Reaserch On Hydro-Ecology Of Terrace And Its Effect

Terrace is one kind of multistep farmland built along contour lines in sloping fields, which is an effective measure to improve agriculture production conditions and to tackle the problems of sand and soil erosion. The region of Loess Plateau is a severe problem of sand and soil erosion. In such region, terrace is an effective measure, with the function of retaining river runoff, and increasing soil moisture to be used as rain resources, mealwhile, also plays an essential role in dealing with the problems of water shortage restricted to dry framing.The present study systematically expounds the history of terrace, and has a comprehensive analysis of hydro-ecosystems of terrace, and then summarizes the general features of terrace. Taking the terrace in region of Loess Plateau in Zhuanglang County in Gansu Province and Qianxian Country in Shaanxi Province as examples, adopting both the investigation and the field test, both qualitative and quantitive method, based on on-the-spot investigation Mathematical Statistics, Issue of hydro-ecology of terrace and its effectiveness is researched.as a result,made the following main research results.(1) This paper systematically expounds everything of terrace to source, formation, history, types and its characteristics., combining with the field survey and study in loess plateau, probes into the role of terraces and its function of ecological environmental effect.(2) Hydro-ecosystems of terrace.coud be probed and studied in this paper. In the process of water circulation, terrace quickly reinforces the infiltration of recharge by rainfall; therefore it reduces the sheet flow, even makes the infiltration of recharge by rainfall on the spot. In the region of Loess Plateau, because of the intrinsic attribute of high Permeate and higher to retain water proper to provide smooth gateway for rainfall. The result is that the terraced fields acted for providing abundant water factor assurance in the growth of vegetation, and the positive shape of" Hydro-ecosystems " providing backing for it. (3) The mechanism of Hydro-ecosystems of the terrace is researched. Through the slope soil (soil) body force analysis that terrace mechanisms of ecosystems is to make the slope conditions, along with runoff and soil system (body) of non-stability of the resulting loss of soil easily has changed, then changed the path of the water cycle characteristics and spatial distribution of storage, resulting in the dominant mechanism of the ecological environment.(4) Adopting the soil drills-baking drying method,combine to use the probe type time domain reflection instrument(TRIME-PICO), Changes of soil water storage in terraced field is compared with Sloping fields.The results showed that accumulating soil water storage of terraced field increase by37.12mm, soil water storage of Sloping fields increase by17.98mm. When it has41.72mm rainfall by three accumulating rain. It is show that infiltration function of Terrace are more than slopes, in Hydro-ecosystems.(5) With different plant cultivation conditions, changes in soil moisture terrace. Studied under different vegetation (corn, beans and orchard land) changes in soil moisture. Results of the study, the soil at the depth of0-2m, beans to the mean of14.76%soil moisture, soil moisture corn mean of13.29%, the mean soil moisture orchard to11.98%. Also studied under different plants inside terrace, central and lateral soil depth under different soil moisture variation.(6) Adopting water conservation methods and survey methods, based on the terrace effective area and index of storage water and sediment, calculated economic benefits in terraces of ZhuangLang county, in Gansu Province. it is storage wate of22.11million m3,reduce sediment11.90million t in wet year; storage wate of17million m3,reduce sediment8.50million t in average year; storage wate of13.04million m3, reduce sediment5.67million t in dry year. grain yield Increased by0.05million t in terrace than sloping fields of ZhuangLang county, in Gansu Province.Terrace and its Hydro-ecosystems has two the function of storage water and sediment,of fine production crops.