Which of the four regions in China has the lowest land productivity?

Of course, the Qinghai-Tibet region is dominated by alpine meadows, and there is a large area of cold desert in northern Tibet. It is cold desert soil and mountain meadow soil. Details: 1. Northern region: Daxinganling, Helan Mountain and bayan har in the east, Qinling and Huaihe River in the north, that is, the northern region of the eastern monsoon region of China. Topographic features: the plain area is vast, among which the northeast plain is the largest plain in China, mainly with black soil, numerous swamps in the north and thick frozen soil; North China Plain is the flattest plain in China, which is mainly formed by alluvial deposits of the Yellow River, Haihe River and Huaihe River, with deep soil layers. The Loess Plateau is the widest and thickest loess accumulation area in the world, with loose soil, strong uprightness, poor surface vegetation protection, serious soil erosion, criss-crossing gullies and large sediment concentration in rivers flowing through the plateau area. Climate characteristics: temperate continental monsoon climate is dominant, with cold temperate zone in the north of Daxinganling, middle temperate zone in the north of the Great Wall and warm temperate zone in the middle and lower reaches of the Yellow River. The frost-free period is 4-8 months, and the heat conditions between north and south are quite different. The annual precipitation is 400 ~ 800 mm, mainly concentrated in July ~ August, mostly in semi-humid and semi-arid areas (the eastern and northern mountainous areas of Northeast China are humid areas); It is warm and rainy in summer (shorter in northeast) and cold and dry in winter; Main disastrous weather: cold wave in winter, low temperature in northeast summer, early frost in autumn, drought in spring, sandstorm in North China and rainstorm in summer. Hydrological characteristics: the hydrological characteristics of north and south are quite different. The amount of water in the north is more than that in the south, and the north is long and the south is short. During the ice age, the sediment concentration in the northern rivers was small, while that in the southern rivers was small. Main rivers: Heilongjiang and its tributaries Songhua River, Wusuli River, Yellow River (downstream is Dihe River) and its tributaries Weihe River, Fenhe River, Haihe River and Liaohe River. Characteristics of agricultural activities: important agricultural areas, mainly dry farming. North of the Great Wall, cooked once a year; South of the Great Wall, three crops are harvested every two years. The agricultural area is dominated by animal husbandry. Northeast China has a vast forest area. Main lakes: Baitoushan Tianchi and Xingkai Lake. Vegetation: coniferous forest is dominant in Northeast China (mixed coniferous and broad-leaved forest in Changbai Mountain), and deciduous broad-leaved forest in the middle and lower reaches of the Yellow River. Soil: Black soil is widely distributed in Northeast China, and calcareous soil is dominant in the middle and lower reaches of the Yellow River. Dominant factor: accumulated temperature gradually increases from north to south. Second, the southern region: the southern part of the eastern monsoon region, south of Qinhuai River and east of Qinghai-Tibet Plateau. Topographic features: the terrain is high in the east and low in the west, mainly located in the second and third steps, with vast plains and hills in the east. The plain in the middle and lower reaches of the Yangtze River is the lowest-lying area in China, with criss-crossing rivers and tributaries and dotted with lakes. The hills in the south of the Yangtze River are the largest hills in China, and most of them are distributed alternately with low mountains and valley basins from northeast to southwest. The western part is dominated by plateaus and basins, and the Sichuan Basin (with Chengdu Plain in the northwest) is one of the four great basin in China, which is called "Purple Basin" and "Land of Abundance". Yunnan-Guizhou Plateau has a rugged surface, which is the most typical karst landform distribution area in the world, and the mountain "bazi" is the main agricultural area in this area. Hengduan Mountain and Nanling Mountain are important geographical boundaries in China, and the main peak of Yushan Mountain in Taiwan Province Province is the highest peak in the southeast coast of China. The main topographical areas are: the middle and lower reaches of the Yangtze River plain (Jianghan, Dongting Lake, Poyang Lake and Yangtze River Delta), the Pearl River Delta plain, the southern hills, the Sichuan Basin, the Yunnan-Guizhou Plateau, the Hengduan Mountains, the Nanling Mountains, the Wuyishan Mountains, the Qinba Mountains and the Taiwan Province Mountains. Climate characteristics: tropical and subtropical monsoon climate is dominant, with accumulated temperature of 4500℃-8000℃. There are great differences in thermal conditions between the north and the south. 1 month, the average temperature is above 0℃, and it is warm in winter and hot in summer, with four distinct seasons. The annual precipitation is more than 800 mm, mainly concentrated in summer, and the rainy season is shortened from south to north. The climate in Hengduan mountain area varies greatly vertically. Yunnan-Guizhou Plateau is the intersection of the Pacific Ocean and Indian Ocean monsoon. In winter, the eastern part of Kunming Jingfeng is rainy and cold, and the western part is sunny and warm. The middle and lower reaches of the Yangtze River (east of Yichang, south of Huaihe River and north of Nanling Mountain) are affected by the static front of the Yangtze River and Huaihe River from June to July every year, with plum rains, and summer drought is formed under the control of the Hawaiian high ridge from July to August. Cold wave in winter and typhoon in summer and autumn in coastal areas are the main disastrous weather. Hydrological characteristics: abundant water, long flood season and small seasonal variation of water level (typhoon season is obvious in southern coastal rivers); The rivers in the hilly areas of the south of the Yangtze River, the southern coast, the Yunnan-Guizhou Plateau and the Sichuan Basin have a large drop and abundant water power. The Yangtze River system, the Pearl River system and the Beijing-Hangzhou Canal are of high shipping value. River sediment concentration is small; Ice-free period Major lakes: The Yangtze River basin is the main distribution area of freshwater lakes in China, including Poyang Lake (the largest freshwater lake in China), Dongting Lake, Taihu Lake, Hongze Lake and Chaohu Lake; Sun Moon Lake. Main rivers: Yangtze River and its tributaries, Hanjiang River, Dongting Lake, Poyang Lake and centripetal water system of Sichuan Basin (Minjiang River, Yalong River, Wujiang River and Jialing River); Pearl River and its tributaries Xijiang, Dongjiang and Beijiang; Qiantang River; Huaihe River; Minjiang river; Lancang River and Nujiang River in Hengduan Mountain Area; Characteristics of agricultural activities in Zhuoshuixi: one of the important agricultural areas, mainly paddy fields. Crops are harvested twice a year in the north of the Yangtze River and three times a year in the south of the Yangtze River. South China (Hainan, Xishuangbanna, Yunnan, etc. ) Develop the production of tropical cash crops. The marine fishery is developed, and Zhoushan Fishing Ground is the largest fishing ground in China. Vegetation: subtropical evergreen broad-leaved forest, tropical monsoon forest. Source: (/s/blog _ 6657c13f010grqt.html)-Overview of natural conditions in four regions of China _ Geography Xintiandi _ Sina Blog Soil: zonal soil is red, yellow and lateritic red soil, and non-zonal soil is purple soil in Sichuan Basin and paddy soil in agricultural areas. Dominant factors: the accumulated temperature in the east gradually increases from north to south, and the precipitation in the west gradually decreases from east to west. 3. Northwest: Non-monsoon terrain features of Daxing 'anling, west of Helan Mountain and north of Kunlun Qilian Mountain: mainly located in the second step of China's terrain, mainly plateaus and basins. Inner Mongolia Plateau (including Hetao Plain, Ningxia Plain and Hexi Corridor) is flat and open, with typical temperate grasslands in the east and deserts and Gobi in the central and western regions. The topography of Xinjiang is "three mountains and two basins". Kunlun Mountain, Tianshan Mountain and Altai Mountain are all important mountains in Central Asia. The top of the mountain is covered with snow all year round and the grassland at the foot of the mountain is vast. Among them, the Tianshan Mountains run through the central part, dividing Xinjiang into north and south parts. There are many subsidence basins and valleys (Turpan Basin, Ili River Valley, etc.). ) In the mountainous area, and the elevation of Lake Aiding is-156m, which is the lowest point of China land. The south is the largest Tarim Basin in China, and the landscape is distributed in a ring shape. Oasis is the main agricultural area in this area. There is the largest Taklimakan Desert in China in the middle, and the longest inland river, Tarim River, is distributed in it. North of Tianshan Mountain is Junggar Basin in great basin, China, and Gurbantunggut Desert is the second largest desert in China. Climate characteristics: Living inland, it belongs to a typical temperate continental climate. In winter, Leng Xia is hot, with large daily and annual temperature differences (Turpan Basin is the "hot pole" of China); Precipitation is scarce, the annual precipitation is less than 400 mm, and the climate is dry (the annual precipitation in Tarim Basin is less than 50 mm, which is the "dry pole" in China). Hydrological characteristics: small amount of water, short flood season, large river sediment concentration, many inland rivers, glacier melt water as the main recharge source, and large area of no-flow area. The upper reaches of the Yellow River have a large drop and abundant water power. Main rivers: Yellow River, Irtysh River (the only river in China that flows into the Arctic Ocean), Tarim River and Yili River. Main lake: lop Nur agricultural activity characteristics: important animal husbandry area. Planting is mainly dry farming, and irrigation agriculture is prominent (oasis agriculture in Xinjiang). Once a year ~ three times a year (southern Xinjiang). Vegetation: The eastern part of Inner Mongolia Plateau is a typical temperate grassland, and the western part of the central part of Inner Mongolia Plateau is a temperate desert. Soil: mainly desert lime soil and limestone lime soil. Dominant factor: precipitation decreases from east to west. 4. Qinghai-Tibet region: west of Hengduan Mountains, north of Himalayas, south of Kunlun Mountains and Altun Mountains. Topographic features: Plateau terrain is the main terrain, located in the first step of China. The Qinghai-Tibet Plateau is the highest and youngest plateau in the world, with continuous snow peaks and extensive glaciers, with an average elevation of over 4,000 meters. The crust in southern Tibet is active, and two plates collide here. The Yarlung Zangbo Grand Canyon is the highest in the world. Northern Tibet is more than 4500 meters above sea level, and the surface is undulating; Qaidam Basin is the highest inland great basin in China. Agriculture and animal husbandry are mainly concentrated in lakes and valleys. Climate characteristics: high altitude, low temperature and large temperature difference between day and night; Less precipitation, large regional differences; Strong sunshine and long sunshine time. Hydrological characteristics: Glacier meltwater is replenished, and the south of Gangdise Mountains is affected by the monsoon from the Indian Ocean, with large water volume, large drop and abundant hydraulic resources. Especially the Yarlung Zangbo River Grand Canyon has great potential for hydropower development. Major rivers: Yarlung Zangbo River, the birthplace of major rivers such as Yangtze River and Yellow River. Major lakes: One of the main distribution areas of inland lakes in China, Qinghai Lake is the largest lake in China, Namco. Characteristics of agricultural activities: famous alpine pastoral areas and valley agricultural areas. Vegetation: Alpine meadow is dominant, and there is a large area of cold desert in northern Tibet. The vertical zoning in the marginal areas is obvious. Soil: mainly cold desert soil and mountain meadow soil. Dominant factor: high terrain