读我国某区域图，回答下列问题。（共12分）

(1)根据图中信息，描述该地区地势的总体特征并说明判断依据。(3分)
                                                                                         
                                                                                        。
(2)图中黄河段流域面积狭小，其主要原因              。简要分析图中黄河段流量往下游不断减少的原因。(4分)
                                                                                         
                                                                                        
                                                                                         。
(3)郑州及其附近地区自古以来就是我国重要的农业区，简述其农业发展的有利条件。(5分)
                                                                                        
                                                                                       。