自然灾害学报
自然災害學報
자연재해학보
JOURNAL OF NATURAL DISASTERS
2009年
6期
1-8
,共8页
干旱区%绿洲%枣树%低温%临界温度
榦旱區%綠洲%棘樹%低溫%臨界溫度
간한구%록주%조수%저온%림계온도
arid area%oasis%jujube%low temperature%critical temperature
进入21世纪的短短几年里,甘肃河西走廊临泽小枣就遭受了2次冻害,2008年的冻害比2003年更为严重,位于临泽县北部的四个乡镇的枣粮间作地,全部幼树和绝大部分大树树冠均冻死、绝产.冻害程度调查表明,临泽县南部乡镇轻,北部乡镇重;村庄宅旁轻,枣粮间作地重;靠近林带和小网格林带内轻,远离林带和大网格林带内重;背风面轻,迎风面重.气象资料分析得出,2003年冻害是由于2002年12月下旬的低温所致;2008年冻害是1月下旬到2月上旬的低温所致,冻害期间,最大风力为西北风,吹得最多的是东北风.通过与正常年份气温的比较分析得出,临泽小枣安全越冬的临界气温为-20.0℃,2d日平均温度低于-20℃的低温即可使临泽小枣遭受冻害,但≤1d的-20℃以下的低温对临泽小枣不产生冻害;温度越低,枣树能忍受的时间越短,可忍受的极端最低气温为-27℃.加强绿洲防护体系建设,大力发展村旁、路旁、渠旁、宅旁等四旁枣树种植,及根据天气预报采取应急措施是防止临泽小枣发生冻害的主要对策.
進入21世紀的短短幾年裏,甘肅河西走廊臨澤小棘就遭受瞭2次凍害,2008年的凍害比2003年更為嚴重,位于臨澤縣北部的四箇鄉鎮的棘糧間作地,全部幼樹和絕大部分大樹樹冠均凍死、絕產.凍害程度調查錶明,臨澤縣南部鄉鎮輕,北部鄉鎮重;村莊宅徬輕,棘糧間作地重;靠近林帶和小網格林帶內輕,遠離林帶和大網格林帶內重;揹風麵輕,迎風麵重.氣象資料分析得齣,2003年凍害是由于2002年12月下旬的低溫所緻;2008年凍害是1月下旬到2月上旬的低溫所緻,凍害期間,最大風力為西北風,吹得最多的是東北風.通過與正常年份氣溫的比較分析得齣,臨澤小棘安全越鼕的臨界氣溫為-20.0℃,2d日平均溫度低于-20℃的低溫即可使臨澤小棘遭受凍害,但≤1d的-20℃以下的低溫對臨澤小棘不產生凍害;溫度越低,棘樹能忍受的時間越短,可忍受的極耑最低氣溫為-27℃.加彊綠洲防護體繫建設,大力髮展村徬、路徬、渠徬、宅徬等四徬棘樹種植,及根據天氣預報採取應急措施是防止臨澤小棘髮生凍害的主要對策.
진입21세기적단단궤년리,감숙하서주랑림택소조취조수료2차동해,2008년적동해비2003년경위엄중,위우림택현북부적사개향진적조량간작지,전부유수화절대부분대수수관균동사、절산.동해정도조사표명,림택현남부향진경,북부향진중;촌장택방경,조량간작지중;고근림대화소망격림대내경,원리림대화대망격림대내중;배풍면경,영풍면중.기상자료분석득출,2003년동해시유우2002년12월하순적저온소치;2008년동해시1월하순도2월상순적저온소치,동해기간,최대풍력위서북풍,취득최다적시동북풍.통과여정상년빈기온적비교분석득출,림택소조안전월동적림계기온위-20.0℃,2d일평균온도저우-20℃적저온즉가사림택소조조수동해,단≤1d적-20℃이하적저온대림택소조불산생동해;온도월저,조수능인수적시간월단,가인수적겁단최저기온위-27℃.가강록주방호체계건설,대력발전촌방、로방、거방、택방등사방조수충식,급근거천기예보채취응급조시시방지림택소조발생동해적주요대책.
Linze jujube suffered from twice freezing damage in the few years of 21st century, and the freezing damage in 2008 was severer than that in 2003. All seedlings and crown of most big trees in jujube/crop inter-cropping field of four towns which located in the north of Linze County were freezed to death and had not yields. The investigation of freezing damage shows that, the freezing damage degree of towns which located in the south of Linze County is slight and the towns which located in the north of Linze County is serious; the side of villages and houses is slight and jujube/crop inter-cropping field is serious; the freezing damage degree of jujube trees which is close to forest belt and in the small grid forest belt is slight, and the damage which kept away form forest belt and in the big grid forest belt is serious; the leeward side is slight and the windward side is serious. The analysis of weather data concludeds that the freezing damage in 2003 is resulted from the low temperature of the last ten days of December in 2002; and the low temperature from the last ten days of January to the first ten days of February result in freezing damage of 2008, the direction of most great wind is northwest and the direction with most frequent wind is northeast in the period of freezing damage. Compared with the temperatures in normal years, we conclude that the critical temperature that Linze jujube could live through winter safely is -20.0℃, and it would suffer from freezing damage when average temperature of two days is lower than -20.0℃, but temporary low temperature would not cause freezing damage, and the lower the temperature, the shorter the tolerated time, and the extreme lowest temperature that it could tolerate is -27℃. The main strategies that could prevent freezing damage are to strengthen the construction and protection of oasis shelter belt, to develop planting of jujube trees beside villages, roads, canals, houses, and to take some urgent measures according to weather forecast.