The Study On Ecological Health In The Shi Yang River Basin

The river is the material basis of human survival, social development, it is the material basis for terrestrial ecosystems and aquatic ecosystems, and it is exchange channals for energy flow, infermation.River is play an important ecological function. With the rapid growth of the population,as well as the intensifition of human industrial and agricultural activity, the river ecosystem is constantly subject to human disturbance and damage, mainly in the:unreasonable exploitation of water resources caused many rivers drying up or depletion; the destruction of forests and riparian vegetation cause soil erosion and blockage of river channals; a large number of pollutants discharged into a serious impact on the water quality river; traditional water consevancy project emphasizes economic effect and safety, cause natural river channals and non-continuous, hind the exchange of rivers and riparian systems, cause biodiversity loss, many ecological function and thus weaken or lose.By the area of the river basin as the ecological function of the river ecosystem change, river ecosystem change has a direct impact on the health of the watershed ecosystem. River is the origin and foundation of the development of human activitives. Since ancient times, civilized, and economically developed areas are located in the river basin. The watershed ecological and environmental conditions directly sffect human development. Therefore, how to maintain the service funtion of river, repair damaged systems, promate regional economic, social and environmental sustainable development has because a global problem. Environmental management in recent years has become an important goal to retore and build a healthy watershed ecosystems.River ecosystems always effected by natural and human factors. Watershed land use status is not only reflected the local farming culture, but also expressed the ecological function of river. Land use is a kind of human activities based on land resources, and it is overall performance of the material flow and energy interactions between the human and natural environments, it is the result of huaman activities. The manner and extent of human land use directly the function of the river ecosystem, changes in the river ecosystem is directly reflected in the way of watershed land use, both affect each other,mutual restraint. From the point of view of the ecosystem health, evaluates the characteristics of spatial distribution and coordination has obvious practial significance. The landuse structure not only refect the state of the earth’s surface landscape, become the most prominent of the landscape of the earth surface system flag, but aslo became a re-establishment of the land-use-ecological to produce balanced.In this paper,90township-level administrative units of ShiYang-River Basin are the study objects. From the point of landuse, analysised the health status of the ShiYang River Basin, investigated the spatial distribution characterisitics and the coordination of ecosystem health facters. Main content and results, including the following aspects:(1) Three health facters has significant spatial concentration. Stress facter has the highest number in spatial concentration, state facter and response factor is lower.(2) Three health facters has obvious cold spots and hot spots. Amony the facters: the hot spot of state factor is in the upstream of the Qilian Mountains, cold spot is in the northeast of WuWei basin in middlestream and the west of MinQin basin in downstream; the hot spot of state factor is in WuWei Basin in middlestream and south of MinQin Basin in dowmstream, the cold spot is in the south of Qilian Mountains; the hot spot of response factor is in the southwest of Qilian Mountains, and the cold spot is in MinQin Basin.(3) From the maps department of ecological factors, the differences are much more lage in different levels for each factor. Overall, the maps department of state factor and response factor is similar. With the increase of facter values, the saptial distribution gradually from north to south. The stress factor is more evenly distributed in space. The mean value of stress factor is low in the entire watershed. The highest stress factor is in WuWei Basin in middlestream.(4) The coordination of health factors refflects the stability of ecosystem. Study has shown that19units of the all administrative units in ShiYang River have the low coordintion value, accounting for20.22%of the totall number;53units of the all administrative units in ShiYang River have the general coordination value, accounting for58.51%of the totall number;22units of the all administrative units in ShiYang River have the higher coordination value, accounting for23.4%of the totall number. Coordination of ecological health factor decreased from upstream to downstream.