It is widely understood that hydrological cycles are complex processes influenced by both climate change and human activities. With global warming, the impacts of climate change and human activities on hydrological processes are of widespread concern and a challenge to researchers and policy markers. The Xinjiang River is located in the Poyang Lake Basin, which is one of the five major rivers in Jiangxi Province. Studies show that in 1990s there was an obvious rising trend in precipitation and a downtrend in evaporation in the Poyang Lake Basin. Meanwhile human activities grew intensely. Thus, the response of hydrological processes to climate change and human activities were investigated in this paper by using the Hydrological Simulation Program Fortran (HSPF), which was calibrated and verified for the baseline period 1960-1990, and then used to reconstruct the natural runoff for the affected period during 1991-2005. The results indicated that: 1) The annual runoff increased by 217.9 and 246.3 mm during 1991-1995 and 1996-2000, respectively, but decreased by 64.1 mm during 2001-2005, as compared with those in the baseline period of 1960-1990. The impact of climate change made about 65.6%-88.0% of the contribution to the changes in the annual runoff, while that of human activities made about 12.0%-34.4% of the contribution to the changes in the annual runoff; 2) Extreme series were affected by human activities. During affected period, the modeled 7-day annual maximum flows and 15-day annual maximum flows were smaller than their observed counterparts; 3) The responses of hydrological processes to climate change and human activities were different. In climate change factors, the increase of precipitation played a significant role in the increase of runoff in 1990s, while the decrease of evaporation played minor role. Human activities such as tree planting, urbanization and reservoir construction were the secondary factors that can influence annual runoff. In this study, we found that reforesting can increase runoff while urbanization and the reservoir construction will cause runoff decrease. It can be predicted that with the development of the Xinjiang River Basin, human activities will exert more influence on river discharge of the basin.
Theme parks have been very hot for tourism develolpment since the mid 1980s in Shenzhen and Zhuhai.The current state of theme parks in the two cities,with emphasis on Splendid China in Shenzhen and Pearl Land in Zhuhai,is analysed in this peper.The former has been very successful,getting back the development cost after more than a year;the latter,however,has suffered from loos for a long time.
Under the guidence of the idea of landscape and the method of GIS,the author develops thespatial information database to be used to analyse patches,irregularity and general feature of landscape of forest vegetation in Fujian.It is shown that the complexity of topography and disruptionsof mankind are primary physical parameters of controlling ecosystem functions of landscape(suchas motions of water and soil,rainfall and temperature),diversity of living things and efficiencyof soil water.The synthetical characters of landscape calculated reflect briefly the influences ofthose two physical paraneters.StructUre and shape of artificial vegetation (especially forpaddy) suit fundamentally to toPography.Both southern subtropical rainforest and middle subtropical evergreen broad-leaf forest exist at lower fractal dimension and simple geometrical Patterns.Their shapes are obviously different from these of toPography condition and structures ofothers landscape tares which are more complex.It indicates that human activities have produceddeep influences on the structure of the two zonality landscapes.The author shows spatial distribution of forest vegetation by GIS,surveys spatial strUctureof forest vegetation by quantitative models.From those it can be explained how the forest vegetation in Fujian is restricted by physical,biological,social and economic factors.
Vetiver grass (Vetiveria zizanioides) is a very ideal hedgerow for the vegetative system of soil and moisture conservation,and being widely planted in tropical and sub-tropical regions.The pot and field trials indicated that this plant could efficiently ameliorate soil characteristics.It was capable of lowering acidity and the content of exchangeable Al of strongly acid soil by 0.5-0.7 and 0.3-0.6cmol.kg-1,respectively.Distinct increments of organic matter,total N,available N and K,and total porosity in the soils were found after vetiver was established for 29 months.The vetiver treatment averaged 60% and 93% less runoff and soil loss,and 4%-42% more soil moisture,than the control,respectively.Furthermore,this plant effectively improved the microclimates of fruit garden ecosystem,including an increase of relative humidity by approximately 4%-5%,and a decrease of air temperature by 1-3 degrees centigrade.
