Analysis Of Land Carrying Capacity Index Based On Improved Three-dimensional Ecological Footprint Model

As a key tool of land carrying capacity evaluation,ecology footprint model evaluated whether land was overloaded and the degree of overloading and remainder,and the route of land carrying capacity evaluation based on ecology footprint model was from people to land.This research probed into building the technical route of land carrying capacity evaluation and its result expression system.By clearing up the evolution process of ecology footprint model,the logic relation among three models and the limitation of its application was generalized,then Niccolucci's three-dimension model was improved.And base on the improved model,an index system of land carrying improved was built.Finally,taking Wenzhou city as an example,the condition of load carrying of Wenzhou City was judged.The main research conclusions were as follows:(1)By introducing the new indicator of biological productive land area into land carrying capacity evaluation,the pressure from natural resources consuming was accounted,and taking the whole area of biological productive land in one region as the land carrying capacity,the route of land carrying capacity evaluation based on ecology footprint model was from people to land,and by comparing the pressure with land carrying capacity,whether and how much the land was overloaded could be judged.The result reflected the influence imposed on land.Ecology footprint model was different from other method of land carrying capacity evaluation,it could only analyze the relationship between pressure and land carrying capacity comparatively.And Through an index system,relationship between the them could be depicted,and the result of land carrying capacity evaluation was expressed by a relative value.(2)Ecology footprint model evolved from one-dimension to two-dimension,then from two-dimension to three-dimension,and it was a process of extending and deepening.The one-dimension model was a conception,and by introducing the new indicator of biological productive land area,the ecological nature of land was exposed.The result of one-dimension model was just a value,and lack the spatial expression.The two-dimension model was based on the one-dimension model,and it introduced the biological capacity into the model and make the model be endowed with spatial scale.Based on the two-dimension model,and by introducing the new indicator of footprint depth into the three-dimension model,the degree of natural resources stock appropriation was expresses in the way of time.the three-dimension model was the deepening of the two-dimension model.(3)By extending the scale footprint depth from above 1 to above 0,the degree of natural resource flows and stocks appropriation could be analyzed in the same model.And this improvement remedied the defect of lacking three-dimension expression on ecological remainder.In the improved three-dimension model,whether in ecological remainder condition or deficit condition,ecology footprint could be presented in a cylinder,and ecological remainder or deficit could also be calculated conveniently.(4)In the improved three-dimension model,whether in ecological remainder condition or deficit condition,footprint depth is the result of comparison between land pressure and land carrying capacity,and this result reflected the relative relationship.Footprint depth was one way of result of land carrying capacity evaluation,and it presented whether the land was overloaded and the degree of overloading.The improved three-dimension model provided a theoretical basis for land carrying capacity index,and the extension of footprint depth scale is the key to land carrying capacity evaluating.Therefore,building an index system of land carrying capacity evaluation,and presenting the result of land carrying capacity evaluation in the form of footprint depth,were significant to rich land carrying capacity index system and improve the algorithm of index.(5)Based on the measurement of land's biological productive capacity,the result of ecological footprint in city hectare could explain the land's real biological productive capacity better,and could be compared among counties.Adding pollutant item into model,the accountant of nature resource was made more complete,and the result was closer to real value.(6)From 2000 to 2012,the ecological footprint per capita and ecological productive land area per capita of Wenzhou remained the same,but the ecological deficit was large,the value was 0.18 hm2 per capita,and footprint depth fluctuating in 2.It shows that ecological system ran large deficit,natural resource flows couldn't meet the demand of growing demand,and it need to consume large amount of natural resource stocks to support the current of development and consumption,and the high degree of natural resource stocks appropriation might influence the fairness on resource using between generations.From the perspective of index,the evaluation results showed that the food pressure index was greater than 1,and the arable land was in a state of overload.Water pressure index fluctuated in 1,and it was in a state of balance.Other land didn't overload.In whole,land in Wenzhou city was overloaded,and the main pressure was deprived from food consumption.