Quantitative evaluation of soil conservation in 2000 2010 in Heilongjiang Province using RUSLE model

Soil erosion is a major cause of global land degradation. From the 19th century to date, domestic and foreign scholars have carried out extensive researches on the estimation of the amount of soil erosion. This article conducted a simulation analysis of soil conservation quantity of Heilongjiang Province in 2000 2010 using dates of rainfall, soil properties, elevation and other meteorological data. Then the study used the Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information System (GIS) to quantify soil conservation in Heilongjiang Province. All the factors of the RUSLE model were precisely determined, including rainfall erosion power (R), soil erosion value (K), terrain factors including slope length factor (L) and gradient factor (S) and water/soil conservation measures (P). The study evaluated soil conservation amount and analyzed its distribution and dynamics in Heilongjiang Province for the period 2000 2010. The results showed an increasing trend in the amount of soil conservation in Heilongjiang Province in 2000 2010. Soil conservation quantity in Heilongjiang Province increased on average by 41.95×10⁶ t (a rate of increase of 5.34%) in the 10-year period from 2000 to 2010. The amount of soil maintenance in different areas of Heilongjiang Province increased obviously, except in Mudanjiang and Harbin. In particular, the increase in soil maintenance was highest (over 20%) in Shuangyashan City and Heihe City, lowest (less than 9%) in Suihua City and Yichun City while it increased by less than 10% in Mudanjiang and Harbin. The per unit area soil conservation quantity for various land use types were highest (3 384.36 t·km^-2·a^-1) for forests and lowest (177.17 t·km^-2·a^-1) for bare land. Moreover, the amount of soil conservation of forests was 1.32 times, 6.36 times, 7.42 times, 9.80 times, 10.29 times, 19.10 times higher than that of thicket, grassland, wetland, farmland, cities and bare land. Over the past decade, the trend in soil conservation quantity in various land use types increased. In 2000 2010, the quantity of soil conservation in Heilongjiang Province was at the low state. It, however, gradually improved with enhanced transformation of the low-level into high-level of soil conservation quantity. The area of low-level transformed into high-level soil conservation quantity was 1 055.76 km² and that of high-level transformed into low-level was 37.76 km². To ensure stable and sustainable development of the ecosystem in Heilongjiang Province, it was needed to increase the amount of transformation of low-level into high-level of soil conservation quantity in Songnen Plain and Sanjiang Plain in Heilongjiang Province. There was also the need to enforce agricultural protection, continuous regional integration in Heilongjiang Province, and to promote vigorous forest growth and control land use. Future efforts should also limit intensified urban ecosystems destruction, ensure comprehensive, coordinated and sustainable development and reduce soil erosion issues in the region.