Application of the ESA-CCI land cover maps dataset at 300 m spatial resolution to assess Nicaragua’s agrarian frontier geospatial trend at the country-level and biosphere reserve-level

The encroachment of the agrarian frontier constitutes Nicaragua’s biggest environmental challenge as the major cause of complex processes of ecosystems degradation. I use the ESA-CCI land cover maps dataset and the UNCCD land cover classes (UNCCD-LC) to estimate its geospatial trend in terms of land cover changes and transitions at the country-level and the areas encompassing Bosawas and Río San Juan biosphere reserves from 1992 to 2018. The ESA-CCI land cover maps generated at 300 m spatial resolution on an annual basis from 1992 to 2015 in TIF format (raster layers) were collected from the official website of the ESA-CCI (https://www.esa-landcover-cci.org/). The coordinate reference system of the maps is a geographic coordinate system based on the World Geodetic System 84 (WGS84) reference ellipsoid. The processing of the geospatial data was carried out using QGIS. The 36 ESA-CCI land cover classes (CCI-LC) were re-classified to the 7 UNCCD-LC (i.e., tree-covered, grassland, cropland, wetland, artificial, other land, and water body). The ESA-CCI land cover maps were clipped to the country-level (Nicaragua) using the vector layers in SHP format collected from the official website of GADM (https://gadm.org/), and at the biosphere reserve-level (Bosawas y Río San Juan) using the vector layers in SHP format collected from the official website of Protected Planet (https://www.protectedplanet.net/). A pixel count approach was used to estimate each UNCCD-LC area. STATA was used to calculate UNCCD-LC area estimates in squared kilometers, each pixel counting for 300 m x 300 m which is the ESA-CCI land cover maps spatial resolution.

尼加拉瓜农业边界的扩张构成了该国最大的环境挑战，成为生态系统退化复杂过程的根本原因。本研究采用欧洲空间局-气候变化与地球系统科学中心（ESA-CCI）土地覆盖图数据集以及联合国防治荒漠化公约（UNCCD）土地覆盖类别（UNCCD-LC），以估计该国及包括博萨瓦斯和里奥圣胡安生物圈保护区在内的区域，从1992年至2018年土地覆盖变化和转变的地理空间趋势。自1992年至2015年，ESA-CCI土地覆盖图以300米的空间分辨率每年生成，并以TIF格式（栅格层）存储，数据收集自ESA-CCI官方网站（https://www.esa-landcover-cci.org/）。地图的坐标参考系统基于世界大地测量系统84（WGS84）参考椭球体的地理坐标系。地理空间数据的处理采用QGIS进行。36个ESA-CCI土地覆盖类别（CCI-LC）被重新分类为7个UNCCD-LC类别（即森林覆盖、草地、耕地、湿地、人工地、其他陆地和水体）。ESA-CCI土地覆盖图通过从GADM官方网站（https://gadm.org/）收集的SHP格式矢量层进行裁剪，以适应国家层面（尼加拉瓜）和生物圈保护区层面（博萨瓦斯和里奥圣胡安）。采用像素计数方法来估算每个UNCCD-LC区域面积。使用STATA计算UNCCD-LC面积估计，单位为平方公里，每个像素代表300米×300米的面积，即ESA-CCI土地覆盖图的空间分辨率。