i'm tom maddock. i'm at the university of arizona, and i study hydrology. i work in the area of ground-water/surface-water interactions. basically, the difference between ground water and surface water is you can float a stick in surface water. in ground water, you really can't do that except maybe looking down a well and dropping the stick down the well. narrator: surface water is typically found in lakes, rivers, and streams. ground water is found beneath the earth's surface in small pores and fractures found within large rock formations. when this water is readily available for human use, these formations are called aquifers. almost all of the natural surface water in arizona has been developed leaving only ground water available for human consumption. dr. maddock: the problem in the southwest is that we basically are having continued growth, and, in many places, the only place that you can get water to sustain that growth is from ground-water development. unfortunately, ground water is more available near the streams than it is other places. it's what w

i'm tom maddock. i'm at the university of arizona, and i study hydrology. i work in the area of ground-water/surface-water interactions. basically, the difference between ground water and surface water is you can float a stick in surface water. in ground water, you really can't do that except maybe looking down a well and dropping the stick down the well. narrator: surface water is typically found in lakes, rivers, and streams. ground water is found beneath the earth's surface in small pores and fractures found within large rock formations. when this water is readily available for human use, these formations are called aquifers. almost all of the natural surface water in arizona has been developed, leaving only ground water available for human consumption. dr. maddock: the problem in the southwest is that we basically are having continued growth, and, in many places, the only place that you can get water to sustain that growth is from ground-water development. unfortunately, ground water is more available near the streams than it is other places. it's what

from iraq to north korea, he has dealt with some of the greatest it la maddock dialer mess. now he speaks out about his decade for foreign service. welcome to our views on public television and around the globe. every live in west africa day is a challenge to escape the spread of ebola. a two year girl tested positive. people are adapting. the virus is killing far too many. a warning that you may find of this -- find some of this report distressing. >> this is the epicenter of the outbreak. almost 50 new cases are reported every day. liberia's tiny band of health care workers are throwing everything they have at ebola. this is lorene. of four.e mother she has collected hundreds of highly contagious patients since the start of the outbreak. she and her crews have been called in to collect a woman who has been taken sick for extremely dangerous work. >> they are getting into these white suits, traffic aprons, goggles, and facemasks. unconscious and it is when people are in that state they are most contagious. >> there is a tear. >> any physical contact could be a death sentenc

something very to maddock to get his attention. for him it is all temporary.in believes winter will force -- it is like game of thrones, winter is coming. boot and sells -- putin sells 80% of gas to europe. >> if we were to take a dispassionate look -- you are emotional about this. if you were to look at what vladimir putin has done for the annexation of crimea, it is kind of really and, isn't it? >> it ruined the system of security. back --hink going >> it was as much interest to russia as the west? why wouldn't he want to ruin it? orthe annexation of crimea -- >> you said -- survivemir putin cannot in only the muddy waters of geopolitics. he is doing everything to undermine nato and the european union. >> are there going to be muddy waters? >> yes. we need some cornerstones and integrity of ukraine. there was nursing a case of annexation. from 1945 to nowadays. to analyze putin's strategy as if he were a chessmaster -- , it is not chess, it is poker. he is playing a very different game. he always raises the stakes and blocks. bluffs. >> he has nothing to los