Vulnerability Evaluation And Its Sustainable Utilization Of Eco-water Resource System In Hunan Province

Vulnerability of water resource such as seasonal droughts is an important problem in Hunan province in spite of its enough precipitation as a humid subtropical monsoon climate zone. Moreover, vulnerability of eco-water resource system is affected severely by global climate change and the background of virtual strategy. Therefore, evaluation of vulnerability of eco-water resource system and its sustainable exploitation and utilization in Hunan province is a significant work. A new concept of vulnerability on eco-water resource system in southern humid areas used system method was provided and the vulnerability was calculated. Countermeasures of sustainable utilization of water resource were analyzed used cycle economy theory and virtual water strategy thought.1. There are many characteristics about water resource exploitation and utilization in Hunan province such as low level of water resource exploitation, increasing of the total used water, constantly changing of the structure of water resource utilization, significant regional difference and so on. And there also exist some significant problems such as water shortage (seasonal drought), water disaster(floods), water pollution and degradation of water environment(soil and water erosion).2. Causes of vulnerability of water resource system were analyzed from the point of view climate, topography, soil and vegetation, human activities and economic development. Vulnerability of eco-water resource system in Hunan province mainly represents in seasonal drought, periodic water shortages in some cities, floods and soil and water erosion and so on. An evaluation index system on vulnerability of eco-water resource system in Hunan province which including 12 concrete indices was constructed. The vulnerability scores of eco-water resource system were calculated in 85 counties of Hunan province using fuzzy matter-element analysis method. The results show that the eco-water resource system is somehow fragile in Hunan province, but there have no significant difference in different regions. The spatial distribution pattern of water resource vulnerability is that the vulnerability in the east(south) regions is higher than that in the west(north) regions. An evaluation index system which include 8 concrete indices was constructed and the method of GIS and RS were used to evaluate the vulnerability of eco-water resource system in Hengyang basin.3. Datum of air temperature and precipitation during 1960-2007 in Hunan province were analyzed used the method of moving average, climate trend rate and polynomial fitting and so on. The results show that annual average temperature in Hunan keep upward trend overall in past 48 years, the climate trend rate is 0.106℃/10a, and there are a fastest increasing speed in recent 8 years, the climate trend rate reach to 1.086℃/10a. The increasing trend of annual average temperature is faster in spring and winter than that of in summer and autumn. There have a significant increasing trend of precipitation in recent 48 year, the climate trend rate is 30.8 mm/10a. There are different increasing trend in different seasons in which there is a fastest increasing trend in summer. Climate change have affected the vulnerability of water resource system. The vulnerability of eco-water resource system cuts down from view on the change of precipitation and evaporation. And the vulnerability of ecological water resource system rise from view on the extreme climate events such as rainstorm.4. In order to measure change of the vulnerability of eco-water resource system in Hunan under the background of virtual water strategy, an evaluation index system was constructed and the vulnerability change of eco-water resource system in Hunan was calculated. The results show that the vulnerability of eco-water resource system in Hunan will increase under the background of virtual water strategy. Moreover, the vulnerability change in all-around hilly areas is more notable than that of central regions such as Changsha, Xiangtan, Loudi and Hengyang.5. The principles of reduce, reuse and recycling in circular economy was used to investigate the sustainable exploitation and utilization of water resources. Author believes that paddy field water-saving irrigation is an important way of water resource reduction in agriculture field, and improving water resource cycling rate of water-intensive industries such as petroleum, chemical, electric power, steel, metallurgy, textile and papermaking and so on is important in industry field. Rainwater utilization reflects the principle of reuse and recycling in water resource cycling economy. There are 3 kinds of patterns of rainwater utilization in countryside:First, strengthening rainwater utilization on the spot so as to set up the eco-barrier of the economy and social development; Second, actively popularizing rainwater collecting and storing in the courtyard to develop the courtyard economy; Third, properly constructing small-scaled rainwater collecting and irrigation projects to enhance water productivity of agricultural production. There also have 3 kinds of patterns of rainwater utilization in cities:First, collecting rainwater mainly from roofs use to urban greening. Second, collecting rainwater mainly from residential ground use to maintain water ecological environment. Third, collecting rainwater mainly from road surface use to some public water use in cities. Flood resource utilization is also an important way of water resource sustainable utilization in Hunan province, mainly approach include:Improving water saving of visible and invisible reservoir, implementing river remediation, changing the idea of flood prevention, increasing the level of monitoring and forecasting meteorological and hydrological elements, strengthening research of flood resource utilization, planning land use and so on.6. In order to measure regional affections of virtual strategy, the concept of Advantage Value of Regional Virtual Water Strategy(AVRVWS) is put forward. Then an assessment index system including 12 indices is established, and the grades of AVRVWS of 31 provinces in china are calculated. The results show that the grades of AVRVWS in china have notable regional discrepancy, most of the provinces in china have the medium grades of AVRVWS, the grades in east china are higher than that of the west, at the same the grades in the south and north is higher than that of the central. The score of AVRVWS in Hunan is higher than many of other provinces, it tells us that the development of eco-social and water resource exploitation and utilization will severely affected under the background of virtual water strategy.An index of water resource gift was constructed by which three senior function regional types, namely virtual water import region, virtual water output region and virtual water equilibrium region were divided. Using the method of classification matrix integrated by the commercial index of primary water-density agricultural product and non-agricultural water demand pressure index, several junior function regional types, namely typical virtual water import (output)area, inner optimization area, potential virtual water import (output)area, and composite type area,were divided according to the various combinations of the above 2 indices. The results show that Hunan province is a typical virtual water export region, so, in order to develop its economic and ensure agricultural products and water resource safety in China, Hunan should output more water-density products such as food under the background of virtual water strategy.Spatial distribution status of agricultural production in China was analyzed using the index of per capita main agricultural and animal production of agricultural population. It is found that north China's agricultural and animal production is heavier than that of south China. In order to probe the ideal spatial distribution model of agricultural and animal production under the background of virtual water strategy, a concept of regional agricultural production predominant was put forward, the regional agricultural production predominant in each province was calculated. The regional agricultural production predominant shows a characteristic of the north, west and south is heavier than the center. An index of agricultural production distribution adjustment was built and calculated, it is found that Hunan should contribute more to agricultural products and water resource safety in China. In order to diagnose the internal spatial structure of agricultural production in Hunan province, contrast the scores of per capita virtual water embedded in agricultural and animal products and agricultural production dominance under the background of virtual water strategy in each region. It is found that there is a big difference between the layout status and the ideal layout of agricultural production under the background of virtual water strategy. Layout status of agricultural production in Changsha, Zhuzhou, Xiangtan and Yueyang exceed the ideal layout density, and layout status of agricultural production in Xiangxi, Zhangjiajie, Huaihua and Yongzhou doesn't reach the ideal layout density.Compare the water used in industry to water resource in each region in Hunan province, it is found that distribution of industry doesn't match to the distribution of water resource in Hunan province. Industry layout status in Changsha, Xiangtan, Zhuzhou, Hengyang and Chenzhou exceed the ideal layout density, and the industry layout density in Zhangjiajie, Yongzhou, Xiangxi, Yueyang, Yiyang, Huaihua and Shaoyang doesn't reach the ideal layout density.In order to realize sustainable exploitation and utilization of water resource in Hunan province under the background of virtual strategy, some countermeasures were put forward. Macro-level, we should change the concept of water resource development, improve water use efficiency, strengthen water resources protection and water security resource researches under the background of virtual strategy. Micro-level, we should improve the use efficiency of green water, distribute water-density agriculture rationally, optimize the distribution of water-density industry and prevent over-exploitation of water resources and so on.