Study On Carrying Capacity Evaluation And Dynamic Simulation Of Sustainable Utilization Of Water And Land Resources In Sanjiang Plain

Sanjiang Plain has flat terrain, fertile soil, fitting climate and abundant water which are appropriate for agricultural development. After years of development and construction, Sanjiang Plain has become the important commodity grain production base of China and performs a significant function on ensuring the national food security. However, under the interference of high strength human activities of late years, a lot of unreasonable phenomena existed in the development and utilization of water and land resources, such as low degree of water resources development and utilization, unreasonable water supply structure and low utilization factors of water and land resources, have serious threats to the sustainable utilization of water and land resources and sustainable development of social economy in Sanjiang Plain.Aiming at the problems existed in the development and utilization of water and land resources in Sanjiang Plain, the related issues of sustainable utilization of water and land resources in Sanjiang Plain were studied by taking sustainable development as the guiding ideology and sustainable utilization of water and land resources as the target. The countermeasures for continually utilizing water and land in Sanjiang Plain proposed on the basis of the study can provide theory support and policy guidance of sustainable and efficient utilization of regional water and land resources.The main contents and findings of the study are as follows.1. Analysis of spatial matching pattern of water and land resources in Sanjiang PlainBy analyzing the composition and utilization of water and land resources in Sanjiang Plain, the state of water and land resources in the area was that land resources were abundant but water resources were deficient, not used to be said that "water and land resources were both rich". Based on the analysis, measuring model for water and land resources matching was established from the standpoints of the matching between water availability and land resources. Then the matching coefficient of water and land resources in Sanjiang Plain was calculated and the matching degree of the two resources in the area was partitioned spatially. The results indicated that the matching degree of the total water and land resources in Sanjiang Plain was lower than the national average level, in addition, Qitaihe had the worst matching degree but Hegang and Muling had the best in the regionalization of Sanjiang Plain. The judgment of matching pattern of water and land resources can provide references for drawing up a reasonable plan to exploit regional water resources and to reclaim lands. 2. The regional variation and spatial combination of water and land resources carrying capacity in Sanjiang Plain.From water and land resources carrying capacity respectively, projection pursuit model optimized by particle swarm optimization algorithm was adopted to comprehensively evaluate water and land resources carrying capacity and to analyze its regional variation in Sanjiang Plain based on establishing evaluation index system and criterion. Then the water and land resources carrying capacity level in the area was organized spatially. According to the spatial combination characteristics of water and land resources carrying capacity, the whole area could be divided into four types of zones:Shuangyashan and Muling belonged to water and land resources non-pressure zone, Qitaihe belonged to water resources non-pressure and land resources balanced zone, Yilan County belonged to water resources balanced and land resources non-pressure zone, Hegang, Jiamusi and Jixi belonged to water and land resources balanced zone. On the basis of the spatial combination state of regional water and land resources carrying capacity, scientific and reasonable development and utilization plan for the two resources can be made to guarantee an efficient and sustainable utilization for them and a continual supplying ability for socioeconomic development and environment protection.3. Constructing system dynamics simulation model of sustainable utilization of water and land resources in Jiamusi.Due to bad matching pattern and low carrying capacity of water and land resources in Jiamusi, the city was taking as study area. On condition of the analysis of system structure, operating mechanism and causal feedback relations of water and land resources, system dynamics simulation model of sustainable utilization of water and land resources was constructed and tested by ascertaining model boundary, analyzing system causal relations, confirming quantitative relations between variables and verifying model validity. The constructing and testing results indicated that the model had eight submodules and ninety six variables; the model structure was reasonable and well reflected the operation characteristics of true system quantitatively. At the same time, nine sensitivity parameters which greatly influenced model operation results were screened. The follow-up schematic design for sustainable utilization of water and land resources can be realized by adjusting the sensitivity parameters.4. Dynamic simulation and optimization of sustainable utilization scheme of water and land resources in Jiamusi.According to the dynamic simulation of sustainable utilization of two resources continued . from current situation, serious imbalance of water resources supply and demand in Jiamusi in future was the main restriction factor that restricted the regional industrial and agricultural production and growth of the national economic. Thus, in order to solve the problem, five sustainable utilization schemes were designed, and then simulated dynamically and evaluated. The simulation and evaluation results indicated that future water resources still restricted socioeconomic development under natural continuation, increase income and reduce expenditure schemes; the development and utilization degree of water and land resources, industrial and agricultural production scale and socioeconomic development speed under integrated scheme were the highest among the five schemes, however, the scheme would cause excessive mining and serious waste of water resources which were against resources sustainable utilization; coordinate scheme could not only resolve the contradiction between water supply and demand in Jiamusi but also speed up socioeconomic development and realize the target of sustainable utilization simultaneously. Therefore the coordinate scheme is the best one for Jiamusi which can provide theoretical basis for policy adjustment of sustainable utilization of the two resources in Jiamusi and Sanjiang Plain.5. Sustainable utilization countermeasure of water and land resources in Sanjiang Plain.On the basis of the analysis of quantity, development and utilization state, spatial matching and carrying capacity of water and land resources in Sanjiang Plain, the sustainable utilization countermeasure of the two resources in the whole area was proposed by using the optimal strategy in Jiamusi as a reference. The countermeasure can provide policy supports for sustainable and efficient utilization of water and land resources in Sanjiang Plain.In conclusion, under the researches of development and utilization state, spatial matching and carrying capacity spatial combination of water and land resources in Sanjiang Plain, the development and utilization degree, coordinated growth ability and supporting capacity to socioeconomic development of the two resources were realized roundly. Meanwhile, constructing system dynamics simulation model, designing and optimizing schemes for sustainable utilization of water and land resources in Jiamusi could offer references to sustainable utilization policies adjustment of the two resources and provide theoretical direction for sustainable utilization mode of the two resources and sustainable development of social economics in Sanjiang Plain.