[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"item-2796":3},{"id":4,"title":5,"url":6,"summary":7,"summary_zh":8,"content":9,"source_name":10,"source_url":6,"published_at":11,"category":12,"cover_url":9,"hotness":13,"is_selected":14,"score":15,"score_detail":16,"sources":18,"tags":20,"view_count":15,"doi":24,"paper":25,"created_at":48},2796,"Spatio-Temporal Analysis of Urban Expansion in Awka and its Environs, Nigeria Using Sentinel-2 Satellite Imagery and Google Earth Engine (2021 to 2026)","https:\u002F\u002Fdoi.org\u002F10.31223\u002Fx52v3s","Abstract Rapid urbanization in secondary administrative and educational hubs across sub-Saharan Africa presents significant challenges for regional planning, infrastructure development, and sustainable resource allocation. This study evaluates the spatio-temporal dynamics of urban expansion in Awka and its environs Anambra State, Nigeria, between 2021 and 2026 using cloud-based remote sensing infrastructure. By leveraging Google Earth Engine (GEE) and multi-temporal Sentinel-2 Surface Reflectance imagery, the Normalized Difference Built-up Index (NDBI) was computed across dry-season composites to isolate concrete and structural surfaces from surrounding vegetation and bare soil. The findings reveal an intensive peri-urban transformation of the landscape: the built-up area surged from a baseline of 239.87 hectares in 2021 to 2,752.91 hectares by 2026. This represents a net urban expansion of 2,513.04 hectares, translating to an extraordinary percentage growth rate of 1,047.67% over the five-year period, supported by a model validation accuracy of 98.50% and a Kappa coefficient of 0.98. Spatial clustering of new development was predominantly observed along the Okpuno, Ifite and Awka-Enugu expressway corridors, driven largely by educational expansion and demographic influx. The results demonstrate the efficacy of cloud-native geospatial computing for monitoring rapid urban sprawl, providing essential empirical metrics to guide master plan enforcement, real estate investment modeling, and municipal infrastructural planning.","摘要 撒哈拉以南非洲地区次级行政与教育中心城市的快速城市化，给区域规划、基础设施建设及可持续资源配置带来了重大挑战。本研究利用基于云端的遥感基础设施，评估了尼日利亚阿南布拉州阿瓦卡及其周边地区2021年至2026年间的城市扩张时空动态。通过借助谷歌地球引擎（Google Earth Engine, GEE）和多时相哨兵2号地表反射率影像，在旱季合成影像上计算归一化建筑指数（Normalized Difference Built-up Index, NDBI），以将混凝土及结构性表面与周围植被和裸土区分开来。研究结果揭示了景观剧烈的城郊转型：建成区面积从2021年基线的239.87公顷激增至2026年的2,752.91公顷。这意味着净城市扩张面积为2,513.04公顷，五年间增长率高达1,047.67%，模型验证精度为98.50%，Kappa系数为0.98。新增开发的空间集聚主要沿奥克普诺、伊菲特和阿瓦卡-埃努古高速公路走廊分布，其驱动力主要来自教育扩张和人口涌入。研究结果证明了云原生地理空间计算在监测快速城市蔓延方面的有效性，为总体规划执行、房地产投资建模和市政基础设施规划提供了重要的实证指标。",null,"OpenAlex","2026-09-16T00:00:00Z","论文",10,false,0,{"impact":15,"substance":15,"depth":15,"authority":15,"freshness":15,"relevant":15,"comment":17},"研究对象为尼日利亚城市建成区扩张，属城市遥感与区域规划范畴，与三农、农业信息化、数字乡村无直接关联，不建议进入每日精选。",[19],{"name":10,"url":6},[21,22,23],"遥感监测","土地利用","城市扩张","10.31223\u002Fx52v3s",{"doi":24,"openalex_id":26,"authors":27,"venue":9,"cited_by_count":15,"oa_url":40,"card":41,"direction":45,"ingested_from":47},"W7213407140",[28,30,32,34,36,38],{"name":29,"orcid":9},"ADEBOBOYE ADEYEMI DR",{"name":31,"orcid":9},"Adaobi Olisa",{"name":33,"orcid":9},"CHINEDU ANADEBE",{"name":35,"orcid":9},"EVAWERE OKPUGWO",{"name":37,"orcid":9},"ODO OFORBUIKE",{"name":39,"orcid":9},"SYLVESTER EKWEALOR","https:\u002F\u002Feartharxiv.org\u002Frepository\u002Fobject\u002F15011\u002Fdownload\u002F26080\u002F",{"tldr":42,"method":43,"finding":44,"direction":45,"opportunity":46},"基于GEE与Sentinel-2影像，分析尼日利亚Awka及周边2021-2026年城市扩张动态。","GEE平台、Sentinel-2地表反射率影像、NDBI指数、干季合成与精度验证","建成区从239.87公顷增至2752.91公顷，增长1047.67%，扩张集中于教育走廊。","农业遥感与作物表型","可延伸至城乡交错带耕地流失监测，结合多源遥感与机器学习预测城市扩张对农业的影响。","openalex","2026-09-17T23:30:37.315472Z"]