Scientific Journal of Earth Science June 2013, Volume 3, Issue 2, PP.71-80
Spatial Distribution Characteristics of Intercepted Rainwater on Rock Desertified Shrub Slopes in the Northern Guangdong Region* Xinghu Wei 1, Xizhen Xu 2, Li Lei 3 1. Research Center of territorial Resource Environment and Tourism, Foshan Scientific and Technologic College, Foshan, 528000, PRC 2. The second middle school of Zhongshan City, Zhongshan 528429, PRC 3. School of Geographic Science, South China Normal University, Guangzhou 510630, PRC Email: 1#weixinghu1964@163.com; 2 xuxizhen@163.com; 3 leili0106@163.com
Abstract In this study, typical cone karst slopes in Jiulong Township of Yingde City, Guangdong Province were selected as the study area. The plant species and residue amounts in the runoff experiment plots with different rock desertification degrees were surveyed. The weight of plant, litter, limestone rocks, and bulk were investigated before and after rains. The results show that as the stony desertification aggravated, the exposure percentage of rocks increased, but the soil cover and thickness and vegetation cover decreased. The interception amount of the surface plant and residue show a trend of parabola, the maximal interception amount of the surface plant in slight stony desertification plot was 920g/m2,but significantly decreased in the very severe cases, was 160g/m2.The maximal interception amount of the residue in moderate stony desertification plot was 906.70g/m2,minimal in the very severe cases, was 306.7g/m2.Water storage capacity of soils gradually increased with the aggravation of rock desertification degree but tended to decrease in the very severe case. The maximal water storage capacity of soils in severely stony desertification plot was 170kg/m3, minimal in the potential cases, was 90kg/m3; The natural rainfall storage amount on the limestone rock averaged 32.77 kg/m3. The total amount of rainwater intercepted and storage on the surface basically showed an increase trend with the aggravation of the stony desertification; but the proportions of the interception amounts of plants, residue, soils and rocks in the total interception volume differed greatly. The interception amount of plants and residue within the different rock desertified plot occupied 9~23% of total storage amount ,but in the very severely rock desertified slope,the interception amount of plants and residue only occupied 2.3% and 4.4% of total storage amount respectively, and water storage amount of rock exceeded 88%; The total interception and stoarg amount of plants, litters and soils in the potential rock desertified sample plot occupied 81% or more; According to the simulate rainfall (35mm/h), the effectively intercepted rainfall and water storage of plants, litters, soils and rocks on the potential, slightly, moderately, severely and very severely rock desertified slopes were 2.94 mm, 4.95mm, 6.21 mm, 7.73 mm and 6.9 mm respectively, account for 8.4%,14.14%,17.74%,22.09%,19.71% of total rainfall amount. Keywords: Rock Desertification; Rainwater; Interception; Spatial Distribution; Mountain Area in Northern Guangdong
1 INTRODUCTION Water cycle, carbon cycle and calcium cycle jointly determine the karst dynamic processes. Rainfall infiltration and surface runoff are the main pathway of the water cycle. Unlike non-karst areas, underground water plays an important role in ecosystem of the Karst region in South China. Adequate rainwater is the main dynamic force to mould the karst environment. Due to well developed cracks, karst caves, funnels, sink holes and wells in the karst environment the surface water seepage is serious, even if there is adequate rainfall, it mostly flows into the *
This paper is funded by the Natural Science Fund of Guangdong Province (S2012010009272). - 71 http://www.j-es.org/