The modulus of infiltration (MOI),modulus of runoff(MOR) and modulusof sediment (MOS) are introduced as the index for evaluating the anti-water erosion ability of the soil-root composite(SRC).

For the sake of filling a vacancy in the technique of rainwater harvesting in test area, using the information of precipitation and water needed for planting and through one year's rainwater harvesting experiment, the results show that the average modulus of runoff was 0.8989, and the volume of harvesting water was 14.76 m3 in the greenhouse with 13.44 m~2 superficial area.

The annual mean runoff on the ground and modulus of runoff were 105.8 L and 10.58 m~(3)·km~(-2)·a~(-1) inside the mixed plantation. But those in pure plantation were 1 349.05 L and 134.9 m~(3)·km~(-2)·a~(-1).

年均地表径流量105.8 L,径流摸数为10.58 m3.km-2.a-1,纯林分别为1 349.05 L和134.9 m3.km-2.a-1,土壤侵蚀模数为0.65 t.

The length of the slope in runoff area had obvious influence on the total runoff, but the gradient of the slope in the runoff area had the greatest influence not only on the total runoff, but also on the modulus of runoff.

The modulus of infiltration (MOI),modulus of runoff(MOR) and modulusof sediment (MOS) are introduced as the index for evaluating the anti-water erosion ability of the soil-root composite(SRC). The relationship of MOI, MOR and MOS with the ground slope, rainfall intensity, seepage coefficient and anti-water erosion strength of SRC are found out through the rainfall simulation experiment, which provides thescientific basis for evaluating the soil-water conservation efficiency.

Landscape metrics have been widely used to describe landscape patterns quantitatively in the last two decades. With the quick development of geographical information system, more and more metrics are designed and calculated with ever increasing speed. Packages which can provide numerous varieties of landscape metrics, such as FRAGSTATS and APACK, make it more convenient for users to calculate those metrics without querying about their ecological meaning, or even without knowing their arithmetic formulas. Therefore...

Landscape metrics have been widely used to describe landscape patterns quantitatively in the last two decades. With the quick development of geographical information system, more and more metrics are designed and calculated with ever increasing speed. Packages which can provide numerous varieties of landscape metrics, such as FRAGSTATS and APACK, make it more convenient for users to calculate those metrics without querying about their ecological meaning, or even without knowing their arithmetic formulas. Therefore more and more users are using and interpreting landscape metrics arbitrarily, especially in China. It is high time to clarify if the metrics we are using so often can really indicate the desired pattern or not.This paper tested the behavior of some landscape pattern metrics against six pattern scenarios generated by neutral landscape models, by changing one spatial parameter while keeping all the others stable. The scenarios include: (1) Number of Classes, with map size 1000×1000, and 2～100 classes randomly distributed at equal area percentages; (2) Scale - Map Extent, with 10 equal classes randomly distributed at map size 8×8, 16×16,…, 500×500, and 1000×1000; (3) Scale - Resolution, with a 3-class predefined 10×10 map resampled by cell size 1, 0.5,…, and 0.05; (4) Proportion of One Class, with the area of one class changing from 1%, 10%, …, to 99% consequently in binary maps; (5) Aggregation Level - Rule, with 4-equal-classes in 1024×1024 cells maps at different aggregation levels according to the neutral landscape model RULE; and (6) Aggregation Level - SimMap, with 4-equal-classes in 500×500 cells maps at different aggregation levels according to the neutral landscape model SimMap. Landscape metrics were calculated and compared for different pattern cases in each scenario.Results demonstrated that most of the metrics response to some of the pattern scenarios only, for example, Average Patch Perimeter/Area Ratio and Shonnon Diversity, while they are not sensitive to the others. Therefore none of them can indicate all aspects of a landscape pattern. However, in spite of those limitations, still some of the metrics are recommended for future use: Total number of patches, Average patch size, Total edge density, Fractal double-logged, Contagion (Li & Reynolds), and Aggregation index. But attention must be paid on the limitation, redundancy and real meaning of the metrics. The relationship between metric values and ecological processes are more important than the values themselves. For instance, suitable habitat area, number of patches and lacunarity metrics might be well related to population size and growth, while pattern metrics of erosion-sensitive land use types could be related to hydrological indicators such as modulus of runoff, or modulus of erosion. However, this paper could not answer all questions regarding to the relationship between metrics and landscape patterns. For example, why there is a peak at class level when N=5 for Number of Patches in the Number of Classes scenario? Why the landscape level Average Patch Size is the lowest when one class reaches 10%～20% in a binary map? Similar questions also arise for more complicated indicators such as Fractal and Contagion. Further study on mathematical analysis of the research results is expected for future consideration.

By the way of micro-plot field experimentation and theoretical analysis, micro-relief characteristic and runoff formation under the conditions of site preparation by reverse-slope terrace were studied. The results showed that site preparation by reverse-slope terrace can enlarge the degree of slop where runoff was generated. The range of slope gradient increased was in direct proportion to the width of terrace, which was 2.5°~11.5° per meter, and in the inverse ratio of the slope length, which was 0.5°~7.0°...

By the way of micro-plot field experimentation and theoretical analysis, micro-relief characteristic and runoff formation under the conditions of site preparation by reverse-slope terrace were studied. The results showed that site preparation by reverse-slope terrace can enlarge the degree of slop where runoff was generated. The range of slope gradient increased was in direct proportion to the width of terrace, which was 2.5°~11.5° per meter, and in the inverse ratio of the slope length, which was 0.5°~7.0° per meter. The length of the slope in runoff area had obvious influence on the total runoff, but the gradient of the slope in the runoff area had the greatest influence not only on the total runoff, but also on the modulus of runoff. Therefore, the regulative mechanism of site preparation by reverse-slope terrace to runoff formation demonstrated shortening the length, increasing the gradient of the slope and changing the form of the slope in the runoff area, which made apparently different formation of runoff and erosion from that of the original slope. So the site preparation work designed according to traditional records of runoff plot with straight slope cannot reach the design standard desired.