1980—2010年间安徽省土壤侵蚀动态演变及预测

基于修正的通用土壤流失方程(RUSLE)和GIS技术,定量分析了1980年、2000年、2010年安徽省土壤侵蚀空间分布及动态变化特征,并利用马尔柯夫模型预测了未来30年土壤侵蚀变化趋势。利用GIS空间分析方法进一步探讨了土壤侵蚀强度空间变化与高程、坡度等地形因子间的关系。结果表明：(1)1980—2010年安徽省土壤侵蚀状况明显改善,平均土壤侵蚀模数由1980年的461.09 t/(km₂ a)减少为2010年的245.26 t/(km₂ a)；相应的侵蚀总量由6 199.92万t/a减少为3 297.84万t/a。全省微度侵蚀面积增加了8 188.65 km₂；强度以上侵蚀面积减少了1 576.93 km₂。(2)安徽省三个时期的土壤侵蚀强度空间分布规律一致,侵蚀强度由北向南逐渐加剧。淮北与沿淮平原、江淮丘陵岗地以微度土壤侵蚀为主,皖南丘陵山区和皖西大别山区以强度侵蚀为主。(3)1980—2010年全省土壤侵蚀等级减弱面积达11 762.83 km₂,侵蚀等级加剧面积仅811.21 km₂。土壤侵蚀等级空间变化主要分布在200—500 m和15°—25°区域。土壤侵蚀等级转化逐级进行,主要以向侵蚀程度较弱等级转化为主,仅有少量微度侵蚀向侵蚀强度较强等级转化。(4)根据马尔柯夫方法预测,未来30年安徽省土壤侵蚀状况逐渐减轻,微度土壤侵蚀面积逐渐增加,其他侵蚀等级的面积持续减少。

Dynamic Evolution and Prediction of Soil Erosion in Anhui Province from 1980 to 2010

Based on revised universal soil loss equation (RUSLE) and GIS technique, this research analyzed the spatial distribution of soil erosion in 1980, 2000, and 2010, and its dynamic evolution in Anhui Province, and predicted soil erosion change over the next 30 years based on Markov model. Furthermore, this paper explored relationships of spatial change of soil erosion intensity with elevation and slope based on spatial analysis of GIS. The results showed: 1) soil erosion of Anhui Province obviously improved from 1980 to 2010, and mean soil erosive modulus decreased from 461.09 t/(km² a) to 245.26 t/(km² a), the amount of soil erosion decreased from 6 199.92 × 10⁴ t/a to 3 297.84 × 10⁴ t/a. Slight soil erosion areas increased by 8 188.65 km², and intensive soil erosion areas reduced by 1 576.93 km². 2) Spatially, soil erosion strengthened from north to south in three periods. Slight soil erosion mainly distributed in Huaibei Plain and Jianghuai Hilly Region, while intensive soil erosion mainly in hilly mountain of southern and western Anhui. 3) From 1980 to 2010, area of soil erosion grade weakened was 11 762.83 km², area of soil erosion strengthened only was only 811.21 km². Soil erosion change mainly distributed in region of 200 ~ 500 m and 15° ~ 25°. Soil erosion grade transformed stepwise. Erosion grade mainly transformed into weaker grade, and only a few of slight erosion transformed into the stronger grade. 4) According to the Markov prediction, soil erosion improved over the next 30 years, area of slight soil erosion gradually increased while areas of other erosion grades declined.