage, and a permissions/operations dossier. (Drone Based LiDAR Survey) |
| 2 | Establishing and tie DGPS/GNSS control to Survey of India or a trusted CORS via one long static primary control, several 2–4 h secondary controls, and independent RTK checkpoints, then run a network adjustment in the project datum/projection using dual‑frequency survey‑grade receivers with documented antenna heights; for UAV LiDAR, include in‑field boresight targets to support trajectory/boresight calibration and absolute accuracy verification. Place high‑contrast, photo‑visible GCP/target panels at corners, edges, interior, and high/low elevations (minimum 4–5 for small blocks, increased density for larger/complex terrain), and validate by reporting horizontal/vertical RMSE from checkpoints with coverage/density and geometry maps, plus a QA pack containing field logs, calibration/trajectory reports, and metadata. (Establishing DGPS Control Survey for Drone Survey) |
| 3 | Data processing from drone LiDAR to DEM and Ortho mosaic typically follows these steps: preprocess GNSS/IMU trajectories with boresight calibration; align strips; classify the point cloud to ASPRS classes; generate a bare‑earth DTM (grid 0.25–0.5 m) and DSM; then apply hydro‑flattening/enforcing using 3D break lines for rivers, lakes, and coastlines to ensure level water surfaces and monotonic flow where required. Ortho mosaics are produced from synchronized nadir RGB imagery by computing exterior orientation (from RTK/PPK trajectories plus tie points), rectifying each image to the DTM/DSM, colour balancing, and mosaicking to seamless tiles, after which QA includes density/coverage maps, vertical RMSE checks against checkpoints, and consistency checks between DEM and ortho for hydrologic feature alignment. (Data Processing for DEM and Ortho) |
| 4 | Digitize drains and roads from the Ortho mosaic and LiDAR-derived layers by setting up an edit schema with topology rules (e.g., drains/roads must not self-overlap, drains must flow downstream), loading hydro-flattened DTM/DSM, contours, break lines, and hill shade as references, then tracing centrelines and edges at appropriate map scales (typically 1:500–1:1000 for urban corridors), snapping to visible features and to enforced 3D break lines for hydrologic consistency. Attribute each feature with standardized fields (type, material, width, invert/soffit where surveyed, carriageway class, surface), maintain planimetric accuracy through QA checks against checkpoints and tile indexes, and run completeness/consistency checks and hydrologic connectivity validations; where automation helps, apply ML/edge-detection pre-extraction and then perform manual QA to meet Ortho mapping best practices and elevation-derived hydrography requirements. (Digitization of Ortho Imagery for Drains, Roads) |
| 5 | Prepare the DPR in alignment with national stormwater and urban flooding manuals/guidelines, adopting the official DPR submission checklist format used by ULBs, and ensure all designs, drawings, estimates, and technical sanctions conform to the competent authority’s requirements and current Schedule of Rates. (DPR for Drainage Master Plan) |
| 6 | a) Baseline and surveys: Compile rainfall/IDF and climate allowances, land use/master plan status, topography, soil/utility data, and inventory of drains/outfalls/pumps; conduct surveys ( and problem hotspot mapping with contour and administrative maps annexed. (DPR for Drainage Master Plan) |
| 7 | b)Hydrology and hydraulics: Estimate runoff for design storms, build and calibrate hydrologic–hydraulic models, verify capacities and backwater/surcharge, and produce longitudinal and cross-sections, deficiency analysis, and augmentation needs for gravity and pumped systems. (DPR for Drainage Master Plan) |
| 8 | c) Options and prioritization: Develop and compare alternatives covering capacity upgrades, new drains/culverts/bridges, detention/retention, pump stations with reliable power, and non-structural measures; bottlenecks and prepare a phased investment plan. (DPR for Drainage Master Plan) |
| 9 | d) Prepare an integrated Drainage Master Plan and DPR that compiles baseline and survey data, develops calibrated hydrology–hydraulic models and prioritized upgrade options (capacity augmentation, new drains/culverts, detention, pumps, ), and produces GFC drawings, SoR‑mapped BOQs, E&S due diligence, and an implementation plan with phasing, procurement, O&M and monsoon SOPs, compliant with national stormwater and urban flooding manuals. (DPR for Drainage Master Plan) |
| 10 | SITC of AWLR of Quantity 24 Nos with necessary hardware and mounting arrangements as per technical specifications and instructions from engineer in charge. (Instrumentation) |
| 11 | SITC of ARG with necessary hardware and mounting arrangements as per technical specifications and instructions from engineer in charge. (Instrumentation) |
| 12 | Cloud Hosted Data Acquisition Software. (Cloud Services) |
| 13 | Labour cess and GST will be paid extra as per Govt. orders. Please Enable Macros to View BoQ information |
