Lake Tana is the largest lake in Ethiopia, and it is the origin of the Blue Nile River (Abay). It harbors winter birds and globally threatened bird species. The wetlands in the area are nesting places of Wattled and Black Crowned Cranes. The wetlands are being converted into different land uses; however, how much area of these wetlands is being converted into different land uses is not known yet. This study therefore investigated the land-use change of the main nesting place of cranes in Chimba and Yiganda wetlands, in the Lake Tana Biosphere Reserve area. The land-use cover change was estimated by analyzing satellite images (Landsat images-ETM + from USGS website) from 1986 to 2016. The result showed that in 1986, the Chimba wetland area covered a total of 15,134,974.6 m², which is 7.4% of the total area of Chimba watershed (203,312,456.3 m²). Other land use land cover types in the study area namely cultivated land covered 31.9%; farm village 2.1%, natural forest 41.3% and grass land 17.3%. However, the land-use land cover change (LULC) in 2016 showed that the wetland coverage declined to 10,708,894 m². About 27.6% of the wetland is converted completely into cultivated land. Yiganda watershed covered about 28,075,506 m² in 1986 of which 5,351,641.7 m² was wetland area; however, the wetland area has shrunk to 4,668,162.9 m². When it is compared to the wetland change in 1986 to 2016, Chimba wetland was more affected in which 663.5 ha was changed into another land-use land cover; whereas in Yiganda it was about 137.2 ha changed during the last 30 years. When the exponential trend change of LULC is observed, it could affect crane ecology by reducing the habitat availability for cranes nesting spaces.

塔纳湖是埃塞俄比亚最大的湖泊，它是青尼罗河（Abay）的起源。它拥有冬季鸟类和全球受威胁鸟类。该地区的湿地是Wattled和Black Crown起重机的筑巢地。湿地正在转变为不同的土地用途；然而，目前尚不清楚这些湿地中有多少被转化为不同的土地用途。因此，本研究调查了塔纳湖生物圈保护区的钦巴和伊干达湿地的起重机主要筑巢地的土地利用变化。通过分析1986年至2016年的卫星图像（USGS网站上的Landsat images-ETM +），估算了土地利用的变化。结果显示，1986年，钦巴湿地面积总计为15134974.6 m ²，占钦巴流域总面积（203,312,456.3 m ²）的7.4％。研究区其他土地利用类型的土地覆盖类型是耕地，占31.9％；农场村庄占2.1％，天然林占41.3％，草地占17.3％。然而，2016年的土地利用土地覆被变化（LULC）显示，湿地的覆被减少至10,708,894 m ²。大约27.6％的湿地被完全转化为耕地。1986年，依干达流域面积约28,075,506 m ²，其中湿地面积5,351,641.7 m ²；然而，湿地面积已缩小至4,668,162.9 m ²。与1986年至2016年的湿地变化相比，钦巴湿地受到的影响更大，将663.5公顷的土地改为了另一片土地利用的土地覆盖物。在过去的30年中，Yiganda改变了约137.2公顷。当观察到LULC的指数趋势变化时，它可能会通过减少起重机嵌套空间的栖息地可用性而影响起重机生态。