Rainwater harvesting to combat rock desertification in karst areas

Rock desertification has become the most serious ecological disaster in southwest China. Area of rock desertification is expanding at an alarming rate and is restricting social and economic development in southwest China. The objective of this study is, therefore, to assess the impact of rock desertification in southwest China and to suggest means to alleviate intensification of rock desertification problem with rainwater harvesting using natural ground catchment and open water reservoir. Besides providing direct water use, natural ground catchment and open ponds can recharge ground water and near-by ponds also. However, the negative effects of ponds may include siltation, high evaporation, seepage, construction and maintenance. The stagnant water may breed vectors and cause degraded microbiological and chemical water quality. Proper siting, design, construction, operation and maintenance are therefore essential in ensuring success in combating rock desertification problem in southwest China.