(1) From the spatial location of the concentrated rice production areas in the figure, it can be seen that they are the middle and lower reaches of the Yangtze River; rice is mainly distributed in flat areas, which leads to the difference between concentrated production areas and scattered production areas; the thermal conditions are good In areas with poor thermal conditions, double-cropping rice can be produced, while in areas with poor thermal conditions, single-cropping rice can be produced.
(2) Rice requires a lot of water, but the Ningxia plain area has less precipitation and lacks water resources. If planted in large quantities, it will consume a lot of water resources and aggravate the shortage of water resources; and, planting in this area Rice mainly relies on irrigation, but over-irrigation will cause the groundwater level to rise and easily lead to secondary salinization of the land.
(3) From the analysis of supply sources, Wuhan is a major rice producing area with sufficient supply of rice; from the analysis of market, it is densely populated and has a vast market; from the analysis of transportation conditions, it is located at the intersection of the Yangtze River and Han River There are many Beijing-Guangzhou railways passing through, and the water and land transportation is convenient, which is conducive to the distribution of rice. From the analysis of service conditions, Wuhan has good information, finance, warehousing and other supporting conditions, and can provide all aspects of services for rice trading.
(4) Long-term rice planting is not conducive to the restoration of soil fertility, while fallowing can restore soil fertility and achieve sustainable agricultural development; however, fallowing will reduce rice yield and affect food supply.
So the answer is:
(1) The middle and lower reaches of the Yangtze River? Topography? Heat
(2) A large amount of water resources are consumed, exacerbating the shortage of water resources; Extensive irrigation can easily cause secondary salinization of land.
(3) It is located in the main rice-producing area in the middle and lower reaches of the Yangtze River plains; it has a broad market; it is located at the intersection of the Yangtze River and the Han River, with Beijing-Guangzhou and other railways
passing through it (transportation Convenience); information, finance, warehousing and other supporting conditions are good
(4) OK. Maintain soil fertility (or not. Affect food supply security)