Data for: The Environmental Cost of Rapid Urbanization: Residential Construction and Lake Depletion in Astana, Kazakhstan

RESEARCH HYPOTHESIS: Tests whether rapid urbanization in Astana, Kazakhstan contributed to Bolshoy Taldykol Lake depletion through groundwater extraction and land use changes. Hypothesis predicts increased construction activity correlates with decreased lake surface area when controlling for climatic variables.

WHAT THE DATA SHOWS: Dataset combines satellite-derived lake surface area, residential construction statistics, and weather data for Astana (2015-2024). Three sources: (1) Lake surface area from Landsat 8/9 imagery using Modified Normalized Difference Water Index (MNDWI); (2) Monthly residential construction data; (3) Weather indicators. Analysis reveals 70% lake reduction from 2017 peak (0.856 km²) to 2024 (0.260 km²), coinciding with construction boom.

DATA COLLECTION:

Lake Surface Area: Google Earth Engine with Landsat 8/9. Processing: filter cloud cover <15%, create summer composites (June-September), calculate MNDWI=(Green-SWIR1)/(Green+SWIR1), apply threshold MNDWI>0, export GeoTIFF 30m resolution for 2015, 2017, 2020, 2022, 2024. Collection 2 Level-2 surface reflectance, scaling: multiply 0.0000275, add -0.2. Region: lake plus 500m buffer. JavaScript code provided.

Surface Area Calculation: Python with rasterio loads water masks, sums water pixels (value=1), multiplies by pixel area (900 m²), converts to km². Visualization includes temporal grids, before/after comparisons, change detection. Python code provided (Google Colab compatible).

Weather Data (March 2001-December 2024): Weather Underground (wunderground.com) Astana/UACC station via Selenium scraper. Monthly: max/avg/min temperatures, dew point, precipitation (with sum), snow depth (with sum), wind, gust wind, sea level pressure. Python script with retry logic, checkpoints. 285 monthly observations.

Residential Construction (January 2015-December 2024): Bureau of National Statistics Kazakhstan (taldau.stat.gov.kz). "Total area of commissioned residential buildings" in m². Monthly completed construction. Manually extracted from "Investment and Construction Statistics / Commissioning of Housing / Residential Buildings Information". 120 monthly observations.

INTERPRETATION: Water masks processed using provided Python code (rasterio) or GIS software. Each pixel=900 m². Water detected where MNDWI>0. Weather variables control for climate (precipitation inputs, evaporation via temperature/wind/dew point). Construction represents urbanization pressure on groundwater. Account for seasonal lake variations.

Limitations: (1) Summer satellite data only; (2) No direct groundwater measurements; (3) Completed buildings only; (4) Missing water policy data.

Applications: environmental impact assessment, urban planning, water management, climate adaptation, sustainable development.

Files: Water mask GeoTIFFs (5 years), RGB composites (5 years), weather CSV (285 months), construction CSV (120 months), JavaScript code (GEE), Python analysis code.