Studies On The Origin Of Flooding-drought Disasters And Establishment Of Water Circulation Safety System In Hunan Province

The water situation is the biggest issue for Hunan province, and flooding is the most severe disaster in the province. Nowadays, either the flooding or drought creates the biggest obstacles for Hunan's social and economical development. In the past few years, the occurrence of flooding and droughts tended to be in ever-increasing trend, especially in the hilly areas. It is characterized by quick occurrence, many deaths and great loss. Based on the problem of ecological safety in Hunan's water system, with the purpose of surveying the causes of flooding and drought, the author made some explorations on how to solve the ecological safety problems in the water system of Hunan province, through the method of data collection, investigation and comprehensive analysis approach. The theories of ecology, bionics, system theory and recycle theory and other correlative sciences are applied in this paper as new theoretical basis for controlling the disaster. In practice, some creative designs for management of water and preventing disasters were proposed, which aimed to establish the water ecological safety system. The results were as follows:1. Design viewpoint of bionic water system. Based on the principle that the construction determines the function, the study initiatively proposed the design viewpoint of bionic water system in which the construction of transportation system and micro living cell in plant leaves were sampled to design the macro water system, it is held that the transportation system of plant leaves—stem and the organism of alive cell—vacuole is the extension of the water system on the land and concluded that the design of macro—water—system on the land can follow the design of micro—water-system in the plant.2. Viewpoint of small circulation of matters. Based on the law of matter motion of living cell in plant, that is, the circulation law of cytoplast circling around vacuole, this paper proposed that the circulation of matters in a relative independent scope is beneficial to the establishment and maintenance of a good ecosystem. Furthermore, the viewpoint is used as theoretical background to the application of the design of regional water system.3. The decentralized storage mode of regulating water in Hunan mountainous areas. A flood-control model of graded interception and decentralized storage mode, or called the model of "melon pullulated on stem" or "fruit produced on branch" is put forward in the study, utilizing the theory of bionic water system design and small circulation of matter, therefore, the storage of macro- water can be evenly implemented so as to safeguard the circulation.4. Mountainous, instant reservoir of foundation controlling flooding system. According to the trend of ever-increasing occurrence of flooding disaster in Hunan mountainous region, the concepts of instant reservoir and the establishment of instant flooding control system are initiatively put forward in this paper. Instant reservoir is the place where water can be stored in very short time, it contains three types: terraced field, terraced hole and terraced dam. Instant reservoir is used to delay the time of flooding flow, to reduce its flow, change the runoff on the surface into underground, then minimize the influence on its lower reaches, other ecological service functions of instant reservoir are also discussed in this research.5. Stealthy water-storage system in urban greenbelt. From the perspective of saving and maximizing the utilization rates, the stealthy water- storage system should be established in urban greenbelt, which could accumulate rainy water from roof, square and road then filter through soil and store underground or in the garden, therefore, both the quantity of rainy water in the city and the cost of maintaining greening land are decreased.Controlling flooding and drought disaster is the top priority of Hunan Mountainous region. The model of storing water, graded interception and decentralized water storage, building reservoir extensively, establishing the instant reservoir flooding control system, can decrease the runoff on the surface and soil loss on the slope which will deposit in lower reaches, by this means the ability to prevent flooding and drought disaster, especially in Hunan province, will be greatly strengthened.