K.0.2_Hydrological_model_INPUT_ImperialValley_USA

Data Sources, Provenance, Processing, Licensing and Conditions of Reuse 1. General description This repository contains spatial modelling datasets prepared for the Imperial Valley transboundary case study, covering parts of California, United States, and Baja California, Mexico, in connection with the WaterTheft project, Grant Agreement No. 101124884. The deposited or documented products comprise: Digital Elevation Models prepared at approximately 30 m and 10 m output grid spacing; soil spatial and tabular information derived from the Soil Survey Geographic Database — SSURGO for the United States portion of the study area; a 250 m × 250 m model-oriented land-use allocation generated using the Hydro-economic Interoperable Land-use Allocation Method — HILAM; lookup tables, provenance records and processing documentation; and supporting spatial identifiers prepared for hydrological and hydro-economic modelling. The deposited files are research products derived from third-party geographic datasets and from original processing undertaken by the repository creators. Depending on the file, the processing included study-area extraction, clipping, mosaicking, reprojection, raster alignment, spatial aggregation, interpolation, thematic reclassification, constrained land-use allocation, patch regularisation, soil-attribute preparation and integration into a common modelling grid. The files deposited in this repository are not official products of the original data providers and must not be represented as such. Copyright, database rights and any other pre-existing rights in the source datasets remain with their respective data providers and rights holders. The repository creators claim authorship only over their original processing, spatial harmonisation, HILAM allocation, derived-grid preparation, coding, documentation and other original contributions. No licence granted through this repository extends, replaces or overrides the rights and conditions attached to the underlying source datasets. Where source-specific terms are more restrictive than the conditions applied to the repository creators’ original contributions, the source-data conditions prevail. 2. Digital Elevation Models 2.1 United States 30 m source product The approximately 30 m elevation information for the United States portion of the study area was obtained from the: USGS 1 arc-second Digital Elevation Model distributed through the U.S. Geological Survey 3D Elevation Program — 3DEP and accessed through OpenTopography. OpenTopography collection identifier: OTNED.012021.4269.2 The source product is a seamless Digital Elevation Model with a nominal grid spacing of one arc-second, corresponding to approximately 30 m. The dataset represents the topographic bare-earth surface and forms part of the elevation layers distributed through the USGS National Geospatial Program. The horizontal reference system of the downloaded product is based on the North American Datum of 1983 — NAD83. Elevation values are expressed in metres. Over the conterminous United States, USGS 3DEP elevations are normally referenced to the North American Vertical Datum of 1988 — NAVD88. 2.2 United States 10 m source product Where the original United States elevation data were obtained directly at approximately 10 m grid spacing, the source product was: USGS 1/3 arc-second Digital Elevation Model distributed through the U.S. Geological Survey 3D Elevation Program — 3DEP and accessed through OpenTopography. OpenTopography collection identifier: OTNED.012021.4269.1 The source product has a nominal grid spacing of one-third arc-second, corresponding to approximately 10 m over the study area. This source must be distinguished from any 10 m output raster generated by resampling a lower-resolution source. A raster generated by interpolation from a 30 m source does not contain the same effective spatial information as the native USGS 1/3 arc-second product. 2.3 Mexican elevation source The elevation information used to cover the Mexican portion of the study area was obtained from: NASA Shuttle Radar Topography Mission Global 1 arc second, Version 003 — SRTMGL1 V003 Google Earth Engine dataset identifier: USGS/SRTMGL1_003 Recommended source citation: NASA JPL. (2013). NASA Shuttle Radar Topography Mission Global 1 arc second [Dataset]. NASA Land Processes Distributed Active Archive Center. DOI: 10.5067/MEASURES/SRTM/SRTMGL1.003. The SRTMGL1 V003 product has a nominal spatial resolution of one arc-second, approximately 30 m. Version 003 includes void filling based on additional open elevation sources, including ASTER GDEM2, GMTED2010 and the former National Elevation Dataset. The source SRTM elevation values are referenced horizontally to WGS84 and vertically to the EGM96 geoid. 2.4 Cross-border elevation harmonisation The United States and Mexican elevation sources were transformed into a common spatial framework to produce a continuous Digital Elevation Model covering the transboundary study area. The processing included, as applicable: extraction of the Imperial Valley and Mexicali study domain; clipping of the original elevation products; reprojection to WGS 84 / UTM Zone 11N, EPSG:32611; conversion or confirmation of horizontal and vertical units; alignment of raster origins and pixel grids; resampling to a common target grid; treatment of NoData values; mosaicking of the United States and Mexican elevation surfaces; examination of the source-data transition zone; application of a smoothing or blending procedure to reduce artificial discontinuities at the source-data junction; hydrological conditioning, where applicable; sink filling, where applicable; and preparation of final terrain inputs for hydrological modelling. The exact method used to treat the transition between the two elevation sources was: A focal neighbourhood smoothing procedure was applied in Google Earth Engine within a defined transition zone along the United States–Mexico DEM boundary. The method reduced abrupt elevation discontinuities between the USGS 3DEP and SRTM-derived surfaces while preserving the processed source values outside the transition area. The smoothing or blending operation was implemented in: Google Earth Engine — custom cross-border DEM harmonisation and transition-smoothing workflow developed using the Earth Engine JavaScript API for the Imperial Valley case study, 2026. The transition treatment was intended to reduce artificial local discontinuities associated with joining elevation products with different origins, effective spatial resolutions and reference systems. It must not be interpreted as independent validation of the vertical accuracy of either source product. Where the USGS and SRTM products retained different vertical reference datums, the smoothing operation alone does not constitute a formal vertical-datum transformation. Any vertical-datum conversion applied before mosaicking must therefore be documented explicitly, including the geoid model and conversion procedure used. 2.5 Thirty-metre transboundary product The approximately 30 m transboundary Digital Elevation Model was generated from the USGS 3DEP one-arc-second product for the United States portion and the NASA SRTMGL1 V003 product for the Mexican portion. The two surfaces were clipped, reprojected, aligned, mosaicked and processed to reduce artificial discontinuities across their source-data junction. The final product has: output coordinate reference system: WGS 84 / UTM Zone 11N, EPSG:32611; horizontal units: metres; vertical units: metres; output cell size: 30m. 2.6 Ten-metre output-grid product A second transboundary elevation product was prepared with an output grid spacing of 10 m. For the United States portion, the elevation information was obtained from: the USGS 3DEP one-arc-second Digital Elevation Model resampled to a 10 m grid. For the Mexican portion, the NASA SRTMGL1 V003 elevation surface was resampled from its native approximate 30 m grid spacing to a 10 m output grid using bilinear interpolation in Google Earth Engine. The processing code applied the following operation: Bilinear resampling of USGS/SRTMGL1_003, followed by reprojection to WGS 84 / UTM Zone 11N at an output scale of 10 m. This procedure is a downscaling operation. It is not a machine-learning or statistical super-resolution method. No training dataset, predictive model or machine-learning algorithm was used in the code associated with this operation. The 10 m output cell size therefore does not imply that new terrain detail was observed or reconstructed at a true effective resolution of 10 m in the Mexican portion. The effective source resolution of the Mexican elevation information remains approximately 30 m, and the interpolated cells are spatial estimates derived from the surrounding SRTM elevation values. The product should therefore be described as: A transboundary Digital Elevation Model with a 10 m output grid spacing, incorporating native USGS 3DEP elevation data where available and bilinearly resampled NASA SRTMGL1 V003 elevation data for the Mexican portion. It should not be described as: A uniformly observed 10 m resolution DEM for the entire United States–Mexico study area. 2.7 Elevation-data attribution Required United States source acknowledgement: Data available from the U.S. Geological Survey, National Geospatial Program. OpenTopography acknowledgement: USGS 3DEP elevation data accessed and processed through OpenTopography. Recommended SRTM citation: NASA JPL. (2013). NASA Shuttle Radar Topography Mission Global 1 arc second [Dataset]. NASA Land Processes Distributed Active Archive Center. DOI: 10.5067/MEASURES/SRTM/SRTMGL1.003. Derived-product attribution: Derived transboundary elevation products based on USGS 3DEP elevation data and NASA SRTMGL1 V003. Modifications included clipping, reprojection, grid alignment, resampling, mosaicking, transition-zone processing and preparation for hydrological modelling. 2.8 Elevation-data licence and rights USGS 3DEP data and data distributed through the USGS National Map are United States Government data and are made available in the United States public domain. NASA SRTMGL1 V003 is openly shared without restriction in accordance with NASA Earth Science Data and Information System data-use guidance. The repository creators do not claim ownership over the original USGS, NASA, JPL or SRTM elevation data. To the extent that copyright or related rights subsist in the repository creators’ original selection, processing, harmonisation, organisation and documentation, those original contributions are released under: Creative Commons Attribution 4.0 International — CC BY 4.0. The CC BY 4.0 licence applied to the repository creators’ contributions does not remove the public-domain status of the underlying United States Government data. Users must acknowledge the original source products, acknowledge OpenTopography as the access and processing service where applicable, cite this Zenodo repository and indicate any subsequent modifications. Neither the U.S. Geological Survey, NASA, JPL, OpenTopography nor any United States or Mexican public authority has reviewed, validated, certified or endorsed the derived elevation products. 3. Soil dataset 3.1 United States soil source The soil spatial and attribute information used for the United States portion of the Imperial Valley study area was obtained from the: Soil Survey Geographic Database — SSURGO produced and maintained by the: Soil Survey Staff, Natural Resources Conservation Service — NRCS, United States Department of Agriculture — USDA. The data were accessed through Web Soil Survey and/or Soil Data Access. The exact soil survey areas used were: Imperial Valley subbasin (Alamo and New River catchments). The source-data access date was: 06/10/2025. SSURGO contains spatial soil-map units and associated tabular information describing soil components, horizons, physical and chemical properties, interpretations and supporting metadata. Individual SSURGO map units may contain several soil components. Consequently, a map-unit polygon must not be interpreted automatically as a spatially homogeneous soil body. Recommended source citation: Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Soil Survey Geographic — SSURGO — Database for [survey area, state]. Available online through Web Soil Survey or Soil Data Access. Accessed [date]. 3.2 Mexican soil source The soil information used for the Mexican portion of the Imperial Valley–Mexicali study area was obtained from the: Conjunto de datos vectoriales edafológico, escala 1:250 000, Serie II — Continuo Nacional. The dataset was produced by the: Instituto Nacional de Estadística y Geografía — INEGI and was accessed through the: Geoportal del Sistema Nacional de Información sobre Biodiversidad, Comisión Nacional para el Conocimiento y Uso de la Biodiversidad — CONABIO. Recommended source citation: INEGI (2014). Conjunto de datos vectoriales edafológico, escala 1:250 000, Serie II — Continuo Nacional, second edition. Instituto Nacional de Estadística y Geografía, Aguascalientes, Mexico. Distributed through the CONABIO Geoportal. The source product is a national vector soil dataset prepared at a nominal cartographic scale of 1:250 000. The dataset represents mapped soil units and soil types rather than direct observations at every location. Its nominal cartographic scale must be taken into account when interpreting the information or adapting it to the 250 m modelling grid. The presence of a soil category within a mapped polygon does not imply that the soil properties are spatially uniform throughout the polygon. The source information was extracted for the Mexican portion of the transboundary study area and subsequently processed for integration with the soil information available for the United States portion. 3.3 Cross-border soil harmonisation The SSURGO information for the United States and the INEGI–CONABIO soil information for Mexico differ in: original data model; thematic classification; mapping scale; spatial resolution and effective spatial support; soil-property content; representation of soil components and horizons; and original institutional purpose. The two products were therefore not joined as if they constituted a single homogeneous soil survey. Instead, the source information was harmonised to construct a common soil representation suitable for hydrological modelling. The processing included, as applicable: extraction of the United States and Mexican portions of the study area; reprojection to EPSG:26911 - NAD83 / UTM zone 11N - Projected; correction of invalid geometries; harmonisation of soil classes and attribute names; linkage of SSURGO spatial map units with their tabular component and horizon information; interpretation of the INEGI soil-map units; conversion of soil classifications into common modelling categories; calculation or assignment of SWAT soil parameters; unit conversion; treatment of missing values; conversion to a regular 250 m × 250 m modelling grid; alignment with the HILAM land-use and elevation grids; assignment of unique soil and grid-cell identifiers; and preparation of the soil database and lookup tables required by SWAT. For SSURGO, representative soil properties were calculated using: Component-percentage-weighted mean For the INEGI–CONABIO soil units, representative properties were assigned or estimated using: Pedotransfer functions from Soilgrids Continuous soil properties were transferred to the 250 m grid using: nearest neighbour method. Categorical soil attributes were assigned using: dominant-area rule. Where properties required by hydrological modelling were unavailable in the Mexican source dataset, the corresponding values were obtained using: pedotransfer functions from Saxton relations. Such values must be interpreted as model parameters or estimates rather than as direct field observations. No new soil samples or field observations were collected during the preparation of the harmonised soil dataset. The conversion to a 250 m grid changes the spatial representation of the original information but does not increase its observational accuracy or effective source resolution. 3.4 United States soil-data rights SSURGO is produced by USDA–NRCS as United States Government information. United States Government-generated source information is generally available in the United States public domain, subject to appropriate acknowledgement and any qualifications contained in the corresponding source metadata. Required acknowledgement: United States Department of Agriculture, Natural Resources Conservation Service, Soil Survey Staff. Derived-product attribution: Derived soil information based on USDA–NRCS SSURGO data for the United States portion of the Imperial Valley study area. Modifications included spatial and tabular joins, soil-component and horizon processing, unit conversion, spatial aggregation, grid alignment and preparation for the hydrological model. The repository creators do not claim ownership over the original SSURGO map units, soil observations, component descriptions or soil-horizon records. 3.5 Mexican soil-data licence and attribution The INEGI soil dataset distributed through the CONABIO Geoportal is subject to the: Creative Commons Attribution–NonCommercial 2.5 Mexico licence — CC BY-NC 2.5 MX. The source metadata specify that the data must not be used for commercial purposes and that both the original source and CONABIO must be acknowledged. Mandatory source acknowledgement: Instituto Nacional de Estadística y Geografía — INEGI, original data producer. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad — CONABIO, data-access and distribution portal. Recommended attribution: Contains modified information from INEGI (2014), Conjunto de datos vectoriales edafológico, escala 1:250 000, Serie II — Continuo Nacional, accessed through the CONABIO Geoportal and made available under CC BY-NC 2.5 Mexico. Changes made to the source information included: extraction of the study area; reprojection; thematic harmonisation; conversion to a common modelling classification; assignment or estimation of hydrological soil properties; conversion to a 250 m grid; integration with SSURGO-derived information; and preparation for SWAT. The Mexican source information and any derived component incorporating it may be shared and adapted only in accordance with the non-commercial condition of the applicable licence. The repository creators cannot grant commercial-use rights over the INEGI–CONABIO source information. Neither INEGI nor CONABIO has reviewed, verified, certified or endorsed the harmonised soil dataset or its use in SWAT. 4. Original land-use information 4.1 California source dataset The original crop and land-use information for the California portion of the study area was obtained from the: Statewide Crop Mapping dataset published by the: California Department of Water Resources — DWR through the: California Natural Resources Agency Open Data Portal. The source products used corresponded to the following years: 2014-2023. Recommended source citation: California Department of Water Resources. (2026). Statewide Crop Mapping. California Natural Resources Agency Open Data Portal. Accessed 06/10/2025. The source datasets identify agricultural crop types and other land uses using remotely sensed imagery, GIS processing, ancillary spatial information, agronomic interpretation and ground-reference information. Certain Statewide Crop Mapping products were prepared with the participation of Land IQ, LLC. The field boundaries and classifications contained in the source data must not be interpreted as definitive cadastral, ownership or legal boundaries. 4.2 Mexican source dataset The original land-use and vegetation information used for the Mexican portion of the Imperial Valley–Mexicali study area was obtained from the: Uso del suelo y vegetación, escala 1:250 000, Serie VII — Continuo Nacional. The dataset was produced by the: Instituto Nacional de Estadística y Geografía — INEGI and was accessed through the: Geoportal del Sistema Nacional de Información sobre Biodiversidad, Comisión Nacional para el Conocimiento y Uso de la Biodiversidad — CONABIO. Recommended source citation: INEGI (2021). Uso del suelo y vegetación, escala 1:250 000, Serie VII — Continuo Nacional. Instituto Nacional de Estadística y Geografía, Aguascalientes, Mexico. Distributed through the CONABIO Geoportal. The dataset contains vector information on land use, agricultural areas, natural vegetation, secondary vegetation and other land-cover categories classified according to the INEGI land-use and vegetation classification system. The source information was generated principally through interpretation of Landsat satellite imagery with a reference year of 2018, supported by ancillary information and field verification. The product was prepared at a nominal cartographic scale of 1:250 000. Its nominal scale and source methodology must be taken into account when comparing it with the more spatially detailed California Statewide Crop Mapping products. The Mexican source map does not necessarily identify individual agricultural crop species with the same thematic detail as the California crop-mapping products. Where a Mexican source category represented general irrigated agriculture, rainfed agriculture or another aggregated agricultural class, any subsequent allocation to more detailed HILAM crop categories must be identified as a modelling allocation rather than as an original observation. 4.3 Mexican land-use licence and attribution The INEGI land-use and vegetation dataset distributed through CONABIO is subject to the: Creative Commons Attribution–NonCommercial 2.5 Mexico licence — CC BY-NC 2.5 MX. The applicable conditions permit copying, redistribution, transformation and preparation of derived products, provided that: appropriate attribution is given; the original source is identified; CONABIO is acknowledged as the distribution portal; the licence is identified; the derivative nature of the product is made clear; and the material is not used for commercial purposes. Mandatory source acknowledgement: Instituto Nacional de Estadística y Geografía — INEGI, original data producer. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad — CONABIO, data-access and distribution portal. Recommended attribution: Contains modified information from INEGI (2021), Uso del suelo y vegetación, escala 1:250 000, Serie VII — Continuo Nacional, accessed through the CONABIO Geoportal and made available under CC BY-NC 2.5 Mexico. Changes made to the source information included, as applicable: extraction of the Mexican study area; clipping; reprojection; thematic harmonisation; reclassification into the common HILAM categories; conversion to a 250 m grid; preservation of selected static land-use and vegetation classes; identification of agriculturally eligible cells; spatial allocation of agricultural categories; patch regularisation; and integration with the California land-use representation. Neither INEGI nor CONABIO has reviewed, verified, certified or endorsed the resulting HILAM-derived product. 5. HILAM-derived transboundary land-use allocation 5.1 Source integration The HILAM land-use product combines information derived from two institutionally and methodologically different source systems: the California Department of Water Resources Statewide Crop Mapping dataset for the United States portion; and the INEGI Uso del suelo y vegetación dataset distributed through CONABIO for the Mexican portion. The sources differ in: thematic detail; original mapping scale; classification system; spatial representation; reference date; source imagery; identification of individual agricultural crops; and applicable licence and redistribution conditions. The source layers were therefore harmonised into a common set of modelling categories before the HILAM allocation procedure was applied. A correspondence table documenting the relationship between the original source classes and the final HILAM classes should accompany the dataset. 5.2 HILAM processing The Hydro-economic Interoperable Land-use Allocation Method — HILAM was used to create a regular 250 m × 250 m transboundary modelling grid. The principal operations included: harmonisation of the California and Mexican land-use classifications; reclassification into a common set of HILAM land-use and crop categories; establishment of a regular 250 m × 250 m spatial template; preservation of land uses considered spatially static, structurally persistent or unavailable for agricultural allocation; preservation, as applicable, of: water bodies; rivers and principal canals; urban and built-up areas; major roads and transport infrastructure; forests; shrublands; natural vegetation; wetlands; bare or non-productive land; protected areas; and major irrigation and drainage infrastructure; calculation of agricultural areas and proportions within 1km2; identification of grid cells eligible for agricultural allocation; allocation of agricultural categories while attempting to preserve the source areas or proportions within a tolerance of 516m; spatial regularisation to favour compact and coherent agricultural patches; reduction of isolated cells and salt-and-pepper patterns; alignment with the elevation, soil and hydrological-model inputs; and assignment of common grid-cell, soil, land-use and modelling identifiers. 5.3 Interpretation limitations The resulting HILAM dataset is a model-oriented, spatially regularised representation of the available source information. The location of preserved static classes is based on the corresponding source maps. However, the position of individual agricultural cells may have been generated, adjusted or regularised by the HILAM procedure. For Mexico, agricultural classes that were more detailed than those explicitly identified in the INEGI source map were allocated using model assumptions, area proportions, ancillary information or harmonisation rules. Consequently: the HILAM product must not be interpreted as an observed parcel-level crop map; individual 250 m cells do not confirm that a particular crop occurred at that exact location; modelled Mexican crop categories must not be attributed directly to INEGI or CONABIO unless they existed explicitly in the original source; the product must not be used for cadastral, ownership or legal-boundary applications; the product must not be used for subsidy verification, regulatory enforcement or individual field identification; the product must not be represented as an official DWR, INEGI, CONABIO, United States Government or Mexican Government dataset; and the intended uses are hydrological modelling, hydro-economic modelling, scenario analysis and model-interoperability research. 5.4 Licence and access implications The transboundary HILAM land-use file incorporates source information subject to different rights conditions. The Mexican component is subject to: Creative Commons Attribution–NonCommercial 2.5 Mexico — CC BY-NC 2.5 MX. The licence status of the California Statewide Crop Mapping source must be confirmed for the exact years used, because the catalogue record does not currently state a specific standard licence and some products include third-party contributions. For that reason, the transboundary HILAM land-use file should not presently be declared simply as: Creative Commons Attribution 4.0 International — CC BY 4.0. Pending clarification from the California Department of Water Resources, the recommended Zenodo configuration is: Metadata visibility: Public. File access: Restricted. Licence: Custom rights statement. Suggested custom licence title: Transboundary HILAM land-use dataset — non-commercial use and source-specific rights Suggested custom licence description: This dataset incorporates modified land-use information from the California Department of Water Resources Statewide Crop Mapping products and from INEGI land-use and vegetation information distributed through the CONABIO Geoportal. The Mexican source information is subject to the Creative Commons Attribution–NonCommercial 2.5 Mexico licence. Use, transformation and redistribution of the files are therefore limited to non-commercial purposes and require acknowledgement of INEGI and CONABIO, identification of the applicable licence and disclosure of the modifications made. The licensing and redistribution conditions applying to the California Statewide Crop Mapping source information remain subject to the terms established by the California Department of Water Resources and any relevant third-party rights holders. The repository creators grant no rights beyond those that they hold and claim authorship only over their original HILAM allocation, class harmonisation, spatial regularisation, grid preparation, coding and documentation. No commercial-use permission is granted for the source information incorporated into the Mexican portion. Neither DWR, INEGI, CONABIO nor any other source-data provider has reviewed, certified or endorsed the derived product. 6. Updated file-level rights statement File category Source status Status USGS 3DEP-derived elevation data United States public-domain information Public NASA SRTM-derived Mexican elevation data Open NASA Earth-observation data Public with attribution Cross-border DEM Derived from USGS and NASA sources Public with full provenance and modification statement SSURGO-derived United States soils United States public-domain information Public with USDA–NRCS attribution INEGI–CONABIO-derived Mexican soils CC BY-NC 2.5 Mexico Public under exact non-commercial source conditions, or restricted for greater prudence Harmonised transboundary soil file Includes public-domain and CC BY-NC information CC BY-NC 2.5 MX or custom non-commercial rights statement California Statewide Crop Mapping source Exact licence not stated in catalogue Do not redistribute until clarified INEGI–CONABIO Mexican land use CC BY-NC 2.5 Mexico Redistribution permitted for non-commercial purposes with attribution Combined HILAM land-use file DWR source status unresolved and Mexican CC BY-NC source Restricted with custom rights statement HILAM methodology, documentation and original code Original contribution May be published separately under CC BY 4.0 or a software licence 7. Copyright statement Copyright © 2026 David Rivas Tabares and the dataset creators for the original HILAM spatial allocation, cross-border data harmonisation, derived-grid preparation, coding, documentation and other original contributions. USGS 3DEP, USDA–NRCS SSURGO and other United States Government source information remain in the United States public domain. Pre-existing rights in NASA/JPL SRTM data, California Department of Water Resources Statewide Crop Mapping data, Land IQ materials, Mexican source datasets and other third-party information remain with their respective providers and rights holders. No ownership is claimed over unmodified source datasets, underlying observations, official classifications, trademarks, agency logos or governmental insignia. 8. No endorsement Reference to the U.S. Geological Survey, NASA, JPL, OpenTopography, USDA, NRCS, California Department of Water Resources, California Natural Resources Agency, Land IQ, Mexican public authorities, the European Union or the European Research Council is made solely to identify data provenance, institutional responsibility, access services or research funding. Such reference does not imply that any of these organisations: participated in the HILAM allocation; approved the cross-border DEM harmonisation; reviewed the deposited files; certified their accuracy; guaranteed their suitability for a particular purpose; endorsed the repository creators’ interpretations; or endorsed any subsequent analysis, decision or publication based on the files. 9. Accuracy, uncertainty and fitness for purpose The datasets are provided for scientific and research purposes on an “as is” and “as available” basis. Although reasonable care was taken in their preparation, the repository creators do not warrant that the files are complete, error-free or suitable for every purpose. The products incorporate uncertainty inherited from their source datasets and additional uncertainty introduced through: reprojection; datum handling; clipping; mosaicking; resampling; bilinear interpolation; transition-zone smoothing; soil-component aggregation; soil-horizon aggregation; thematic reclassification; HILAM spatial allocation; patch regularisation; and other processing operations. The United States and Mexican elevation sources may differ in acquisition method, effective spatial resolution, temporal reference, horizontal reference and vertical datum. A visually smooth transition between two elevation products does not by itself demonstrate that their vertical references or absolute accuracies are equivalent. The Mexican portion of the 10 m output-grid DEM is interpolated from an approximately 30 m SRTM source and does not contain independently observed 10 m elevation information. SSURGO soil-map units may contain multiple soil components and do not imply homogeneous soil properties throughout each polygon. The California Statewide Crop Mapping information does not cover Mexico. The HILAM agricultural allocation is a model-oriented representation and not an observed parcel-level reconstruction. Users are solely responsible for: assessing fitness for their intended purpose; consulting the original metadata; checking coordinate and vertical reference systems; independently validating the data; retaining all mandatory source acknowledgements; complying with source-specific rights and licence conditions; obtaining permission for further redistribution where required; and avoiding use for decisions requiring legal, cadastral, engineering, regulatory or parcel-level accuracy. To the maximum extent permitted by applicable law, the repository creators accept no responsibility for direct or indirect loss, damage, cost or adverse consequence arising from the use, inability to use, interpretation or redistribution of the files. Nothing in this statement excludes any responsibility that cannot lawfully be excluded. 10. Rights-holder notification and correction procedure The repository creators have made a good-faith effort to identify the relevant source-data providers, rights holders, licences, attribution requirements and redistribution conditions applicable at the time of deposit. Any data provider or rights holder who believes that a deposited file has been incorrectly attributed, inadequately documented or made available under incompatible conditions is invited to contact: David Rivas-TabaresIMDEA Water [e-mail] The notification should identify: the affected file; the rights or conditions concerned; the basis of the request; supporting documentation; and the corrective action requested. Upon receipt of a sufficiently substantiated notification, the repository creators will promptly review the matter and, where appropriate: correct the metadata or attribution; restrict access to the affected file; replace the affected file; remove it from a subsequent repository version; or request withdrawal of the affected material. The inclusion of this procedure reflects a commitment to responsible data stewardship and does not constitute an admission of infringement, fault or liability. 11. Citation requirements Users of the elevation products should cite: this Zenodo repository; the relevant USGS 3DEP source product; OpenTopography as the data-access service; NASA SRTMGL1 V003 and its DOI where the Mexican elevation surface was used; and the processing description identifying the cross-border harmonisation and resampling. Users of the soil dataset should cite: this Zenodo repository; the relevant USDA–NRCS SSURGO survey areas; Web Soil Survey or Soil Data Access; the date on which the source data were accessed; and any separate Mexican soil source. Users of the HILAM land-use dataset should cite: this Zenodo repository; every California DWR Statewide Crop Mapping year used; the California Department of Water Resources; any relevant third-party creator identified in the source metadata; the Mexican land-use source, where applicable; and the future HILAM methodological publication once available. Until the HILAM methodological article is published, this Zenodo record should be cited as the primary description of the HILAM processing applied to the Imperial Valley case study. 12. Funding acknowledgement This dataset was prepared in connection with the WaterTheft project, Grant Agreement No. 101124884. Funded by the European Union under Grant Agreement No. 101124884. Views and opinions expressed are, however, those of the author or authors only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them.