Assessment Of Water Ecological Security Based On The Third Level Aquatic Ecoregion Of Liao River Basin

Aquatic ecoregion of watershed can offer an important foundation for thelong-term planning and integrated management. Water ecological security assessmenthas a practical significance and practical value to the water quality objectivemanagement and aquatic ecosystems management. According to the natural featuresand social attributes of the spatial differentiation of ecological security pattern inbasins at small and medium scale, this thesis calculates water ecological securitycomprehensive index of each ecoregion by using the watershed ecological securityevaluation model which takes Liao River Basin of Liaoning province as the researchobject on the basis of the third level aquatic ecoregion and each of the third levelaquatic ecoregion as basic evaluation units. Finally, ecological security classificationof Liao River can be obtained. Thesis research content and research outcome asfollow:1. This research constructs technical framework of the comprehensive indexevaluation by taking the driving force of aquatic ecological health-socio-economicpressure-aquatic ecological service functions as a core. Social and economic pressuresubsystem screens out13evaluation indexes and builds the water ecological securityevaluation system according to the pressure-state-response model （PSR） whichincludes pressure, state and response, considering6element layers consisted ofsocio-economic pressure, environmental pressure, urban development indicators,development of resources and environment indicators, investment indicators,governance indicators.2. This research establishes social and economic pressure subsystem evaluationindex database， then investigates and collects watershed ecological securityevaluation data, standardized in accordance with a unified data framework, andassigns weights, calculates social economic safety index of each ecoregion throughcombining aquatic ecological health and aquatic ecological service functions, thisresearch evaluates water ecological security state of each ecoregion by using comprehensive index.3. According to the comprehensive ecological security index, the degree ofecological security is divided into five degrees, namely, specially insecurity,insecurity, basically security, security and specially security. The securityclassification was respectively Ⅴ、Ⅳ、Ⅲ、Ⅱ、Ⅰ grade,Water ecological securityindex are0-0.19,0.20-0.39,0.40-0.59,0.60-0.79and greater than or equal to0.80,respectively.4. According to comprehensive ecological security index of the90ecoregions ofLiao River basin, compared with the water ecological security classification standard,the results indicated that: the water ecological security status classification of themost the third level aquatic ecoregions gives priority to insecurity, basically security.The security classification was respectively Ⅳ, Ⅲgrade. Only a small part of theecoregions belongs to class Ⅱ, security. There are43ecoregions belonging toinsecurity,37ecoregions belonging to basically security,10ecoregions belonging tosecurity accounting for47.78%,41.11%,11.11%of total, respectively.