Geographical environment and development of Guangzhou

Guangzhou is the capital of Guangdong Province and the political, economic, scientific, technological, educational and cultural center of Guangdong Province. Guangzhou is located in the south of Chinese mainland, south-central Guangdong Province, on the northern edge of the Pearl River Delta, close to the lower reaches of the Pearl River Basin. Its range is 1 12 degrees 57 minutes east to 1 14 degrees 3 minutes north to 22 degrees 26 minutes north to 23 degrees 56 minutes. It is adjacent to Boluo and Longmen counties in Huizhou in the east, Sanshui, Nanhai and Shunde districts in Foshan in the west, Qingyuan, Fogang and Xinfeng counties in Shaoguan in the north, Dongguan and Zhongshan in the south, and faces Hong Kong and Macao Special Administrative Regions across the sea.

Due to the numerous islands and dense waterways in the Pearl River Estuary, including Humen, Jiaomen, Hongqimen, etc., Guangzhou has become an excellent seaport for ocean transportation in China and the import and export shore of the Pearl River Basin. Guangzhou is also the intersection of Beijing-Guangzhou, Guangzhou-Shenzhen, Guang Mao and Guangzhou-Meishan railways, and the civil aviation transportation center in South China, with very close ties with all parts of the country. Therefore, Guangzhou is called the "South Gate" of China.

(2) Characteristics of land resources

The cultivated land area in Guangzhou is 86 1 10,000 hectares, and the forestry land area is 254,000 hectares. Guangzhou has diverse land types, wide suitability and complex terrain. The terrain decreases from north to south, and the highest peak is the paradise top at the junction of Conghua City and Longmen County in the north, with an altitude of 12 10 m; Northeast China is a middle and low mountainous area; The middle is a hilly basin; The south is the coastal alluvial plain, which is an integral part of the Pearl River Delta. Due to the interaction of various natural factors, various land types have been formed. According to the vertical zone of the land, it can be divided into the following types: (1) medium and low mountains. It is a mountainous area with an altitude of 400-500 meters, mainly distributed in the northeast of Guangzhou, with a general slope of more than 20-25 degrees. The soil-forming parent materials are mainly granite and sand shale. This kind of land is an important water conservation forest base, which is suitable for developing ecological forest and hydropower. (2) Hilly land. It is a slope in the vertical zone below 400 meters to 500 meters above sea level, mainly distributed between mountains, basins and plains, and distributed in Zengcheng City, Conghua City, Huadu District and the eastern and northern parts of the urban area. Soil-forming parent materials are mainly composed of sand shale, granite and metamorphic rocks. This kind of land can be used as the growth base of timber forest and economic forest. (3) Gangtai. The relative elevation is less than 80m, and the slope is less than 15 degree. Mainly distributed in Zengcheng, Conghua, Baiyun, Huangpu, Panyu, Huadu and Tianhe. Soil-forming parent materials are mainly accumulated red soil, red rock series and sand shale. This kind of land can be developed and utilized as agricultural land, and is also suitable for planting fruits, economic forests or pastures. (4) alluvial plain. There are mainly the Pearl River Delta Plain, the Guanghua Plain alluvial by Liuxi River, the coastal alluvial and marine plains in Panyu District and Nansha District. With deep soil layer and fertile land, it is the main production base of grain, sugarcane and vegetables in Guangzhou. (5) the beach. It is mainly distributed in the coastal areas of Nansha, Wanqingsha and Xinken Town in Nansha District.

(3) Climate characteristics

Guangzhou is located in the Pearl River Delta, bordering on the South China Sea. Its maritime climate features are particularly remarkable, with warm and rainy, sufficient light and heat, small temperature difference, long summer and short frost period. Because of the same period of water and heat, it is very beneficial to crop growth, but natural disasters are also frequent. Disastrous weather such as typhoon, rainstorm, cold wave, thunder and lightning, smog, etc. often bring adverse effects to Guangzhou's industrial and agricultural production, transportation and citizens' life. In 2007, although some local disasters occurred in some areas, there were basically no large-scale natural disasters in Guangzhou, which was a good year on the whole.

Sufficient light and heat resources. 2007 was the warmest year in Guangzhou since the founding of the People's Republic. The sunshine hours in each district (county-level city) in Guangzhou are between1481.7-21.5 hours, the annual average temperature is between 22. 1℃-23.2℃, and the annual extreme minimum temperature is between/kloc. The extreme maximum temperature in all districts (county-level cities) in Guangzhou has not broken records, but the duration of high temperature above 35℃ is rare in the same period in history.

Rainfall is unevenly distributed. In 2007, the total precipitation of all districts (county-level cities) in Guangzhou was between 1370.3— 1964.5 mm, which was less than the average of previous years except Zengcheng. The annual total rainfall in Laoba District, Huadu District, Conghua City and Panyu District of Guangzhou City is 361.3mm and 284.3mm respectively. The annual total rainfall in the old eight districts of Guangzhou is 1370.3mm, which is the lowest in the city, and the annual total rainfall is rare in recent years. In that year, the temporal and spatial distribution of precipitation in the city was extremely uneven. Zengcheng in the east is more than Huadu District in the west, Conghua City in the north is more than Panyu District in the south, and the rainfall in all districts (county-level cities) is more in June and August, especially in June. The monthly rainfall in Zengcheng City, Conghua City, Huadu District, Laoba District and Panyu District of Guangzhou City reached 58 1.7mm, 4 12.7mm, 363.3mm, 3 19.8mm and 259.0mm respectively, which were 66.2% and/kl higher than the historical period. However, from June 5438+00 to February 12, the rainfall in Guangzhou was obviously less. In the past three months, there has not been a soaking rain in the city (the daily rainfall is greater than or equal to 20 mm). Zengcheng 5438+0 10, which has the most rainfall in June, has a rainfall of only 4.9 mm, and other areas have less rainfall, so the drought is very serious.

The monsoon climate is prominent. The alternation of winter and summer monsoon is a remarkable feature of Guangzhou monsoon climate. The north wind in winter is formed by the cold air mass extending southward from the polar continent. The weather is dry and cold, and sometimes there will be disasters such as cold wave, frost and freezing. The southerly wind in summer is caused by the northward expansion of tropical ocean heating mass, and the weather is warm and humid. Common disasters include typhoon, rainstorm, lightning and strong convection. Summer monsoon usually turns into winter monsoon in September every year, and winter monsoon usually turns into summer monsoon in April every year.

Meteorological disasters occur frequently. In 2007, meteorological disasters were still frequent in some areas of Guangzhou. First of all, the lightning disaster is serious. The thunderstorm season in each district (county-level city) is as long as 186-223 days, and the thunderstorm days are 66-80 days. There were * * * lightning disasters 169 in the city, resulting in 7 fire and explosion accidents, with1/person killed and 65,438 injured. Secondly, the weather is hot in summer, and the number of days with high temperature of 35℃ and above in each district (county-level city) is 3 1-39 days, which is obviously more than in previous years. Due to the long duration of high temperature in midsummer and the very hot weather, meteorological stations (stations) around the country frequently issue high temperature warning signals. Third, strong convective weather in some areas has an impact on transportation and citizens' lives. There were several strong convective weather in that year, which had a great impact. For example, on the afternoon of April 17, due to the influence of the trough on the front, there was a thunderstorm and gale accompanied by hail in Conghua City and Baiyun District, and the gust reached 12. On May 26-27, there were heavy rains, thunderstorms and strong winds in Guangzhou. The rainfall in Huangpu District, Huadu District and Conghua City reached more than 100 mm, and many roads in Guangzhou were flooded, causing traffic jams. More than 30 flights at Baiyun Airport were affected, causing delays.

(4) Water source characteristics

Guangzhou is located in the south water-rich area, with developed water system, numerous rivers (swells) and vast waters. There are 22 rivers with rainfall collection area over 65,438+000 square kilometers, and there are 2,365,438+0 main rivers in the old eight districts, with a total length of about 965,438+03 kilometers, which not only constitutes the unique cultural characteristics of Lingnan water town, but also helps to improve the urban landscape and maintain the stability of the urban ecological environment.

The main characteristics of Guangzhou's water resources are that there are few local water resources and relatively abundant transit water resources. The water area of the city is 74,400 hectares, accounting for 10% of the land area of the city. The main rivers are Beijiang River, Dongjiang River, Zengjiang River, Liuxi River, Baini River, Guangzhou Section of Pearl River, Shiqiao Waterway and Shawan Waterway. Beijiang River and Dongjiang River flow through Guangzhou, join the Pearl River and enter the sea. The local average total water resources is 7.979 billion cubic meters, including 78.8 1 100 million cubic meters of surface water and 6.5438+0.487 billion cubic meters of groundwater. In terms of local water resources, per square kilometer 106.0 1 10,000 cubic meters, per capita water resources 1 139 cubic meters, which is half of the national average water resources. The water resources of transit passengers are 65.438+086.024 billion cubic meters, which is 23 times of the total local water resources. Passenger water resources are mainly concentrated in Nanwanghe area and Zengcheng city, among which the passenger water resources diverted from Xijiang River and Beijiang River into Guangzhou reach1591500,000 cubic meters, the passenger water resources diverted from Dongjiang River into the main stream of Dongjiang River are142.03 million cubic meters, and the water from the upper reaches of Zengjiang River is 2.828 billion cubic meters. The southern river network area is in the tidal influence area, with large runoff and strong tidal action. Humen, Jiaomen and Hongqimen of the Pearl River enter Lingdingyang and leave Guangnan South China Sea, with an annual high of 27 1 100 million cubic meters and an annual low of 408.8 billion cubic meters. Compared with Sanmen's annual runoff of 65.438+03.77 billion cubic meters, the annual tidal current can bring a lot of water, part of which is available fresh water resources.

(5) Biological resources

The natural conditions in Guangzhou provide a good ecological environment for the habitat and reproduction of many animals and the growth of plants. There are many kinds of creatures and they grow rapidly. The zonal vegetation is subtropical monsoon evergreen broad-leaved forest, but there are few natural forests, and the forests in mountainous and hilly areas are secondary forests and artificial forests.

Cultivated crops are characterized by the transition from tropical to subtropical, which is one of the regions with the richest fruit resources in China, including tropical, subtropical and temperate categories, 4 1 family, 82 genera, 174 species, and more than 500 varieties (including 55 litchi varieties), which are formed by the origins and types of litchi, longan and black olive. Vegetables are famous for their high quality and variety, with more than 300 varieties in 14 category. Flowers include fresh cut flowers, potted plants (foliage plants, succulents, potted flowers and bonsai), green seedlings, flowers for industrial raw materials, lawns and seedlings. In recent years, more than 3000 traditional varieties and new varieties have been introduced and developed. There are many kinds of grain, cash crops, livestock and poultry, aquatic products and wild animals, and there are many famous and special varieties. Among them, Zengcheng Simiao rice is the first variety in Guangzhou to be protected by national geographical indication products.

(6) Mineral resources

The geological structure of Guangzhou is quite complex and has good metallogenic conditions. 47 kinds of minerals and 820 deposits have been discovered, including large and medium-sized deposits 18. The main minerals are granite for building, limestone for cement, ceramic soil, potassium, albite, salt mine, mirabilite, nepheline syenite, fluorite, marble, mineral water and hot mineral water. Energy minerals and non-ferrous metal minerals in the area are in short supply, scattered, small in scale and unstable in grade.