This chapter first summarizes the state of knowledge of climate change impacts on hydrology and water resources (Section 4.2), before assessing effects on the hydrological cycle and water balance on the land (Section 4.3). Section 4.4 examines potential changes in water use resulting from climate change, Figure 1. Precipitation may be in the form of rain or snow. Vegetation may intercept some fraction of precipitation. Precipitation that penetrates the vegetation is referred to as throughfall and may consist of both precipitation that does not contact the vegetation, or that drops or drains off the vegetation after being intercepted. A The usual precipitation is rainfall, hail snowfall frost, and dew. Among these, all types of precipitation, rainfall and snowfall contribute a significant amount of water. Rainfall is the predominant form of precipitation. It is used synonymously with precipitation. It is usually expressed as depth either mm or cm. Module -1: Hydrology and Precipitation Definitions: Hydrology: is defined as science dealing with the occurrence, circulation, distribution and properties of the waters of the earth and its atmosphere. or Hydrology: is defined as Hydro (Water) + Logus (Science). Hydrology is further divided into: Scientific and Engineering Hydrology. Usually precipitation is in two forms: It is major factor controlling hydrology of a region. It is major input of water to the earth surface. Knowledge of rainfall in space and time is necessary for understanding soil moisture, groundwater, recharge and river flow. Data of rainfall (precipitation) is more readily available, for cities and ODOT Roadway Drainage Manual November 2014 List of Figures 7-v List of Figures Figure Page Figure 7.1-A — ODOT DESIGN STORM SELECTION GUIDELINES FOR ROADWAY 4.13 Precipitation over India. 4.1 DEFINITION. All water flowing or stored on the land surface or subsurface is derived directly or indirectly from precipitation, i.e. rainfall including snowfall. It is one of the important basic processes in the hydrological cycle. Precipitation is the general term for all the moisture emanating from the relationship between precipitation and runoff, hydrographs, Flood Routing Chemical Hydrology: Study of chemical characteristics of water. Eco-hydrology: Interaction between organisms and the hydrological cycle. Hydrogeology: Also referred to as geo-hydrology, is the study of the presence and movement of ground water. Rainfall Abstractions Interception Interception Demo Materials: Two separate plants - preferablybro adleaf and no-bro Water spray bottle (fan may help!) • Portion of precipitation that wets above-ground objects • function of: storm size, species age and density, season Depression Storage • Portion of precipitation that is captured in Hydrology -Collection of formulas- (Aid for the Exam and the Assignments) Zurich, 2011. Remark This formulary is meant to be of assistance in working on the exam and the exercises. The Precipitation Synthetic hyetographs: Triangular hyetograph: / 0 0 d a a dd d ad bb d it t t t Summary This chapter contains sections titled: Introduction Precipitation Process Rainfall Snowfall Summary and Learning Points References Webliography Hydrology Homework Problems 1. Using the Figure 3.6, calculate the maximum precipitation for a 4 day storm. 2. Calculate the soil texture, cumulative infiltration depth and infiltration rate at time equals 2 hours. The soil is composed