Water Surfrace dynamics of El Chafi Marchland Iraq

This version integrates the specific file names, the technical details of the sensors, the processing methodology, and the socio-political conclusions from your previous analysis. It is designed to be a comprehensive and professional README for your Zenodo repository. Dataset: Multidecadal Surface Water Dynamics and Spatial Extent for Ahwar el Shafi, Iraq (2003–2024) Overview This dataset provides a comprehensive hydrological record of the Ahwar el Shafi marshes in Southern Iraq. It was developed to serve as a high-fidelity demonstrator of regional water resource variability, bridging the gap between high-resolution spatial observations and long-term historical trends. The repository provides the empirical evidence used to analyze the "pulse" of the Iraqi marshes, reflecting a complex interplay between hydro-climatic forcing and human management. 1. Spatial Dataset: Sentinel-2 High-Resolution Maps Files: WaterRatio_2016.tif, WaterRatio_2017.tif, WaterRatio_2018.tif, WaterRatio_2019.tif, WaterRatio_2020.tif, WaterRatio_2021.tif, WaterRatio_2022.tif, WaterRatio_2023.tif, WaterRatio_2024.tif. These GeoTIFF files represent the surface water extent at a 10-meter spatial resolution. Source: Copernicus Sentinel-2A and 2B Level-2A (L2A) Bottom-of-Atmosphere (BOA) reflectance products. Temporal Consistency: Each map represents a snapshot from the month of July. This period was selected to capture the marshes at their most vulnerable state during the peak of the dry season, providing a consistent baseline for monitoring summer water retention. Methodology: Surface water was delineated using the Normalized Difference Water Index (NDWI): NDWI = (B3 - B8) / (B3+ B8) where B3 is the reflectance from Green and B8 reflectance from Near InfraRed Technical Specifications: A standardized threshold (NDWI > 0.0) was applied. All files are georeferenced to WGS 84 / UTM zone 38N (EPSG:32638). 2. Temporal Dataset: Multidecadal Time Series File: modis_timeseries.xlsx This dataset provides the foundational data for the long-term hydrological narrative from 2003 to 2024. Source: NASA MODIS Terra (MOD09A1) 8-day composite BOA reflectance maps (500m resolution). Sensor Fusion & Harmonization: To account for the spatial and spectral differences between the 500m MODIS and 10m Sentinel-2 sensors, a linear correction was applied based on the overlapping operational period (2016–2024): y = 0.983x + 0.062 (Where y is the corrected area and x is the raw MODIS estimation). Content: The file includes raw and corrected flooded area calculations (km2), allowing for a robust assessment of shifts in the hydrological regime over 21 years. 3. Key Findings & Scientific Significance The data contained in these files reveals critical insights into the water security of Southern Iraq: Extreme Variability: The spatial maps (e.g., WaterRatio_2018.tif vs WaterRatio_2019.tif) vividly depict the radical shifts between severe drought and record-breaking flood pulses. Resilience and Vulnerability: The modis_timeseries.xlsx data highlights that while the marshes show a capacity for rapid recovery (as seen in 2003 and 2019), the baseline water availability remains under constant threat. Drivers of Change: Our analysis concludes that water availability in El Chafi is not merely a function of local climatology. The results demonstrate a strong dependency on: Climatological conditions constraining inbound water from upstream headwaters. Transboundary water management and riparian governance. National water management priorities. The impact of regional political instability.