Study On Land Resource Evaluation And Land Carrying Capacity In Hanzhang City

Hanzhong City is located in the Qin-Ba mountain areas in south of Shaanxi Province, it topographical features are complicated and landform multiplicity. It population are more and farmland areas are lower, the interrelation between the human and land is very intensity in Hanzhong. In the situation there is an important significance through the studying of the quality and amounts of land resource, population increase, land production potentiality and land carry capacity. Based on field review and data collection, we study the land resource evaluation, the land production potentiality and the land carry capacity in Hanzhong. The main conclusions are as follows.1. Gain the result of land resource evaluation by use of APH method. And the result shows that the land quality of the Hanzhong is not high as a whole. The first grade land has 40.23 104hm2, 14.84% of total area; The second grade land has 75.11 104hm2, 27.71%; The third grade land has 84.04 104hm2, 31.01%; The forth grade land has 71.66 104hm2, 26.44%. The second and third grade land is the most, the first grade land is very small. Generally speaking, the first grade land is mostly located in Hanjiang Flatland; the second grade land is mostly located in hill region; the third and firth grade land is mostly located in mountain region.2. The research estimates the farmland production potentiality by step correct method. It is surveyed that in Hanzhong the light production potentiality is 20820 kg·hm-2, the thermal production potentiality is 12321 kg·hm-2, the climate production potentiality is 8858 kg·hm-2, the land production potentiality is 5005 kg·hm-2. The order of the land production potentiality is: Hanjiang Flatland>Bashan Beipo>Qinling Nanpo. The soil production potentiality of irrigated farmland is higher than dry farmland. The soil fertility level is lower in Hanzhong. Irrigation and soil are chief limiting factors. At the same time, this paper describes the guiding suggestions to improve the farmland production potentiality.3. The research calculates the grassland production potentiality Miami Model. We can see the grassland temperature potential is higher than grassland precipitation potential. According to the Liebig Law, the grassland production potentiality is the precipitation potential. The crude grassland production potentiality is 14001.63 kg·hm-2,and the edible grass is 8400 kg·hm-2, which is 59.99% of production potentiality. There has great potential to...