Study On System Dynamics Modeling Of Desertification-salinization In Keriya Oasis

Oasis is core to human life and human production activities, focal point ofinteraction between human and nature, and it is also one of the landscapes that morevulnerable to the impact of desertification. In recent years, with increasing intensity ofhuman activities, the oasis was fueled by the development and utilization of naturalresources of fragile ecological environment, as a result, human-nature coupled systemand sustainable development of oasis eco-environment lost its balance, and broughtserious threat to human survival and development. The ecological environment ofKeriya oasis is very fragile, there are many eco-environmental problems, such asshortage of water resources, intensive groundwater exploitation,humans’constantlyexpanding production scale, and constant amplitude enhancing state of socialeconomic and cultural activities. Thus, contradiction between human and ecologicalenvironment is getting increasingly prominent, and the oasis ecological environmentisbeing gradually deteriorating, as a result, land desertification, salinization and othereco-environmental problems are restricting the social and economic sustainabledevelopment to a great extent. Therefore, using qualitative and quantitative methodsto explore the temporal and spatial dynamic evolution process of the oasis ecologicalenvironment and its natural and human driving factors is conductive to monitoringand decision making to prevent and control oasis’ eco-environmental degradation;The study also provides a scientific basis for socio-economic and eco-environmentsustainable development. Carry on a research in the field of contradiction betweenhuman and ecological environment, find out the reason for occurrence and respond toeach other, is useful to relieve the contradiction amongpopulation and land; Thestudyhas an applicable value in optimizing the relationship between human andnature.In this paper, by using statistical and field survey data, by means of PrincipalComponent Analysis, quantitative analysis are made on dynamic change of oasisdesertification and salinization and its natural and human driving factors; by using SDmodel, considering the study area as a big system, analyze its natural environmentand social economic subsystems, select corresponding indicators, determine therelationship between each factors and their influence on a large system evolution,built a dynamic evolution model, at last, put forward an optimization scheme for theoasis sustainable development;Select a typical study area in which problems ofdesertification and salinization is more prominent, such as Oytograk and Karke, withthe help of field and household survey method, two villages’ humanity factorsonecological and environmental changes are compared, finally,found out the differenceof two villages’ human factors which effects area’ eco-environment;Using systemdynamic and system simulation method to two areas’ desertification and salinization,optimization suggestions for eco-environment are put forward;The main results include:1. In Keriya oasis desertification-salinization process, human factors’ contributionrate is54.37%, the natural factors’ contribution rate is19.8%, combined effect ofboth natural and human factors’ contribution rate is18.87%. In the process of Keriyaoasis’ desertification-salinization development, influences of natural factors andnatural-human factors are in the low level, influence of human factors are in a higherlevel, in which population and agricultural population, total output of grain andlivestock quantity have the biggest effect, influence of population growth andstrengthen of humans’ agricultural activities on oasis ecological environment is themost obvious.2. Water resource, population, cultivated land and GDP coupled subsystem modelshows that in the next20years, cultivated land, population, and GDP wouldcontinuously increase, while the total amount of water resource, ecological water use,irrigation quota and per capita arable land would decrease; water resources control thewhole model that its influence on the various subsystems is the biggest. In the next20years, the total amount of water resources would reduce, occur shortage of waterresources that hardly meet the demand for irrigation, even could not get the minimumpoint of irrigation quota; Ecological water would also decrease because of occupationby other type of water usage, which seriously affect the oasis ecological environment, economic growth and development will be accomplished at the price of eco-environment destruction, sustainable development of oasis eco-environment andso-economics will be constrained.In order to achieve coordinated development of oasis economic and ecologicalenvironment, regulation and optimization scheme is established on the basis ofpromoting sustainable economic development without eco-environmental damage.;To practice the optimization scheme, it is essential to improve the efficiency of waterresource utilization, steady speed up economic development, at the same time, ensurescientific use of water resources, reduce blind reclamation and traditional floodingirrigation methods, efficient use of irrigation water, increase the investment onimprovement of irrigation water saving facilities, reduce per unit water depletion onagricultural production;3. Comparative analysis of human factors on desertification of Oytograk andsalinization of Karki are made by using field investigation、household survey andstatistical analyzing method, study shows that eco-environmental problems in Karkeis more serious than in Oytograk; In the oasis area of Oytograk, humans’unreasonable economic activities led to bordering oasis and desert together, andbrought direct negative effects to the ecological environment of the oasis; In Karke,over exploiting and utilizing groundwater for both drinking and irrigating,inappropriate agricultural irrigation method and outdated poor irrigation drainagesystem, aggravated salinization in the oasis area.