Question

Conclusion and recommendation of soil erosion

Answer 1

CONCLUSIONS AND RECOMMENDATIONThe main objective of this research was to assess the flood hazard at downstream areas of the Nam Chun watershed, taking into account the influence of soil and land cover parameters upstream. The other objectives were to assess the effects of different land cover types on soil properties; assess the effects of soil parameters in influencing runoff and to assess the flood downstream consequence as a result of upstream land use changes by using an integrated hydrological model with a hydraulic model. Based upon the results discussed in previous section, it was possible to draw the following conclusions:The soil analysis results indicated that changes of land cover types have a significant effect on the physical properties of the soil. The agriculture areas show lower hydraulic conductivity, higher bulk density and less porosity than under natural vegetation. This could be an indication that the soil in agricultural areas is more compacted due to land use practices.
The impact of land cover types on the runoff generation was revealed by hydraulic conductivity measurements that show significant differences between different land cover types, especially between agricultural land use and natural vegetation. The consequence of this was shown in the results of runoff prediction. The results revealed that there is a trend in surface runoff rate on different land cover types. The agriculture areas including corn cultivation, mixedcrop and orchard generated high rates of surface runoff than in the natural vegetation areas.Precipitation volume and hydraulic conductivity are of major importance for the degree to which land use can influence storm-runoff generation.The results of this study show the possibility to link the upstream catchment runoff model (LISEM) with a downstream 1D2D-flood model (SOBEK) for assessing the effects of upstream land use changes on downstream flood characteristics. Two models performed remarkably well when compared with real flood event data.The scenario studies revealed that land cover change by which natural vegetation is changed into agricultural land results in increased runoff amounts and peak discharges of river Huai Nam Chun leading to a significant change in flood characteristics in the downstream floodplain by increasing the extent, depth and velocity of the flood water.The results of the scenario analysis could be useful for decision making process on catchment and floodplain management for example: soil and water conservation plan, flood control measure and flood defence system focussing on the most flood susceptible areas. RecommendationsThe study revealed that land cover change influences runoff charateristics that can lead to flood problems in downstream area. The ongoing rapid land use change and expansion of agricultural area in this catchment will have negative effects on the runoff and on soil properties. To attenuate the rapid land use change, a better land management system is required, which can impede the unregulated conversion of forest for agriculture use in the study area. To avoid future flood disasters, flood management and flood mitigation plans are needed to be able to react swiftly to areas threatened by flooding. A monitoring system is required to assess, on a continuous basis, the areas affected by floods and to have emergency measures plan to reduce the damage of exceptional floods. Land use changes in upstream catchment can increase severe flooding on downstream territory. But, not only flood disaster can occur, also large debris flows can happen and damage settlements. Further investigations should also consider the possibility of debris flow and debris floods in the area.

Answer 2

Answer:

dude

Explanation: