Interrupting the processes which control ecosystem resources has dramatic impacts on the rangeland conditions. To protect ecosystems and landscape, it needs to understand the ecosystem processes which regulate the ecosystem resources. As main components of ecosystems, patches and inter-patches play important roles in energy and materials cascade. Ecologically, functional parameters such as stab...

2 TCA, time compression approximation, is a practical and often quite accurate tool to predict 3 postponding infiltration for field applications. A modified approximation (MTCA) can be used 4 just as easily and, in general, will reduce the error by about 50%. This is based on two results: 5 1. After ponding, TCA and MTCA predict very close infiltration rates; and 6 2. MTCA, but not TCA, uses th...

Polyacrylamide (PAM) is used at rates of i to 2 kg ha per irrigation on a half million hectares of United States irrigated farmland to prevent 94% of irrigation-induced erosion and to enhance infiltration by i5% to 5o% on medium to fine-textured soils. The polyacrylamides used for this application are large (i2 to i5 megagrams per mole), water-soluble anion molecules applied in the irrigation s...

In cold climate regions winter conditions significantly influence the performance of stormwater infiltration devices. Frozen soil and water storage by snow changes their operation. In this paper winter operation of a grassed infiltration swale was investigated using on-site and laboratory measurements. The field investigation of a grassed swale at a parking place in an Alpine region showed that...

Infiltration techniques for managed aquifer recharge (MAR), such as soil aquifer treatment (SAT) can facilitate low-cost water recycling and supplement groundwater resources. However there are still challenges in sustaining adequate infiltration rates in the presence of lower permeability sediments, especially when wastewater containing suspended solids and nutrients is used to recharge the aqu...

The application of additives (e.g., wheat straw (WS) or rapeseed-oil residue (RR)) to soils is a common agronomic practice, used for improving soil water retention. Through a laboratory investigation, this study examined the effects of RR and WS on infiltration, evaporation, water distribution, and water retention. The results indicated that the migration rate of the wetting front, as well as t...