Study On Model And Evaluation Of Agricultural Water Resources Carrying Capacity

Hebei Province is one of the provinces which are extreme shortage of water resources in China.Because of the low amount of water resources for per capita and severe shortage of water, the social and economic developments have been restricted badly in Hebei province. Agricultural production is a dominical part in Hebei province, so ensuring the proper development of it is one of the essences for keeping a sustainable economic development. The agricultural water resources is one of the basic resources for agricultural development. It is the requirement for agricultures. Meanwhile, its capacity is also a restriction for sustainable agricultural development. According to the results of water resources evaluation, the average agricultural water resources were 43.3 billion cubic meters, in addition, surface and underground water were about 14.2 billion cubic meters used for irrigation, and 29.1 billion cubic meters from soil water resources.At present,the Hebei province is facing with the serious waste of the water. Hence, research for developing and utilizing agricultural water resources rationally will hold great significance for its agricultural development.In order to sustainable healthy development of the society, the water resources,especially agricultural water resources should be managed, utilized and protected rationally, during the social development.In this paper, we will elaborate the definition for the agricultural water resources carrying capacity:(1) Basing on the overseas and domestic research status for agricultural water resources, its definition will be first analyzed in this paper, which definition is analyzed that the water resources that can be used for agricultural production and keeping balance of environment. It includes surface water resources and underground water resources in artificial water cycle system provided by the water supply project, and soil water resources in natural water cycle system. The agricultural production will be carried and the balance of the environment will be keeped by surface water resources and the underground water resources irrigated into the soil.That is mean,agricultural water resources includes irrigation under the condition of irrigation and soil water resources.(2)The meaning of the agricultural water resources carrying capacity is illuminated in this paper. It is supported by those three kinds of the water resources. Under the conditions of present social economy and technology, agricultural can be continuously supported and the well agricultural development and environmental stability of the Hebei province will be keeped. Agricultural production and environment will be clarified to the main target for the agricultural water resources carrying capacity.(3)The computing method for the surface water resources, the underground water resources and the soil water resources has been introduced in this paper. According to that, the amount of agricultural water resource in Baoding are figured out, which was the example in this paper. The amount of agricultural water resources in Baoding as the example was 5.89 billion cubic meters,frequency(50%) of agricultural water resources was 5.43 billion cubic meters,requency(75%) of agricultural water resources was 4.35 billion cubic meters.(4)According to the connotation and conception of the agricultural water resources carrying capacity, the multi-objective optimization models are established. In the model, the maximum agricultural output, the maximum total grain yield, and the maximum agricultural and ecological water using are taken as the goals, the crop structure, the valume of water resources, the valume of soil water resources and etc. are taken as the constraint condition in the model, then these single-objective model will be a comprehensive objective model by weighted method, and the comprehensive model are optimized by linear programming.(5)The agricultural water resources carrying capacity calculation model has been used to calculate the carrying capacity of agricultural water of Baoding city in Hebei province. Two plan level and two rain frequency had been considered in this paper, and 2 cases(general and efficient) had been established, the agricultural output, total grain yield, the utilization of agricultural water resources will be calculated and analyzed in the paper.(6)Based on the feature and the influencing factor for the agricultural water resources carrying capacity, water supply index, water use index, management index and efficiency index of agricultural water resources are selected for proper evaluating standard and fuzzy comprehensive evaluation method is selected for the case in this paper, and then the evaluation index system for the agricultural water resources carrying capacity is established to evaluate the two cases of Baoding, the evaluation results is:general type case is in V2 level with a certain capacity of agricultural water resources, efficient type case is in V3 level with a strong ability capacity of agricultural water resources.(7)Take Baoding as an example, analyzed with evaluating result, the measure for increasing the agricultural water resources utilization rate is brought up, expecting to make a contribution to keep sustainable using for agricultural water resources in Hebei province.