The variation in processes of river connectivity in the Jingjiang River
and its influencing factors from 1955-2015
Abstract
Rivers with good connectivity are conducive to the development of
various functions of rivers, such as hydrological regulation and
storage, water and sediment transport, and ecological environment. Human
activities have greatly reduced the sediment load in the Yangtze River
Basin and have changed the channel connectivity of the Jingjiang River.
In this paper, the analytic hierarchy process (AHP) is used to establish
the assessment model of channel connectivity based on the river
function. Then, combined with the flow, sediment and boundary data of
the main hydrological stations, we analyze the variation in processes of
the channel connectivity of the Jingjiang River from 1955 to 2015. The
results show that the change in process of channel connectivity of the
Jingjiang River is basically the same in different reaches. The value of
the comprehensive function of connectivity increases gradually with time
and is greater than 1.0 after 1990, indicating that the channel
connectivity has improved. Spatially, the Shashi-Jianli reach has the
best connectivity, while the Zhicheng-Shashi reach has the worst
connectivity. In addition, reservoir construction and river
straightening are the main factors affecting the channel connectivity of
the Jingjiang River system. Soil and water conservation changes the
channel connectivity by changing the water and sediment yield, which is
the secondary factor. The study means, method and achievement are
universally applicable to the evaluation of other channel connectivity.