Assessing Model Of Satisfied Degree For Crop Water Requirement Based On GIS

As the important material basis for human survival and development, water resources and their utilization were focused widely by international communities and the academia. Researches on water resources and their utilization pushed forward human society from primitive society to modern society. In modern society, precise water resources management and utilization need the support of precise data.In terms of data exactness, there are two paradoxes in traditional assessment for water resources and satisfied degree of crop water requirement, that is, "spot-surface matching paradox" and "element matching paradox". To avoiding these paradoxes, we have developed the SHRD model and the SDCWR model. By the international peer review, it is difficult to operate for SHRD model and there are not operational norms for regional parameter in SDCWR model. So we have improved SHRD model and SDCWR model and developed a new CroWA model based on these two improved models in this paper. As an empirical study, we assess the satisfied degree of crop water requirement using the CroWA model with the support of GIS software in Hanjiang River basin.This paper includes theoretical research and empirical study. Achievements of these researches are as follows:(1) We extract the basic hypothesis of the SDCWR model, infer the computational process and develop the modeling norm.(2) We extract the basic hypothesis of the SHRD model and improve the modeling method.(3) We develop a new CroWA model to assess the satisfied degree of crop water requirement on the grid scale.(4) We assess the satisfied degree of water requirement of the main food crops in Hanjiang River basin.The conclusions of this paper are as follows:(1) After the improvement, the SHRD model and the SDCWR model can meet the needs of pervasive model and the CroWA model is a pervasive model. These three models can be used to assess water resources and satisfied degree of crop water requirement for any crop combination in any region. Our models and methods push the macroscopic (regional) water resources assessment forward from the microcosmic (grid) analysis and can provide accurate data for water resource management as well as social and economic sustainable development.(2) The empirical study shows that:the satisfied degree of crop water requirement (CroWA index) varies from<-20% to>200% in Hanjiang River Basin. The maximum CroWA index of the main food crop is in the plain beside trunk stream and tributary of Hanjiang River, parts of Jianghan Plain in Hanjiang River basin and west Shenlongjia forest region. The minimum CroWA index is in low mountains and hills. These area differentiations are caused by topography, river system, crop combination, land use and water use formations. The assessing results of CroWA model are identical with the agricultural practice in this region and also prove the scientificalness and practicability of CroWA model.