|
|
|
| Effects of rainfall and vegetation change on soil erosion and sediment yield in typical small watershed in hilly area of central Sichuan Basin |
| FU Yan1, ZHENG Jiangkun1, REN Yuzhi1, WANG Wenwu1, ZEN Qianting1, XIANG Minghui2, CHENG Xin2, ZHANG Yunqi1, ZHAO Peng1 |
1. Key Laboratory of Soil and Water Conservation & Desertification Combating of Sichuan Provincial Colleges and Universities, College of Forestry, Sichuan Agricultural University, 611130, Chengdu, China;
2. Water and Soil Conservation Experiment Station of Suining City, 629006, Suining, Sichuan, China |
|
|
|
|
Abstract [Background] It is found that vegetation plays an important role in soil and water conservation. This paper is to understand the effect of vegetation change on soil erosion and sediment yield in Xiejiawan watershed,a small watershed in hilly area of central Sichuan Basin, under annual and individual rainfall scales.[Methods] Based on the data of rainfall and sediment yield of Xiejiawan watershed over 30 years, RUSLE model was used to calculate the rainfall erosivity of the small watershed. Combined Land-Use and Land-Cover Change (LUCC) with soil and water conservation engineering adjustment, the causes of soil erosion and sediment yield were quantitatively evaluated by the double cumulative curve method and the separation discriminant method during different periods in the small watershed.[Results] 1) During 1986-2016, rainfall and erosive rainfall in Xiejiawan watershed occurred mainly in June, July and August which accounted for 80% of that in all the year. Therefore,soil and water conservation projects should be strengthened in summer. 2) Interannual variability of rainfall and erosive rainfall were not obvious during 1986-2016, meanwhile, annual mean sediment modulus during 1990-2008 was obviously less than the values during 1986-1989 and 2009-2016. Soil erosion and sediment yield decreased dramatically when LUCC changed from farmland to orchard. The soil and water conservation engineering measures were destroyed seriously when the forest land was abandoned, resulting in the amount of soil erosion increased at initial stage of abandoned period and decreased gradually after the restoration of understory herbs at later stage of abandoned period. According to LUCC and the trend of double cumulative curve, the time period was divided into crop period (1986-1989), orchard period (1990-2008) and abandoned period (2009-2016). 3) Taking crop period as the base period, the contribution rates of vegetation and rainfall on sediment reduction were 78% and 22%, respectively when crop was transformed into orchard, which indicated that planting orchard effectively reduced the sediment transport modulus in the small watershed. This was mainly due to the increase of canopy coverage enhanced soil consolidation capacity of roots, and the strengthened repair and management of terrace ridges. 4) Taking orchard period as the base period, the contribution rates of vegetation change and rainfall on sediment increase were 88% and 12%, respectively in abandoned period. As the results of lacking land management and drainage, terrace ridges were damaged a lot, which increased sediment yield. Furthermore, sediment yield was positively correlated with rainfall during crop period. Sediment yield was directly related to vegetation coverage and the improvement of terrace ridge measures during orchard period and abandoned period. The sediment reduction effect of vegetation coverage was obvious in a certain range of rainfall erosivity. When the vegetation coverage exceeded the critical value, the sediment reduction effect of vegetation became weaker.[Conclusions] When other conditions remain unchanged, soil erosion and sediment yield is reduced significantly by increasing surface coverage. It plays an important guiding role in soil and water conservation in purple soil watershed by increasing tree and shrub layer, laying soil and water conservation projects, and effective field management.
|
|
Received: 03 September 2018
|
|
|
|
|
|
| [1] |
YIN Zhongdong, ZHOU Xincheng, ZHU Jinzhao. Study on the factors affecting soil erosion[J]. World Forestry Research, 2003, 16(3):32.
|
| [2] |
黄明, 张建军, 茹豪, 等. 晋西黄土区不同植被覆盖小流域的产流输沙特性[J]. 中国水土保持科学, 2012, 10(5):22. HUANG Ming, ZHANG Jianjun, RU Hao, et al. Characteristics of runoff and sediment in small watersheds under different vegetation cover in the Loess Plateau of western Shanxi province[J]. Science of Soil and Water Conservation, 2012, 10(5):22.
|
| [3] |
王浩, 张光辉, 张永萱, 等. 黄土高原小流域次降雨径流深预报模型[J]. 中国水土保持科学, 2015, 13(5):34. WANG Hao, ZHANG Guanghui, ZHANG Yongxuan, et al. Rainfall event based runoff prediction model for small watersheds in the Loess Plateau[J]. Science of Soil and Water Conservation, 2015, 13(5):34.
|
| [4] |
程甜甜, 李赛, 张兴刚, 等. 山东药乡小流域降雨径流关系研究[J]. 水土保持学报, 2016, 30(2):37. CHENG Tiantian, LI Sai, ZHANG Xinggang, et al. Study on the relationship between rainfall and runoff in Yaoxiang Small Watershed of Shandong province[J]. Journal of Soil and Water Conservation, 2016, 30(2):37.
|
| [5] |
HE Jijun, SUN Liying, GONG Huili, et al. The characteristics of rill development and their effects on runoff and sediment yield under different slope gradients[J]. Journal of Mountain Science, 2016, 13(3):397.
|
| [6] |
郑江坤, 李静苑, 秦伟, 等. 川北紫色土小流域植被建设的水土保持效益[J]. 农业工程学报, 2017, 33(2):143. ZHENG Jiangkun, LI Jingyuan, QIN Wei, et al. Effects of vegetation construction on soil and water conservation in small watershed of purplish soil region, northern Sichuan[J]. Transactions of the CSAE, 2017, 33(2):143.
|
| [7] |
DIYABALANAGE S, SAMARAKOON K K, ADIKARI S B, et al. Impact of soil and water conservation measures on soil erosion rate and sediment yields in a tropical watershed in the central Highlands of Sri Lanka[J]. Applied Geography, 2017, 79:103.
|
| [8] |
朱连奇, 许叔明, 陈沛云. 山区土地利用/覆被变化对土壤侵蚀的影响[J]. 地理研究, 2003, 22(4):432. ZHU Lianqi, XU Shuming, CHEN Peiyun. Study on the impact of land use/land cover change on soil erosion in mountainous areas[J]. Geographical Research, 2003, 22(4):432.
|
| [9] |
袁应飞, 戴全厚, 李昌兰, 等. 喀斯特典型坡耕地模拟降雨条件下的土壤侵蚀响应[J]. 水土保持学报, 2016, 30(3):27. YUAN Yingfei, DAI Quanhou, LI Changlan, et al. Response of soil erosion in simulated condition rainfall on typical slope farmland in karst[J]. Journal of Soil and Water Conservation, 2016, 30(3):27.
|
| [10] |
刘春, 杨静, 聂云鹏, 等. 不同时间尺度喀斯特小流域溪流水文水化学特征[J]. 应用生态学报, 2015, 26(9):2617. LIU Chun, YANG Jing, NIE Yunpeng, et al. Stormflow hydrochemical characteristics at different time scales in a typical karst catchment of northwest Guangxi, China[J]. Chinese Journal of Applied Ecology, 2015, 26(9):2617.
|
| [11] |
WISCHMEIER W H, SMITH D D. Rainfall energy and its relationship to soil loss[J]. Transactions of American Geophysical Union, 1958, 39(3):285.
|
| [12] |
朱强, 陈秀万, 樊启祥, 等. 基于TRMM的降雨侵蚀力计算方法[J]. 中国科学:技术科学, 2011, 41(11):1484. ZHU Qiang, CHEN Xiuwan, FAN Qixiang, et al. A new procedure to estimate the rainfall erosivity factor based on Tropical Rainfall Measuring Mission(TRMM) data[J]. Scientia Sinica (Technologica), 2011, 41(11):1484.
|
| [13] |
李斌斌, 李占斌, 郝仲勇, 等. 植被格局特征对大理河流域侵蚀产沙的响应[J]. 农业工程学报, 2017, 33(19):174. LI Binbin, LI Zhanbin, HAO Zhongyong, et al. Response of vegetation pattern characteristics to sediment yield in Dali River Basin[J]. Transactions of the CSAE, 2017, 33(19):174.
|
| [14] |
宫渊波, 陈林武, 张健, 等. 嘉陵江上游低山暴雨区植被恢复对小流域产流产沙的影响[J]. 水土保持学报, 2011, 25(1):13. GONG Yuanbo, CHEN Linwu, ZHANG Jian, et al. Effect of vegetation restoration on runoff and sedimentation in small river basins in the upper reaches of Jialing River[J]. Journal of Soil and Water Conservation, 2011, 25(1):13.
|
| [15] |
符素华, 刘宝元, 路炳军, 等. 官厅水库上游水土保持措施的减水减沙效益[J]. 中国水土保持科学, 2009, 7(2):23. FU Suhua, LIU Baoyuan, LU Bingjun, et al. Effect of soil conservation practice on runoff and sediment in upper reach of Guanting Reservoir[J]. Science of Soil and Water Conservation, 2009, 7(2):23.
|
| [16] |
郑江坤, 杨帆, 王文武, 等. 不同降雨等级下耕作措施对坡地产流产沙的影响[J]. 中国水土保持科学, 2018, 16(1):44. ZHENG Jiangkun, YANG Fan, WANG Wenwu, et al. Effects of tillage measures on runoff and sediment yield of farmland under different rainfall levels[J]. Science of Soil and Water Conservation, 2018, 16(1):44.
|
|
|
|
