A supervised land cover classification of a western Kenya lowland endemic for human malaria: associations of land cover with larval Anopheles habitats.
A supervised land cover classification of a western Kenya lowland endemic for human malaria: associations of land cover with larval Anopheles habitats.
复制标题
DOI：
10.1186/1476-072x-8-19
复制
发表时间：
2009-04-16
影响因子：
4.9
通讯作者：
Walker ED
中科院分区：
文献类型：
--
作者：
Mutuku FM;Bayoh MN;Hightower AW;Vulule JM;Gimnig JE;Mueke JM;Amimo FA;Walker ED
受监督的土地覆盖分类是根据非常高分辨率的 IKONOS 卫星数据和约 1000 公里的广泛地面实况采样开发的。肯尼亚西部 10 平方公里的疟疾流行低地。然后将该分类应用于按蚊幼虫栖息地分布的调查。该假设是，按蚊属不同种类蚊子的幼虫水生栖息地的分布和丰富度与可识别的景观特征相关。该分类产生了 7 种可区分的土地覆盖类型，每种类型都有可区分的植被模式，分类准确度很高（89%，Kappa 统计量 = 0.86），并且遗漏率和委托错误率较低。雨季样本中总共对 9 个物种的 1,198 个栖息地和 19,776 只按蚊幼虫进行了定量，旱季样本中对 184 个栖息地和 582 只按蚊幼虫进行了定量。冈比亚按蚊 s.l.是优势种复合体（占总数的 51%），而 A. arabiensis 是优势种。农业用地覆盖（成熟的玉米田、新开垦的田地和牧场）与幼虫栖息地的存在呈正相关，并且位于相对靠近河道的位置；而非农业土地覆盖（矮灌木、中等灌木、高灌木和住宅周围的裸土）与幼虫栖息地的存在呈负相关，并且距离河道更远。幼虫栖息地的数量随着距溪流的距离呈指数下降。 IKONOS 图像无法直接检测幼虫栖息地，因为它们又小又浑浊（类似于裸土），但可通过与特定土地覆盖的统计关联来定位幼虫栖息地。对肯尼亚西部农村、低地的土地覆盖类型进行了监督分类，揭示了由农业和家庭土地利用组成的很大程度上受到人类改造和破碎的景观。其中，人类疟疾按蚊媒介的幼虫栖息地与某些土地覆盖类型有关，主要是农业来源，并且靠近溪流。了解这些关联可以为疟疾控制提供信息，从而比实地调查更有效地收集有关潜在幼虫栖息地的信息，并且可以在大面积范围内这样做。
A supervised land cover classification was developed from very high resolution IKONOS satellite data and extensive ground truth sampling of a ca. 10 sq km malaria-endemic lowland in western Kenya. The classification was then applied to an investigation of distribution of larval Anopheles habitats. The hypothesis was that the distribution and abundance of aquatic habitats of larvae of various species of mosquitoes in the genus Anopheles is associated with identifiable landscape features. The classification resulted in 7 distinguishable land cover types, each with a distinguishable vegetation pattern, was highly accurate (89%, Kappa statistic = 0.86), and had a low rate of omission and commission errors. A total of 1,198 habitats and 19,776 Anopheles larvae of 9 species were quantified in samples from a rainy season, and 184 habitats and 582 larvae from a dry season. Anopheles gambiae s.l. was the dominant species complex (51% of total) and A. arabiensis the dominant species. Agricultural land covers (mature maize fields, newly cultivated fields, and pastured grasslands) were positively associated with presence of larval habitats, and were located relatively close to stream channels; whilst nonagricultural land covers (short shrubs, medium shrubs, tall shrubs, and bare soil around residences) were negatively associated with presence of larval habitats and were more distant from stream channels. Number of larval habitats declined exponentially with distance from streams. IKONOS imagery was not useful in direct detection of larval habitats because they were small and turbid (resembling bare soil), but was useful in localization of them through statistical associations with specific land covers. A supervised classification of land cover types in rural, lowland, western Kenya revealed a largely human-modified and fragmented landscape consisting of agricultural and domestic land uses. Within it, larval habitats of Anopheles vectors of human malaria were associated with certain land cover types, of largely agricultural origin, and close to streams. Knowledge of these associations can inform malaria control to gather information on potential larval habitats more efficiently than by field survey and can do so over large areas.