Evaluation, Monitoring And Early-warning On Total Dynamic Balance Of Cultivated Land

The cultivated land is the material base of mankind's existence and social-economic development. The ultimate strategic aim of Total Dynamic Balance Of Cultivated Land (TDBCL) is to ensure the security of food supplies. Our country has gained much achievement since 1996 when the strategy of TDBCL is putted forward. However, the quantity and quality of cultivated land descend quickly, the output of grain is reducing astonishingly, and the grain per unit area yield is also pacing up and down. In one word, it is not successful to achieve the final aim of TDBCL, namely not to satisfy people's constant need for food. In my opinion, the reasons for above is that we did not understand completely the genuine intension of TDBCL, the mechanism of implement is not perfect and the measure we taken is ineffective, with the exception of those, there is no suitable method to imitate and appraise the total farmland, no accurate early-warning mechanism.The article imitates and appraises TDBCL based on scientifically analysis of the concept of TDBCL, by the means of System Dynamics. Furthermore, with suitable monitoring indexes chosen, we can monitor the factors that influence TDBCL in the course of change of cultivated land in order to adopt effective measure to guard the emergence of disbalance of Total Cultivated Land in advance.This paper includes following contents mainly:(1)ForewordFirstly introducing some problem that have appeared in the course of cultivated land uses and emphasize the necessity and meaning to carry out TDBCL. Then, it refers to the domestic and international present research situation and the question of existence. Last, the purpose, content and thought of thesis are expounded.(2)Theory basis of carrying out TDBCLThis chapter includes two part.First part firstly introduces the definition of cultivated land. After explaining and comparing three different kind intensions of TDBCL,it brings forward the genuine purpose and intension .In second part, six theoretical basis about TDBCL are elaborated, including the land sustainable utilization theory, ecology economy theory, relation between man and land theory, intensive farming theory, scarce of land theory and dynamic equilibrium theory for plough.(3)Construction and evaluation of TDBCL systemBy analyzing the major influencing factors, it is made clear that the structurecharacteristic of the system is complicated. Then introduce the basic viewpoint and the merit of SD and the concrete course of building model: purpose, structure of system, main feedback return circuit, system flows, acquirement and procession of data, model inspection and sensitivity analysis, and finally carrying on the simulation and evaluation.(4)Monitoring and early-warning of TDBCLThis chapter includes three major sections. Firstly, monitoring and early warming indexes system were built by way of the completely analysis on the factor of TDBCL. Secondly, alert limit and the degree alarming are divided to the quota according to the fixed principle. Finally, according to the result of above system simulation, short-term and long-term early-warning have been carried on and suggestions to eliminate alert are put forward.(5)Conclusions and prospectsAt last, this thesis makes some conclusions from the construction and its application and pointes out the direction about the system and the contents for further amelioration.