Research On Characteristics Of Soil And Water Loss Of Typical Small Watershed In The Southern Mountainous Area In Jinan

Water and soil loss is resulted from interaction of several factors in multi-scale space, which is an important cause of land deterioration, a problem resulting in ecological environment deterioration and loss of agricultural production and human life and a key problem relating to social and economic sustainable and healthy development of China. Therefore, it is necessary to correctly and objective evaluate the water and soil loss conditions of the key drainage basins for purposeful comprehensive treatment.As the mountain chain of Mount Tai, the mountainous area in south of Jinan is a supply area of spring water, an important water source of surface water in Jinan and an important area with high reclamation index for ecological planning. Therefore, it is of great importance in improving the urban ecological environment and quality of living in Jinan. However, the fragile ecological landscape and the development and construction projects with large scale, high intensity and overload result in the water and soil loss in the mountainous area in the south, which becomes an outstanding problem for ecological recovery for Jinan. For this reason, using high resolution remote sensing data of typical small watershed and ground test data to modify a number of factors of the universal soil loss equation (USLE), and combined with Landsat8data inverse soil and water loss characteristics in the southern mountainous area in Jinan and obtains the following conclusions:(1)Soil erosion characteristics studied and analyzed on the basis of medium-resolution remote sensing dataThe soil erosion modulus in the southern mountainous area studied and analyzed on the basis of medium-resolution remote sensing data is 0?2,676.45 t�km-2� a-1 in the Southern mountainous area, with the mean value of 145.98 t�km-2�a-1, and annual total erosion amount of 774,681.23 t. A minor erosion area is 3,878.84 km2, which accounts for 73.09% of the total area studied and an annual erosion amount is 566,215.22 t; a slight erosion area is 1,428.09 km2, which accounts for 26.91% of the total area studied and an annual erosion amount is 208,465.62 t; a medium erosion area is 27 hm2, with an annual erosion amount of 0.39 t. The spatial distribution law is high in the southwest and northeast and low in the middle. Shizhong District, Changqing District, Lixia District, Licheng District and Zhangqiu District mainly have the minor erosion and Pingyin County has slight erosion, which is the mainly distributed area in the southern mountainous area.(2)Based on the USLE model and the scale transformation of multi-source remote sensing data, construct the soil erosion model in the southern mountainous area:Based on LSligh= 0.8431�LSmedium+9.6772 and CPhigh=0.6508-0.3436�1g(0.5373�Nmedium+0.2092), construct the high-resolution soil erosion characteristics in the southern mountainous area:Ahigh=R�K�(0.8431�LSmedium+9.6772)�[0.6508-0.3436�lg(0.5373�Nmedium+0.2092)].(3)Soil erosion characteristics studied and analyzed on the basis of high-resolution remote sensing dataThe soil erosion modulus calculated using the soil erosion model in the southern mountainous area is 0?1,510.11 t�km-2�a-1, with the mean value of 223.40 t�km-2�a-1, and annual total erosion amount of 1,185,577.22 t. Compared with that with the inversion result of medium resolution, the simulated erosion increase rate is 53.04%. The erosion intensity is divided into the minor erosion and slight erosion. A minor erosion area is 3,339.12 km2, which accounts for 62.92% of the total area studied and an annual erosion amount is 745,965.19 t, with the increase rate of 31.75% compared with that with the medium resolution; a slight erosion area is 1,967.81 km2, which accounts for 37.08% of the total area studied and an annual erosion amount is 439,612.03 t, with the increase rate of 110.88% compared with that with the medium resolution. The spatial distribution law is high in the southwest and northeast and low in the middle. Licheng District and Zhangqiu District mainly have the minor erosion and Shizhong District, Changqing District, Lixia District and Pingyin County have slight erosion, showing that Shizhong District, Changqing District, Lixia District and Pingyin County are the mainly distributed area in the southern mountainous area.(4)Give the management suggestions according to the medium- and high-resolution soil erosion characteristicsThe spatial distributions of soil erosion characteristics in the southern mountainous area are consistent with the spatial distributions of the LS factor and CP factor, showing that the landform, vegetation coverage and operation management measures are important influence factors of soil erosion in the southern mountainous area. In future, the soil erosion should be prvented and managed by changing the landform, increasing vegetation coverage and reducing the human activities destruction, establishing integrated protection system for soil and water loss and so on.