Natural reasons why black-necked cranes like to go to Xianghe for winter.

Xianghe, located in three provinces, has convenient transportation and beautiful scenery and belongs to the tropical climate of North Asia. It is neither cold in winter nor hot in summer, which is convenient for winter.

Xianghe is a first-class tributary of Danjiang River (in Shangnan County, Shaanxi Province), which flows through Xianghe Town with a catchment area of 232 square kilometers. Consists of three tributaries. Among the tributaries, Lengshui River (Liangcha River) is the longest and has the largest amount of water, which should be regarded as the mainstream of Xiangjiang River. The other two tributaries are Xiaoxiang River and Bohe River (Hot Water River). The catchment area is 62.5 square kilometers and 52.8 square kilometers respectively. Lengshui River originates from Chenjiagou, Liangjiafen Township, and its source is limestone mountain area with karst caves. All the precipitation seeps into the ground and becomes an undercurrent, so there is more than 4 kilometers of unstable water in Heyuan. The rivers below Nianziping and Geping in Liangjiafen Township in this area began to flow regularly, and the total drop from here to the estuary was about 875 meters. According to the topography, geomorphological characteristics and the conditions of development and utilization of hydraulic resources, the whole river can be divided into three sections: the first section is the valley from the watershed to the upper reaches of Huazitan. The line length of this section is 1 1 km, the river slope is relatively gentle (average 1/50), the valley is wide, and there are many floodplains, so it is the main farmland distribution area. The second is the section from Huazitan to Duiwoping. This section is a canyon. It is about 9 kilometers long and has a drop of 280 meters. The river gorge is deep and steep, especially there are several waterfalls from Huazitan to Yangjiaozhai, which are very spectacular. The third is the section from Woping to Hekou. This 26-kilometer-long canyon is generally 30-50 meters wide. In some places, there are Nana Ogawa Road and many bends.