1、ASCWEWRI 42-04 American Society of Civil Engineers Standard Practice for the Design and Operation of Precipitation Enhancement Projects This document uses both the International System of Units (SI) and customary units. , 4SCE ASCE/EWRI 42-04 American Society of Civil Engineers Standard Practice for
2、 the Design and Operation of Precipitation Enhancement Projects This document uses both the International System of Units (SI) and customary units. ASCE Published by the American Society of Civil Engineers Library of Congress Cataloging-in-Publication Data Environmental and Water Resources Institute
3、 (US.). Atmospheric Water Management Standards Committee. Precipitation Enhancement Subcommittee. precipitation enhancement projects. American Society of Civil Engineers standard practice for the design and operation of p. cm.-(ASCE standards) “ASCE-EWRI 42-04.” Includes bibliographical references a
4、nd index. ISBN 0-7844-07 14-2 and operation of precipitation enhancement projects. II. American Society of Civil Engineers. III. Environmental and Water Resources Institute (U.S.) IV. Title. 1. Precipitation (Metereo1ogy)-Modification. I. Title: Standard practice for the design QC928.6.E58 2004 551.
5、6877422 2004046124 Published by American Society of Civil Engineers i 801 Alexander Bell Drive Reston, Virginia 20191 www.pubs.asce.org Any statements expressed in these materials are those of the indi- vidual authors and do not necessarily represent the views of ASCE, which takes no responsibility
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12、left to the user of this document. This document defines means through which pre- cipitation enhancement operations may be conducted. The information contained herein is intended to be helpful to those persons who wish to implement opera- tional precipitation enhancement activities, and it pro- vide
13、s information on the planning, conduct, and evaiu- ation of such efforts. It is not a technical meteorological monograph on the subject. However, it is intended to provide the best scientific information currently available on the subject, to optimize the like- lihood of success. The provisions of t
14、his document have been written This Standard has been prepared in accordance with recognized engineering principles and should not be used without the users competent knowledge for a given application. The publication of this Standard by ASCE is not intended as warrant that the information contained
15、 herein is suitable for any general or specific use, and ASCE takes no position respecting the valid- ity of patent rights. The user is advised that the deter- mination of patent rights or risk of infringement is en- tirely their own responsibility. The units used throughout this document are those
16、recommended by the American Meteorological Society (AMS) and the Weather Modification Association (WMA) for their reports and journals. However, some of the sections refer to documents that used English common units to meet the desires of their sponsors. Many individuals contributed materially to th
17、is document by their comments, review, illustrations, and photographs. The primary authors of this document were the ASCEEWRI Atmospheric Water Manage- ment Standards Committee (AWMSC) Precipitation Enhancement Subcommittee members: George W. Bo- mar (vice-chair), Roelof T. Bruintjes, Joseph H. Gold
18、en, Don A. Griffith (chair), Harold O. Orville (past chair), and Maurice D. Roos. Others who materi- ally contributed include Robert R. Cyzs, Thomas P. DeFelice, Ronald C. Grosh, Thomas J. Henderson, Conrad G. Keyes, Jr., James H. Renick, Gary Riley, and Jose L. Sanchez. V FOREWORD v LISTOFFIGURES x
19、 SECTION 1 .O INTRODUCTION TO PRECIPITATION ENHANCEMENT PROJECTS . 1 1.1 Historical Perspective . 1 1.1.1 Orographic Clouds . 1 1.1.2 Convective Clouds . 2 1.1.3 Summary 3 1.2 Status of Precipitation Enhancement Technology 3 1.2.1 American Society of Civil Engineers . 3 1.2.2 Weather Modification As
20、sociation 4 1.2.3 American Meteorological Society . 4 1.2.4 World Meteorological Organization . 5 SECTION 2.0 SCIENTIFIC BASIS OF NATURAL PRECIPlTATION EFFICIENCY ANDITSMODIFICATION . 7 2.1 CloudCondensate 7 2.1.1 Properties of Cloud Condensate . 7 2.1.2 Destination of Cloud Condensate . 7 2.2 Growt
21、h of Precipitation-Sized Particles from Cloud Condensate 7 2.2.1 Direct Collision and Coalescence . 8 2.2.2 Supercooled Cloud Droplets and Ice Crystals 8 2.3 Precipitation Augmentation Concepts . 9 2.3.1 Cloud Seeding to Increase Precipitation Efficiency 2.3.2 The Role of Cloud Seeding to Enhance Cl
22、oud Development (Static Seeding Process) . 9 (Dynamicseeding) . 10 2.3.2.1 Seeding to Enhance Development of an Individual Convective Cloud 10 2.3.2.2 Complexities of the Dynamic Seeding Concepts 11 2.3.2.3 Expansion of Dynamic Seeding Concepts to Cloud Clusters and Mesoscale Systems 13 SECTION 3.0
23、THE DESIGN OF PRECIPITATION ENHANCEMENT RESEARCH AND OPERATIONAL PROJECTS . 13 3.1 Definition of Project Scope 14 3.1.1 3.1.2 Initial Design Considerations 16 3.1.3 Climatology . 16 3.2 Targeting and Delivery Methods 16 3.2.2 Ground Applications 19 3.2.3 Advantages and Disadvantages of Aerial and Gr
24、ound Systems . 21 3.3 Seeding Agent Selection 22 3.3.1 Silver Iodide . 22 3.3.2 DryIce . 24 3.3.3 Other Ice Nucleants . 24 3.3.4 Hygroscopic Agents . 24 3.3.5 Quality Control 25 Basic Target Area Concepts . 15 3.2.1 Aerial Applications . 17 vii CONTENTS 3.4 Meteorological Data Collection and Instrum
25、entation 25 3.4.1 Real-Time Decision-Making and Monitoring Instrumentation 26 3.4.1.1 Available National Weather Service Data . 26 3.4.1.2 Special Project Precipitation Gauges . 27 3.4.1.3 Special Project Weather Radar 28 3.4.1.4 Computer-Based Radar Storm Tracking 29 3.4.1.5 Special Project Rawinso
26、ndes . 29 3.4.1.6 Real-Time Liquid Water Observations 30 3.4.1.7 Special Project Cloud Physics Instrumentation . 31 3.4.2 Measurements of Potential Value in Post-Project Assessments . 33 3.4.1.8 Other Instrumentation and Equipment 32 3.4.2.1 Precipitation Gauge Data 33 3.4.2.2 Remote Sensor Data 33
27、3.4.2.3 Cloud Physics Data . 34 3.4.2.4 Streamflow Data . 34 3.4.2.5 Snow Course Data . 34 3.4.2.6 Snow Sample Data . 35 3.4.2.7 Numerical Cloud Modeling 35 3.5 Choice and Siting of Cloud Seeding Equipment 36 3.5.1 Dispersion Rates of Cloud Seeding Materials in Wintertime Clouds . 37 3.5.2 Aerial Cl
28、oud Seeding Modes 38 3.5.3 Ground-Based Cloud Seeding Modes . 38 3.6 Legal Issues 39 Potential for Litigation . 39 3.6.2 Regulation 39 3.6.1 3.7 Environmental Concerns 40 3.7.1 Redistribution of Precipitation . 40 3.7.2 Seeding Agent Safety 40 SECTION 4.0 OPERATIONS OF PRECIPITATION ENHANCEMENT PROJ
29、ECTS 40 4.1 The Operations Manual . 41 4.2 Personnel Requirements 41 4.2.1 Meteorological Staff 41 4.2.2 Cloud-System Treatment Pilots 41 4.2.3 Direction of Operations 41 4.2.4 Support Personnel 42 4.3 Operational Decision-Making 42 4.3.1 Chronology 42 4.3.2 Opportunity Recognition . 42 4.3.2.1 Airc
30、raft Flight Crews . 42 4.3.2.2 IN Treatment by Ground-Based Generators 43 4.4 Communications 43 4.5 Safety Considerations 44 4.5.1 Safety of Field Personnel . 44 4.5.1.1 Radar Safety 44 4.5.1.3 Severe Weather Hazards . 44 4.5.1.4 Aircraft Safety 45 4.5.2 Seeding Suspension Criteria 45 4.6 Public Rel
31、ations, Information, and Involvement 46 4.5.1.2 Use, Handling, and Storage of Seeding Agents . 44 . v111 CONTENTS SECTION 5.0 EVALUATION OF PRECIPITATION ENHANCEMENT PROJECTS 46 5.1.1 Randomized versus Nonrandomized Projects . 47 5.1.2 Selection of Target and Control Areas . 47 5.1.2.1 Precipitation
32、 Patterns . 47 5.1.2.2 Storm Frequency . 47 5.1 Project Design Constraints 46 5.1.2.3 Contamination . 47 5.2 Evaluation Measures . 47 5.2.1 Evaluations Using Direct Evidence . 48 5.2.1.1 Precipitation Data 48 5.2.1.2 RadarData . 48 5.2.2 Evaluation through Indirect Evidence . 48 5.2.2.1 Crop Yield D
33、ata . 48 5.2.2.2 Runoff Data 48 5.2.2.3 Chemical Analyses . 49 5.3 Dissemination of Results 49 SECTION 6.0 GLOSSARY OF TERMS AND ACRONYMS 49 SECTION 7.0 REFERENCES . 53 SECTION 8.0 CONVERSION OF UNITS . 58 Index 61 FIGURES 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 Precipitation enhancement project areas 1
34、5 Cloud base seeding aircraft with wing-tip ice nuclei generators 17 Wing rack for burn-in-place cloud seeding flares . 18 Example of a droppable Ag1 pyrotechnic rack 18 Example of a dry ice dispenser mounted in an aircraft . 19 Ground-based ice nuclei generators 20 Example of a ground-based Ag1 pyr
35、otechnic dispenser . 21 Example of a propane dispenser . 21 or delivered to field sites premixed 23 3-10 Dry ice, in extruded pellet form . 24 3-1 1 Hygroscopic flares on wing-rack 25 3-12 Example of a weighing bucket recording precipitation gauge 28 3-13 Example of a self-contained weather radar in
36、stallation in the field 29 3-14 Example of a rawinsonde receiver system . 30 3-15 Example of a microwave radiometer and Lidar . 31 3-16 University of Wyoming King Air cloud physics aircraft 32 3-18 Depiction of cloud and precipitation at 285 min . 37 Acetone-based seeding solutions may be mixed as needed in the field, 3-17 The observed maximum temperature for each day of the North Dakota Thunderstorm Project, and the corresponding model-predicted temperature 36 3-19 Graphical depiction of three seed lines produced from airborne AgIseeding . 38 ix
