Evaluation method of rain–flood resource utilization availability and its application in the Hanjiang River Basin

Rain–flood utilization refers to transforming some amount of rain or floodwater into ordinary water resources without decreasing flood control standards or damaging the ecological environment of rivers, which has gained widespread attention as it can alleviate water shortages and gain benefits. This paper put forward the evaluation method of rain–flood utilization availability at the distributed watershed scale. Based on the water node, some indices of rain–flood utilization availability were defined. Then the evaluation method and calculation process were unified. Finally, the status and potential of the rain–flood utilization of Hanjiang River Basin were analyzed. The results indicated that the rain–flood resource in the whole basin is 48.9 billion m3, the outflow is 29.9 billion m3, and the actual utilization is about 19.0 billion m3. The current available rain–flood amount and rain–flood utilization potential are 27.7 billion m3 and 11.0 billion m3, and the rain–flood utilization rate is 49.4%. Limited by regulation ability and the rain–flood resources, current rain–flood utilization has a clear threshold range. The potential utilization objects are mainly for a rainfall process of about two to ten years return period. The application in Hanjiang River Basin offers some practical information for assessing rain–flood utilization scientifically, and the premise for effectively guiding and formulating adaptive countermeasures for water resources management.

Assessment of the feasibility of floodwater utilization in North-East China

In order to alleviate the water supply–demand problem, a flood resource utilization strategy is proposed, called ‘Flood Utilization’. The strategy focuses on building large-scale water conservancy facilities and improving management measures. This paper presents the probability analysis of floodwater utilization in a confluence area, where a tributary joins a main river. Baicheng is used as the study area, where the Taoer River joins the Nenjiang River. After a large number of analyses, the main results and conclusions are as follows: First, the upper limit of available floodwater corresponds to the Taoer River's flood with a 5% probability of occurrence. Secondly, there are compensation characteristics between the two rivers which mean that the Nenjiang River can supply water to the Taoer River area. The analysis of monthly runoff, shows that there are compensation characteristics in 50.9% of the data period. The compensation rates (CRs) for the months from June to October are 0.2, 0.27, 0.25, 0.27, and 0.2, respectively. Thirdly, the differences in the runoff characteristics show that it is suitable for floodwater utilization. Finally, it is proposed that floodwater utilization measures are based on local conditions, such as the regional water storage characteristics and the runoff characteristics of the two rivers, and should be applied for different periods.