Study On Effect Of Oasis Water And Land Resources Development And Environment In Kaidu-Kongque River Basin

Land utilization interacts with the water resource, and its type and extend of function depends on the synthetic effect of both the natural environment and the human factors in the field. Natural environment is the basic context of the water and land resource of the zone. To some degrees, the natural environment holds the domination. Human factors, take the society, economy, technology and policy for example, are the guiding factors, and play the role of leading to some extend. The basin of Kaidu-Kongque river located in the hinterland of Xinjiang Uigur autonomy region and the foot of south Tian mountain, and is a part of Tarim basin. Since the 1950s, because of its large-scale development of land and water resources, leading to the regional ecological environment of great change.This paper builds up the database of the water and land resources utilization of Kaidu-Kongque River basin, on the base of completing the research National Nature fund projects of the water and land resource development impact on environmental ecological. It involves the water resource investigation throughout the whole basin, the ecologic environmental investigation relating to water, the remote sensing investigation of the Salinization and the achievement of the national"973"special preparatory research, and selects the remote sensing impression as the major source of the information, making use of the GIS space analytical technology, quantitatively anatomizes the process and rate of the land utilization/coverage conversion in the year of 1973, 1990, 2000 and the ability of the nature and the social economy affection, calculates the effect of the land utilization/coverage conversion on the water reources, water quality, the ecological effects of groundwater, the ecological effects of water and salt pattern and the distribution of vegetation.with the technology of remote sensing, ecohydrologic analytical method. Its chief content is as follows:(1) In the past 30 years, the Oasis land-use conditions of Kaidu-Kongque River Basin have remarkable change, such as the large increase in farmland and natural vegetation gradually decrease. The exponent of Land use grade indicates that the exponent of land-use land has always a degree of upgrading, in a period of development, and the development is fast the latter than the prophase. The trend of integrative land-use change show that the study area is in a quasi-state balance, and has two-way conversion momentum in 1973-1990; the study area in an unbalanced state in the years 1990-2000, for each category of speaking, the imbalances are mainly one-way conversion. And its main driving force comes from the two factors such as population growth, socio-economic development.(2) From the landscape pattern analysis, in past 30 years, the acreage of infield is rapidly enlarged and become to the largest oasis landscape. The number of patch is increase and its area is reducing for natural vegetation, the aggregation degree is significantly reduced. On the contrary, farmland showed the opposite trend, which that the landscapes of natural vegetation fall to piece; from the index of patch density reflects that the various types of landscape present the trend of fragmentation. The patch numbers of rural and urban continue to increase, its show that the region's population continued to increase. While the increase in population and economic growth, lead to the area of natural vegetation are strength developed. The simulation of Markov model also shows that the land change is main effect by people in Yanqi Basin in the future period.(3) The developments of oasis agricultural are profound influence on the basin's rivers and lakes environment. Research shows that the water quality of Bosten Lake Kongque river affected by agricultural irrigation, drainage salt water. The concentration of TP, TN and NH4 has increased in the river flows through agricultural areas. The development of the agricultural oasis greatly resulted in the area of application of chemicals. Irrational use of fertilizers, and the way led to a lower utilization of fertilizers, fertilizers is serious loss of with the irrigation water. A lot of water has led to the rapid decline to lake water level, the Bosten Lake have also become a brackish lake from freshwater lake because of agricultural drainage salt drainage, at the same time also caused wetlands reed output reduction and the loss of its function.(4) Based on the principle of Geo-statistics show that the oasis agricultural development of water and land resources have significantly affected groundwater in the past decades. On the semi-variogram function analysis showed that the groundwater random variability on the small-scale is replaced by the structural variation on the larger scale space with the agricultural drainage and irrigation groundwater exploitation. And groundwater salinity in the small-scale structural variation has been totally larger scale replaced by the random variation. After decades of irrigation drainage, the area of low salinity is increased and high salinity zoning area be reduced in the Yanqi Basin and the groundwater level decreased. The groundwater level of the temporal and spatial variation in depth greater extent depends on the production of human activities on the exploitation of underground water in the edge of Yanqi Basin. But to the area of human activities in the most concentrated centre of the oasis, the groundwater level is not significantly decrease. At the same time, the groundwater level decreased more serious for the regional of better the quality. Through the study of groundwater Spatial variability of TDS analysis showed that groundwater salinization in the direction of increasing development.(5) The research of salt-water evolution and vegetation distribution show that the bio-diversity depends on the effects of water and salt dual-gradient in the interior oasis irrigation area. The ecosystem are worsen due to slat continued accumulation to Bosten lakefront in Yanqi Basin. The research on the relation of species diversity and groundwater level on the edge of the river that species diversity reduce along with the increasing depth of groundwater less than 1.5 m in depth, depth greater than 2 m, species diversity increased as the groundwater level up in the region groundwater depth less than 3 m. but in the depth between 3-5m, due to the lack of data, further study to determine the best groundwater level for water control in the oasis irrigation area.